Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy...

102
Metal Clusters, Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction to FTMS •Two peptide problems •Distinguishing isomers: primary structure problem •Secondary structure of HPTH •Dynamics and mechanism of transition metal redox reactions •A useful gas phase dehydrogenation reaction •A selective oxidation of CO by O 2 •Equilibrium in charge transfer reactions: Theory and Experiment Flavin semiquinones Flavin semiquinones •Halogenated iron porphyrins •IR spectra of gas phase anionic metal clusters

Transcript of Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy...

Page 1: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Metal Clusters, Metalloporphyrins , p p yand Gas Phase Redox Chemistry:

Applications of FTMS

•Introduction to FTMS•Two peptide problems

•Distinguishing isomers: primary structure problem•Secondary structure of HPTH

•Dynamics and mechanism of transition metal redox reactions•A useful gas phase dehydrogenation reaction•A selective oxidation of CO by O2

•Equilibrium in charge transfer reactions: Theory and ExperimentFlavin semiquinones•Flavin semiquinones

•Halogenated iron porphyrins•IR spectra of gas phase anionic metal clusters

Page 2: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 3: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 4: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

TRAPPING PLATE

Page 5: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 6: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 7: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

NHHN

HNNH2

O O

NHN

OH O

O

O

OH

RGD

N

NH

O

OHO

H

-H2O

OH

O

NH

OH

H2O

NNH

HN

NHNH

OO

O

NH2

OHO

O O

ISOPEPTIDE

Scheme 1

Page 8: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 9: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

HN

HN

NO

OO

OH

OO

m/z 354 from RGD

HN

HN

N

O O

+ H2OO

H2O

OC

m/z 336

HHNO

O

HN

N

O C+ CO

m/z 308

Scheme 5Total Δm = 46.0032 (measured) vs. 46.0036 calculated)

Page 10: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

NNH

HNO

OO O

HO

m/z 354from isopeptide

NNH

HNO

H ON

O OC

O

+ H2O

m/z 336

NHHN

O

NNH

O C

Om/z 308

+ CO

Scheme 6

Page 11: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 12: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 13: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 14: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Synthetic hPTH (1-31) 1 2 3 4 5 6 7

H – ala – val – ser – glu – ile – gln – leu – nle 30 29 28 27 26 25 24 8 9 10 11 12 13 14 15

- his – asn – leu – gly – lys – lys – leu – asn 23 22 21 20 19 18 17 1623 22 21 20 19 18 17 16 16 17 18 19 20 21 22 23

– ser – asp – glu – arg – val – glu - trp – leu ser asp glu arg val glu trp leu 15 14 13 12 11 10 9 8 24 25 26 27 28 29 30

– arg – lys – leu - leu – gln – asp – val – NH2

7 6 5 4 3 2 1

Conlon, et al., JACS 122, 3007(2000)Conlon, et al., Bioorg. Med Chem. 10, 731(2002)

Page 15: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

SORI-CIDSORI CID

• Charge state of interest was isolated (+4)Charge state of interest was isolated (+4)

• SF6 was introduced through a computer t ll d l d l ( i P 13controlled pulsed valve (reservoir P ~ 13

mbar)

• Collision excitation was 500 Hz off-resonance

Page 16: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

SORI-CIDSORI CID

7.7e+7 4+

2.6e+6

3.8e+6

A

m

p

l

i

B20

5.2e+7A

m

p

l

i

t

B30

0 e+0

1.3e+6

t

u

d

e

B7

2.6e+7

u

d

e

B20 B25 Z29

0.e+0741 742 743 744 746

m/z

0.e+0500 750 1000 1250 1500

m/z

B20 B25B22

Page 17: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

SORI-CIDSORI CID

0 8

0.9

1

0.6

0.7

0.8

ve in

tens

ity

0.3

0.4

0.5

Nor

mal

ized

rel

ativ

0

0.1

0.2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Bond # (From N-terminus)

Page 18: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Electron Capture Dissociation (ECD)

• Sample is irradiated with low energy highSample is irradiated with low energy, high current electrons (10 eV)

• A cooling gas (Ar or SF6) is introduced through a computer controlled pulsed valve during the irradiation step

• ECD is a neutralization reaction• ECD is a neutralization reaction

Page 19: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD MechanismECD Mechanism

Major ProductsMajor Products

HO

H2OH O

R CHN CHR' R C

2N CHR' R C NH2CHR'+ +

a y

or

O OHH OH

R CHN CHR'

O

R CHN CHR'

OHH

R C

OH

NH + CHR'c zc z

Page 20: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Why ECD?Why ECD?

• Neutral H radical is highly energetic andNeutral H radical is highly energetic and highly reactive

C b k hi h b d th SORI– Can break higher energy bonds than SORI-CIDCan cleave disulfide bonds and post– Can cleave disulfide bonds and post-translational modificationsDoes not denature peptide Cleavage local to– Does not denature peptide. Cleavage local to protonation site.

Page 21: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (SF6 Cooling Gas)ECD (SF6 Cooling Gas)

4.e+7 4+

6.e+5

9.1e+5

A

C25

2.7e+7A

m

p

l

i

3.e+5

m

p

l

i

t

u

d

e

C24 Z25Z12

1.3e+7

t

u

d

e

0.e+01380 1418 1457 1496 1535

m/z

0.e+0600 950 1300 1650 2000

C9

3+

Z22 C25

600 950 1300 1650 2000m/z

Page 22: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (SF6 Cooling Gas)ECD (SF6 Cooling Gas)

0.9

1

ity

0 5

0.6

0.7

0.8

elat

ive

inte

nsi

0.2

0.3

0.4

0.5

Nor

mal

ized

re

0

0.1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

B d # (F N i )

N

Bond # (From N-terminus)

Page 23: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Synthetic hPTH (1-31)Synthetic hPTH (1 31) 1 2 3 4 5 6 7

H ala val ser glu ile gln leu nleH – ala – val – ser – glu – ile – gln – leu – nle 30 29 28 27 26 25 24 8 9 10 11 12 13 14 15

H+8 9 10 11 12 13 14 15

- his – asn – leu – gly – lys – lys – leu – asn 23 22 21 20 19 18 17 16 16 17 18 19 20 21 22 23

– ser – asp – glu – arg – val – glu - trp – leu 15 14 13 12 11 10 9 8 24 25 26 27 28 29 30

– arg – lys – leu - leu – gln – asp – val – NH2

7 6 5 4 3 2 1

Page 24: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Peptide Bond #9Peptide Bond #9

H H H H

O O9 13

• Helical structureHN

HC C

HN

HC C

CH2 CH2

CH2

• Helical structure can di-solvate proton.N

NH

His

CH2

CH2

proton.• His-9 may

delocalize the

Lys

HNH2 radical.

Page 25: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 26: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

N. R. for M=Fe

Ekeberg, Lin, Sohlberg, Chen, Ridge, et al., Organomet. 18, 40(1999)

N. R. for M Fe

Page 27: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Criteria for an Ideal Charging Agent for Polyolefins:

• Chemical modification inside the mass spectrometer

Polyolefins:

• Functionality in the hydrocarbon not required

• The predominant product characteristic of the original hydrocarbon (distribution)

• Minimal fragmentation +

++

AdductCharging Agent

Hydrocarbon

Page 28: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Current Approach - Chain-end Derivatization

• Organic species (e.g. PR3) covalently attached to the polymer forming an organic salt

• Labile endgroup necessary for derivatization– e.g. polyethylene – presence of vinyl group

• Aggressive reaction conditions necessary for saturated polyolefin derivatization p y

• Several days required for synthesis, sample work-up, and characterizationand characterization

Page 29: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Current Approach - Atomic Transition Metal Ion (M+) Chemistry

On Product+

Metal Ion (M ) Chemistry

M+

Energetic!!!

+Fragments

+

Hydrocarbon

Energetic!!!

HydrocarbonNo Reaction

OffOffMS interpretation very complicated

Ligated TM chemistry allows better control of the ion-molecule reaction.

Page 30: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Higher MW Hydrocarbons Show Similar DoubleSimilar Double

Dehydrogenation ReactivityC-36

C-60

rb. U

nits

)

m/z 626

Inte

nsity

(Ar

F’m/z 962

Arb

. Uni

ts)

m/z

m/z 738Uni

ts)

/

F’

Inte

nsity

(C-44

F′ C H l f Add t 2HF’

m/z 738

nsity

(Arb

. U m/z

F′ - C5H6 loss from Adduct – 2H2m/zIn

ten

Page 31: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Comparison with Past WorkWork

ti f C 28 ith C +Uni

ts)

LDI-TOF MS (Chen & Li, 2000)

• reaction of C-28 with Co+

produces adduct ion as well as extensivens

ity (A

rb. U AdductF

FF F FF well as extensive

fragmentation200 287 374 462 550

m/z

Inte

n F

• reaction with CpCo•+

h i i l

FTMS(Byrd, Guttman, Ridge 2003)

. Uni

ts)

Adduct - 2H2

/

shows minimal fragmentation

ensi

ty (A

rb

F′F′ C H l f Add t 2H

200 287 374 462 550m/z

Inte F′ - C5H6 loss from Adduct –2H2

Page 32: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Oxidation of Metal Monocarbonyl Cations

M(CO)+ + O2 MO+ + CO2 (1)observed only for M = Fe

y

observed only for M Fenot observed for M = Cr, Mn, Co, Ni

Thermochemistry of O2 Oxidation of CO Ligand

M D(M+-CO) [state]

D(M+-O) [state]

ΔH(1)

C 21 4 [6Σ+] 85 8 [4Σ ] 72 4

y g(Kcal/mol)

Cr 21.4 [6Σ+] 85.8 [4Σ-] -72.4

Mn 22.1 [5Π] 68.0 [5Π] -52.3

Fe 31.3 [4Σ-] 80.0 [6Σ+] -56.7

C 41 [3Δ] 4 9 [5Δ] 41 1Co 41.5 [3Δ] 74.9 [5Δ] -41.1

Ni 41.7 [2Σ+] 63.2 [4Σ-] -29.6

Page 33: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Reaction of FeCO+ w/ O2; Xfer Method, 2.1x10^-7 Torr

1.2

0.8

1

ensi

ty

Fe(CO)+ FeO+

0.4

0.6

Rel

ativ

e Io

n In

te m/z 72

m/z 84

m/z 88

F (O )

0

0.2

0 0.5 1 1.5 2 2.5 3 3.5

Fe(O2)+

Time (s)

Page 34: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

F (CO)+ + O d t

00 0.5 1 1.5 2 2.5

Fe(CO)+ + O2 products

F O+

-0.5

nsity

FeO+

-1.5

-1

elat

ive

Ion

Inte

n

m/z 84

-2

Ln R

e

Fe(O2)+

-2.5

Time (s)

Page 35: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

The Effect of Exciting Fe(CO)+

00 0.5 1 1.5 2 2.5

-1

-0.5

nten

sity

-1.5

n R

elat

ive

Ion

I

m/z 84Begin excite pulse

Excite Pulse

-2

Ln

-2.5

Time (s)

Page 36: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Potential Energy Surface for Fe(CO)+ + O2

4FeCO+ + 3O2 (0) 6Fe(O)2+ + CO (+5)

6Fe(O2)+ + CO (+7)

T. S.

4Fe(CO)(O2)+

6FeO+ + CO2 (-57)

Page 37: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Potential Energy Surface for Cr(CO)+ + O2

6CrCO+ + 3O2 (0)

6Cr(O2)+ + CO (+11)

6C (CO)(O )

T. S.

6Cr(CO)(O2)+2Cr(O)2

+ + CO (-34)

4CrO+ + CO2 (-72)

Page 38: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

1.0

0.8

0.9

e

0.5

0.6

0.7

Abu

ndan

ce Lumiflavin-

0.2

0.3

0.4

Rel

ativ

e

N hth i -

0.0

0.1

0

0 10 20 30 40 50 60 70 80

Naphthaquinone

Reaction Time (sec.)

Variation with time of lumiflavin anion and 1 4 naphthoquinoneVariation with time of lumiflavin anion and 1,4 naphthoquinone anion in a mixture of the neutrals

Page 39: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

R R

Flavin in Various Oxidation States

N

N

NH

N O

O

NH

N

NH

N O

H

-PA(Fl)

O

N N O

R

N N O

R

A. Oxidized (Fl)O

A. Protonated Oxidized (Fl)-EA(Fl)

PA(Fl-)IP(FlH)

N

N

NH

N O

O

NH

N

NH

N O

O

..-

-PA(Fl )

HR

B. Red Semiquinone (Radical Anion, Fl-)

C. Blue Semiquinone (Radical, FlH)

NH

N

NH

HN O

OO

D. Fully Reduced (FlH2)

Page 40: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Measured and Computed Properties of Redox Forms of Lumiflavin

Property B3-LYP/6-31G(d)a,b B3-LYP/6-31+G**a,c ExperimentalFTMS(Electrochemistry)

EA(Fl) 1.54 eV(B3 LYP/6 311++G(d)

1.96 eV 1.86 ± 0.06 eV(B3-LYP/6-311++G(d) 2.00 eV)

PA(Fl) 221 kcal mol⁻1(B3-LYP/6-311++G(d)

225.5 ± 2.2 kcal mol⁻1

215kcal mol-1)PA(Fl⁻) 332 kcal mol⁻1 322 kcal mol-1 332 ± 3.2 kcal

mol⁻1

D(Fl H) 54 8 k l l⁻1 54 2 k l l⁻1 59 7 ± 2 2 k lD(Fl-H) 54.8 kcal mol 1 54.2 kcal mol 1 59.7 ± 2.2 kcal mol⁻1(60.6 ± 2.4 kcal mol-1)

IP(FlH) 6.38 eV 6.40 ± 0.10 eV

a) Theoretical numbers correspond to 0 K.b) Present Resultsb) Present Resultsc) Hadad, et al. JACS 124, 7226(2002)d) Experimental measurements at 298 K.e) Anderson, Biochem. Biophys. Acta 722, 158(1983).

Page 41: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

X X

Iron Tetraphenyl-porphyrin Series

X, Y, Z

X = H Y =

Symbol used in this work

FeTPP

X X

YYX H, Y C6H5, No Z

X = H, Y = C6H5, Z = Cl

FeTPP

FeTPPClXXN

N

Z

X = H, Y = C6F5, No Z

X = H, Y = C F Z = Cl

FeTPPF20

FeTPPF20ClXX

N

N

N Fe

C6F5, Z = Cl

X = Cl, Y = C6F5, No Z

X = Cl, Y =

FeTPPF20Cl8

FeTPPF20Cl9

YY

X Cl, Y C6F5, Z = Cl

20 9XX

Page 42: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

X X

Fluoroalkyl Series

X X

YY X, Y, ZSymbol used in this work

XXN

N

Z X = Y = H, No Z

X = Y = H,

in this work

FeP

FePCl

XX

N

N

N Fe Z=Cl

X = H, Y = CF3, Z = Cl

X H Y C F Z

FeP(CF3)4Cl

(C ) ClYY

X = H, Y = C3F7, Z = Cl

FeP(C3F7)4Cl

XX

Page 43: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Octaethyl Series

X X

X Y ZSymbol used in

Y

XX

Y

N Z

X, Y, Z

X = C2H5, Y = H, No Z

ythis work

FeOEP

X

XX

NN Fe

No Z

X = C2H5, Y = H, Z = Cl

FeOEPCl

YY

N X = C2H5, Y = NO2,

Z = Cl

FeOEP(NO2)4Cl

XX

Page 44: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

C d

Electron Affinity Ladder

Compound EA

TCNE

Fe(OEP)(NO 2 ) 4 Cl

[3.17]

2.93

[2 70]

(eV)

F 4 -BQ

Fe(OEP)(NO 2 ) 2 Cl

Fe(OEP)(O)Cl

[2.70]

2.54

2.53 2,6-Cl 2 BQ

NO 2

Fe(OEP)Cl 4 NO NB

[2.48]

[2.29] 2.07

4-NO 2 NB

BQ

NPQ

[2.00]

[1.91]

[1.81] Fe(OEP)

3-NO 2 NB 1.68

[1.65]

Page 45: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

An Iron (II) Porphyrin (FeTPPF20) with C4v Symmetry

Page 46: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Dmol program, geometry optimized, BPW functionals, DNP basis set with “frozen” core potentialspotentials

Page 47: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Dmol program, geometry optimized, BPW functionals, DNP basis set with “frozen” core potentialspotentials

Page 48: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Distances for Spin Unrestricted C4 Fluoroalkyl Series

FeP(CF3)4Cl Neutral 2.0064 2.1727 0.1333

Anion 2 0022 2 2538 0 0685

Distances for Spin Unrestricted C4v Fluoroalkyl SeriesMolecule Charge Fe-N (Å) Fe-Cl (Å) Fe-N4 plane (Å)

Anion 2.0022 2.2538 0.0685

FeP(C2F5)4Cl Neutral 2.0121 2.1714 0.1603

Anion 2.0088 2.2447 0.0978

F P(C F ) Cl N t l 2 0121 2 1672 0 1823FeP(C3F7)4Cl Neutral 2.0121 2.1672 0.1823

Anion 2.0102 2.2376 0.1163

Page 49: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 50: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Bond Lengths from X-ray Diffraction for Tetraphenyl Series [Present Results]

[M l l F N (Å) F Cl (Å) F N4 l (Å)[Molecule Fe-N (Å) Fe-Cl (Å) Fe-N4plane (Å)

FeTPP 1.972(4)[i], [1.9846a] N/A

FeTPPCl 2.049(9)[ii], [1.9902a] 2.192(12)[ii][, [2.1812a] 0.383(5)[ii], [0.2200a]

FeTPPF20Cl 2.062(8)[iii], [1.9962a] 2.199(2)[iii], [2.1675a] 0.449(3)[iii], [0.1906a]

a: Present spin unrestricted results for C4v structures.

[i] J P Collman J L Hoard N Kim G Lang C A Reed J Am Chem Soc 1975 97 2676[i]. J.P. Collman, J. L. Hoard, N. Kim, G. Lang, C. A. Reed, J. Am. Chem. Soc., 1975, 97, 2676.[ii]. J. L. Hoard, G. H. Cohen, M. D. Glick, J. Am. Chem. Soc., 1967, 89, 1992. [iii]. B. Song, D. C. Swenson, H. M. Goff, Acta Crys. Sect C., Volume 54, Part 11 (November 1998), cif-access (metal-organic compounds). IUC9800058.

Page 51: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Electron Affinities(eV)

M l l El t Affi it El t Affi itMolecule Electron Affinity (DFT)

Electron Affinity (Exp)

FeOEP 1.7557 1.68±0.03

FeTPP 2 134 1 87±0 03FeTPP 2.134 1.87±0.03

FeOEPCl 2.2724 2.07±0.03

FeTPPCl 2.4704 2.15±0.15

FeTPPF 2 9887 2 15±0 15FeTPPF20 2.9887 2.15±0.15

FeTPPF20Cl 3.3162 3.14±0.03

FeP(CF3)4Cl 3.363 3.16±0.03

F P(C F ) Cl 3 5151 3 30±0 03FeP(C3F7)4Cl 3.5151 3.30±0.03

Page 52: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

EAs of C4v Iron Porphyrins

y = 1 0064x + 0 19224

y = 1.0064x + 0.1922R2 = 0.9884

2.53

3.5

(eV)

D t

11.5

2

DFT

EA

( DataFitted line

00.5

1

0 1 2 3 40 1 2 3 4

Experimental EA (eV)

Page 53: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

IR Spectra of Gas Phase IonsIR Spectra of Gas Phase Ions

• Absorption spectroscopy inaccessibleAbsorption spectroscopy inaccessible• Multiphoton IR photodissociation possible

IRMPD t fl t b ti• IRMPD spectrum reflects absorption spectrum

• Candidate ions: Mn(CO)m+/-,

Mn(CO)m(alkane)+, Mn(CO)m(O2)+/-, etc.• Requires tunable IR laser

Page 54: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Free Electron Laser for Infrared eXperiments "FELIX"Free Electron Laser for Infrared eXperiments "FELIX"

FEL-25 - 30

spectrometermagnet

OTRμm

Undulator

25-45 MeV15-25 MeV

FEL-1

Linac 1 Linac 2

16 - 250

injector

μm

Undulator

16 - 250μm

Page 55: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Principles of FTICR-MS

-charged particles trapped by strong, homogeneous magnetic field B (Lorentz force)- particles orbit magnetic field with frequency dependent only on m/z (for fixed B)- trapped particles are confined axially by small static voltage to trapping plates (T)- applying RF to excite plates (E) at cyclotron frequency bunches ions and expands their orbital radii, improving dynamic range also used to eject unwanted ions- current induced by moving ions is detected (D) and amplified in time domain, then Fourier Transformed to obtain frequencies of trapped ions

Cyclotron frequencyf B /f ~ Bz/m

Page 56: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 57: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Anionic Metal Carbonyl Clustering Reactions

Page 58: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

3.e+0

4.5e+0s\doug\My Documents\FTICR files from FOM\030825-007_Fe2CO8-_PV_p=1e6_8avg_FEL

A

m

p

FELIX off

0.e+0

1.5e+0

354705 359822 364939 370056 375173

l

i

t

u

d

e

54Fe56Fe(CO)8-

off

354705 359822 364939 370056 375173Frequency (Hz)

4.3e+0doug\My Documents\FTICR files from FOM\030825-013_Fe2CO8-_PV_p=1e6_10avg_FEL

A

m FELIX on

0 e+0

1.4e+0

2.9e+0p

l

i

t

u

d

e

o4.76μm

3.2e+0doug\My Documents\FTICR files from FOM\030825-008_Fe2CO8-_PV_p=1e6_10avg_FEL

0.e+0354910 359976 365042 370107 375173

Frequency (Hz)

1.1e+0

2.1e+0

A

m

p

l

i

t

u

d

e

FELIX on 5.12μm

56Fe2(CO)7-

0.e+0354880 359963 365046 370129 375212

Frequency (Hz)

Page 59: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

m1008 [Fe8(CO)20- ?]

0.9

1.0

0.90

0.95

1.00

0.80

0.85

0.90

0.95

1.00

m896 [Fe7(CO)18- ?]

m952 [Fe9(CO)16- ?]

0.6

0.7

0.8

0.9

SORI up to higher masses

• By adding additional frequencies to

plet

ion

Fe (CO) -0.95

1.00

0.85

0.90

0.95

1.00

Fe5(CO)14-

• By adding additional frequencies to the SORI excitation pulse, larger and larger cluster can be synthesized• In each case, a large percentage (40-

rmal

ized

dep

1.0

Fe4(CO)13

Fe4(CO)12-

0.85

0.90

0.95

1.00

0.85

0.90100%) of the ion population is transferred into the target mass channel• Spectra show a blue shift with increasing size, converging to a value

Nor

0.7

0.8

0.9

1.0

Fe2(CO)8-

0.7

0.8

0.9

Fe3(CO)10-

increasing size, converging to a value around 2000 cm-1

• Structure in spectrum also disappears with increasing size -- indication of transition from organometallic

0.95

1.00

Fe2(CO)7-

Fe(CO) -

0.7

0.8

0.9

1.0

0transition from organometallic complexes to metal-cluster-adsorbate systems?

1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 21500.85

0.90 Fe(CO)4

Wavenumber (cm-1)

Page 60: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Fe2(CO)8- cluster IRMPD spectrum

E t C l (B3LYP / LACVP+* / 0 965 li f t )

( d )

Expt. vs. Calc. (B3LYP / LACVP+* w/ 0.965 scaling factor)rb

. uni

ts)

Expt. (0 dB) Calc. w/ 12 cm-1

Gaussian conv.

sect

ion

(ar

tion

cros

s s

ve a

bsor

ptR

elat

iv

1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150Wavenumber (cm-1)

Page 61: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 62: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

IR spectrum of anionic Fe2(CO)7 cluster

IRMPD (0 dB) B3LYP/LACVP+*

(scaled by 0.965) (convoluted

/12 -1 i ) w/12 cm gaussian)

1800 1825 1850 1875 1900 1925 1950 1975 2000 2025 2050Wavenumber (cm-1)

Page 63: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 64: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Acknowledgments

Delaware

Scott Robinson

David Finneran

Rhone-Poulenc Rorer

Runzhi Zhao

Robert McKean

NHFML & FOM (Utrecht)

David Moore

John EylerRichard Ochran

Jim Witkoski

Nganha Luu

O Ch

Stephen Conlon

Sun Company

Ji L

John Eyler

NIST

Michelle Byrd

Ounan Chen

Jennifer Sterner

Steve Bennett

L i Ji

Jim Lyons

Paul Ellis

Tilak Wijesekera

Charles Guttman

University of Oslo

Einaar UggerudLei Jin

Tianlan Zhang

Fred Arnold

Henglong Chen

Funds

NSF

Sun

gg

Dag Ekeberg

Bruker InstrumentsHenglong Chen

Karl Sohlberg

Hung-Yu Lin

RPR

NISTGary Kruppa

Page 65: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 66: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Acknowledgements

Delaware

Scott Robinson

David Finneran

Delaware (contd)

Robin Kinser

Hung Yu Lin

Rhone-Poulenc Rorer

Runzhi Zhao

Robert McKean

HeeYeon Park

Richard Ochran

Tom Bailey

g

Yi Lin

Ying Pan

Barbara Larsen

Steve Conlon

Sun Company

Nganha Luu

Ounan Chen

Steve Bennett

Fred Strobel

John Wronka

Gary Kruppa

Jim Lyons

Paul Ellis

Jennifer Sterner

Lei Jin

Fred Arnold

Thuy Nguyen

Art Smith

Rob Freas

NHFML & FOM

John Eyler

David Moore

Tianlan Zhang

Henglong Chen

Gary Weddle

Dana Chattalier

Tom Dietz

John Allison

Page 67: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 68: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ESI of (KAA)10

Page 69: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Products of reaction of +9 charge state ion with di-n-butyl ether

Page 70: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 71: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 72: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

MethodsMethods

• SORI-CID and ECD were performed on aSORI CID and ECD were performed on a All samples were dissolved to 5 μM in 50:50 MeOH:water 1% acetic acid50:50 MeOH:water, 1% acetic acid

• Bruker Apex 4.7T instrument

• IRMPD experiments were performed on a Bruker Apex 3T instrumentBruker Apex 3T instrument

Page 73: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

SORI-CIDSORI CID

• Cleavage observed at 25 of 30 backboneCleavage observed at 25 of 30 backbone positions

• Produced 7 a, 19 b, 5 c, 2 x, 13 y, and 16 z ions

• No cleavage observed within the lactam bridgebridge

Page 74: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (Ar Cooling Gas)ECD (Ar Cooling Gas)

2.3e+7 4+

2.6e+5

3.9e+5

A

m

p

C12

Z22Y22

1.5e+7

A

m

p

l

i

t 5+1.3e+5

l

i

t

u

d

e

7.6e+6

u

d

e 0.e+01290 1298 1307 1316 132

m/z

0.e+0600 850 1100 1350 1600

m/z

3+C9Y29

Page 75: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (Ar Cooling Gas)ECD (Ar Cooling Gas)

0 8

0.9

1

0.6

0.7

0.8

ve in

tens

ity

0.3

0.4

0.5

Nor

mal

ized

rel

ativ

0

0.1

0.2

01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Bond # (From N-terminus)

Page 76: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (Ar Cooling Gas)ECD (Ar Cooling Gas)

• Cleavage observed at 16 of 30 backboneCleavage observed at 16 of 30 backbone positions

• Produced mostly c and z ions (1 a, 1 b, 13 c, 1 x, 7 z)

• No cleavage observed within the lactam bridgebridge

Page 77: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD: A Non-selective Technique?

0.9

1

0.4

0.5

0.6

0.7

0.8

rmal

ized

rel

ativ

e in

tens

ity

0

0.1

0.2

0.3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Bond # (From N-terminus)

No

• ECD w/ Ar: Cleavage between His-9 and Asn-10 accounted for 29.8% of the total normalized ion abundance

• ECD w/ SF6: Cleavage after His-9 = 29.4%

Page 78: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Major ProductsMajor Products

R CHN CH R'

O

R CH 2N CH R'

OH

R C NH 2CH R'

O

+ +

a y

R CHN CH R'

O

R CHN CH R'

O HH

R C

O H

NH + CHR'c zc z

• Peptide Bond #9– Only site where reverse products (a, y., c., z) are

observed– Is there an explanation in the structure?

Page 79: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

ECD (SF6) Cooling GasECD (SF6) Cooling Gas

• Cleavage observed at 21 of 30 backboneCleavage observed at 21 of 30 backbone positions

• Produced 2 a, 14 c, 1 x, 4 y, 13 z

N l b d ithi th l t• No cleavage observed within the lactam bridge

Page 80: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Polyolefin Mass

• Polyethylene (PE) & polypropylene (PP)

Spectrometry - Importance• Polyethylene (PE) & polypropylene (PP)

•Large production volume and fast growth •New metallocene catalysts produce new polyolefin•New metallocene catalysts produce new polyolefin types• NIST provides saturated polyolefin standardsNIST provides saturated polyolefin standards

• Central Challenge in PE/PP mass spectrometry

•Polymer functionality for cationization absent

•Masses over ~ 2000 u cannot be determined

Creating an intact, gas-phase macromolecular ion

Page 81: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

New Approach -η5-Cyclopentadienylcobalt Ion (CpCo•+)

CpCo•+ ion shows favorable ( p )

reactivity toward low mass alkanesalkanes.

CpCo•+ + CnH2n+2 CpCoCnH2n-2m+2 •+

- mH2

• predominant dehydrogenation d t

n = 2-6, m = 1, 2

product• little fragmentation in MS

Müller & Goll ’73, Jacobson & Freiser ’85, & Ekeberg, Ridge, et al. ‘99

Page 82: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Double Dehydrogenation Dominates All Three ReactionsDominates All Three Reactions

C-1515 %

C-2025 %

C-2840 %

0.8

1

sity 0.8

1

ensi

ty 0.81

tens

ity

15 % 25 % 40 %

0.4

0.6

0 8

ativ

e In

tens

0 20.40.6

ativ

e In

te

0 20.40.6

ativ

e In

t

0

0.2

0 0.5 1 1.5 2 2.5

Rel

a

00.2

0 1 2 3

Rel

a

00.2

0 1 2 3 4 5

Rel

a

0 0.5 1 1.5 2 2.5Time (s) Time (s) Time (s)- CpCo•+ loss - CpCoCnH(2n-2)

•+ formation- other products

Byrd, Ridge & Guttman, J. Am. Chem. Soc. Mass Spectrom. 2003, 14, 51-57.

Page 83: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Structures of Flavins

H+ H+ or OH-Photolysis

N N CH2 (CH2O)3 P O

O

P

O

O O N N

N

N NH2

H2CCH2O10

67 8

9

5

Isoalloxazi

pH>9pH<7

HN

N

O

O

OH OH

HO OH3

142

ine ring

Lumiflavin

Lumichrome

Riboflavin (vitamin B2)

Riboflavin-5-monophosphate (FMN)

l i d i di l id ( )Flavin-adenine-dinucleotide (FAD)

Page 84: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 85: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Distances for Spin Unrestricted C4v Tetraphenyl Series

Molecule Charge Fe-N (Å) Fe-Cl (Å) Fe-N4 plane (Å)

FeTPP Neutral 1.9846 N/A 0.0093

Anion 1.9856 N/A 0.0040

FeTPPCl Neutral 1.9902 2.1816 0.2200

Anion 1.9868 2.2496 0.1300

FeTPPF20 Neutral 1.9914 N/A 0.0116

Anion 1.9889 N/A 0.0109

F TPPF Cl N t l 1 9962 2 1675 0 1906FeTPPF20Cl Neutral 1.9962 2.1675 0.1906

Anion 1.9945 2.2400 0.1239

Page 86: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Di t f S i U t i t d C O t th l S iDistances for Spin Unrestricted C4v Octaethyl Series

Molecule Charge Fe-N (Å) Fe-Cl (Å) Fe-N4 plane (Å)

FeOEP Neutral 1.9906 N/A 0.0008

Anion 1.9898 N/A 0.0007

FeOEPCl Neutral 1.9893 2.2271 0.1593

Anion 1.9898 2.264 0.1241

FeOEP(NO2)4Cl Neutral 2.0377 2.1695 0.2061

Anion 2.0326 2.2403 0.1064

Page 87: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

I R M P D s p e c t r a o f a n i o n i c i r o n c a r b o n y l c l u s t e r s

F ( C O ) - ( 6 7 2 ) F e 5 ( C O ) 1 4 ( m 6 7 2 ) F e 4 ( C O ) 1 3

- ( m 5 8 8 ) F e 4 ( C O ) 1 3

- ( m 5 6 0 ) F e 3 ( C O ) 1 0

- ( m 4 4 8 ) F e 2 ( C O ) 8

- ( m 3 3 6 )F e ( C O ) - ( m 3 0 8 ) F e 2 ( C O ) 7 ( m 3 0 8 )

1 7 5 0 1 8 0 0 1 8 5 0 1 9 0 0 1 9 5 0 2 0 0 0 2 0 5 0 2 1 0 0 2 1 5 0W a v e n u m b e r ( c m - 1 )

Page 88: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Theoretical spectrum from pSchaefer’s calculations for D2h unbridged structure. Frequencies lowered by 46 cm-1.

1750 1800 1850 1900 1950 2000 2050 2100 2150Frequency (cm-1)

Page 89: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Theoretical spectrum from Schaefer’s calculations for tetrabridged structure. Average lowered by 40 cm-1and range expanded 10% about average10% about average. Imported from Excel plot

1750 1800 1850 1900 1950 2000 2050 2100 2150Frequency (cm-1)

Page 90: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Theoretical spectrum from Schaefer’s calculations for a dibridged C2h structure. Average lowered by 57Average lowered by 57 cm-1. Imported from Excel plot

1750 1800 1850 1900 1950 2000 2050 2100 2150Frequency (cm-1)

Page 91: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Fe2(CO)8- anion

spectrum

1750 1800 1850 1900 1950 2000 2050 2100 2150

Frequency (cm-1)Theoretical spectrum from Schaefer’s calculations for dibridged C2v structure. Average lowered by 60 cm-1 and range expanded

Frequency (cm )

g pby 10%. Imported from Excel plot

Page 92: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Fe2(CO)7- anion spectrum

Fe2(CO)7 neutral harmonicFe2(CO)7 neutral harmonic frequencies (lowered by 52 cm-1 and expanded by 10% about the average) and intensities from DFT calculations for triply bridgedcalculations for triply bridged structure in ref. 1.

1750 1800 1850 1900 1950 2000 2050 2100 2150F ( 1)Frequency (cm-1)

Fe2(CO)7 neutral tribridged C2v2( )7 g 2vstructure optimized using DFT from ref. 1.

1. Xie, Schaefer and King, JACS, 122, 8746(2000)

Page 93: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Fe2(CO)7- anion spectrum

Fe2(CO)7 neutral harmonicFe2(CO)7 neutral harmonic frequencies (lowered by 52 cm-1 and expanded by 10% about the average) and intensities from DFT calculations for singly bridgedcalculations for singly bridged structure in ref. 1.

1750 1800 1850 1900 1950 2000 2050 2100 2150Frequency (cm-1)

Fe2(CO)7 neutral b id d Cmonobridged C2v

structure optimized using DFT from ref. 1.

1. Xie, Schaefer and King, JACS, 122, 8746(2000)

Page 94: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Fe2(CO)7- anion spectrum

Fe2(CO)7 neutral harmonicFe2(CO)7 neutral harmonic frequencies (lowered by 62 cm-1 and expanded by 10% about the average) and intensities from DFT calculations forcalculations for unsymmetrically doubly bridged structure in ref. 1.

1750 1800 1850 1900 1950 2000 2050 2100 2150Frequency (cm-1)

Fe2(CO)7 neutral asymmetrically dib id d C t t ti i ddibridged Cs structure optimized using DFT from ref. 1.

1. Xie, Schaefer and King, JACS, 122, 8746(2000)

Page 95: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 96: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 97: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

“The goddammed mass spectrometer is broken again!” (title by Frank Field)

Page 98: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Electron Capture Dissociation of Human Parathyroidof Human Parathyroid

HormoneA comparison with common

fragmentation techniques and gselective cleavage at histidine

Page 99: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

Human Parathyroid Hormone (hPTH)

• 84 amino acid protein that regulates84 amino acid protein that regulates calcium levels in blood

• Mild to moderate hyperthyroidism results• Mild to moderate hyperthyroidism results in increased bone densityT t t ith th i ti f hPTH• Treatment with the amino portion of hPTH (amino acids 1-34) promotes bone f tiformation

Page 100: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction

( u n s c a l e d f r e q u e n c i e s )

F e ( C O ) 4- E x p . v s . C a l c .

( u n s c a l e d f r e q u e n c i e s )

I R M P D w / 2 0 d B F i t t o E x p t . F i t t e d p e a k @ 1 8 5 8 . 4F i t t e d p e a k @ 1 8 4 9 4 F i t t e d p e a k @ 1 8 4 9 . 4

B 3 L Y P / L A C V P ( * * ) ( + + )

1 8 0 0 1 8 2 5 1 8 5 0 1 8 7 5 1 9 0 0 1 9 2 5 1 9 5 0 1 9 7 5 2 0 0 0 2 0 2 5 2 0 5 0 2 0 7 5 2 1 0 0W b ( - 1 )W a v e n u m b e r ( c m 1 )

Notes:The calculated curve was generated by convoluting the stick spectrum with a 12 cm-1

gaussian lineshape. The fitted widths for the two peaks in the experimental spectrum are ~15 andgaussian lineshape. The fitted widths for the two peaks in the experimental spectrum are 15 and ~10 cm-1 . Forcing them to be 12 cm-1 does not significantly alter the fit, other than to make the areas of the peaks more similar.

The calculated frequencies are unscaled, but the “optimal” factor is ~0.97, which I find quite reasonable, particularly since the basis set used an ECP (effective core potential). Also, thisquite reasonable, particularly since the basis set used an ECP (effective core potential). Also, this scaling makes the splittings more similar (9 cm-1 and 12 cm-1 for the expt. and calc, repsectively.)

Page 101: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction
Page 102: Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox ... FTMS INTRO.pdf · Metal Clusters,,ppy Metalloporphyrins and Gas Phase Redox Chemistry: Applications of FTMS •Introduction