1

Coordination-Driven Self-Assembly of Metallodendrimers Possessing Well-Defined and C

ontrollable Cavities as Cores

Hai-Bo Yang,* Adam M. Hawkridge, Songping D. Huang, Neeladri Das,Scott D. Bunge, David C. Muddiman, and Peter J. Stang*

J. Am. Chem. Soc. 2007, 129, 2120-2129.

2

The Dendritic Structure

Host-guest chemistry

Material science

Membrane chemistry

Catalysis

Stoddart, J. F. et al. Prog. Polym. Sci. 1998, 23, 1-56.

3

“Convergent” Dendrimer Growth

Stoddart, J. F. et al. Prog. Polym. Sci. 1998, 23, 1-56.

4

“Divergent” Dendrimer Growth

Stoddart, J. F. et al. Prog. Polym. Sci. 1998, 23, 1-56.

5

Metallodendrimer

Newkome, G. R. et al. Chem. Rev. 1999, 99, 1689-1746.

6

Metals as Branching Centers

Denti, G. et al. J. Am. Chem. Soc. 1992, 114, 2944-2950.

7

Metals as Building Block Connectors

Puddephatt, R. J. et al. Organometallics 1995, 14, 1681-1687.

8

Metals as Cores

Fréchet, J. M. et al. Chem. Mater. 1998, 10, 30-38.

9Lemo, J.; Heuze, K.; Astruc, D. Org. Lett. 2005, 7, 2253-2256.

Metals as Termination Groups (Surface Functionalization)

10Kaneda, K. J. Am. Chem. Soc. 2004, 126, 1604-1605.

I I + RPd complex

KOAc, 100oC, ArI

R+

R

R

major minor

Metals as Structural Auxiliaries

11Mirkin, C. A. et al. Angew. Chem. Int. Ed. 2001, 40, 2022-2043.

Supramolecular Coordination Chemistry

Hydrogen bonding

Metal-ligand coordination

π-π stacking

Eletrostatic interactions

van der Waals forces

Hydrophobic interactions

Hydrophilic interactions

etc.

12Stang, P. J.; Olenyuk, B. Acc. Chem. Res. 1997, 30, 502-518

Supramolecular Assembly of Polyhedra

13

Self-Assembly of Rhomboidal andHexagonal, “Snowflake-Shaped”

Metallodendrimers.

14

Synthesis of [G0]-[G3] 120o

Angular Dendritic Donor Precursors

acylation

Sonogashira coupling

hydrolysis etherification

15

Structures of [G0]-[G3] 120o

Angular Donor Precursors 5a-d

16

Self-Assembly of Rhomboidal Metallodendrimers 7a-d

Hα Hβ

5a 8.60 7.39-7.455b 8.60 7.33-7.445c 8.60 7.31-7.425d 8.60 7.31-3.42

Hα Hβ

7a 9.35, 8.72 7.597b 9.36, 8.70 7.597c 9.37, 8.68 7.597d 9.36, 8.65 7.58

96-99%

31P{1H} NMRδ14.6 ppm (-6.4 ppm)1JPt-P=2707.7 (-177 Hz)

17

O

N NPt Pt

PEt3

Et3P

Et3P

PEt3

Pt PtN N

PEt3

Et3P

Et3P

PEt3

O

OO

OO

O

O

O O

O

O

O

O

O

O

O O

O O

O

O

OO

O

O

O

O

O

O

O

N NPt Pt

PEt3

Et3P

Et3P

PEt3

Pt PtN N

PEt3

Et3P

Et3P

PEt3

O

OO

OO

OO

O O

O O

O O

Structures of [G0]-[G3]-Rhomboidal Metallodendrimers 7a-d

O

N NPt Pt

PEt3

Et3P

Et3P

PEt3

Pt PtN N

PEt3

Et3P

Et3P

PEt3

O

OO

O O

O

N NPt Pt

PEt3

Et3P

Et3P

PEt3

Pt PtN N

PEt3

Et3P

Et3P

PEt3

O

7a

7b

7c

7d

18

Calculated and Experimental ESI-MS Spectra of [G0]-[G2]-Rhomboidal Metallodendrimers 7a-c

[M-2NO3]2+ [M-3NO3]3+ [M-2NO3]2+ [M-3NO3]3+ [M-2NO3]2+ [M-3NO3]3+ C130H172N8O14P8Pt4 C158H196N8O18P8Pt4 C214H244N8O26P8Pt4

H 1(100.0%)C 12(98.9%) 13(1.1%)N 14(99.6%) 15(0.4%)O 16(99.8%) 18(0.2%)P 31(100.0%)Pt 192(0.8%) 194(32.9%) 195(33.8%) 196(25.3%) 198 (7.2%)

Isotope %

19

H 1(100.0%)C 12(98.9%) 13(1.1%)N 14(99.6%) 15(0.4%)O 16(99.8%) 18(0.2%)P 31(100.0%)Pt 192(0.8%) 194(32.9%) 195(33.8%) 196(25.3%) 198 (7.2%)

Calculated and Experimental ESI-FT-ICR-MSSpectra of [G3]-Rhomboidal Metallodendrimer 7d

C326H340N8O42P8Pt4

Isotope %

20

3.3 nm long2.8 nm wide

Crystal Structure of[G0]-Rhomboidal Metallodendrimer 7a

21

Crystal Structure of[G1]-Rhomboidal Metallodendrimer 7b

4.2 nm long2.8 nm wide

22

Wireframe Representation of the Crystal Structureof Metallodendrimer 7a and 7b

2.3 nm

1.3 nm

23

Self-Assembly of Hexagonal, “Snowflake-Shaped” Metallodendrimers 10a-d and 11a-d

24

Partial 1H NMR spectra of 5d, 10d and 11d

αβ

25

31P NMR Spectra of [G3]-Hexagonal Metallodendrimer 10d and 11d

Compaired with 8δ (-6.5 ppm)

Δ1J PPt = -131 Hz

Compaired with 9δ (-6.4 ppm)

Δ1JPPt = -150 Hz

26

H 1(100.0%)C 12(98.9%) 13(1.1%)N 14(99.6%) 15(0.4%)O 16(99.8%) 18(0.2%)F 19(100.0%)P 31(100.0%)S 32(95.0%) 33(0.8%) 34(4.2%)Pt 192(0.8%) 194(32.9%) 195(33.8%) 196(25.3%) 198 (7.2%)

Calculated and Experimental ESI-FT-ICR-MS Spectraof [G0]-[G2]-Hexagonal Metallodendrimers 10a-c

C282H348F36N12O42P24Pt12S12 C366H420F36N12O54P24Pt12S12 C534H564F36N12O78P24Pt12S12

Isotope %

27

Full ESI-FT-ICR Mass Spectrum of [G1]-Hexagonal Metallodendrimer 10b

28

Calculated and Experimental ESI-FT-ICR-MS Spectraof [G0]-[G2]-Hexagonal Metallodendrimers 11a-c

H 1(100.0%)C 12(98.9%) 13(1.1%)N 14(99.6%) 15(0.4%)O 16(99.8%) 18(0.2%)F 19(100.0%)P 31(100.0%)S 32(95.0%) 33(0.8%) 34(4.2%)Pt 192(0.8%) 194(32.9%) 195(33.8%) 196(25.3%) 198 (7.2%)

C390H516F36N12O42P24Pt12S12 C474H588F36N12O54P24Pt12S12 C642H732F36N12O78P24Pt12S12

Isotope %

29

Space-Filling Models of Hexagonal Metallodendrimers 10d and 11d

Optimized with the MM2 Force-Field Simulation

30

Conclusions

1. This approach makes it possible to prepare a variety of metallodendrimers with well-defined and controlled cavities as cores through the proper choice of subunits with predefined angles and symmetry, which enriches the library of different-shaped cavity-cored metallodendrimers.

2. Metallodendrimers having nonplanar hexagonal cavities with different internal radii of approximately 1.6, 2.5, and 2.9 nm have been obtained.

3. We have demonstrated that highly convergent synthetic protocols of appropriate predetermined building blocks allow the rapid construction of novel cavity-cored metallodendrimers. The shape of the cavities of the supramolecular dendrimers can be rationally designed to be either a rhomboid or a hexagon.

31

Acylation

ROHO

O O

RO

O

Mechanism of acylation

O

O O

ROH

O

O O

OHR

RO

O

H

+O

O

1. ice

2. baseRO

O

+ H-baseO

O+

32

ROR'

O+ OH R

O

O+ R'OH

Hydrolysis of Esters

ROR'

O

OH

ROR'

O

HOR

OH

O+ R'O

Base-catalysed hydrolysis

Mechanism of hydrolysisStep 1 : Reversible attack at carbonyl carbon by base

Step 2 : Protion transfer

ROH

O+ R'O R

O

O+ R'OH

33

Mechanism of Sonogashira Coupling

organic-chemistry.org

34

Mechanism of Heck Coupling

organic-chemistry.org

35

Mechanism of Suzuki Coupling

organic-chemistry.org

36