The Stability and Aromaticity of Metallasilapentalynes : A DFT S tudy
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Transcript of The Stability and Aromaticity of Metallasilapentalynes : A DFT S tudy
The Stability and Aromaticity of Metallasilapentalynes : A DFT Study
Speaker: Xuerui WangAdvisor : Jun Zhu
Wang, X.; Zhu, C.; Xia, H.; Zhu, J. Organometallics 10.1021/om500170w.
Outline
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3
Background
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2 Results and Discussion
3 Summary
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Background In 1979 ,Thorn and Hoffmann predicted the three classes of stable metallabenzenes
Thorn, D. L.; Hoffman, R. Nouv. J. Chim, 1979, 3, 39
In 1982, the first metallabenzene
Os(CO)(CS)(PPh3)3 + 2HCCH
Os
PPh3
PPh3
S
CO
In 2001, the first metallabenzyne
W. R. Roper, J. M. Waters, J. Chem. Soc. Chem.Commun, 1982, 811T. Wen, G. Jia, Angew. Chem. Int. Ed, 2001, 40, 1951
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Background
Os
H
PPh3
Cl
Ph3PCl
Os
PPh3
PPh3
PPh3
Cl
ClBF4
Only a few examples of aromatic metallabicycles complex
Zhu, C.; Li, S.; Luo, M.; Zhou, X.; Niu, Y.; Lin, M.; Zhu, J.; Cao, Z.; Lu, X.; Wen, T. B; Xie, Z.; Schleyer, P. v. R.; Xia, H. Nat. Chem. 2013, 5, 698.
Zhu, C.; Luo, M.; Zhu, Q.; Zhu, J.; Schleyer, P. v. R.; Wu, J.; Lu, X.; Xia, H. Nat. Commun. 2014, 5, 3265.
[M] = transition metal fragment
[M] [M] Si
Antiaromatic Aromatic Aromatic
Pentalyne Metallapentalyne Metallasilapentalyne
I II III
?
silicon atom is reluctant to participate in bonding
Kutzelnigg, W. Angew. Chem., Int. Ed. Engl. 1984 , 23 , 272.
Wang, X.; Zhu, C.; Xia, H.; Zhu, J. Organometallics 10.1021/om500170w.
2. Computational Method2. Computational Method
Package : Gaussian 03
Method: DFT(B3LYP)
Basis sets : C, H, O, N : 6-311++G **
LanL2DZ: P(ζ(d) = 0.340), Cl(ζ(d) = 0.514), Si (ζ(d) = 0.262)
Fe(ζ(f) = 2.462, Ru(ζ(f) = 1.235), Os(ζ(f) = 0.886)
1. Ehlers, A. W.; Böhme, M.; Dapprich, S.; Gobbi, A.; Höllwarth, A.; Jonas, V.; Köhler, K. F.; Stegmann, R.; Veldkamp, A.; G., F. Chemical Physics
Letters 1993, 208, 111.
2. Check, C. E.; Faust, T. O.; Bailey, J. M.; Wright, B. J. J. Phys. Chem. A. 2001, 105, 8111.
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Results and Discussion
Geometry and Stability of Metallasilapentalyne.
[Fe] Si
10.536.6 29.20.0 19.6 20.5 34.9
0.0 51.3 25.8 30.1 35.3 46.3 15.9
0.0 50.5 29.2 30.9 37.6 46.3 16.9
[Fe]
SiH
[Fe]
SiH
Si
[Fe]
SiH
[Fe]
HSi
[Fe] [Fe]HSi
[Ru] Si [Ru]
SiH
[Ru]
SiH
Si
[Ru]
SiH
[Ru]
HSi
[Ru] [Ru]HSi
[Os] Si [Os]
SiH
[Os]
SiH
Si
[Os]
SiH
[Os]
HSi
[Os] [Os]HSi
[M] = MCl(PH3)2
Figure 1. Relative stability of the isomers of metallasilapentalynes with the silicon atom at different positions.
most stable second most stablediffuse d-orbitals
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Results and Discussion
[Os] E
[Os] = OsCl(PH3)2
1a (E = C)1b (E = Si)1
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4
5
6
2.299
1.809
1.3811.4291.3821.420
1.363
2.035
2.147
112.6
1b
Figure 2. The optimized structure with selected bond lengths (Å) and bond angles () in osmasilapentalyne 1b.
♦ 2.325 Å in the first osmium silylene ♦ 2.176 Å in the first osmium silylyne
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Results and Discussion
Table 1. The bond lengths (Å), Wiberg bond indices and charges of Os≡E triple bonds (E = C or Si) in 1a and 1b.
1b 1b''1b'
[Os] Si[Os] Si [Os] SiA
Figure 3. A. The resonance structures of osmasilapentalyne 1b. B. Electron localization function (ELF) calculations with isovalue of 0.85 on osmasilapentalyne 1b and osmapentalyne 1a.
Bond length (Å)
Wiberg bond order
Charge(Os) Charge(E)
C 1.845 1.70 -0.97 +0.17
Si 2.299 1.25 -1.42 +0.14
highly polarized
OsSi triple bond
1a 1b
B
OsSi bond : 27% Os 73% Si
Si :components of s and p orbitals are 56% and 44%
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Results and Discussion
[Os]
CH3
CH3
SiH3C
112.6°
[Os]
CH3
CH3
SiH3C
partially optimized optimized
74.7°
74.0°
1
3
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E = - 8.7
[Os] = OsCl(PH3)2
[Os]
CH3
CH3
H3C
129.5°
[Os]
CH3
CH3H3C
partially optimized optimized
74.5°
72.8°
E = - 24.8
[Os] = OsCl(PH3)2
141.8°
167.0°
112.6° 141.8°
129.5° 167.0°
29.0
37.5
Figure 4. The calculated strain energy of osmasilapentalyne 1b based on acyclic reference compounds. The correction of the zero-point energy is included in kcal mol -1.
Ring Strain
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Results and Discussion
The Aromaticity of Metallasilapentalynes[Os] Si
[Fe]=FeCl(PH3)2
ISE = -15.0
[Ru]=RuCl(PH3)2
ISE= - 17.3
[Os]=OsCl(PH3)2
ISE = -18.3
ISE= - 17.5
ISE= - 16.5
ISE= - 16.9
[Os] Si
[Os] Si[Os] Si
[Os] Si[Os] Si
[Os] Si[Os] Si
[Ru] Si[Ru] Si
[Fe] Si[Fe] Si
[M] SiA B
[M] = MCl(PH3)2
Os Ru FeNICS(1)zz
-19.8-16.2
-14.2-10.2
-15.3-13.4
Ring ARing B
Figure 7. The NICS(1)zz values (ppm) for rings A
and B in metallasilapentalynes.
Figure 8. “isomerization stabilization energy” (ISE) of
metallasilapentalyne.
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Results and Discussion
The Aromaticity of Osmasilapentalynes
HOMO (-5.67 ev) HOMO-1(-5.90 ev) HOMO-2 (-6.14 ev)
HOMO-3 (-6.96ev) HOMO-8 (-8.63 ev) HOMO-12(-9.96 ev)
x
y
z
SiPH3
PH3
Os
NICS(1)zz
Total
HOMO HOMO-2 HOMO-12
All orbitals
Orbitals
HOMO-1
Cl
+2.1 / -7.6 +6.2 / +10.1 +4.7 / +5.0
-5.3 / +1.2 -6.9 / -8.4 -7.0 / -2.2
HOMO-3 HOMO-8
-0.2 / -4.8
-12.2 / -7.2
+6.2 / +10.1
-19.8 / -16.2
-13.6 / -14.3
1b
A
B
three Hückel-type MOs HOMO, HOMO-2, and HOMO-12
two Möbius-type MOs HOMO-3 and HOMO-8
mixed aromaticity with Möbius aromaticity dominated
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Effect of the Phosphonium Substituent on the Aromaticity in Osmasilapentalynes:
[Os] Si[Os] SiISE= - 25.1
ISE= - 31.0
PMe3PMe3
[Os]
PMe3
[Os]
PMe3
[Os] = OsCl(PH3)2
ISE= - 17.5
[Os] Si[Os] Si
ISE= - 23.3
[Os][Os]
SiCO
CO
Os Cl
Bond lengthBond order
2.3291.09
2.2921.30
2.2991.25
SiPMe3
PMe3
Os Cl
SiPH3
PH3
Os Cl
-19.8/-16.2 -16.3/-14.2 -21.9/-17.8NICS(1)ZZ A/B
A
B
OsSi
Ligand Effects on the Structure for Osmasilapentalynes
Effect of Lewis Base on the Stabilization for Osmasilapentalyne:
[Os] = OsCl(PH3)2
= -32.8+
= -12.1
[Os] Si
N N
[Os] Si
N
N
+
[Os] SiN
[Os] SiN
1b
1b
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Summary
1.The computed negative ISE and NICS(1)zz values reveal
aromatic character of osmasilapentalyne.
2. Aromaticity in osmasilapentalyne is reduced in comparison with osmapentalyne.
3.The phosphonium substituent, -donor ligands and Lewis base can enhance the aromaticity or stability of osmasilapentalynes.
4.All these findings could be helpful for the synsthesis of the first metallasilapentalyne.
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Future work
[M] = transition metal fragment
[M] [M] Si
Aromatic Aromatic
Metallapentalyne Metallasilapentalyne
I III
?
[M]
Aromatic
Metallapentalene
II
[M] Si
Aromatic
Metallasilapentalyne
IV
Geometry and stability of metallasilapentaleneThe aromaticity of metallasilapentalynesEffect of the substituent on the aromaticity in osmasilapentalenesLigand effects on the structure for osmasilapentalenes
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