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Theoretical Study on the Stability
of Metallasilabenzyne and Its
Isomers
Speaker: Xuerui Wang
Advisor : Jun Zhu
Outline
1
Background
2
Computational Method
3
Results and Discussion
34
Summary
2
1. Background
1953 14C label
reaction intermediate
2001
First osmabenzyne
Robert et al, J. Am. Chem. Soc.,
1956,78,601.
Jia et al, Angew. Chem. Int. Ed.,
2001, 113, 2005.
Unknown
Zhu et al, Dalton Trans.,
2014, 43, 7570.
reluctant to participate in
 bonding
sp3
Kutzelnigg, W. Angew. Chem., Int.
Ed. Engl. 1984 , 23 , 272.
Lin et al, Organometallics, 2003, 22. 3898..
3
1. Background
Theoretical study on the stability of osmasilabenzyne
Zhu et al, Dalton Trans., 2014, 43, 7570.
4
1. Background
Proposed structures of osmasilabenzyne and its isomers
5
2. Computational Method
Package : Gaussian 03
Method: DFT(B3LYP)
Basis sets : C, H, O: 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.
3. Results and Discussion
Geometry and Stability of osmasilabenzyne and its isomers
Organometallics, 2014, 33, 1845–1850
7
3. Results and Discussion
 Aromaticity (Isomerization Stabilization Energy)
8
3. Results and Discussion
 Ring strain
9
3. Results and Discussion
 Structure
silicon atom is reluctant to
participate in  bonding
10
3. Results and Discussion
 How to tune the relative stability of two isomers？
 Metal center
contracted d orbitals
M
Fe
Rh+
Ir+
-19.1
-1.0
-10.8
-17.5
0.5
-9.0
Ru
Os
G
-10.2
E
-8.2
Co+
11
3. Results and Discussion
 How to tune the relative stability of two isomers？
 Ligand
trans influence
12
3. Results and Discussion
 How to tune the relative stability of two isomers？
 Ligand
Stability reversed
13
3. Results and Discussion
 How to tune the relative stability of two isomers？
 substituent
phosphonium substituent
14
3.Results and Discussion
 Difference between metallasilabenzynes and metallasilapentalynes.
most stable
second most stable
Relative stability of the isomers of metallasilapentalynes with the silicon atom at
different positions.
Organometallics, 2014, 33, 1845–1850
15
3.Results and Discussion
 Why?
 Aromaticity (Isomerization Stabilization Energy)
16
3.Results and Discussion
 Why?
 Ring strain
17
4.Summary
• 1. The relative stability of osmasilabenzyne and its isomers
can be tuned by more contracted d orbitals metal center .
(especially for Rh)
• 2. The carbonyl ligand (CO) can be used to tune the relative
stability of two isomers.
• 3. In comparison with ring strain, aromaticity plays a more
important role in the relative stability of osmasilabenzyne and
its isomers.
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