1. Theoretical Study on the Stability of Metallasilabenzyne and Its Isomers Speaker: Xuerui Wang Advisor : Jun Zhu

2. Outline 1 1 3 Background 2 3 Results and Discussion 4 Summary 2 Computational Method

3. 3 1. 1. Background 1953 14 C label reaction intermediate Robert et al, J. Am. Chem. Soc., 1956,78,601. 2001 First osmabenzyne Jia et al, Angew. Chem. Int. Ed., 2001, 113, 2005. Unknown Zhu et al, Dalton Trans., 2014, 43, 7570. reluctant to participate in  bonding sp 3 Kutzelnigg, W. Angew. Chem., Int. Ed. Engl. 1984, 23, 272. Lin et al, Organometallics, 2003, 22. 3898..

4. 4 Theoretical study on the stability of osmasilabenzyne 1. 1. Background Zhu et al, Dalton Trans., 2014, 43, 7570.

5. 5 1. Background Proposed structures of osmasilabenzyne and its isomers

6. 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.

7. 7 3. Results and Discussion Geometry and Stability of osmasilabenzyne and its isomers Organometallics, 2014, 33, 1845–1850

8. 8 3. Results and Discussion  Aromaticity (Isomerization Stabilization Energy)

9. 9 3. Results and Discussion  Ring strain

10. 10 3. Results and Discussion  Structure silicon atom is reluctant to participate in  bonding

11. 11 3. Results and Discussion  How to tune the relative stability of two isomers ？  Metal center MFeRuOsCo + Rh + Ir + GG -10.2-19.1-10.8 EE -8.2-17.50.5-9.0 contracted d orbitals

12. 12 3. Results and Discussion  How to tune the relative stability of two isomers ？  Ligand trans influence

13. 13 Stability reversed 3. Results and Discussion  How to tune the relative stability of two isomers ？  Ligand

14. 14 3. Results and Discussion  How to tune the relative stability of two isomers ？  substituent phosphonium substituent

15. 15 3.Results and Discussion  Difference between metallasilabenzynes and metallasilapentalynes. Relative stability of the isomers of metallasilapentalynes with the silicon atom at different positions. most stablesecond most stable Organometallics, 2014, 33, 1845–1850

16. 16 3.Results and Discussion  Why?  Aromaticity (Isomerization Stabilization Energy)

17. 17 3.Results and Discussion  Why?  Ring strain

18. 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. 18