Speaker: Xuerui Wang Advisor : Jun Zhu Dec. 27. 2013

1. Theoretical study on the interconversion of X-benzenes （X=Ge、Sn）and their non-aromatic isomers via the [1,3]-substituent shift: Interpaly of aromaticity and Bent's rule Speaker: Xuerui Wang Advisor : Jun Zhu Dec. 27. 2013

2. Outline 1 1 Background Results and Discussion 2 Summary and Future work 3 3

3. Background Interpaly of aromaticity and Bent's rule Figure 1.The plot of s character of Si to the Si-X σ bond vs reaction energies(ΔG) Figure 2. The plot of s character of Si to the Si-X σ bond vs reaction barriers (ΔG)

4. Background examine the scope of our findings aromaticity can be evaluated quantitatively

5. Background History of Germabenzenes • 1980 Märkl et al. confirmed the existence of 1,4-di-tert -butyl-germabenzene indirectly supported by the formation of its [2 + 2] dimer and the trapping reaction with 2,3-dimethyl-1,3-butadiene1. • 1982 Spectroscopic detection of 1,4-dialkylgermabenzenes2. • 2002 First stable germabenzene3. 1. G. Märkl, D. Rudnick, Tetrahedron Lett. 1980, 21, 1405. 2. G. Märkl, D. Rudnick, R. Schulz, A. Schweig, Angew. Chem. 1982, 94, 211; Angew. Chem. Int. Ed. Engl. 1982, 21, 221. 4. N. Nakata, N. Takeda, N. Tokitoh, J. Am. Chem. Soc. 2002, 124, 6914.

6. Background stable and neutral stanna aromatic compounds Computational detail Package : Gaussian 09 Method : M06-2X Basis sets : 6-311+G ** ( C、H、O、Si、Ge) aug-cc-pVTZ-PP ( Sn ) 1.(a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (b) Miehlich, B.; Savin, A.; Stoll, H.; Preuss, H. Chem. Phys. Lett. 1989, 157, 200. (c) Lee, C.; Yang, W.; Parr, G. Phys. ReV. B 1988, 37, 785. 2. Zhao, Y.; Truhlar, D. G. Theor. Chem. Acc. 2008, 120, 215. 3. Frisch, M. J. et al. Gaussian, Inc., Wallingford CT, 2010.

7. Results and Discussion Figure 3.The plot of s character of Ge to the Ge-X σ bond vs reaction energies(ΔG)

8. Results and Discussion 28.6 Figure 4.The plot of s character of Ge to the Ge-X σ bond vs reaction energies(ΔG) in nonaromatic system

9. Results and Discussion Figure 5.The plot of s character of Sn to the Sn-X σ bond vs reaction energies(ΔG)

10. Results and Discussion aromaticity can not be evaluated quantitatively Figure 6.The plot of s character of Sn to the Sn-X σ bond vs reaction energies(ΔG) in nanaromatic system

11. Results and Discussion Figure 8. Plot of reaction free energies (ΔG) against the percentage of the s character of Si in the Si-X bonds in the osmasilabenznes.

12. Results and Discussion 33.4 Figure 9. Plot of reaction free energies (ΔG) against the percentage of the s character of Si in the Si-X bonds .

13. Summary 1. The contribution from aromaticity can be evaluated quantitatively in such rearrangement. 2. Bent's rule plays an important role in both the thermodynamics and kinetics of the rearrangement . 3. Our findings could be a useful guide to the synthesis of X-benzenes (X = Ge、Sn).

14. Experiments Organophosphorus compounds pesticide medicine antibacterial agents enzyme inhibitors flame retardant anti HIV agents 14

15. Condition Optimization ？

16. Proposed Reaction Mechanism

17. By product • Yang et al, Angew. Chem. Int. Ed. 2013, 52, 3972. • Zou et al, Synthesis2013, 45, 1529 .

18. Thank you for your attention！