报告题目: Chemistry of Low-Valent Group 14 Element Complexes
报告人: Assistant Prof. Cheuk-Wai So （蘇卓威）
新加坡南洋理工大学化学与生物系
报告时间: 2013年11月20日（星期四）上午10：30
报告地点：独墅湖校区701号楼B501室
报告摘要: Recently, a series of novel base-stabilized group 14 element(I) dimers [RË-ËR] (E = Si, Ge, Sn, R = amidinate, guanidinate, β-diketiminate, N-functionalized aryl, P-functionalized amide etc.) was synthesized.1 They are considered as base-stabilized heavier alkyne analogues. Their reactivities showed that they are powerful reagents for the activation of small molecules, unsaturated substrates etc. We demonstrated that base-stabilized group 14 element(I) dimers can serve as synthons for the preparation of group 14 elements-containing aromatic/delocalized p-conjugated system. Firstly, the first examples of the 2,6-diiminophenyl-stabilized germanium(I), tin(I) and lead(I) dimers [{2,6-(CH=NAr)2C6H3}E:]2 (E = Ge, Sn, Pb; Ar = 2,6-iPr2C6H3) can be reduced by alkali metal to form novel aromatic low valent group 14 analogue of indenyl anions [{2,6-(CH=NAr)2C6H3}E:]-.2 Secondly, the reaction of three equivalents of the amidinate-stabilized silicon(I) dimer [PhC(NtBu)2Si:]2 with two equivalents of ArN=C=NAr afforded the singlet delocalized 2,4-diimino-1,3-disilacyclobutanediyl [LSi(m-CNAr)2SiL] (L = PhC(NtBu)2). Moreover, the reaction of [PhC(NtBu)2Si:]2 with two equivalents of the amido trichlorosilane [L’SiCl3] (L’ = 2,6-iPr2C6H3NSiMe3) and six equivalents of KC8 afforded the extensive n, p, σ-electron delocalized Si4 ring [LSi(µ-SiL’)2SiL].3 Thirdly, the incorporation of heavier group 14 elements into cyclobutadiene can be achieved from the reactivity of amidinate-stabilized heavier group 14 element(I) dimers.4 Finally, we report the first example of B-H bond activation of borane by stable carbenoid species.5
Reference
1. Selected recent articles: a) C. Jones, S. J. Bonyhady, N. Holzmann, G. Frenking, A. Stasch, Inorg. Chem. 2011, 50, 12315; b) S. Khan, R. Michel, J. M. Dieterich, R. A. Mata, H. W. Roesky, J.-P. Demers, A. Lange, D. Stalke, J. Am. Chem. Soc. 2011, 133, 17889; c) D. Gau, R. Rodriguez, T. Kato, N. Saffon-Merceron, A. de Cózar, F. P. Cossío, A. Baceiredo, Angew. Chem. Int. Ed. 2011, 50, 1092.
2. a) S.-P. Chia, R. Ganguly, Y. Li, C.-W. So, Organometallics 2012, 31, 6415; b) S.-P. Chia, H.-X. Yeong, C.-W. So, Inorg. Chem. 2012, 51, 1002; c) S.-P. Chia, H.-W. Xi, Y. Li, K. H. Lim, C.–W. So, Angew. Chem. Int. Ed. 2013, 52, 6298.
3. S.-H. Zhang, H.-W. Xi, K. H. Lim, C.-W. So, Angew. Chem. Int. Ed. DOI: 10.1002/anie.201305567.
4. H.-X. Yeong, H.-W. Xi, Y. Li, S. B. Kunnappilly, B. Chen, K.-C. Lau, H. Hirao, C.-W. So, Chem. Eur. J. DOI: 10.1002/chem.201300447.
5. H. Heuclin, S. Y.-F. Ho, X. F. Le Goff, C.-W. So, N. Mézailles, J. Am. Chem. Soc. 2013, 135, 8774.
About the speaker:
Dr. Cheuk-Wai So obtained a PhD degree under the guidance of Prof. Kevin W.-P. Leung at the Chinese University of Hong Kong in 2003. From 2005-2007, he was an Alexander von Humboldt research fellow at the University of Göttingen under the supervision of Prof. Herbert W. Roesky. Consequently, he was a JSPS research fellow at the Nagoya University under the guidance of Prof. Shigehiro Yamahuchi. Since 2008, he is an assistant professor at Nanyang Technological University, Singapore. His research area focuses on the synthesis of novel main-group organometallic complexes and their application in electronic materials and small molecules activation.
