Synthesis and Characterization of a Singlet Delocalized 2,4‐Diimino‐1,3‐disilacyclobutanediyl and a Silylenylsilaimine |
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| Authors: | Shu‐Hua Zhang Dr. Hong‐Wei Xi Prof. Dr. Kok Hwa Lim Qingyong Meng Prof. Dr. Ming‐Bao Huang Prof. Dr. Cheuk‐Wai So |
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| Affiliation: | 1. Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Fax: (+65)?6791‐1961;2. Division of Chemical and Biomolecular Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459;3. College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (P. R. China) |
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| Abstract: | The synthesis and characterization of a singlet delocalized 2,4‐diimino‐1,3‐disilacyclobutanediyl, [LSi(μ‐CNAr)2SiL] ( 2 , L: PhC(NtBu)2, Ar: 2,6‐iPr2C6H3), and a silylenylsilaimine, [LSi(?NAr)? SiL] ( 3 ), are described. The reaction of three equivalents of the disilylene [LSi? SiL] ( 1 ) with two equivalents of ArN?C?NAr in toluene at room temperature for 12 h afforded [LSi(μ‐CNAr)2SiL] ( 2 ) and [LSi(?NAr)? SiL] ( 3 ) in a ratio of 1:2. Compounds 2 and 3 have been characterized by NMR spectroscopy and X‐ray crystallography. Compound 2 was also investigated by theoretical studies. The results show that compound 2 possesses singlet biradicaloid character with an extensive electronic delocalization throughout the Si2C2 four‐membered ring and exocyclic C?N bonds. Compound 3 is the first example of a silylenylsilaimine, which contains a low‐valent silicon center and a silaimine substituent. A mechanism for the formation of 2 and 3 is also proposed. |
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| Keywords: | density functional calculations N ligands radicals silicon silylenes |
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