Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371.
Chemistry. 2012 Apr 2;18(14):4258-63. doi: 10.1002/chem.201103351. Epub 2012 Feb 29.
The synthesis and characterization of a singlet delocalized 2,4-diimino-1,3-disilacyclobutanediyl, [LSi(μ-CNAr)(2)SiL] (2, L: PhC(NtBu)(2), Ar: 2,6-iPr(2) C(6) H(3)), 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)(2)SiL] (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 Si(2)C(2) 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.
描述了一个单重离域的 2,4-二亚氨基-1,3-二硅环丁二烯基，[LSi(μ-CNAr)(2)SiL]（2，L：PhC（NtBu）（2），Ar：2,6-iPr(2) C(6) H(3)），和一个硅亚胺基硅胺，[LSi(=NAr)-SiL]（3）的合成和表征。在室温下，将三当量的二硅烯[LSi-SiL]（1）与两当量的ArN=C=NAr 在甲苯中反应 12 小时，得到了[LSi(μ-CNAr)(2)SiL]（2）和[LSi(=NAr)-SiL]（3），它们的比例为 1:2。化合物 2 和 3 已通过 NMR 光谱和 X 射线晶体学进行了表征。还通过理论研究对化合物 2 进行了研究。结果表明，化合物 2 具有单重双自由基特征，其电子离域性贯穿 Si(2)C(2) 四元环和外消旋 C=N 键。化合物 3 是第一个硅亚胺基硅胺的例子，它含有一个低价硅中心和一个硅亚胺取代基。还提出了形成 2 和 3 的机制。
