首个含桥连胍基配体的双核B(II)单阳离子：合成与性质

First dinuclear B(II) monocations with bridging guanidinate ligands: synthesis and properties.

作者信息

Ciobanu Oxana, Emeljanenko Dimitri, Kaifer Elisabeth, Mautz Jürgen, Himmel Hans-Jörg

机构信息

Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.

出版信息

Inorg Chem. 2008 Jun 2;47(11):4774-8. doi: 10.1021/ic8000812. Epub 2008 Apr 26.

DOI:10.1021/ic8000812

PMID:18439006

Abstract

Reaction between the diborane (4) B2Cl2(NMe2)2 and Li(hpp) (hpp-=1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate) leads to [(Me2N)B(mu-hpp)] 2. This species can be protonated by HCl.OEt2 to give [(Me2HN)B(mu-hpp)]2Cl2 featuring two B(II) cations with direct B-B bonding. The unsymmetrical monocation [(Me2N)B2(mu-hpp)2(NHMe2)]+ is also obtained. [(Me2HN)B(mu-hpp)]2Cl2 eliminates NHMe2 in a slow reaction leading to [ClB2(mu-hpp)2(NHMe2)]Cl and ultimately, presumably, to [ClB(mu-hpp)]2. We report the crystal structures of the two monocations [ClB2(mu-hpp)2(NHMe2)]Cl and [(Me2N)B2(mu-hpp)2(NHMe2)]Cl. The experimental results are accompanied by some quantum chemical density-functional theory calculations.

摘要

二硼烷（4）B2Cl2（NMe2）2与Li（hpp）（hpp- = 1,3,4,6,7,8-六氢-2H-嘧啶并[1,2-a]嘧啶盐）反应生成[(Me2N)B(μ-hpp)] 2。该物种可被HCl·OEt2质子化，得到[(Me2HN)B(μ-hpp)]2Cl2，其具有两个通过直接B-B键相连的B(II)阳离子。还得到了不对称单阳离子[(Me2N)B2(μ-hpp)2(NHMe2)]+。[(Me2HN)B(μ-hpp)]2Cl2在一个缓慢的反应中消除NHMe2，生成[ClB2(μ-hpp)2(NHMe2)]Cl，并最终可能生成[ClB(μ-hpp)]2。我们报道了两种单阳离子[ClB2(μ-hpp)2(NHMe2)]Cl和[(Me2N)B2(μ-hpp)2(NHMe2)]Cl的晶体结构。实验结果还伴有一些量子化学密度泛函理论计算。