Preparation and coordinating properties of {CH2(o-C6H4CH2SbMe2)}2, a novel wide-angle cis-chelating distibine
作者:Michael D. Brown、William Levason、Gillian Reid、Michael Webster
DOI:10.1039/b610808c
日期:——
The unique wide-angle distibine, CH2(o-C6H4CH2SbMe2)}2, 1, has been prepared indirectly by reaction of Me2SbCl with the di-Grignard formed unexpectedly by coupling of o-C6H4(CH2MgCl)2 in concentrated thf solution, and directly by treatment of the CH2(o-C6H4CH2MgCl)}2 with Me2SbCl. The very oxygen-sensitive distibine 1 has been characterised by 1H and 13C1H} NMR spectroscopy and high-resolution EIMS. Oxidation of 1 with Br2 gives the air-stable tetrabromide CH2(o-C6H4CH2SbMe2Br2)}2. Surprisingly, 1 shows a very strong tendency to function as a cis-chelate, e.g. to Pt(IV) in the complex [PtMe3I(1)], forming an 11-membered ring and providing a stable Pt(IV) stibine complex, the crystal structure of which shows the Sb–Pt–Sb angle to be 95.96(1)°. The yellow Pt(II) complex [PtCl2(1)] is obtained from reaction of [PtCl2(MeCN)2] with 1 and IR spectroscopic data and a crystal structure determination confirm the Cl ligands are mutually cis in this species. Reaction of [W(CO)4(piperidine)2] with 1 in refluxing EtOH gives [W(CO)4(1)], the IR spectrum of which shows four ν(CO) bands, also consistent with cis-Sb2 coordination. The cis-chelation is also confirmed by single-crystal X-ray structure determinations of two polymorphs of [W(CO)4(1)].
通过 Me2SbCl 与 o-C6H4(CH2MgCl)2在浓 thf 溶液中意外偶联形成的二格里格纳反应,间接制备出了独特的广角二联碱 CH2(o-C6H4CH2SbMe2)}2,1;通过 Me2SbCl 直接处理 CH2(o-C6H4CH2MgCl)}2,制备出了二联碱 CH2(o-C6H4CH2MgCl)}2。通过 1H 和 13C1H} NMR 光谱以及高光谱分析,对这种对氧非常敏感的二碳化物 1 进行了表征。NMR 光谱和高分辨率 EIMS 对其进行了表征。用 Br2 对 1 进行氧化,可得到在空气中稳定的四溴化物 CH2(o-C6H4CH2SbMe2Br2)}2。令人惊讶的是,1 显示出非常强烈的顺式螯合物倾向,例如在[PtMe3I(1)]络合物中与铂(IV)形成 11 元环,并提供稳定的铂(IV)链烷络合物,其晶体结构显示 Sb-Pt-Sb 角为 95.96(1)°。通过[PtCl2(MeCN)2]与 1 的反应,得到了黄色的铂(II)配合物[PtCl2(1)],红外光谱数据和晶体结构测定结果证实,该物种中的 Cl 配体互为顺式。将[W(CO)4(哌啶)2]与 1 在回流的 EtOH 中反应可得到[W(CO)4(1)],其红外光谱显示出四条 ν(CO)带,也符合顺式-Sb2 配位。两种多晶体[W(CO)4(1)]的单晶 X 射线结构测定也证实了顺式鞘合作用。