Methylzinc tetrahydroborate: physical and chemical properties and crystal structure at low temperature
作者:Simon Aldridge、Alexander J. Blake、Anthony J. Downs、Simon Parsons、Colin R. Pulham
DOI:10.1039/dt9960000853
日期:——
Methylzinc tetrahydroborate, MeZnBH4, has been prepared by two routes and initially characterized by elemental analysis and its spectroscopic properties. The structure has been determined by X-ray crystallography at 150 K [trigonal, space group R3c, a=b= 15.831(10), c= 8.36(2)Å, Z= 18, R= 0.072] to reveal helical polymers in which MeZn+ and BH4– units alternate, with the latter functioning as a bidentate ligand with respect to both of the adjacent metal atoms. It thus resembles the structure of solid Be(BH4)2 with the difference that the zinc is five-co-ordinated, the Me and H ligands adopting a distorted square-pyramidal geometry. Chemical properties of methylzinc tetrahydroborate investigated include its thermal decomposition and its reactions with ammonia, dimethyl sulfide, triphenylphosphine and CO; disproportionation into Me2Zn and Zn(BH4)2 appears to be a common feature of its chemistry.
甲基锌四氢硼酸盐(MeZnBH4)已通过两种途径制备,并通过元素分析和光谱特性进行了初步表征。其结构通过X射线晶体学在150 K下确定 [三方晶系,空间群R3c,a=b= 15.831(10)Å,c= 8.36(2)Å,Z= 18,R= 0.072],揭示了螺旋聚合物,其中MeZn+和BH4–单元交替排列,后者作为双齿配体与两个相邻金属原子配位。因此,其结构类似于固体Be(BH4)2,但区别在于锌是五配位的,甲基和氢配体呈现畸变的正方形金字塔几何形状。对甲基锌四氢硼酸盐化学性质的研究包括其热解和与氨、二甲基硫、三苯基磷和一氧化碳的反应;其化学反应的一个共同特征是发生不成比例反应,生成Me2Zn和Zn(BH4)2。