双-(0,0′-二正丁基二硫代磷酸酯)合镍(Ⅱ)与氮碱加合反应的研究

ADDUCTIVE REACTION OF BIS-(0,0′-n-BUTYLDITHIOPHOSPHATO) NICKEL (Ⅱ) WITH NITROGEN BASES

本文报道了Ni[(C_4H_9O)_2PS_2]_2与氮碱的加合反应,用光谱法测定了苯溶液中加合反应的平衡常数,在31℃时吡啶加合物的K_1=33.1,β_2=7.94×10~3,联吡啶加合物的K=2.51×10~6,用热重分析和NMR方法研究了加合物的热分解性质、磁性质和自旋密度分布。当d^s低自旋的标题化合物与吡啶和正丁胺反应生成d^s高自旋的加合物时,观察到了顺磁效应,未成对自旋密度离域到吡啶环和正丁胺上,导致各类质子共振向低场位移。未成对电子自旋密度通过σ键体系从Ni(Ⅱ)离域到配体上。

Reactions of Ni[(C_4H_9O)_2PS_2]_2 with pyridine and 2,2＇-bipyridine in benzene have been studied spectrophotom-etrically. The isosbcstic points were observed(Figl). The equilibrium constants with pyridine were found to be K_1=32.9 mol e^(-1). 1 andβ2=8.13×10~3moI e^(-2). 1~2. The stability constant with bipyridine was found to be 2.51×10~6mo1 e^(-1). 1.Thermogravimetric study showed thar Ni[(C_4H_9O)_2PS_2]_2. biPy is more stable thanNi[(C_4H_9O)_2PS_2]_2. 2Py. Adduct formations by Ni[(C_4H_9O)_2PS_2]_2 with nitrogen bases were also detected by means of NMR spectra. When d^8 low spin Ni[(C_4H_9O)_2PS_2]_2 reacted with pyridine and n-propylamine formed d^8 high spin adducts, paramagnetic effects were observed(Fig2). The unpaired spin density distribution on pyridine ring and n-propylamine was recognized. The various proton resonances were shifted down field from their normal diamagnetic ralues by an amount proportional to the concentration of the paramagnetic species. Unpaired electron spin density reaches ligand protons from nickel(Ⅱ)via the σ-bonding system.