Solution chemistry in non-co-ordinating solvents (CH2Cl2, CHCl3) of nickel(II) and nickel(III) complexes of the lipophilic macrocycle 1-hexadecyl-1,4,8,11-tetra-azacyclotetradecane. The emphasized role of the anion co-ordination
作者:Michela Di Casa、Luigi Fabbrizzi、Mario Mariani、Barbara Seghi
DOI:10.1039/dt9900000055
日期:——
Nickel(II) complexes of the lipophilic tetramine macrocycle N-cetylcyclam (1-hexadecyl-1,4,8,11-tetra-azacyclotetradecane) L1, dissolve in non-co-ordinating solvents such as CH2Cl2 and CHCl3 as intact Ni(L1)X2 species, whose spin state and colour depend on the co-ordinating tendencies of the apically bound X– anions: Cl–, and SCN–, blue, high-spin complexes; ClO4–, BF4–, and I–, yellow, low-spin complexes
亲脂性四胺大环N-鲸蜡基环酰胺(1-十六烷基-1,4,8,11-四氮杂环十四烷)L 1的镍(II)配合物溶解在非配位溶剂如CH 2 Cl 2和CHCl 3中作为完整的Ni(L 1)X 2种且自旋状态和颜色取决于顶部结合X的统筹倾向-阴离子:氯-和SCN - ,蓝色,高自旋络合物; ClO 4 –,BF 4 –和I –黄色低自旋复合物。Ni(L 1)Br络合物2在溶液中以蓝色和黄色物质的平衡混合物形式存在,并且蓝色到黄色的转换是放热的;此外,在进一步加入背景电解质,四烷基铵或四乙基溴化ide后,平衡向右移动。提出了一个通用模型来解释在配位(例如水)和非配位介质中高自旋/低自旋互变的热力学方面。最后,在CH 2 Cl 2溶液(0.1 mol dm –3 Bu n 4中,Ni II(L 1)X 2络合物NX),经历可逆的单电子氧化过程,得到[Ni III(L 1)X 2 ] X物种。在Ni III