obtained for the butyl-bridged compound 3e-H4, showing an intramolecular proton transfer and the formation of a chinoidic "keto-amine" structure. The dicatechol derivatives 3b-g-H4 form dinuclear triple-stranded helicates M4[(3)3Ti2] with titanium(IV) ions in the presence of alkali-metal carbonate. For the phenyl- and the trans-1,4-cyclohexyl-bridged complexes, K4[(3b)3Ti2] and Na4[(3f)3Ti2], X-ray structures
通过与一系列不同的二胺1b-g
亚胺形成2,3-二羟基
苯甲醛2来简单地制备二
儿茶酚配体3b-g-H4。对丁基桥连的化合物3e-H4进行了X射线结构分析,显示了分子内质子转移和
胆甾醇型“酮胺”结构的形成。在碱
金属
碳酸盐存在下,二
儿茶酚衍
生物3b-g-H4与
钛(IV)离子形成双核三链螺旋产物
M4 [(3)3Ti2]。对于苯基和反式1,4-环己基桥接的配合物K4 [(3b)3Ti2]和Na4 [(3f)3Ti2],获得了X射线结构。