Zinc dicarboxylate polymers and dimers: thiourea substitution as a tool in supramolecular synthesis
作者:Nichola J. Burke、Andrew D. Burrows、Adele S. Donovan、Ross W. Harrington、Mary F. Mahon、Caroline E. Price
DOI:10.1039/b307420j
日期:——
The reactions of the zinc thiourea complexes [ZnSC(NHR)(NHR′)}4]Cl2
(L =
L1, R = H, R′
= Me; L =
L2, R = Me, R′
= Me) with a range of dicarboxylates have been investigated. From these reactions eleven products –
[Zn(L1)2(μ-terephthalate)]n, [Zn(L1)2(μ-fumarate)]n, [Zn(L1)2(μ-isophthalate)]·H2O}n, [Zn(L1)2(μ-1,3-phenylenediacetate)]n, [Zn(L1)2(μ-phthalate)]2·4H2O, [Zn(L2)2(μ-terephthlate)]·0.5H2O}n, [Zn(L2)2(μ-fumarate)]n, [Zn(L2)2(μ-isophthalate)]2·2H2O, [Zn(L2)2(μ-phthalate)]n, [Zn(L2)2(μ-maleate)]2·2H2O and [Zn(L2)2(μ-citraconate)]2·2H2O – have been crystallographically characterised. The structural characterisation of these compounds demonstrates that by increasing the number of methyl substituents on the thiourea ligand, the likelihood of forming a dimer as opposed to a coordination polymer also increases. Moreover, dimer formation is only favoured for non-linear dicarboxylates – those in which the angle between the carboxylate groups is less than 180°.
已研究锌硫脲络合物 [ZnSC(NHR)(NHR′)}4]Cl2(L = L1, R = H, R′ = Me; L = L2, R = Me, R′ = Me)与一系列二羧酸盐的反应。从这些反应中获得了十一种产物,分别为:[Zn(L1)2(μ-对苯二甲酸盐)]n、[Zn(L1)2(μ-苹果酸盐)]n、[Zn(L1)2(μ-间苯二甲酸盐)]·H2O}n、[Zn(L1)2(μ-1,3-苯基二乙酸盐)]n、[Zn(L1)2(μ-苯二甲酸盐)]2·4H2O、[Zn(L2)2(μ-对苯二甲酸盐)]·0.5H2O}n、[Zn(L2)2(μ-苹果酸盐)]n、[Zn(L2)2(μ-间苯二甲酸盐)]2·2H2O、[Zn(L2)2(μ-苯二甲酸盐)]n、[Zn(L2)2(μ-马来酸盐)]2·2H2O 和 [Zn(L2)2(μ-顺烯丙二酸盐)]2·2H2O。这些化合物的结构特征表明,随着硫脲配体上甲基取代基数量的增加,形成二聚体而非配位聚合物的几率也随之增加。此外,二聚体的形成仅对非线性二羧酸盐更为有利——这些盐的羧酸根之间的夹角小于180°。