Isolated Magnetic Clusters of Co(II) and Ni(II) within 3-Dimensional Organic Frameworks of 6-Mercaptonicotinic Acid: Unique Structural Topologies Based on Selectivity for Hard and Soft Coordination Environments

Hydrothermal reaction of the mixed thiolate−carboxylate−aromatic
amine ligand, 6-mercaptonicotinic acid (6-mnaH2) with Co(II) and
Ni(II) leads to two network coordination solids [M9(6-mna)8(μ3-O)2(OH3)2(OH2)6] (M = Co, Ni), 1, and [M2Ni12(6-mna)12(μ3-OH)2(OH2)6]·8H2O (M = K, Rb, Cs), 2. These compounds are unusual
for two reasons:  they are thiolate-bridged networks and they are
three-dimensional lattices which contain isolated metal clusters and
chains. The magnetic behavior of these compounds has been
studied, showing that 2 contains ferromagnetically coupled Ni6
wheels.

将硫醇盐-羧酸盐-芳香胺混合配体6-巯基烟酸（6-mercaptonicotinic acid，6-mnaH2）与二价钴（Co(II)）、二价镍（Ni(II)）进行水热反应，可得到两种网络状配位固体：分别为通式[M9(6-mna)8(μ3-O)2(OH3)2(OH2)6]（M = Co, Ni，记为化合物1）与[M2Ni12(6-mna)12(μ3-OH)2(OH2)6]·8H2O（M = K, Rb, Cs，记为化合物2）。这类化合物具有双重特殊性：其一为以硫醇盐作为桥连配体的网络结构，其二为同时包含孤立金属簇与链状结构的三维晶格。目前已针对这两类化合物的磁学行为展开研究，结果表明化合物2中存在铁磁耦合的六元镍轮簇（Ni6 wheels）。