Solvatomagnetic Studies on Cyano‐Bridged Bimetallic Chains Based on [Mn(cyclam)]3+ and Hexacyanometallates
Solvatomagnetic Studies on Cyano‐Bridged Bimetallic Chains Based on [Mn(cyclam)]3+ and Hexacyanometallates
复制标题
基于[Mn(cyclam)]3+和六氰基金属盐的氰基桥双金属链的溶剂磁学研究
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发表时间：
2017
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通讯作者：
B. Sieklucka
中科院分区：
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作者：
B. Nowicka;M. Heczko;M. Rams;Mateusz Reczyński;B. Gaweł;W. Nitek;B. Sieklucka
Structure and solvatomagnetic properties of two 1D CN-bridged assemblies based on the [Mn(cyclam)]3+ complex (cyclam = 1,4,8,11-tetraazacyclotetradecane) have been characterised. The isostructural {[Mn(cyclam)][Cr(CN)6]·6H2O}n (1·6H2O) and {[Mn(cyclam)][Fe(CN)6]·6H2O}n (2·6H2O) chains crystallise in the space group C2/m. Dried in air at a slightly elevated temperature the hexahydrates undergo irreversible partial dehydration to stable dihydrates 1·2H2O and 2·2H2O, respectively. The structure model of 1·2H2O proposed from the PXRD data shows lower symmetry of the network described by the space group P21 and markedly different relative arrangement of the chains. The Mn-Cr chains are characterised by antiferromagnetic exchange through the CN-bridges (J = −2.8 K for 1·6H2O and −6.0 K for 1·2H2O), which was modelled using quantum Monte Carlo simulations. Together with weaker AF Mn-Cr interactions between the chains it leads to ferrimagnetic ordering. Ferromagnetic intra-chain interactions (J = 4.5 K for 2·6H2O and 7.1 K for 2·2H2O) and antiferromagnetic 3D ordering is observed for the Mn-Fe chains. The dehydration process in both compounds causes an increase in the strength of magnetic exchange, reflecting changes in the CN-bridge geometry.
