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Solvatomagnetic Studies on Cyano‐Bridged Bimetallic Chains Based on [Mn(cyclam)] 3+ and Hexacyanometallates
Author(s) -
Nowicka Beata,
Heczko Michał,
Rams Michał,
Reczyński Mateusz,
Gaweł Bartłomiej,
Nitek Wojciech,
Sieklucka Barbara
Publication year - 2017
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201601007
Subject(s) - cyclam , chemistry , ferrimagnetism , crystallography , isostructural , antiferromagnetism , monoclinic crystal system , crystal structure , metal , magnetization , organic chemistry , physics , quantum mechanics , magnetic field , condensed matter physics
Structures and solvatomagnetic properties of two 1D CN‐bridged assemblies based on the complex [Mn(cyclam)] 3+ (cyclam = 1,4,8,11‐tetraazacyclotetradecane) were characterised. The isostructural {[Mn(cyclam)][Cr(CN) 6 ] · 6H 2 O} n ( 1· 6H 2 O) and {[Mn(cyclam)][Fe(CN) 6 ] · 6H 2 O} n ( 2· 6H 2 O) chains crystallise in the space group C 2/ m . When dried in air at a slightly elevated temperature the hexahydrates undergo irreversible partial dehydration to stable dihydrates 1· 2H 2 O and 2· 2H 2 O. The structure model of 1· 2H 2 O proposed from the powder XRD data shows lower symmetry of the network, described by the space group P 2 1 , and a markedly different relative arrangement of the chains. The Mn–Cr chains are characterised by antiferromagnetic (AFM) exchange through the CN bridges ( J = –2.8 K for 1· 6H 2 O and –6.0 K for 1· 2H 2 O), which was modelled by quantum Monte Carlo simulations. Together with weaker AFM Mn–Cr interactions between the chains, it leads to ferrimagnetic ordering. FM intrachain interactions ( J = 4.5 K for 2· 6H 2 O and 7.1 K for 2· 2H 2 O) and AFM 3D ordering are observed for the Mn–Fe chains. The dehydration process in both compounds causes an increase in the strength of magnetic exchange, which reflects changes in the CN bridge geometry.