Synthesis, Crystal Structures, and Magnetic Properties of Cyano-Bridged Honeycomblike Layers M^V−Cu^II (M = Mo, W) Chelated by a Macrocyclic Ligand

Abstract

Two cyano-bridged Cu(II)-M(V) [M = Mo (2), W (3)] complexes formed by self-assembly of octacyanometalates [M(CN)8]3- (M = Mo, W) with a new molecular precursor [Cu(L2)]2+ (1) (L2 = a macrocyclic ligand) in a 2:3 ratio have been investigated in terms of structures and magnetic behaviors. The M2Cu3 repeating unit of both bimetallic compounds is extended to a two-dimensional honeycomblike layered structure. The pendant ethyl groups on L2 noticeably influence the structural parameters around the Cu center. Compared with the system composed of a macrocycle without a side group, Cu-N(ax) (ax = axial) distances become shorter and the Cu-N(ax)-C(ax) angles are more bent for 2 and 3. The magnetic data denote that the Cu(II) and M(V) spins undergo explicit ferromagnetic interactions via CN bridges. From a structural and magnetic point of view, given that the Cu-N(ax) bond length in the tetragonally distorted octahedral Cu(II) environment is long enough, the overall ferromagnetic character remains despite the variation of Cu-N(ax)-C(ax) angle in this system.

A high-spin cyanide-bridged Mo6Mn9 cluster: crystal structure and magnetism

“…Following the pioneering work of Kahn's group [13][14][15], these flexible species may be used as versatile synthons to construct a variety of architectures or networks with novel topological structures and interesting magnetic properties. For example, M V -Mn II [16][17][18][19][20][21][22][23][24][25][26], M VMn III , [27,28], and M V -Cu II [29][30][31][32][33][34][35][36][37][38][39][40], bimetallic assemblies with a variety of extended structures, have been obtained; a few polynuclear clusters with M 6 V Mn 9 II type (M = Mo and W) have been reported as well [41][42][43][44][45][46] …”

Three types of heterometallic structural motifs based on [Mo(CN)8]3−/4− anion and MnII cation as building blocks

“…These complexes have been fully characterized by elemental analysis, IR spectroscopy, and X-ray crystallography. The most conspicuous features of the IR spectra concern the existence of 2149 cm -1 for 1, which may be attributed to characteristic CN stretching vibrations of [Mo(CN) 8 ] 3-ion (2141 cm -1 for free) [35], and 2124 cm -1 , 2129 cm -1 for 2 and 3, which are assigned to characteristic CN stretching vibration of [Mo(CN) 8 ] 4-ion (2125 cm -1 for free) [43]. The Mo V ions have been reduced during the reaction processes obviously for the syntheses of 2 and 3…”

“…Following the pioneering work of Kahn's group [13][14][15], these flexible species may be used as versatile synthons to construct a variety of architectures or networks with novel topological structures and interesting magnetic properties. For example, M V -Mn II [16][17][18][19][20][21][22][23][24], M V -Cu II [25][26][27][28][29][30][31][32][33][34][35], and M 6 V Mn 9 II (a few polynuclear clusters) [36][37][38][39] (M = Mo and W) bimetallic assemblies with a variety of extended structure have been obtained. In order to provide more examples of Mo V or Mo IV ion with CN --bridged system, in this paper, [Mo V (CN) 8 ] 3-and Mn II ions are utilized as building blocks for designing and synthesis of Mo V /Mn II magnetic compounds.…”

Neutral Low-Dimensional Assemblies of a Mn(III) Schiff Base Complex and Octacyanotungstate(V): Synthesis, Characterization, and Magnetic Properties

“…Some of them are 1D polymers [53][54][55][56]; others possess layered [57][58][59][60][61][62][63] or 3D network structures [64][65][66][67][68]. The paramagnetic cyanotungstate(V) tectones have been used to build discrete molecules [69][70][71], chains [53][54][55][56], 2D [57] and 3D networks [64][65][66][67][68], and some of them have displayed variable magnetic properties such as high ordering temperatures [72], photo-induced magnetism [73,74], SMMs [75], and SCMs [17,54,55].…”