Magnetic and Electrical Behaviors of the Homo- and Heterometallic 1D and 3D Coordination Polymers Based on the Partial Decomposition of the [Cr(CO)] Building Block.

One-dimensional (1D) oxalate-bridged homometallic {[Mn(bpy)(CO)]·1.5HO} () (bpy = 2,2'-bipyridine) and heterodimetallic {[CrCu(bpy)(CHOH)(HO)(CO)][Cu(bpy)Cr(CO)]·CHCl·CHOH·HO} () coordination polymers, as well as the three-dimensional (3D) heterotrimetallic {[CaCrCu(phen)(CO)]·4CHCN·2HO} () (1,10-phenanthroline) network, have been synthesized by a building block approach using a layering technique, and characterized by single-crystal X-ray diffraction, infrared (IR) and impedance spectroscopies and magnetization measurements. During the crystallization process partial decomposition of the tris(oxalate)chromate(III) happened and 1D polymers and were formed. The antiferromagnetic interactions between the manganese(II) ions was mediated by oxalate ligands in the chain [Mn(bpy)(CO)] of , with intra-chain super-exchange interaction ? = (-3.134 ± 0.004) K; magnetic interaction between neighbouring chains is negligible making this system closer than other known Mn-chains to the ideal 1D Heisenberg antiferromagnet. Compound comprises a 1D coordination anion [Cu(bpy)Cr(CO)] () with alternating [Cr(CO)] and [Cu(bpy)] units mutually bridged through the oxalate group. Another chain () is similar, but involves a homodinuclear unit [Cu(bpy)(HO)(-CO)Cu(bpy)(CHOH)] () coordinated as a pendant group to a terminal oxalate oxygen. Magnetic measurements showed that the cationic unit is a strongly coupled antiferromagnetic dimer, independent from the other magnetic ions within ferromagnetic chains and . A 3D polymer {[CaCrCu(phen)(CO)]·4CHCN·2HO} () comprising three different metal centers (Ca, Cr and Cu) oxalate-bridged, contains Ca atoms as nodes connected with four Cr atoms through oxalate ligands. The network thus formed can be reduced to an underlying graph of diamondoid () or (6) topology. Magnetization of shows the ferromagnetic oxalate-bridged dimers [CuCr], whose mutual interaction could possibly originate through the spin polarization of Ca orbitals. Compounds and exhibit lower electrical conductivity at room temperature (RT) in comparison to compound .