Synthesis, characterization and crystal structures of monomeric and imidazolate-bridged polymeric copper(II) complexes of 5-methyl-1,5, 9-triazanonane

Two complexes [Cu(mtan)(H2O)(ClO4)](ClO4) (Im = imidazolate) (1) and [Cu(mt an)(Im)](n)(ClO4)(2n) (mtan = 5-methyl- 1, 5, 9-triazanonane) (2) have been prepared and characterized. Single-crystal X-ray analysis reveals that (1) crystallizes in the orthorhombic space group Pbcm, with a 8.906(5), b 12.2 55(6), c 14.821(4) Angstrom and V 1618(1) Angstrom (3), and complex (2) cry stallizes in the orthorhombic space group Pca2(1), with a 11.125(7), b 9.14 9(6), c 15.180(7) Angstrom and V 1545(1) Angstrom (3). The copper( II) atom in complex (1) is in a distorted square-pyramidal geometry, being coordina ted by three nitrogen atoms from an mtan ligand and one oxygen atom from an aqua ligand at the basal plane and one perchlorate oxygen atom at the apic al position. The structure of complex (2) features polymeric cationic chain s composed of [Cu(mtan)(Im)](+) repeating units and discrete perchlorate an ions. The Cu(1) atom in each unit has a severely distorted trigonal-bipyram idal geometry, being coordinated by three nitrogen atoms from one mtan liga nd and two nitrogen atoms from two Im groups. The structural units are link ed by mu -Im groups to give one-dimensional chains. The variable-temperatur e magnetic measurement on the powder sample of (2) reveals intrachain, medi um antiferromagnetic interaction with g = 2.240 and J = -36.45 cm(-1) throu gh the mu -Im bridges.