Synthesis crystal structure and magnetic properties of a thiocyanate bridged one-dimensional chain copper(II) complex: {[(232-tet)Cu(NCS)](CLO_4)}_n

摘要

A thiocyanate bridged one-dimensional chaincopper(II) complex, {[(232-tet)Cu(NCS)]-(ClO_4)}_n, where232-tet= N,N'-bis(2-aminoethyl)-1 ,3-propanediamine, has beensynthesized and its crystal structure determined at roomtemperature. This complex crystallises in the orthorhombic system.space group Pca2_1, with a = 23.565(3), b = 9.01 1(2), c=14.290(3) A and Z=4. Least-squares refinement of the structureleads to conventional R_1 and wR_2 factors of 0.052 and 0.142.The asymmetric unit consists of two [(232-tet)Cu(NCS)]~+ unitsand two per-chlorate anions. The two symmetric independent[(232-tet)Cu(NCS)]~+ units form two different chains in thecrystal lattice. The intrachain copper(II)-copper(II). separations are7.282(5) [Cu(1)~a, a: 1.5 -x.y.0.5+z] and 7.334(5)A [Cu(2)-Cu(2)~b, 1 – x, 1 – y, 0.5+z], respectively. The interchaincopper(II)-copper(II) separation is 6.870(5) A [Cu(1) - Cu(2)~b, b:1 – x, 1 – y, 0.5+z]. The coordination environments of the twoCu(II) atoms are similar. Each Cu(II) atom is (4 + 1 + 1')coordinated in a distorted. elongated, tetragonal octahedron withfour N atoms 0f the 232-tet ligand in the equatorial positions andone N atom of the thiocyanate and one S atom of the otherthiocyanate in the axial positions. The ESR spectrum appeared toshow axial symmetry with g_perpendicular = 2.05 and g_||=2.16.Variable temperature magnetic susceptibility shows that there is aweak antiferromagnetic interactions in intrachains.