Crystal structure and magnetic properties of copper(II) macrocyclic compounds

The two higly unsaturated copper(II) macrocyclic complexes [CuL1](ClO4)(2) (1) (L-1 = N-d1-5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) and [CuL2](ClO4)(2) (2) (L-2 = N-d1-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) were synthesized and the crystal structures of both compounds were determined at 173(2) K. Complex I crystallizes monoclinic, space group P2(1)/c, with a = 9.0929(5) angstrom, b = 13.4683(5) angstrom, c= 8.2886(4) angstrom, beta = 109.469(6)degrees, Z=2, whereas 2 crystallizes at the same space group with a = 10.4891(2) angstrom, b = 16.9924(4) angstrom, c = 13.8780(3) angstrom, beta = 105.150(2)degrees and Z = 4. Their magnetic measurements have been carried out over the temperature range 1.8-300 K using a Quantum Design SQUID magnetometer (MPMSXL - 5 type). The results indicate that both compounds behave as weakly interacting copper centers in the crystal lattice.