Mono, di and polynuclear Cu(II)–azido complexes incorporating N,N,N reduced schiff base: syntheses, structure and magnetic behavior

Three kinds of copper(II) azide complexes have been synthesised in excellent yields by reacting Cu(ClO4)2 · 6H2O with N,N-bis(2-pyridylmethyl)amine (L1); N-(2-pyridylmethyl)-N′,N′-dimethylethylenediamine (L2); and N-(2-pyridylmethyl)-N′,N′-diethylethylenediamine (L3), respectively, in the presence of slight excess of sodium azide. They are the monomeric Cu(L1)(N3)(ClO4) (1), the end-to-end diazido-bridged Cu2(L2)2(μ-1,3-N3)2(ClO4)2 (2) and the single azido-bridged (μ-1,3-) 1D chain [Cu(L3)(μ-1,3-N3)]n(ClO4)n (3). The crystal and molecular structures of these complexes have been solved. The variable temperature magnetic moments of type 2 and type 3 complexes were studied. Temperature dependent susceptibility for 2 was fitted using the Bleaney–Bowers expression which led to the parameters J = −3.43 cm−1 and R = 1 × 10−5. The magnetic data for 3 were fitted to Baker’s expression for S = 1/2 and the parameters obtained were J = 1.6 cm−1 and R = 3.2 × 10−4. Crystal data are as follows. Cu(L1)(N3)(ClO4): Chemical formula, C12H13ClN6O4Cu; crystal system, monoclinic; space group, P21/c; a = 8.788(12), b = 13.045(15), c = 14.213(15) Å; β = 102.960(10)°; Z = 4. Cu(L2)(μ-N3)(ClO4): Chemical formula, C10H17ClN6O4Cu: crystal system, monoclinic; space group, P21/c; a = 10.790(12), b = 8.568(9), c = 16.651(17) Å; β = 102.360(10)°; Z = 4. [Cu(L3)(μ-N3)](ClO4): Chemical formula, C12H21ClN6O4Cu; crystal system, monoclinic; space group, P21/c; a = 12.331(14), b = 7.804(9), c = 18.64(2) Å; β = 103.405(10)°; Z = 4.