Structural and Magnetic Properties of Three One-Dimensional Nitrato-, Azido- and Phenoxido-Bridged Copper(Ii) Coordination Polymers

Three coordination polymers, 1 ∞ [Cu 3 L 2 (NO 3 )](NO 3 )·2MeOH·2H 2 O ( 1 ), 1 ∞ [Cu 3 L 2 (N 3 )](CH 3 COO) ( 2 ) and 1 ∞ [Cu 3 L 2 (H 2 O)](ClO 4 ) 2 ( 3 ), based on the Schiff base H 2 L (H 2 L = N,N'-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine) have been synthesized and characterized. X-ray single-crystal analysis shows that compounds 1 - 3 consist of trinuclear complex entities, {Cu 3 L 2 } 2+ , connected via different bridges, nitrato ( 1 ), azido ( 2 ) and phenoxido ( 3 ), depending on the nature of the counterion. The cryomagnetic measurements reveal weak ferromagnetic interactions between the copper(II) ions bridged by the nitrato ligands in 1 ( J = +1.026 cm -1 , H = - J S 1 S 2 ) and a weak antiferromagnetic coupling between the copper(II) ions connected by azido groups in 2 ( J = -0.295 cm -1 ). The exchange interaction between the copper(II) ions connected by two phenoxido groups is antiferromagnetic, J = -12.780 cm -1