Inorganic–organic hybrid structure: Synthesis, structure and magnetic properties of a cobalt phosphite–oxalate, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3

Abstract

A hydrothermal reaction of a mixture of cobalt (II) oxalate, phosphorous acid, piperazine and water at 150 °C for 96 h followed by heating at 180 °C for 24 h gave rise to a new inorganic–organic hybrid solid, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3], I. The structure consists of edge-shared CoO 6 octahedra forming a [Co 2O 10] dimers that are connected by HPO 3 and C 2O 4 units forming a three-dimensional structure with one-dimensional channels. The amine molecules are positioned within these channels. The oxalate units have a dual role of connecting within the plane of the layer as well as out of the plane. Magnetic susceptibility measurement shows the compound orders antiferromagnetically at low temperature ( T N = 22 K ). Crystal data: I, monoclinic, space group= P2 1/ c (No. 14). a = 7.614 ( 15 ) , b = 7.514 ( 14 ) , c = 17.750 ( 3 ) Å , β = 97.351 ( 3 ) ° , V = 1007.30 ( 3 ) Å 3 , Z = 2 , ρ calc = 2.466 g / cm 3 , μ ( Mo K α ) = 3.496 mm - 1 , R 1 = 0.0310 and w R 2 = 0.0807 data [ I > 2 σ ( I ) ] .