Metal Phosphonates Based on {[(Benzimidazol-2-ylmethyl)imino]bis-(methylene)}bis(phosphonic Acid):Syntheses,Structures and Magnetic Properties of the Chain Compounds [M{(C_7H_5N_2)Ch_2N(Ch_2PO_3H)_2}] (M =Mn,Fe,Co,Cu,Cd)

摘要

Five compounds based on {[(benzimidazol-2-ylmethyl)imino-]bis(methylene)}bis(phosphonic acid)[(C_7H_5N_2)Ch_2N(Ch_2-PO_3h_2)_2],namely [M{(C_7H_5N_2)CH_2N(CH_2PO_3H)_2}] [M =Mn (1),Fe (2),Co(3),Cu (4),Cd (5)] have been synthesized under hydrothermal conditions.These compounds are iso-structural,crystallizing in the orthorhombic space group Pbca,with a=15.331(2),b=10.7150(16),and c=16.715(2)A for 1;a=15.320(3),b =10.477(2),and c=16.764(3)A for 2;a=15.207(2),b=10.4626(16),and c=16.794(3)A for 3;a=15.101(3),b=10.3517(17),and c=16.997(3)A for 4;and a=15.4679(19),b=10.8923(13),and c=16.6175(19)for 5.Eachcompound shows a one-dimensional chain structure where (MO_3N_2} trigonal bipyramids are connected by (CPO_3)tetra-hedra through corner-sharing.The chains are further connected to each other through aromatic stacking of the benz-imidazole rings and extensive hydrogen bonds,forming a supramolecular 3D structure.Magnetic susceptibility studies of 1-4 reveal that weak antiferromagnetic interactions occur between the metal centers.