Synthesis, structures, and magnetic properties of two closely-related manganese(II) coordination polymers

摘要

The reactions of Mn2+ ion with 4-nitrobenzene-1,2-bicarboxylic acid in the presence of bipyridyl-type coligands gave two new manganese(II) coordination polymers, [Mn-2(Nbdc)(2)(Bipyp)(H2O)(4)] (n) (I) and [Mn-2(Nbdc)(2)(Bipye)(H2O)(4)] (n) (II) (H(2)Nbdc = 4-nitrobenzene-1,2-bicarboxylic acid, Bipyp = 1,3-bi(4-pyridyl)propane, and Bipye = 1,2-bi(4-pyridyl)ethane). Both two complexes contain uniform carboxyl-bridged manganese chains with the composition of [Mn-2(Nbdc)(2)(H2O)(4)] (n) , which are interlinked by interchain Bipyp/Bipye spacers to afford two closely-related layers (CIF files CCDC nos. 1008182 (I) and 1008183 (II)). Magnetic studies for two compounds show the presence of similar antiferromagnetic couplings between the adjacent Mn2+ ions through the carboxyl bridges, the best fittings to the experimental magnetic susceptibilities gave J =-0.20 cm(-1) and g = 1.96 for I, and J =-0.24 cm(-1) and g = 1.98 for II. Similar magnetic parameters and thermal behaviors further verify that two compounds possess closely-related structures.