Crystal structure and magnetic properties of dicarboxylate-bridged linear chain Mn(II) complexes

摘要

Two manganese(II) comlexes,[Mn(mtm)(CH_3OH)_2H_2O)]_n (1) and [Mn_2(mtm)_2(2,2'-bipy)_2(2) (bipy=bipyridine,mtm=[bis(methylthio)methylene]malonate) were synthesized and characterized by X-ray crystallography.Structure of 1 consists of octahedral manganese(II) species which are extended by carboxylate bridges in syn-anti fashion along the c-axis.Chains of 1 are associated by hydrogen bonding among coordinatingwater and methanol molecules and carboxylate oxygen atoms,forming two-dimensionalstructures.Thecrystallographic asymmetric unit of 2 comprises two [Mn(2,2]-bipy)(mtm)] units in which Mn(II)atoms are bridged by #mu#_2-oxygens from carboxylate to form Mn_2O_2 rhombus.Thedimeric units are linked doubly by second carboxylates in syn-anti fashion,resulting in a chain structure.The antiferromagnetic coupling of Mn(II) ions in 1 (-0.2 cm~(-1) and 2 (-1.57 cm~(-1) was determined from variable-temperature magnetic susceptibility dat ain the temperature range of 2-300 K.