One-Dimensional Homochiral Cyano-Bridged Heterometallic Chain Coordination Polymers with Metamagnetic or Ferroelectric Properties.

Two couples of enantiomedcally pure chiral cyano-bridged heterobimetallic chain coordination polymers, [Mn((R,R)Salcy)Fe(Tp)(CN)3∙H2O∙1/2CH3CN]n (1), [Mn((S,S)-Salcy)Fe(Tp)(CN)3∙H2O—1/2CH3CN]n (2), [Mn((R,R)Salcy)Fe(bpca)(CN)3—H2O]n (3), and [Mn((S,-Salcy)Fe(bpca)(CN)3∙H2O]n (4) [(R,R)-Salcy or (S,S)-Salcy = (R,R)- or (S,S)-N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion, Tp = tris(pyrazofyl)hydroborate, bpca = bis(2-pyddylcarbonyl)amidate anion], were synthesized using the mod8ied cyanometalate building blocks [Fe(L)(CN)3]- (L = Tp, bpca) and the chiral polydentate Schiff base manganese(lll) complex fragments. The circular dictiroism measurements showed Cotton effects of the opposite sign at the same wavelength for each pair of enantiomers. Magnetic property studies indicated that complexes 1 and 2 show not only intrachain but also interchain field-induced metamagnetic transitions from an antiferromagnetic to a ferromagnetic state and exhibit an antiferromagnetic tong-range ordering with a TN of 3.2 K, while enantiomers 3 and 4 are typical antiferromagnetic coupling compounds. Furthermore, complex 3 exhibits a ferroetectric behavior that relates to the polar point group C2, in which it crystallizes. [ABSTRACT FROM AUTHOR]