One-dimensional homochiral cyano-bridged heterometallic chain coordination polymers with metamagnetic or ferroelectric properties.
Two couples of enantiomerically pure chiral cyano-bridged heterobimetallic chain coordination polymers, [Mn((R,R)-Salcy)Fe(Tp)(CN)(3) x H(2)O x 1/2 CH(3)CN](n) (1), [Mn((S,S)-Salcy)Fe(Tp)(CN)(3) x H(2)O x 1/2 CH(3)CN](n) (2), [Mn((R,R)-Salcy)Fe(bpca)(CN)(3) x H(2)O](n) (3), and [Mn((S,S)-Salcy)Fe(bpca)(CN)(3) x H(2)O](n) (4) [(R,R)-Salcy or (S,S)-Salcy = (R,R)- or (S,S)-N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion, Tp = tris(pyrazolyl)hydroborate, bpca = bis(2-pyridylcarbonyl)amidate anion], were synthesized using the modified cyanometalate building blocks [Fe(L)(CN)(3)](-) (L = Tp, bpca) and the chiral polydentate Schiff base manganese(III) complex fragments. The circular dichroism 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 long-range ordering with a T(N) of 3.2 K, while enantiomers 3 and 4 are typical antiferromagnetic coupling compounds. Furthermore, complex 3 exhibits a ferroelectric behavior that relates to the polar point group C(2), in which it crystallizes.
Wen
He-Rui
HR
School of Materials and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China. wenhr@mail.jxust.cn
Tang
Yun-Zhi
YZ
Liu
Cai-Ming
CM
Chen
Jing-Lin
JL
Yu
Chang-Lin
CL