摘要 :
ABSTRACT: Two acentric, i.e., noncentrosymmetric, mononuclear complexes, Co(5-
ATZ)4Cl2, 1, and Cu(5-ATZ)4Cl2, 2, where 5-ATZ is the monodentate 5-amino-1-Htetrazole
ligand, have been prepared and characterized. Both complexes cry...
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ABSTRACT: Two acentric, i.e., noncentrosymmetric, mononuclear complexes, Co(5-
ATZ)4Cl2, 1, and Cu(5-ATZ)4Cl2, 2, where 5-ATZ is the monodentate 5-amino-1-Htetrazole
ligand, have been prepared and characterized. Both complexes crystallize in the
tetragonal system with the P4nc space group, a member of the polar noncentrosymmetric
4mm class, and thus both 1 and 2 can exhibit ferroelectric and
nonlinear optical properties. Magnetic studies indicate that 1 is a paramagnetic high-spin
cobalt(II) complex with a rather extensive spin−orbit coupling, modeled as a zero-field
splitting parameter, D, of ±91(3) cm−1 and with very weak long-range antiferromagnetic
exchange interactions. Direct current (dc) and ac magnetic studies indicate that 2 is a
paramagnetic copper(II) complex that exhibits weak ferromagnetic exchange
interactions below 15 K. Both 1 and 2 exhibit ferroelectric hysteresis loops at room
temperature with remanent polarizations of 0.015 μC/cm2 and coercive electric fields of
5.5 and 5.7 kV/cm, respectively.
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