Synthesis, reactivity and magnetochemical studies on copper(II) complexes derived from N-salicylidenearoylhydrazines.: X-ray structure of [mononitratoOO(-1) (N-salicylidenatobenzoylhydrazine)-ONO(-1)]copper(II) monohydrate

A series of new mononuclear and binuclear copper(II) complexes derived from N-salicylidenearoylhydrazines (H2L) of the types K-2[{Cu(L)(OH)}(2)] . nH(2)O [Cu(HL)Cl . H2O] . nH(2)O [{Cu(HL)Cl}(2)], [Cu(HL)NO2] . H2O, [{Cu(HL)}(2)] . 2NO(3) [{Cu(HL)- H2O}(2)] . 2NO(3) . nH(2)O and [Cu(HL)NCS] . H2O have been prepared and characterized. The X-ray crystal and molecular structure of [Cu(HSBzh)NO3] . H2O, where HSBzh refers to the mononegative N-salicylidenebenzoylhydrazine anion, has been determined. The complex is monomeric with the copper(II) adopting a (4 + 1) distorted square pyramidal coordination, with the ONO aroylhydrazone tridentate anion and an oxygen atom of the unsymmetric bidentate nitrate ion occupying the basal plane. The fifth coordination site is occupied by the other oxygen of the nitrate ion. The magnetic susceptibilities of both mononuclear and binuclear complexes were measured within the temperature range 4.2-298 K. All binuclear copper(II) complexes show strong antiferromagnetic interactions, and the singlet-triplet separation ( - 2J) recorded for mu-dihydroxy bridged complexes K-2[{Cu(L)OH}] . nH(2)O an within the range 172-276 cm(-1), while ( -2J) for binuclear complexes [{Cu(HL)Cl}(2)], [{Cu(HL)}(2)] . 2NO(3) and [{Cu(HL)H2O}(2)] . 2NO(3) . nH(2)O are respectively within the range 400-460, ca. 340 and ca. 390 cm(-1). There are no appreciable exchange interactions between copper(II) ions in the monomeric complexes [Cu(HL)Cl . H2O] . nH(2)O, [Cu(HL)NO2] . H2O and [Cu(HL)NCS] . H2O. The IR spectra of the prepared complexes are also discussed. (C) 2000 Elsevier Science Ltd All rights reserved.