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 ha ve been prepared and characterized. The X-ray crystal and molecular structu re of [Cu(HSBzh)NO3] . H2O, where HSBzh refers to the mononegative N-salicy lidenebenzoylhydrazine anion, has been determined. The complex is monomeric with the copper(II) adopting a (4 + 1) distorted square pyramidal coordina tion, with the ONO aroylhydrazone tridentate anion and an oxygen atom of th e unsymmetric bidentate nitrate ion occupying the basal plane. The fifth co ordination site is occupied by the other oxygen of the nitrate ion. The mag netic susceptibilities of both mononuclear and binuclear complexes were mea sured within the temperature range 4.2-298 K. All binuclear copper(II) comp lexes show strong antiferromagnetic interactions, and the singlet-triplet s eparation ( - 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 c omplexes [{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] . H2 O and [Cu(HL)NCS] . H2O. The IR spectra of the prepared complexes are also discussed. (C) 2000 Elsevier Science Ltd All rights reserved.