Untitled

Abstract

The synthesis, X-ray and e.p.r. spectral studies of a 3d-4f couple are described here. The crystal structure of [Cu(salbn)Gd(NO 3) 3 AE H 2 O], (2), salbn ¼ N,N¢-butylenebis(salicylideaminato), has been determined by X-ray crystallography. Compound (2) crystallizes in the monoclinic system, space group p21/n, with a ¼ 9.025(1), b ¼ 22.912(1), c ¼ 12.790(1) Å , b ¼ 99:36(1), Z ¼ 4. The deviations of the four coordinating atoms (O(1)O(2)N(1) and N(2) of salbn and the copper atom is displaced from the plane in spite of the lack of any apical ligand. The gadolinium(III) ion is nine-coordinated by the two oxygen atoms of the salbn moiety, three bidentate nitrate ions and one water molecule. The geometry of Gd III can be described as a square antiprism, in which compound Cu II and Gd III are bridged by the two phenolic oxygens of salbn. The Cu II-Gd III distance is 3.269(1) Å. The bridging core CuO2Gd is a butterfly shape. Significant distortion was observed for the complex having the larger diamino string. The title compound exhibits seven e.s.r. transitions with jDj ¼ 0:0467 cm)1 , which demonstrates the existence of zero field splitting. This outcome indicates that compound (2) consists of a perfectly isolated dinuclear Cu-Gd core and steric bulk alters the dihedral angle in the Cu-O-Gd bridge.

A Brief Review on Homo-/Hetero-nuclear Co-ordination Compounds Derived from Some Single Compartmentl Acyclic Schiff Base Ligands having N-,O-Donor Centres

“…10−13 When several second metal ions (such as s-, p-, d-, f-block metal salt) from different parts of the periodic table are treated with the Cu(II)/Ni(II) mononuclear compounds the Cu(II)/Ni(II)-second metal homo-/ hetero-nuclear complexes are produced. However various types of copper(II)/nickel(II)-second metal (s-, p-, d-, f-block metal) complexes 14−90 were reported previously from single compartmental salen-type Schiff base ligand which include dinuclear, 20,21,24,[25][26][27][28][29][30][31][32][33][47][48][49][50][80][81][82][83][84] trinucler, 22,23,[36][37][38][39][40][41][42][52][53][54][55][85][86][87] tetranuclear, 16 pentanuclear, 14 hexanuclear, 15 dimer of dinuclear, 21,32,[44][45][46]…”

“…Crystal structure of octanuclear [Ni 8 II (L sal-op ) 4 Cl 8 •(H 2 O) 0.5 ] compound. Hydrogen atoms are omitted for clarity 71Copper(II)/nickel(II)-4f metal ion complexesA number of copper(II)/nickel(II)-lanthanide compounds are known from this class of ligands [81][82][83][84][85][86][87][88][89]. The types of systems include: (i) Dinuclear Cu II Pr III , Cu II Gd III , Ni II Pr III , Ni II Gd III and Ni II Yb III ; 81-84 iii) Trinuclear Cu II Ce III Cu II , Cu II Sm III Cu II and Cu II Gd III Cu II Cu II Dy III Cu II ;[85][86][87] (iii) Dimer-of-dinuclear [Cu II Pr III ] 2 (linker is 4,4'-bipyridine, pyrazine),81 Dimer-ofdinuclear [Cu II Eu III ] 2 (linker is nitrate),88 [2×1+1×1] Dinuclear-mononuclear cocrystals of i) one Dinuclear Ni II Pr III and one mononuclear Ni II units 81 ii) one Dinuclear Cu II Er III and one mononuclear Cu II units 89 (iv) [3×1+1×2] Trinuclear-mononuclear cocrystal of one Cu II Gd III Cu II and two Cu II units 90.…”