US EPA

4186173 

Journal Article 

Playing with different metalloligands [NiL] and Hg to [NiL] ratios to tune the nuclearity of Ni(II)-Hg(II) complexes: Formation of di-, tri-, hexa- and nona-nuclear Ni-Hg clusters 

Das, LK; Gomez-Garcia, CJ; Drew, MGB; Ghosh, A 

2015 

1 

Polyhedron
ISSN: 02775387 

87 

311-320 

10.1016/j.poly.2014.11.025 

WOS:000353316800041 

Five new hetero-metallic nickel(II)-mercury(II) complexes, [(NiL1)HgCl2] (1), [(NiL1)(2)HgCl2] (3), [(NiL1)(2)-Hg(N-3)(2)] (4), ({(NiL2)(2)Hg(N-3)(mu(1.1)-N-3)}(2)] (5) and [{(NiL2)Hg-2(N-3)(mu(1.1)-N-3)HgCl2}(2)(Hg(N-3)(mu(1.1)-N-3))] (6) have been synthesized by reacting metalloligands [NiL1] or [NiL2] (where H2L1 is N,N'-bis(salicylidene)-1,2-ethylenediamine and H2L2 is N,N'-bis(salicylidene)-1,3-propanediamine) with HgX2 (X- = Cl- or N-3(-)) at different molar ratios. All five complexes have been characterised by X-ray single-crystal structural, elemental and spectroscopic analyses. In complex 1, the Hg(II) ion is coordinated to two phenoxido oxygen atoms of one [NiL1] moiety and two terminal chloride ions to form a NiHg dinuclear complex. In the trinuclear complexes 3 and 4, the central Hg(II) ion is coordinated by two terminal [NiL1] units through two phenoxido oxygens from each and two terminal chloride (in 3) or azide (in 4) ions. The centrosymmetric hexanuclear complex 5 consists of two trinuclear [(NiL2)(2)Hg(N-3)(mu(1.1)-N-3)] units, where the phenoxido bridges connect two terminal Ni(II) atoms of the trinuclear units. In these trinuclear units, one azido ligand adopts a mu(l),(1)-briding mode between Hg and Ni whereas the other one is terminal. In the nonanuclear complex 6, two tetranuclear [{(NiL2)(2)Hg(N-3)(mu(1).(1)-N-3))HgCl2] units are linked to a central Hg(II) positioned on a two fold axis, via chlorido, azido, and phenoxido bridges. The tetranuclear unit is formed by the addition of a HgCl2 molecule to a trinuclear [(NiL2)(2) Hg(N-3)(mu(1.1)-N-3)] unit, similar to that present in 5. Complex 5 shows weak ferromagnetic interactions (J = +2.1 cm(-1)) between the two octahedral Ni(II) ions through double phenoxido bridges with a Ni-O-Ni bond angle of 95.87(11)degrees. (C) 2014 Elsevier Ltd. All rights reserved. 

Nickel(II); Mercury(II); Hetero-metallic complexes; Crystal structure; Ferromagnetic interaction