trans-[N,N′-Bis(salicylidene)cyclohexane-1,2-diaminato]nickel(II)–chloroform (1/1)

Abstract

In the title complex, trans-(2,2'-[cyclohexane-1,2-diylbis(nitrilomethylidyne)]diphenolato-kappa(4)O,N,N',O')nickel(II)-chloroform (1/1), [Ni(C(20)H(20)N(2)O(2))].CHCl(3), the Ni atom has a square-planar geometry, slightly tetrahedrally distorted. The Ni-N and Ni-O bonding distances are within the expected ranges for Ni-Schiff base derivatives. The diimine bridge has a gauche conformation with the cyclohexyl ring almost coplanar with the NiN(2)O(2) plane. The complex molecules pack in dimers with an Ni.Ni distance of 3.59 (1) A and form a three-dimensional structure displaying a herring-bone configuration. Channels are occupied by solvent molecules, which are involved in C-H.O hydrogen bonds with the ligand O atoms.

{4-Bromo-2-[2-(5-bromo-2-oxidobenzylideneaminomethyl)phenyliminomethyl]phenolato-κ4O,N,N′,O′}nickel(II)

“…2). The observed NiÁ Á ÁNi distance, 3.480 (3) A Ê , in (I) is well within the values reported [3.201 (1)± 3.582 (1) A Ê ] for analogous Schiff base complexes (de Castro et al, 2001;Ercan et al, 1997;Wojtczak et al, 1997) with NiÁ Á ÁNi interactions.…”

“…The dihedral angle between planes L1 and L2 is 8.8 (1) , indicating a¯at arrangement of the two bromosalicylideneimine groups in the molecule. This geometry is similar to that observed in the [Ni(salchd)] (de Castro et al, 2001) and [Ni(À)(chxn)(sal) 2 ] (Wojtczak et al, 1997) complexes [salchd is bis(salicylidene)cyclohexane-1,2-diaminate, chxn is cyclohexylene and sal is salicylideneiminate] (see Table 3). The pronounced distortion of the planar geometry in the [Ni(salpd)] [salpd is bis(salicylidene)-2,2-dimethylpro-panediaminate; Arici et al, 2001] and [Ni(À)(chxn)(hapi) 2 ] (hapi is hydroxyacetophenonylideneiminate; Szlyk et al, 1999) complexes (see Table 3), where the bridging moiety between the two imine N atoms has methyl substitution, is due to the steric requirements imposed by the interaction between the bulky methyl group and other H atoms of the ligand.…”

“…The distortion of the metal coordination geometry from an ideal square-planar arrangement is revealed by the cisoid OÐ NiÐO angle of 82.64 (10) ( Table 1) and the dihedral angle of 8.2 (1) between the two Ni/N/O planes. Similar distortions in the metal coordination geometry have been reported for tetradentate nickel(II)±Schiff base complexes (Arici et al, 2001;Elmali et al, 2000;de Castro et al, 2001) where the substituents in the imine bridge are bulky.…”

“…In addition to their diverse chelating ability, magnetic properties and applications in catalysis, Schiff base ligands derived from salicylaldimine can serve as ef®cient models for biologically important systems (Long, 1995). In general, nickel(II) complexes of diamine Schiff bases display square-planar metal coordination (Elerman et al, 1996;Sony et al, 2004), but when the substituents in the imine bridge are bulky or the substitution is asymmetric, the metal coordination often exhibits tetrahedral distortion (Elmali et al, 2000;de Castro et al, 2001). As part of a systematic study of the characterization of tetradentate nickel(II)±diamine complexes (Datta et al, 2003), and to build up a hierarchy for such systems, the synthesis, spectroscopy and X-ray structural studies of the title complex, (I), were undertaken.…”

2-[5-(Cyclohexylamino)-1,3,4-thiadiazol-2-yl]phenol

“…2), similar to that reported in the structural arrangement of trans-[N,N 0 -bis(salicylidene)cyclohexane-1,2-diaminato]nickel(II) (de Castro et al, 2001). 2), similar to that reported in the structural arrangement of trans-[N,N 0 -bis(salicylidene)cyclohexane-1,2-diaminato]nickel(II) (de Castro et al, 2001).…”