Doubly Pyridazine-bridged Dicobalt(II) and Dinickel(II) Side-by-side Complexes of Variously Substituted Conjugated Bis-bidentate Ligands

2010 ◽  
Vol 63 (5) ◽  
pp. 779 ◽  
Author(s):  
Jason R. Price ◽  
Yanhua Lan ◽  
Boujemaa Moubaraki ◽  
Keith S. Murray ◽  
Sally Brooker

A family of six acyclic bis-bidentate Schiff base ligands, Lx (prepared by condensation of 3,6-diformylpyridazine with a range of anilines: 2,4-dimethylaniline Lo,p-Me; 3,5-dichloroaniline Lm,m-Cl; 3,5-difluoroaniline Lm,m-F; p-toluidine Lp-Me; 4-aminophenol Lp-OH; 2,4,6-trimethylaniline Lo,o,p-Me), was complexed, 1:1, with cobalt(ii) or nickel(ii) perchlorate or tetrafluoroborate in refluxing dry acetonitrile. A family of dinuclear, doubly pyridazine-bridged complexes, M2II(Lx)2(solvent)n(ClO4)4 and [Ni2(Lo,o,p-Me)2(2H2O)4](BF4)4, resulted. An X-ray crystal structure determination on [Co2II(Lo,o,p)2(H2O)2(MeCN)2](ClO4)4·MeCN confirmed that it has the expected side-by-side architecture with axial solvent molecules completing the octahedral coordination sphere of the two cobalt(ii) ions. Magnetic analysis showed that the pyridazine bridges mediate weak-to-medium antiferromagnetic interactions between the metal ions. Specifically, for the cobalt(ii) complexes J was in the range –12 to –6 cm–1, while for the nickel(ii) complexes J was in the range –22 to –17 cm–1. There is no clear cut correlation of J values with electron-donating or -attracting properties of ligand substituent peripheral groups, although it is noted that the smallest J occurs in both the NiNi and CoCo families for the ligand Lo,o,p-Me.

2021 ◽  
Author(s):  
SOUMYA SUNDAR MATI ◽  
Dr. SAUGATA KONAR ◽  
BOBY SAMAI

A zinc coordinated rare binuclear complex was synthesised and characterized by elemental analysis and single-crystal X-ray diffraction. Two mononuclear units formed by two Schiff base ligands 2-((2-(pyrimidin-2-yl)hydrazono)methyl)phenol (PHP) coordinated with...


1988 ◽  
Vol 43 (5) ◽  
pp. 611-615 ◽  
Author(s):  
T. Sogo ◽  
J. Romero ◽  
A. Sousa ◽  
A. de Blas ◽  
M. L. Durán ◽  
...  

Abstract The electrochemical synthesis and physico-chemical properties of neutral zinc(II) complexes of bidentate Schiff bases derived from salicylaldehydes are presented together with the X-ray structure of bis[N-(4-methylphenyl)salicylaldiminato]zinc(II). The crystal is monoclinic, a = 21.877(3), b = 8.801(2), c = 12.027(5) Å, β = 96.55(3)°, space group C2/c. The complex is a monomer, and the zinc atom is tetrahedrally coordinated.


2014 ◽  
Vol 70 (10) ◽  
pp. 164-166 ◽  
Author(s):  
Elena A. Buvaylo ◽  
Vladimir N. Kokozay ◽  
Olga Yu. Vassilyeva ◽  
Brian W. Skelton

The title compound, [Co(C13H9N2O2)2]·1.5C3H7NO, is formed as a neutral CoIIcomplex with dimethylformamide (DMF) solvent molecules. The CoIIatom has a distorted O2N4octahedral coordination sphere defined by two tridentate anionic Schiff base ligands with the O atoms beingcis. The coordination sphere around the CoIIatom is geometrically different from that reported for the co-crystal [Co(C13H9N2O2)2]·AA·H2O (AA is anthranilic acid). One of the DMF solvent molecules was modelled as being disordered about a crystallographic inversion centre with half-occupancy. The crystal structure is made up from alternating layers of complex molecules and DMF molecules parallel to (010). C—H...O hydrogen-bonding interactions between the complex molecules and the solvent molecules consolidate the crystal packing.


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