Syntheses, structures, and mesomorphic properties of two series of oxovanadium(IV) salen and salpn complexes with 4-substituted long alkoxy chains

Transition metal complexes of monodentate 2-oxazolines containing long chain alkyl groups. The crystal structure of trans-PdCl2(κ 1-N-rac-2-heptadecyl-4,5-dihydro-5-methyl-2-oxazole)2

The synthesis, characterisation and properties of several divalent metal complexes (Co, Ni, Pd) containing 2-oxazoline ligands L1–L3, appended with long chain alkyl and/or ester groups, is reported. The X-ray crystal structure aspects of one such complex, trans-PdCl2(rac-2-heptadecyl-4,5-dihydro-5-methyl-2-oxazole)2 (i.e. PdCl2(L1)2: 3), is described. This latter material contains one of the longest alkyl chains to be crystallographically characterised appended to an oxazoline ligand. The complexes reported herein represent the first transition metal derivatives of these high molecular weight, long chain and presumably low polarity monodentate oxazoline ligands. A combination of spectral and theoretical calculations (semi-empirical PM6(tm) level of theory) are used to support the proposed structure in the case of the hydrates of NiCl2 and CoBr2 complexes derived from L1. A trio of PdCl2 complexes of the ligand set are likewise detailed. Complex 3 is shown to be a useful pre-catalyst for the promotion of a Heck coupling reaction between bromobenzene and styrene under typical conditions.

Ferroelectric and luminescence properties of zinc(ii) and platinum(ii) soft complexes

Zinc(ii) and platinum(ii) complexes [M(X-4-C₁₈-salmmen)] (M = Zn (1) and Pt (2), X = R, S (optical isomer) and rac (racemate), salmmen = N,N′-monomethylenebis-salicylideneimine) were synthesized and investigated.

Twin effects of induction and stabilization of the SmA* phase by Cu(ii) using 4,4′-disubstituted salicylideneimine containing [1,2,3]-triazole and cholesterol arms

The ligands exhibited N* and SmC* phases, while Cu(ii) complexes exhibited the SmA* phase which was absent in their respective ligands.

Synthesis and aggregation behaviour of luminescent mesomorphic zinc(ii) complexes with ‘salen’ type asymmetric Schiff base ligands

Mesomorphism and solvent dependent aggregation behaviour of a new series of photoluminescent Zn(ii)-salen type asymmetric Schiff base complexes have been investigated.

X-ray and DFT-calculated structures of a vanadyl Schiff base complex: (methanol-κO)[2-methoxy-6-({2-[(2-oxido-3-methoxybenzylidene)amino]benzyl}iminomethyl)phenolato-κ4O1,N,N,O1']oxidovanadium(IV) monohydrate

The central V(V) atom in the title mononuclear oxovanadium complex, [VO(C(23)H(20)N(2)O(4))(CH(3)OH)]·H(2)O, has a distorted octahedral coordination. Two N atoms and two O atoms of the Schiff base define the base of the bipyramid and two O atoms are in the apical positions, one from vanadyl and the second from methanol. Density functional theory (DFT) calculations were performed for the title complex and its ligand to compare their geometry in the solid and gas phases. Additional analyses were made of the changes in the geometry of the ligand during complex formation. The HOMA (harmonic oscillator model of aromaticity) descriptor of π-electron delocalization was calculated to estimate the aromaticity of the benzene rings in the title complex and its ligand.