The influence of counter ion and ligandmethyl substitution on the solid-state structures and photophysical properties of mercury(ii) complexes with (E)-N-(pyridin-2-ylmethylidene)arylamines

Abstract

Ten neutral monomeric, dimeric and polymeric mercury(II) complexes of compositions HgX2L (3,8), [HgX2L]2 (1, 2, 4-6 and 7), [Hg(NO3)2L]n (9) and [Hg(N3)2L]2n (10) where X = chloride, bromide, iodide, nitrate and azide, and L = (E)-N-(pyridin-2-ylmethylidene)arylamine, are described. Compounds 1-10 were characterized by elemental analyses, and IR and 1H NMR spectroscopic studies. The solution-state photophysical properties of the complexes are highly dependent on the anions as seen in the fluorescence emission features. Single-crystal X-ray crystallography showed that the molecular complexes can aggregate into larger entities depending upon the anion coordinated to the metal centre. Iodide gives discrete monomeric complexes, chloride and bromide generate binuclear complexes formed through Hg-X-Hg bridges, while nitrate and azide lead to 1D coordination polymers. The significant differences in the observed aggregation patterns of the compounds indicate that the anions exert a substantial influence on the formation of the compounds. A further influence upon supramolecular aggregation is the presence of methyl substituents in L3 and L4, which generally enhances the probability of forming supramolecular interactions involving the five-membered C2N2Hg chelate rings in their crystal structures.

An organomercury enzyme activator as a versatile template for new organomercury(II) compounds encompassing homobimetallic (RHg/Hg) and heterobimetallic (RHg/Cd) compositions: Syntheses, photoluminescence and structures

“…Metals with the d 10 configuration have attracted much attention recently due to their luminescent [64][65][66][67] and photochromic behavior [8,9,61] and it is from this perspective that the fluorescence properties of the compounds were investigated. In acetonitrile solution, compounds 8-12 ( Fig.…”

Synthesis and Structure of a Polymeric Homobimetallic Mercury Compound Constructed from (E)-Acetyloxy{4-[(pyridin-2-ylmethylene)amino]phenyl}mercury(II)

“…In this perspective, mercury complexes of Schiff-base ligands, such as (E)-N-(pyridin-2-ylmethylene)arylamine, have received attention owing to their distinctive coordination and structural properties [5][6][7]. Recent X-ray crystallographic studies or nitrates and S = coordinating solvent; Scheme 1), revealed that these complexes are promising for the generation of interesting and diverse supramolecular assemblies.…”

“…Recent X-ray crystallographic studies or nitrates and S = coordinating solvent; Scheme 1), revealed that these complexes are promising for the generation of interesting and diverse supramolecular assemblies. These assemblies are produced through the formation of coordination bonds, hydrogen bonds and other intermolecular interactions, thereby creating a large variety of supramolecular architectures [5][6][7]. Although the global topology (monomer, dimer, polymer, etc.)…”

“…Although the global topology (monomer, dimer, polymer, etc.) of the resulting compound is determined by the interplay between Hg 2+ , X -, and L, in the solid-3 state, the crystal structure is frequently controlled by weaker intermolecular interactions such as π-π and CH-π contacts [5][6][7] …”

Synthesis, structures, and spectroscopic properties of Hg(II) complexes of bidentate NN and tridentate NNO Schiff-base ligands

“…Recent X-ray crystallographic studies performed on a variety of mercury(II) compounds derived from Schiff-base ligands, viz. candidates for the generation of interesting and diverse supramolecular assemblies [10,11].…”