Diorgano-Gallium and -Indium Complexes Derived from Benzoazole Ligands: Synthesis, Characterization, Photoluminescence, and Computational Studies

Abstract

The reactions of triorgano-gallium and -indium etherate with benzoazole ligands 2-(2′-hydroxyphenyl)benzoxazole (Hhbo) (1a), 2-(2′-hydroxyphenyl)benzothiazole (Hhbt) (1b), and 2-(2′-hydroxyphenyl)benzimidazole (Hhbi) (1c) in benzene yielded complexes of the type [R2ML] n with n = 1 for gallium and 2 for indium (where R = Me, Et; M = Ga, In; L = hbo, hbt, and hbi) in nearly quantitative yields. These complexes have been characterized by elemental analysis, IR, UV–vis, and NMR (1H and 13C{1H}) spectroscopy. Photoluminescence studies of these complexes showed that the quantum yield is always higher than that of the corresponding ligands due to reduced intermolecular interactions in complexes as compared to free ligands. The molecular structures of [Me2Ga(hbo)] (2a) and [Me2In(μ-hbt)]2 (3b) were established by X-ray crystallography. The analyses revealed that the gallium complex exists as a four-coordinated monomer, whereas the indium complex forms a dimer comprising five-coordinated indium atoms. Density functional calculations have been carried out for computing the structural and energetic parameters of the complexes, which indicate that the formation of the monomer is favorable with the Ga3+ ion, whereas the dimeric structure is preferred with the In3+ ion.

A new azo‐Schiff base: Synthesis, characterization, biological activity and theoretical studies of its complexes

“…[20] The investigated isolates of bacteria were seeded in tubes with nutrient broth (NB). The seeded NB (1 ml) was homogenized in the tubes with 9 ml of melted (45°C) nutrient agar (NA).…”

“…This is due to role of copper in preventing gastrointestinal damage by acidic anti-inflammatory agents. [19][20][21][22][23][24] There are limited studies of metal complexes of the Schiff base: 1H-indole-3-ethylene salicyldamine and its derivatives [25] and there are no data available regarding biological activities of these compounds. In this work, we have been interested in the design and synthesis azo-Schiff base prepared by reaction of m-hydroxy benzoic acid with (Schiff base B) of 3-[2-(1H-indol-3-yl)-ethylimino]-1.5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylamine.…”

catena-Poly[bis[dimethyl(pyridine-κN)indium(III)]-μ4-benzene-1,3-diolato-bis[dimethylindium(III)]-μ4-benzene-1,3-diolato]

“…For background to dimethylindium aryloxides, see: Briand et al (2010); Beachley et al (2003); Hausslein et al (1999); Blake et al (2011); Bradley et al (1988); Trentler et al (1997). For dimethylindium compounds with bidentate imine-alkoxide ligands, see: Hu et al (1999); Wu et al (1999); Pal et al (2013); Lewinski et al (2003); Ghoshal et al (2007). Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008b); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b (Briand et al, 2010;Beachley et al, 2003;Hausslein et al, 1999;Blake et al, 2011;Bradley et al, 1988;Trentler et al, 1997).…”

Fluorescent Dendritic Organogels Based on 2‐(2′‐Hydroxyphenyl)benzoxazole: Emission Enhancement and Multiple Stimuli‐Responsive Properties

“…On the basis of the above experimental evidence and a previous study,20 the reason for the selective response to the Zn 2+ ion among other metal cations was probably due to the higher reactivity of the HPB unit with Zn 2+ ions relative to Ca 2+ , Cu 2+ , Cd 2+ , and Pb 2+ ions in the gel; furthermore, the coordination behavior of HPB with Zn 2+ ions destroyed the π–π interactions between the HPB units, thus leading to the gel‐to‐sol conversion 15b…”