Syntheses, characterization, and supramolecular architectures of two lead(II) complexes of 8-quinolinol

Abstract

Two Pb(II) complexes with 8-quinolinol (8-Quin), 5-chloro thiophene-2-carboxylic acid, and (5-CTPC)/5-bromo thiophene-2-carboxylic acid (5-BTPC) have been synthesized and characterized by IR, 13 C NMR, and solid state photoluminescence spectra. The structures of [Pb(8-Quin) 4 ](5-CTPC) 2 (1) and have been confirmed by X-ray crystallography. Both complexes crystallize in the triclinic crystal system with a space group P 1. In 1, Pb(II) is eight coordinate by four bidentate 8-quinolinol groups, while in 2 it is six coordinate by two bidentate 8-quinolinol groups and one bidentate 8-quinolinolate group. This leads to square antiprismatic and pentagonal pyramidal geometries around Pb(II) in 1 and 2, respectively. Two of the 5-CTPC ligands in 1 and a 5-BTPC in 2 are involved in strong O-HÁ Á ÁO hydrogen bonding in the lattice. ClÁ Á Á interactions are found in 1. The crystal structures are stabilized by weak C-HÁ Á ÁO and -stacking interactions.

Influence of the halogen substituent on the formation of halogen and hydrogen bonding in co-crystals formed from acridine and benzoic acids

“…2a, Table 2). In these heterotetramers the acridine moieties interact via π-π interactions [with 15 centroid···centroid distances d(Cg···Cg) from 3.640(1) to 3.840(1) Å and separation between the mean planes of the acridine skeleton 3.462(1) Å]. Table 2).…”

“…1g, Table 3). The neighbouring inversion-related heterodimers are linked by C-H···O hydrogen bonds [d(C9···O23) = 3.383(3) Å and <(C9-H9···O23) = 144°] 15 to form heterotetramers (Fig. 6b, Table 3).…”

“…Although crystallographic studies of proton transfer between acridine and acids (including benzoic acids) have been carried out, 12 structural investigations into the molecular complexes of acridine and ortho-and meta- 10 halobenzoic acids have not been performed. Thus, in order to explain how the ortho-and meta-halogen substituent in the phenyl ring of the benzoic acid influences the formation and competition of C-H···X hydrogen-bonds and X···O halogenbonds in the co-crystals formed from acridine and benzoic acids, 15 we synthesized and structurally characterized the following compounds: acridine • benzoic acid (1), acridine • 2fluorobenzoic acid (2), acridine • 2-chlorobenzoic acid (3), acridine • 2-bromobenzoic acid (4), acridine • 2-iodobenzoic acid (5), acridine • 3-fluorobenzoic acid (6), acridine • 3- 20 chlorobenzoic acid (7), acridine • 3-bromobenzoic acid (8) and acridine • 3-iodobenzoic acid (9) co-crystals. The number, type and strength of hydrogen bonds, halogen bonds, and melting points of co-crystals 1-9 were compared.…”

“…In all cases, the lattice parameters were obtained by least-squares fit to the optimized setting angles of the reflections collected by means of CrysAlis CCD. 13a Data were reduced using CrysAlis RED software 13a and applying multi-scan absorption corrections (empirical absorption correction using spherical 15 harmonics, implemented in the SCALE3 ABSPACK scaling algorithm). The structural resolution procedure was carried out using the SHELX package.…”

Synthesis, crystal structures and supramolecular architectures of square pyramidal Cu(II) complexes containing aromatic chelating N,N’-donor ligands

“…5-TPC (5-TPC = 5-chloro-2-thiophene carboxylate) not only shows versatile coordination modes but also exhibit non covalent interactions like Cl…π and C-H…Cl [43][44][45][46][47][48].…”