Comprehensive Chemical Characterization of Complexes Involving Lead-Amino Acid Interactions

Abstract

Complexes of lead with L-phenylalanine, L-isoleucine, L-valine, or L-arginine have been isolated from reaction mixtures containing lead nitrate and the respective amino acid in acidic aqueous solution. The compounds have been comprehensively characterized using X-ray crystallography, solid state NMR spectroscopy and solution state NMR spectroscopy, IR and Raman spectroscopies, and electrospray ionization mass-spectrometry. The solid state structures of lead-phenylalanine, lead-valine, and lead-valine-isoleucine complexes show a lead center coordinated by two amino acid ligands, while the lead-arginine complex is a cluster involving two lead centers and three arginine molecules. The structural, spectroscopic, and spectrometric characterization of the complexes provides a basis to establish a fundamental understanding of heavy metal-amino acid interactions.

Spectroscopic, structural, and thermodynamic aspects of the stereochemically active lone pair on lead(II): Structure of the lead(II) dota complex

“…Even so, eight of the structures show evidence of being hemidirected in terms of criteria 1-3 above. For example, the structures of a tetranitrato Pb(II) complex [21] (CSD code: RARZUG) and of a bis-phenylalanine complex [22] of Pb(II) (CSD code: QIXHUB01) appear to be hemidirected, in spite of having coordination spheres comprised only of O donors…”

Reversible solid–gas and solid–solid transformation of lead(II)–phenylalanine coordination polymers

“…Lead(II) contains the 6s 2 lone pair, which can cause distortion in coordination sphere and frequently discussed in considering the "stereo-chemical activity" of valence shell electron lone pairs [32][33][34][35][36][37][38]. Structure of compounds 1 and 2 has been reported previously [41], but single crystals of compound 1 were prepared in a single crystal to single crystal transformation, we placed crystals of 2 upon exposure to diluted HNO 3 fumes in presence of water for 5 hours. Reversible crystal-to-crystal conversion from compound 1 to 2 was confirmed by powder X-ray diffraction patterns.…”

Synthesis of the Bifunctional Ligand N,Nʹ-[1,4- Phenylenebis(iminocarbonyl)]di(L-phenylalanine) and Crystal Structure of Its Supramolecular Coordination Polymer with Lead(II)

“…plex PbL·H 2 O·DMF, 1a, was prepared analogous to a described procedure [40] by isothermal evaporation of a solution of 1 and Pb(II) nitrate in dimethylformamide (DMF) without the addition of base for neutralization of nitric acid formed during the complexation reaction. Crystals of 1a of only moderate quality, however suitable for single crystal X-ray diffraction studies, were obtained by slow solvent evaporation.…”