title: New diorganotin(IV) derivatives of dipeptides: synthesis and characteristic spectral studies.
abstract: Some new diorganotin(IV) derivatives of the formulae, R2SnL, where R=Me, n-Bu, Ph, and n-Oct, and L is the dianion of histidinylalanine (H2L-1) and histidinylleucine (H2L-2) have been synthesized by the reaction of R2SnCl2 and the preformed sodium salt of the respective dipeptides. The bonding and coordination behaviour in these derivatives are discussed on the basis of FT-IR, multinuclear 1H, 13C and 119Sn NMR and 119Sn Mössbauer spectroscopic studies. These investigations suggest that dipeptides in R2SnL act as dianionic tridentate coordinating through the COO(-), NH2 and N(-)peptide groups. The 119Sn Mössbauer studies, together with the NMR data, suggest a trigonal bipyramidal geometry around tin in R2SnL with the alkyl/aryl groups and Npeptide in the equatorial positions, while a carboxylic oxygen and the amino nitrogen atom occupy the axial positions.
authors.affiliation: Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee 247667, India. malanfcy@iitr.ernet.in
authors.forename: Mala
authors.initials: M
authors.lastname: Nath
authors.forename: Hitendra
authors.initials: H
authors.lastname: Singh
authors.forename: George
authors.initials: G
authors.lastname: Eng
authors.forename: Xueqing
authors.initials: X
authors.lastname: Song
mesh_terms: D000588:Amines / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D004151:Dipeptides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009947:Organotin Compounds / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D000588:Amines; D002264:Carboxylic Acids; D004151:Dipeptides; D009947:Organotin Compounds