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Abstract: Stereo-structural analysis and IR-bands assignment of the aromatic dipeptides l-tryrosyl-l-phenylalanine (Tyr-Phe), l-phenylalanyl-l-tyrosine (Phe-Tyr) and their hydrochloride salts have been carried out by means of IR-LD spectroscopy of oriented as nematic liquid crystal suspension solid samples. The experimental data are compared with known crystallographic ones and theoretical predicted geometries at RHF/ and UHF/6-31G**. [Copyright &y& Elsevier]

A solid state, linear dichroic IR analysis of a mononuclear Au(III) complex of the tripeptide glycylmethioninylglycine (GlyMetGly) oriented in a nematic liquid crystal has been carried out. Structural results are compared with 1 H and 13 C NMR data. The ligand coordinates to Au(III) as a tridentate in [Au(C 9 H 17 N 3 O 4 S)Cl]Cl 2 , binding through S, and the N- and O-atoms of neighbouring CONH– and COO - groups. The fourth position is occupied by a terminal Cl - ligand. [ABSTRACT FROM AUTHOR]

Abstract: IR-LD spectroscopic data obtained by the orientated solid samples as a suspension in a nematic liquid crystal of 1-hydroxy-1,2,3-benzotriazole, 2-methyl-, 2-acetonitrilebenzimidazoles and their protonated salts have been presented. The stereo-structures have been predicted and compared with theoretical ones. The IR-characteristic bands assignments of all molecule systems have been achieved. [Copyright &y& Elsevier]

Abstract: Stereo structural characterization of methionine-containing tripeptides glycine-glycine-methionine (Gly-Gly-Met) and methionine-glycine-glycine (Met-Gly-Gly) is carried out by means of linear-dichroic infrared spectral analysis of oriented as nematic liquid crystal suspension solid samples. Thus obtained data are compared with theoretical ones received by ab initio calculations (Hartree-Fock level of theory and 6-31G** basis set). An IR-spectral characterization of both tripeptides is included as well. [Copyright &y& Elsevier]

Abstract: IR-spectroscopic and stereo-structural analysis of aromatic l-Tryptophan containing dipeptides l-Tryptophan–l-Tryptophan (Trp–Trp), l-Tyrosine–l-Tryptophan (Tyr–Trp) and cyclo(Trp–Trp) have been carried out by means of solid-state linear-dichroic infrared (IR-LD) spectroscopy of oriented as suspension in nematic liquid crystal solids. The experimental data have been compared with analogous ones of the simple amino acids l-Tyrosnine (l-Tyr) and l-Tryptophan (l-Trp). In cyclo(Trp–Trp), the IR-spectral changes towards the IR-ones of acyclic Trp–Trp have been determined. A theoretical analysis of Tyr–Trp at Hartree–Fock level of theory and 6-31G** basis set is also applied. [Copyright &y& Elsevier]

A new mononuclear Cu(II) complex of 4-aminopyridine (4AP), [Cu(4AP)4]Cl2·2CH3OH ( 1 ), was obtained and structurally characterized by single-crystal X-ray diffraction methods. The complex is square-planar involving four monodentate 4AP molecules coordinated through the Npy atoms. A solid-state linear-dichroic spectroscopic analysis (IR-LD) as a suspension in a nematic liquid crystal was carried out over the 4000–400?cm -1 range and determined stereochemical parameters compared crystallographic data. Detailed IR characteristics are reported. [ABSTRACT FROM AUTHOR]