New Au (III), Pt (II) and Pd (II) complexes with pentapeptide glycyl-glycyl-(L)-methyonyl-glycyl-glycine and their interaction with calf thymus DNA.

The three new Au (III), Pt (II) and Pd (II) complexes with pentapeptide glycyl-glycyl-(L)-methyonyl-glycyl-glycine have been synthesized, isolated, and spectroscopically and structurally elucidated in solution and in the solid-state. Solid-state linear-dichroic infrared (IR-LD) spectroscopy of oriented colloids in a nematic liquid crystal host, (1)H- and (13)C-NMR, TGA and DSC, UV-VIS spectroscopy, EPR, ESI- and FAB- mass spectrometry and HPLC tandem mass spectrometry (HPLC-MS/MS) have been used. Quantum chemical calculations and molecular modelling were carried out in order to determine the structures and spectroscopic properties of the ligand, the newly synthesised metal complexes and their interactions with calf thymus DNA. The pentapeptide coordinates in a tetradentate manner with the metal ions via an S-atom on the methyonyl-side chain, two N-amide nitrogens, (after a deprotonation of gly(1) and gly(2) residues) and the primary NH(2) nitrogen of N(termini). The MN(3)S chromophores are distorted to near square planar geometry. Their interaction with calf thymus DNA shows the competitive N7 (G) coordination position, where the pentapeptide residues is coordinated with the metal centers in a tridentate manner through the S-atom and both N-amide centers. This interaction leads to a transfer from a distorted square planar geometry (D(4h) symmetry) to a pseudo tetrahedral (T(d) symmetry) of the metal ions with the obtained dihedral angle values of the MN(3)N7(G) chromophors within 114.67 degrees to 110.92 degrees . The isolated Au (III) complex is stable for about 1.5 months, while the stability of the Au (III) complex/DNA adduct is decreased to 33 days.

Synthesis, spectroscopic and structural elucidation of 1-butyl-4-[2-(3,5-dimethoxy-4-hydroxyphenyl)ethenyl)]pyridinium chloride tetrahydrate.

The novel chloride salt of 1-butyl-4-[2-(4-hydroxyphenyl)ethenyl)]pyridine (1), has been synthesized as the tetrahydrate and its structure and properties elucidated in detail spectroscopically, thermally and structurally, using single crystal X-ray diffraction, linear-polarized solid-state IR-spectroscopy, UV-spectroscopy and mass spectrometry. Quantum chemical calculations were performed with a view to supporting and explaining the experimental structural and spectroscopic data. The compound (1) crystallizes in triclinic P1 space group and its unit cell contains two independent 1-butyl-4-[2-(3,5-dimethoxy4-hydroxyphenyl)ethenyl)]pyridinium] cations, differing with respect to the butyl chain torsion angle for which values of 80.0(9) degrees and 173.6(3) degrees are observed. The cations and anions are joined into infinite layers, formed by two different dimers and including solvent molecules. Hydrogen bonds OH...OH(2) (2.814 A), HOH...O(CH(3)) (2.960 A), OH...Cl (2.967 A), HOH...Cl(-) (3.034, 3.188, 3.161 and 3.062 A) and HOH...OH(2) (2.772 A) are observed. For first time in the literature, we are reporting the crystal structure of the dye with the syring-fragment in the molecule. The spectroscopic properties of the novel compound are compared and with those of the corresponding quinoide form (2). Both the forms (1) and (2) are characterized by 21 and 140 nm solvatochromic effects depending of the type of the solvent. The UV-spectroscopic data in solution confirm the formation of classical H-aggregates in polar protic solvent mixture.

1,10-Phenanthrolinium hydrogensquarate monohydrate--a non-centrosymmetric structure from two non-chiral agents.

The novel hydrogensquarate salt of 1,10-phenanthroline has been synthesized, isolated and structurally elucidated by single crystal X-ray diffraction. 1,10-Phenanthrolinium hydrogensquarate monohydrate (1) crystallizes in the non-centrosymmetric P2(1) space group. Its hydrogensquarate anions form a stable dimer by means of ((Sq))OHc...O=C((Sq)) hydrogen bonds with lengths of 2.509, 2.526, 2.510, and 2.524A. The solvent water molecule interacts with the anion dimers by means of strong and moderate hydrogen bonds HOHc...O=C((Sq)) with bond lengths of 2.782 and 2.845A, respectively. The 1,10-phenanthrolinium cation participates in NHc...OH(2) interactions with the water molecule (bond lengths of 2.810, 2.758, 2.779 and 2.760A). Surprisingly, compound contains four independent molecules in the unit cell. Optical properties were elucidated by means of linear-polarized solid-state IR-spectroscopy and UV-spectroscopy. In addition TGA, DSC, DTA data, positive and negative ESI mass spectra as well as (1)H- and (13)C NMR spectra are presented. Quantum chemical methods were used to calculate the electronic structure, vibrational data and electronic spectra as well as non-linear optical properties of neutral 1,10-phenanthroline and its protonated cation. Second harmonic generation measurements of the novel compound demonstrate that the compound possesses effective d coefficients of 1.9+/-0.5 pm V(-1), value that is about three times higher that of the low temperature form of potassium dideuterophosphate.

Hydrogensquarates of 3-nicotinoyl and 3-isonicotinoyl coumarin--crystal structures and spectroscopic elucidation.

Two novel hydrogensquarates of 3-nicotinoyl (1) and 3-isonicotinoyl (2) coumarin have been synthesized and their structures and properties elucidated spectroscopically and structurally, using single crystal X-ray diffraction, linear-polarized solid-state IR-spectroscopy, UV-spectroscopy and negative ESI MS. Quantum chemical calculations were used to obtain the electronic structure, vibrational data and electronic spectra. The IR-spectroscopic elucidation is carried out by a comparison with the characteristics of corresponding neutral 3-nicotinoyl and 3-isonicotinoyl coumarins.

Self-assembly of hydrogensquarates: crystal structures and properties.

The self-assembly of the hydrogensquarates is elucidated by means of linear-polarized infrared (IR-LD) spectroscopy of oriented colloids in nematic host and the so-called reducing-difference procedure for polarized IR-LD spectra interpretation. The scopes and limitation are discussed on five novel derivatives of squaric acid and its anions, that is, 2-chloro-3-aminopyridinium hydrogensquarate (1), bis (1,2,3,4-tetrahydroquinolinium) squarate (2), bis hydrogensquarate dihydrate salt of 4-(aminomethyl)pyridine (3), N-(2-ammoniumethyl)-piperazinium monohydrate hydrogensquarate squarate (4), and 3-nitropyridinium hydrogensquarate monohydrate (5), respectively. The structures of these compounds 1-5 were solved by means of single-crystal X-ray diffraction, and the crystallographic data were used for the experimental elucidation of the corresponding IR spectra of crystals with respect to studying Fermi-resonance (FR), Davydov splitting (DS), and Fermi-Davydov (FD) as well as Evans' hole effects. The various motifs for self-assembly of squaric acid and its anions in the organic crystals are discussed together with their IR-spectroscopic properties.

N-methylcodeinium iodide--crystal structure and spectroscopic elucidation.

The correlation between the structure and the spectroscopic properties of N-methylcodeinium iodide (1) has been studied, using the methods of single crystal X-ray diffraction, IR-LD spectroscopy of oriented samples as a suspension in nematic liquid crystals, UV-vis spectroscopy and 1H and 13C NMR spectroscopy. HPLC tandem mass spectrometry (HPLC ESI MS/MS) and thermal methods were also employed. Quantum chemical calculations have been performed with a view to obtaining the electronic structure and vibrational properties of the title compound. Compound (1) crystallizes in the space group P2(1)2(1)2(1) and its cations and anions are joined by moderate intermolecular OH...I- interaction of length 3.442A. The codeine molecule exhibits the classical T-shape for opiates. A dihedral angle value of 86.4(5) degrees between the A/B/C and D/E planes is obtained. Rings A and B are effectively coplanar with an interplanar angle of 3.6(3) degrees.

Sol-gel materials doped with 3-(3-(4-(dimethylamino)phenyl)propenoyl)-2H-chromen-2-one: spectroscopic and structural elucidation.

Conventional and linear-polarized IR-spectroscopic tools based on reducing-difference procedures for non-polarized and polarized IR-spectra interpretation as well as orientation technique of solids (colloidal suspension in nematic liquid crystal) and UV/vis spectroscopy are applied for investigation of new sol-gel materials with potential optical application of doped organic dye 3-(3-(4-(dimethylamino)phenyl)propenoyl)-2H-chromen-2-one (K2) and Sm3+ ions. The results show that during aging of the monoliths Sm3+ forms an unstable complex with K2, [Sm(K2)(2)(H2O2](NO3)(3), which transforms to [Sm(H2O)(6)](3+) one, typical for gel-Sm3+ system. Quantum chemical ab initio and DFT calculations are reported with a view to support experimental IR-characteristic bands of the system studied.

Spectroscopic, theoretical and structural characterization of hydrogensquarates of L-threonyl-L-serine and L-serine.

Hydrogensquarates of dipeptide L-threonyl-L-serine (H-Thr-Ser-OH) and L: -serine (HSq x Ser) have been synthesized, isolated and spectroscopic characterized by solid-state linear-polarized IR-spectroscopy, 1H- and 13C-NMR, ESI-MS and HPLC with tandem masspectrometry (MS-MS) methods. The structures of the salts and neutral dipeptide have been predicted theoretically by ab initio calculations. In the case of H-Thr-Ser-OH the theoretical data are supported by IR-LD ones. The hydrogensquarates consist in positive charged dipeptide or amino acid moiety and negative hydrogensquarate anion (HSq) stabilizing by strong intermolecular hydrogen bonds. The data about the L-serine hydrogensquarate are compared with known crystallographic data thus indicating a good correlation between the theoretical predicted structures and experimentally obtained by single crystal X-ray diffraction.