A Study of Possible Morphine Complexes Formed with Calcium and Magnesium

Morphine fluorescence spectra were obtained for morphine sulfate in distilled water, in KRP solution, and in KRP solutions with various concentrations of Ca⁺⁺ and Mg⁺⁺. No evidence of fluorescence shifting indicative of complex formation was observed. Similar solutions were used in a potentiometric study, and no evidence for complex formation was observed.     

Synthesis, X-ray studies, spectroscopic characterization and DFT calculations of p-tolylimido rhenium(V) complexes bearing an imidazole-based ligand

Novel p-tolylimido rhenium(V) complexes [Re(p-NC₆H₄CH₃)X₂(hpb)(PPh₃)] and [Re(p-NC₆H₄CH₃)(hpb)₂(PPh₃)]X (X = Cl, Br) have been obtained in the reactions of [Re(p-NC₆H₄CH₃)X₃(PPh₃)₂] with 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpb). The compounds were identified by elemental analysis IR, UV-Vis spectroscopy and X-ray crystallography. The electronic structures of the complex [Re(p-NC₆H₄CH₃)Cl₂(hpb)(PPh₃)] and the cation [Re(p-NC₆H₄CH₃)(hpb)₂(PPh₃)]⁺ have been calculated with the density functional theory (DFT) method. Additional information about binding in the [Re(p-NC₆H₄CH₃)Cl₂(hpb)(PPh₃)] and [Re(p-NC₆H₄CH₃)(hpb)₂(PPh₃)]⁺ has been obtained by NBO analysis. The electronic spectra of [Re(p-NC₆H₄CH₃)Cl₂(hpb)(PPh₃)] and [Re(p-NC₆H₄CH₃)(hpb)₂(PPh₃)]Cl were investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ.     

IR Studies of Iron Complexes with Pyridoxal Isonicotinoyl Hydrazone and Three Other Similar Chelating Agents

Infrared studies of pyridoxal isonicotinoyl hydrazone and of three similar chelating agents in solid state brings out, after complexation with iron (III), the deprotonation of phenol for all the compounds; for those which possess the pyridoxal group, a deprotonation of hydrazine leads to a transformation of the linkage between the rings and for the others, the drastic shift of the carbonyl band proves its engagement in the association with iron.     

Group 6 metal carbonyl complexes of 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)]-one

The spiro-compound 3′H-spiro[indole-3,2′-[1,3]benzothiazole-2(1H)-one (IBTH₂) was synthesized and its structure was determined using spectroscopic techniques (FTIR, ¹H NMR and mass) and X-ray crystallography. This ligand possesses different centers for coordination. Reactions of [M(CO)₆], M = Cr, Mo or W with IBTH₂ in THF under reduced pressure were studied. For chromium a complex with molecular formula [Cr(ITP)₂] was isolated; where ITP is the opened form of the ligand which occurred through C_spiro–S bond, while [Mo(CO)₅(IBTH₂)] and [W(CO)₅(IBTH₂)] were isolated from the reaction of IBTH₂ with molybdenum and tungsten carbonyls, respectively. All complexes were characterized by elemental analysis, IR, mass and ¹H NMR spectroscopy. The biological activity of the ligand and its complexes were studied and compared with the parent compound isatin.     

Hydrogen adsorption on Mo1−xRex(110) (x=0–0.25) surfaces

The effects of adsorbed H on the Mo_1−xRe_x(110), x=0, 0.05, 0.15, and 0.25, surfaces have been investigated using low-energy electron diffraction (LEED) and high-resolution electron energy loss spectroscopy (HREELS). For the x=0.15 alloy only, a c(2×2) LEED pattern is observed at a coverage Θ0.25 ML. A (2×2) pattern is observed for H coverages around Θ0.5 ML from surfaces with x=0, 0.05, and 0.15. Both c(2×2) and (2×2) patterns are attributed to reconstruction of the substrate. At higher coverages, a (1×1) pattern is observed. For the alloy surface with x=0.25, only a (1×1) pattern is obtained for all H coverages. Two H vibrations are observed in HREELS spectra for all Re concentrations, which shift to higher energies at intermediate coverages. Both peaks exhibit an isotopic shift, confirming their assignment to hydrogen. For Re concentrations of x=0.15 and higher, a third HREELS peak appears at 50 meV as H (D) coverage approaches saturation. This peak does not shift in energy with isotopic substitution, yet cannot be explained by contamination. The intrinsic width of the loss peaks depends on the Re concentration in the surface region and becomes broader with increasing x. This broadening can be attributed to surface inhomogeneity, but may also reflect increased delocalization of the adsorbed hydrogen atom.     

Study of photoconductivity and photoluminescence of organic/porous silicon complexes

In this paper, time-varying photoconductivity (PC) and the photoluminescence (PL) of different complexes were studied. Due to thick polymer layer hindering light penetrating into porous silicon (PS) layer, intrinsic PS luminescence in polymer/PS system disappeared. The physical origin of PL may be related to the recombination mechanisms involving surface defect states such as silicon oxide, siloxene. Due to carrier transfer controlled by different energy barrier, different devices prepared from different doped Si wafer showed opposite current-voltage characteristic.     

Synthesis,characterization and spectroscopic studies of pyrazinamide metal complexes

The present paper deals with the synthesis and characterization of Schiff base complexes of pyrazinamide an antitubercular drug. Metals selected for complexation are copper, silver, gold, zinc, mercury, iron and cobalt. The complexes have been suitably synthesized and isolated in pure powdered form. Analytical data agrees with the compositions M(L), M′(L)₂ and M″(L)₂·2H₂O, respectively where M = Ag, M′ = Cu, Au, Zn and Hg and M″ = Fe and Co, ligand metal ratios were also confirmed by monovariation method and Job’s method of continuous variation. Molar conductance values suggest the non ionic nature of the complexes. The tentative structure assigned to the complexes on the basis of stoichiometry and analytical data were further supported by spectral studies viz; IR, NMR, magnetic susceptibility and electronic spectra. A preliminary attempt has also been made to compare the potencies of metal complexes with parent drug. The Cu and Ag complexes are giving encouraging results. Particle size studies further suggest that the drug molecule undergoes reduction in size on complexation.