Showing papers in "Inorganic Chemistry in 1983"

Photochemistry of MLCT excited states. Effect of nonchromophoric ligand variations on photophysical properties in the series cis-Ru(bpy)2L22+

Abstract: Proprietes photophysiques des etats excites (transfert de charge metal a coordinat) emissifs, a vie courte, d'une serie de complexes cis-Ru(bpy) 2 L 2+ , (L= pyridine, pyridazine, 1/2, phenanthroline, 1/2 bipyridine, N'-methylimidazole, (amine-2 ethyl)-2 pyridine)

Redox Properties of Ruthenium(II) Tris Chelate Complexes Containing the Ligands 2,2′-Bipyrazine, 2,2′-Bipyridine, and 2,2/-Bipyrimidine

Abstract: The synthesis of the title chelate complexes is described The redox potentials, photophysical and photochemical properties of the excited states including lifetimes, emission quantum yields, and protonation of the remote nitrogens on the ligands are addressed 9 figures, 3 tables

Temperature dependence of luminescence from Cu(NN)2+ systems in fluid solution. Evidence for the participation of two excited states

Abstract: Proprietes photophysiques d'une serie de complexes Cu(NN) 2 + ou NN est un coordinat heteroatomique tel que la phenanthroline et la bipyridine. Interpretation. On conclut que l'etat emetteur le plus bas a une vitesse radiative caracteristique d'un etat triplet

Early stages of the hydrolysis of chromium(III) in aqueous solution. 1. Characterization of a tetrameric species

Abstract: Formation d'especes contenant Cr 3+ (aq), Cr 2 (OH) 4 4+ (aq), Cr 3 (OH) 4 5+ (aq) et Cr 4 (OH) 6 6+ (aq). Valeurs des pKa. L'ordre de stabilite est dimere >tetramere

Chemistry of ruthenium. 12. Reactions of bidentate ligands with diaquabis[2-(arylazo)pyridine]ruthenium(II) cation. Stereoretentive synthesis of tris chelates and their characterization: metal oxidation, ligand reduction, and spectroelectrochemical correlation

Abstract: Formation de chelates tris RuBL 2 x+ (x=1 ou 2) avec B=coordinat bidente et L=pap ou tap. Etude electrochimique dans l'acetonitrile

Synthetic and mechanistic investigations of the reductive electrochemical polymerization of vinyl-containing complexes of iron(II), ruthenium(II), and osmium(II)

Abstract: Polymerisation electrochimique reductrice de 28 complexes contenant du vinyl. La 1ere etape de la polymerisation met en jeu la formation d'un anion radicalaire qui semble etre l'initiateur

CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES OF (μ-AZIDO)-(μ-HYDROXO)BIS((N,N,N′N′-TETRAMETHYLETHYLENEDIAMINE)COPPER(II)) PERCHLORATE, A COPPER(II) DINUCLEAR COMPLEX WITH A LARGE FERROMAGNETIC INTERACTION

Abstract: Cristallisation dans le groupe P4 2 /mnm avec a=9,50 et c=13,94 A, Z=2. Coordinence 4 des atomes de cuivre selon une geometrie plane. Etude des proprietes magnetiques de 2 a 300 K

Synthesis and characterization of hexakis(alkyl isocyanide) and hexakis(aryl isocyanide) complexes of technetium(I)

Abstract: The complexes, hexakis(alkyl isocyanide) technetium(I) hexafluorophosphate (Tc(CNR)/sub 6/)PF/sub 6/ (where R = tert-butyl, methyl, cyclohexyl, and phenyl), have been prepared by reduction of the pertechnetate ion with aqueous sodium dithionite (Na/sub 2/S/sub 2/O/sub 4/) in the presence of the isocyanide ligands. These complexes have been characterized by elemental analysis, optical, ir, and /sup 1/H NMR spectroscopy, conductance, cyclic voltammetry, and field desorption mass spectrometry.

High-field 11B NMR of alkali borates. Aqueous polyborate equilibria

Abstract: Spectres RMN de 11 B a 127 et 160 MHz de solutions aqueuses de KB 5 O 8 •4H 2 O, K 2 B 5 O 8 (OH)•2H 2 O, K 2 B 4 O 7 •4H 2 O et NaB 5 O 8 •5H 2 O. Separation des signaux et discussion des especes formees en fonction de la concentration

Solvent and substituent effects on the lowest energy excited states of M(CO)4 (diimine) (M=Cr, Mo, W) complexes

Abstract: Etude des effets solvant et substituant sur les plus basses energies des etats excites des complexes M(CO 4 ) L (avec M=Cr, Mo ou W, et L=bipyridine, phenanthroline ou derives), a l'aide de spectres UV-visible

Hydrolysis of cations. Formation constants and standard free energies of formation of hydroxy complexes

Abstract: The formation constants and standard free energies of formation of both mononuclear and polynuclear hydroxy complexes of metal ions throughout the periodic table have been examined. Some empirical correlations are presented that make it possible to predict rough values for these constants. For mononuclear complexes the equation is ..delta..G/sub f//sup 0/)M(OH)/sub y/) = ..delta..G/sub f//sup 0/)M) + By +Cy/sup 2/ + D/y, where B, C, and D are empirical parameterrs and y is the number of coordinated hydroxide ions. These parameters are subject to constraints that limit acceptable values. For example, B, C, and electronegativity are interrelated. This equation can be rearranged to define a new function, U, that is linearly related to y. This allows the interpolation of unmeasured free energies and hence formation constants. For mononuclear complexes predicted values of log K/sub 1//sub y/ have an uncertainty of about +/-0.5. For polynuclear hydroxy complexes a relation previously proposed by Baes and Mesmer has been slightly modified and used to predict unknown formation constants with an uncertainty of log K/sub xy/ of about +/-0.5y. Mercury(II) and silver(I), which form especially stable ''linear'' complexes, do not follow the above correlations because of the structure change that occurs upon going frommore » the M(OH)/sub 2/ to the M(OH)/sub 3/ species. The tetrahedrally coordinated Be/sup 2 +/(aq) ion is more acidic than expected when compared with octahedrally coordinated aquo ions of divalent metals. Each hydrogen must carry a somewhat greater portion of the positive charge than it would in an octahedral complex,Rand this makes the removal of a proton easier. Aqueous Sn/sup 2 +/ is also unusually acidic, and it is suggested that it too has fewer water molecules in the primary cordination sphere than one would expect.« less

Trivacant heteropolytungstate derivatives. 2. Synthesis, characterization, and tungsten-183 NMR of P4W30M4(H2O)2O11216- (M = Co, Cu, Zn)

Abstract: Die Titelverbindungen werden ausgehend von α-Na"P,W"O56 - xHzO (fruher als α-Na"P,W",0,9 formuliert) und Znsrz, Co(NO3), - 6 H2O bzw. CuCl2 - 2 H2O aus 1 M NaCl-Losung nach masigem Erhitzen in 77-88proz. Ausb. ausgefallt.

Redox potentials of bis(1,4,7-triazacyclononane complexes of some first transition series metals(II,III). Preparation of bis(1,4,7-triazacyclononane)nickel(III) perchlorate

Abstract: Etude, par voltammetrie cyclique, du comportement des complexes en solution aqueuse, avec determination dans ce but du potentiel redox des couples [([9] ane N 3 ) 2 M] 3+/2+ avec M=Mn, Fe, Co, Ni

On the nature of the sulfur chromophores in ultramarine blue, green, violet, and pink and of the selenium chromophore in ultramarine selenium: characterization of radical anions by electronic and resonance Raman spectroscopy and the determination of their excited-state geometries

Abstract: Les resultats montrent que le reseau outremer est une matrice extremement utile pour etudier des radicaux mineraux instables

Electron-transfer barriers and metal-ligand bonding as a function of metal oxidation state. 2. Crystal and molecular structures of Tris(2,2'-bipyridine)cobalt(II) dichloride-2-water-ethanol and Tris(2,2'-bipyridine) cobalt(I) chloride-water

Abstract: The structures of tris(2,2'-bipyridine)cobalt(II) dichloride-2-water-ethanol, (Co(C/sub 10/H/sub 8/N/sub 2/)/sub 3/)Cl/sub 2/2H/sub 2/OC/sub 2/H/sub 5/OH (1), and tris(2,2'-bipyridine)cobalt(I) chloride-water, Co(C/sub 10/H/sub 8/N/sub 2/)/sub 3/ClH/sub 2/O (2), have been determined in order to compare bonding of the high-spin d/sup 7/ and high-spin d/sup 8/ configurations and to better understand the electron-transfer reactivity of this couple. Compound 1 crystallizes in the hexagonal crystal system, space group P6/sub 5/22, with a = 13.403 (2) A, c = 62.566 (10) A, and Z = 12. The structure refined to a final R value of 0.056. The coordination spere consists of the six nitrogen atoms of the three bipyridine ligands in an octahedral arrangement about the cobalt with an average Co-N bond length of 2.128 (8) A. One of the chloride ions is surrounded by twelve C-H Cl hydrogen bonds involving the H3 and H3' protons on the bipyridine ligands. Compound 2 crystallizes in the orthorhombic crystal system, space group Pna2/sub 1/, with a = 9.713 (6) A, b = 21.666 (10) A, c = 13.062 (7) A, and Z = 4. The structure refined to a final R value of 0.084. The geometry of the coordination sphere of 2 is almost identical with that ofmore » 1, with an average Co-N bond length of 2.11 (2) A. Hydrogen bonding between the H3 and H3' protons on the bipyridine ligand and the chloride ion is also observed in 2. The C-H Cl hydrogen bonding observed in these complexes and the bond length changes in 1, 2, and tris(2,2'-bipyridine)cobalt(III) are discussed and related to electron-transfer barriers for the series. 48 references, 1 figure, 9 tables.« less

Copper(II) complexes with tetradentate bis(pyridyl)-dithioether and bis(pyridyl)-diamine ligands. Effect of thio ether donors on the electronic absorption spectra, redox behavior, and EPR parameters of copper(II) complexes

Abstract: Etude par spectrometrie UV-visible et RPE, et par electrochimie, d'une serie de complexes du cuivre avec des coordinats tetradentes bis(pyridyl)-dithioether, ou bis(pyridyl)-diamine, pour determiner les effets des donneurs thioether sur les proprietes spectrales et redox de ces complexes