Chemistry of oxo-metal ions-VI 1,10-phenanthrolinium oxopentachloromolybdate(V) and its derivatives

Molybdenum(IV) dimeric complexes with N-alkylphenothiazines and their interactions with L-cysteine, L-histidine, 1,10-phenanthroline and 2,2′-bipyridyl

Abstract: The synthesis and structure elucidation of the dimeric form of molybdenum(IV) oxo-complexes with N-alkylphenothiazines as ligands have been studied. These complexes were identified by IR and electronic spectra, magnetic susceptibility, DTA, TGA, conductometric and analytical data. These results permit us to assign the formula Mo2O4(L)2(H2O)2 (where L = N-alkylphenothiazine). Some interactions of these complexes with biologically important compounds like L -cysteine and histidine and potential ligands such as 1,10-phenanthroline and 2,2′-bipyridyl have been reported.

Stéréoch1mie en chimie minérale: Complexes moléculaires de l'oxo et du dioxo-vanad1um (V) avec le coordinat fluor et des molécules organiques

Abstract: Compounds of the type {VOF3(AA)} (AA = phen, bpyO2), {VO2F(AA)} (AA = phen, bpy) and {VOF3L2} (L = pyO, picO) are the first examples of molecular derivatives of oxofluorovanadium(V) with organic ligands. They were characterised by their conductivity, infrared, visible and Debye-Scherrer spectra and magnetic susceptibility. The properties of the complexes {VOF3(AA)} and {VOF3L2} are consistent with an octahedral structure. The infrared spectra of the three compounds {VO2F(AA)} show two strong absorptions (in the 800–950 cm−1 region) which are likely to arise from vs and vas(VO2). The results of a single crystal X-ray diffraction study for one form of {VO2F(bpy)} (cis VO2 group, vanadium penta-coordinated with a weak sixth bond corresponding to dimers with bridge) seem to be valid for the two others.

Studies on the different forms of some mixed chelate complexes of dioxouranium(VI) with cupferron

Abstract: Mixed chelate complexes of identical composition of the type (NH4)2[UO2(L)2B] and (NH4)2[UO2(L)2X2] where L = anion of cupferron, B  CO″3, C2O″4 and X  F′, Cl′ have been prepared from different starting materials Both the fluoro- and chloro-complexes (NH4)2[UO2(L)2X2] have been isolated in two different forms (one orange-yellow and one yellow) by different methods Yellow forms of (NH4)2[UO2(L)2X2] undergo conversion to the corresponding orange-yellow forms under suitable conditions All these complexes have been thoroughly characterised through elemental analysis, conductance data, X-ray, IR, electronic, NMR spectra as well as thermogravimetric and differential thermal analyses Possibility of the complex (NH4)2[UO2(L)2X2] to exist in two geometrical isomeric forms has been indicated The orange red complex cis-[UO2(L)2(H2O)2] on being refluxed with acetone, changed to a yellow complex, almost insoluble in most of the common organic solvents Various physico-chemical studies indicate it to be a hydroxybridged dinuclear complex H[(UO2)2(L)4OH(H2O)2] The ν3-values (cm−1) of UO22+-entity from IR-spectra have been used to calculate the force constant, FUO in mdynes/A and the bond length RUO in A of the UO bond Using ν3of the UO22+-entity as a molecular probe, the inorganic ligands and acid residues like F′, Cl′, CO″3 and CO″4 have been arranged in a series, which is similar to the mutual displacement series of one ligand by another in the uranyl compounds

The co-ordination chemistry of molybdenum—I: Some complexes of molybdenum(V) with 2:2′-dipyridyl

Abstract: The preparations and chemical magnetic and spectroscopic properties of the following complexes of molybdenum(V) with 2:2′-dipyridyl are described: MoO 2 Cldipy (I), Mo 2 O 3 Cl 4 (dipy) 2 (II), and MoOCl 3 dipy(III). According to the magnetic moments I and II are polymerized and III is a monomer. Possible structures of the complexes are discussed.

The co-ordination chemistry of molybdenum—II(1)

Abstract: The ultraviolet, visible and infra-red spectra of the compounds Ba(MoO 2 C 2 O 4 ) 2 5H 2 O and K(MoO 2 C 2 O 4 )2·5H 2 O have been measured and their magnetic moments determined. The electrical conductance of aqueous solutions of the potassium salt has been measured over a range of concentrations. The results indicate that the complex anion is dimeric in the solid and in solution. A thermogravimetric analysis of the potassium salt has shown that two-fifths of the water is coordinated to the molybdenum. It is proposed that the complex anion should be formulated as a dimer with two oxide bridges: [Mo 2 O 4 (C 2 O 4 ) 2 (H 2 O) 2 ] 2− . The properties of the complexes are described on this basis and the structures of other oxy-complexes of molybdenum (V) are discussed.

Complexes of molybdenum (V) oxide trichloride with nitrogen and phosphorus ligands

Abstract: The reaction of molybdenum (V) oxidetrichloride with aliphatic nitriles (RCN, R = Me, Et, Pr) results in the formation of the complexes, MoOCl 3 , 2RCN. These complexes have been characterised by spectroscopic, magnetic susceptibility and conductivity studies. Further complexes MoOCl 3 L (L = 2:2′-dipyridyl and 1:10 phenanthroline) and MoOCl 3 ,2PPh 3 have been prepared by replacement of nitrile from the acetonitrile complex.