In the title compound, [Mo(C(34)H(54)N(2)O(2))O(2)]·CHCl(3), the molybdenum(VI) ion exhibits a cis-dioxide distorted octa-hedral geometry. Two anionic phenolate O-atom donors and two neutral N-atom donors of the ligand are trans and cis, respectively. The Mo=O bond lengths and the O=Mo=O bond angle are typical for six-coordinated dioxomolyb-denum(VI) complexes. The Mo-N bond lengths are longer ...

In earlier publication1, the authors have reported data on the polarographic behaviour of molybdenum(VI) in three different organic acid media viz. mandelic acid, succinic acid and formic acid — sodium formate and concluded that in medium comprised of 0.1 M mandelic acid, 0.005% thymol and 0.1% camphor Mo(VI) produces a well defined irreversible diffusion controlled doublet wave, the total heig...

In the title compound, [Mo(4)O(12)(C(8)H(7)N(3))(4)], the Mo(VI) ion has a distorted octa-hedral coordination completed by two terminal O atoms, two μ-oxide atoms and two N atoms from one 3-(2-pyrid-yl)-1H-pyrazole ligand. It is noteworthy that in the tetranuclear unit ( symmetry), any three Mo(VI) atoms define a plane, and the fourth lies 1.8 (1) Å out of that plane. The degree of linearity of...

In the different compartments of the environmental chromium occurs mainly in the oxidation states (III) and (VI). Although Cr(III) is an essential trace element for humans, Cr(VI) is highly cancerogenic and mutagenic. It is, therefore, necessary for risk assessment not only to determine total chromium, but also to determine chromium species, especially Cr(VI). Hexavalent chromium can be determi...

A cloud-point preconcentration process using micelle of the non-ionic surfactant Triton X-114 to extract Mo(VI) from aqueous solutions was investigated. The method is based on the color reaction of molybdenum with 5-(2-benzothiazolyl-azo)8-hydroxy-quinoline (BTAHQ) in the presence of potassium bromide at pH 1.75 glycine/HCl buffer media and micelle-mediated extraction of complex. The optimal ex...

The catalytic mechanism of nitrate reduction by periplasmic nitrate reductases has been investigated using theoretical and computational means. We have found that the nitrate molecule binds to the active site with the Mo ion in the +6 oxidation state. Electron transfer to the active site occurs only in the proton-electron transfer stage, where the Mo(V) species plays an important role in cataly...

Monooxo Mo(V) complexes of a N2O heteroscorpionate ligand designated (L10O) are found to exist as isolable cis and trans isomers. We have been able to trap the kinetically labile cis isomer and follow its isomerization to the thermodynamically more stable trans form. We have also followed the kinetics of isomerization between the cis and trans isomers of the corresponding dioxo Mo(VI) and W(VI)...

Determination of molybdenum(VI) by direct spectrophotometry and simultaneous determination of molybdenum(VI) and titanium(IV) are reported. Molybdenum(VI) gives a golden yellow colour with 2,4dihydroxybenzaldehyde isonicotinoyl hydrazone with a 1:2 metal-reagent stoichiometry at pH 1.5. The complex shows an absorption maximum at 445 nm with molar absorptivity and Sandell's sensitivity of 1.02x1...

A sensitive spectrophotometric method for the determination of trace amounts of chromium(VI) is described. Chromium(VI) forms chlorochromate anion in the presence of acid and chloride ion. The formed anion is extracted in toluene as ion-pair with a cationic dye rhodamine 6G. At 535 nlll absorption maximum molar absorptivity is 2x104 I mol-I em-I. The colour is stable for 4 h and the system obey...