A series of molybdenum(VI) complexes containing bidentate ligands: toluene-3,4-dithiol (1), 2-mercaptophenol (2), 2-aminothiophenol (3), ethane-1,2-dithiol (4), dithiooxamide (5) and 2-thiopheno-carboxamide (6) are reported. The hexacoordinated molybdenum tris-chelates compounds: tris-(toluene-3, 4-dithiolate)molybdenum(VI) (7), tris-(2-mercaptophenolate)molybdenum(VI) (8), tris-(2-aminothiophe...

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...

The voltammetric characteristics of Mo (VI) oxinate at the mercury electrode, in the presence of tri-butylammonium perchlorate (tri-BAP) and piperidinium perchlorate (PP) + piperidine (P) as  two different types supporting electrolytes, have been studied in chloroform. With the both supporting electrolytes a two electron irreversible process for the reduction  of Mo (VI) oxinate was observe...

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of molybdenum(VI) using 5,7-dibromo-8-hydroxyquinoline (DBHQ) has been developed. 5,7-Dibromo-8-hydroxyquinoline reacts in a slightly acidic solution (0.05 - 1.0 M H2SO4) with molybdenum(VI) to give a deep greenish-yellow chelate which has an absorption maximum at 4...

* corresponding author. e-mail: [email protected] The interaction of Mo(VI) and tetrazolium violet (TV) has been examined. The ion-associate formed is extracted into 1,2-dichloroethane. The tetrazolium violet : molybdenum(VI) : 3,4,5-trihydroxybenzoic acid ratio (R) is 2 : 1 : 2. The optimum conditions have been established. Beer’s law is obeyed in the range of 0.2–5 μg ml–1 molybdenum(VI...

The reagent 4-hydroxybenzaldehyde thiosemicarbazone (4-HBTS) has been used for the determination of Mo(VI) by spectrophotometric method. The reagent 4-HBTS gives green colour with Mo(VI) solution of weak acidic medium and the maximum absorbance was observed at 365nm, in acidic buffer p H 6.0. The molar absorptivity and Sandell’s sensitivity of Mo(VI)4-HBTS complex are 1.25 x 10 L mol cm and 0.0...

Three chelating ion-exchange resins based on macroreticular polyacrylonitrile-divinylbenzene copolymers with thioglycollic acid and cysteine as functional groups have been tested for separation of molybdenum(VI) and tungsten(VI). On a short column of the thioglycollic acid resin, molybdenum(VI) and tungsten(VI) can be selectively sorbed from pH-4.3 acetate buffer and eluted with 2M hydrochloric...

the formation constants of the species formed in the systems h+ + mo(vi) + histidine and h+ +histidine have been determined at different aqueous solutions of methanol (0 - 45 % v/v) at 25 °c andconstant ionic strength (0.1 mol dm-3 sodium perchlorate), using a combination of spectrophotometricand potentiometric techniques. the composition of the complex species was determined by thecontinuous v...

The present paper describes a simple, selective and sensitive kinetic method for the determination of trace amounts of molybdenum(VI) based on its inhibitory effect on the reaction oxidation of 4-hydroxycoumarine by KMnO(4) in the presence of hydrochloric acid, at pH 1.75 at 25 degrees C. The rate of the indicator reaction was followed spectrophotometrically by measuring the decrease in the abs...