Jacob J. Habeeb

DIRECT ELECTROCHEMICAL SYNTHESIS OF SOME METAL CHELATE COMPLEXES

Abstract A convenient electrochemical synthesis of various ML2, ML3, ML4 and MOL2 complexes (M = Ti, Zr,Hf, V,Cr, Mn,Fe, Co,Ni, Cu,In; L = acetylacetonate anion, 3-hydroxy-2-methyl-4-pyronate anion, 2-acetylpyrrolate anion, and other bidentate ligands) is described. The metal, as the anode of simple cell, is oxidised in the presence of the parent compound of the ligand (HL) in an organic solvent mixture. Gram quantities of complex can be produced in a few hours; other advantages of this method are discussed. Current efficiency measurements serve to identify the reaction mechanism.

The electrochemical synthesis of neutral and anionic organozinc halides

A series of 2,2′-bipyridine adducts of organozinc(II) halides RZnX has been prepared by the electrochemical oxidation of zinc in the presence of organic solutions of RX (R  CH3, C2H5, CF3, C3H3, C6H5, C6H5CH2; X  Cl, Br, I (not all combinations)). Similar methods have been used to prepare the anions RZnX2 (R  CH3, C2H5, C6H5, CF3; X  Cl, Br, I (not all combinations)) as the tetra-n-propylammonium salts.

Electrochemical preparation of some organotin compounds

Abstract Organotin dihalides R 2 SnX 2 (X  Cl, Br, I) and their adducts with bidentate donor ligands have been prepared in high yield by the direct electrochemical reaction of metallic tin with alkyl or aryl halides in organic media at room temperature. Dimethyltin diiodide can be converted to tetramethyltin by reaction with methyl iodide at a cadmium anode. Electrochemical halide abstraction has been used to prepare R 6 Sn 2 (R  Me, Ph) from the corresponding R 3 Sn halide. The mechanism of these reactions is discussed.

Electrochemical preparation of neutral organocadmium halides

The electrochemical oxidation of cadmium metal in the presence of methyl or ethyl iodide leads to the formation of unstable RCdI. These, and related species, can be stabilised with neutral ligands, and a series of adducts of alkylaryl- and perfluoroaryl-cadmium halides have been prepared. The oxidation apparently involves a free radical mechanism. The results support previous studies of solution equilibria involving R2Cd and CdX2 species.

Coordination compounds of indium : XXXVI. The direct electrochemical synthesis of neutral and anionic organoindium halides

Abstract The electrochemical oxidation of indium metal in cells of the type leads to the formation of RInX 2 compounds; if 2,2′-bipyridine is also present, the products are the adducts RInX 2 ·bipy (R = CH 3 , C 2 H 5 , C 6 H 5 , C 6 H 5 CH 2 , C 6 F 5 ; X = Cl, Br, I (not all combinations)). When R′ 4 NX is present instead of bipy, the products are the salts R′ 4 N[RInX 3 ]. The electrochemical oxidation apparently proceeds via the general mechanism discussed previously. Anomalous results with CH 3 I or C 2 H 5 I are discussed in the light of the known solution chemistry of organoindium(III) compounds.

Direct Electrochemical Synthesis of Anionic Complexes of Metallic Elements

Abstract The tetraethylammonium salts of the anionic bromo complexes of Fe(III), Co(II), Ni(II), Cu(II), Au(III), Cd(II), In(III) and Sn(IV) have been prepared in gram quantities by the direct electrochemical oxidation of the metal in question. The novel features of the method are (a) its simplicity and speed; (b) the solution phase, which consists of (C2H5)4NBr + Br2 in 80:20 benzene: methanol; and (c) the high applied voltage (∼ 50 v).

The electrochemical synthesis of some Ph3SnMCl adducts (M = Zn, Cd, Hg)

Abstract The electrochemical oxidation of Zn, Cd or Hg (= M) in a non-aqueous solution of Ph 3 SnCl yields the metal-metal bonded insertion product Ph 3 SnMCl which can be easily isolated as an adduct present in the solvent phase. The mechanism of this direct electrochemical synthesis is discussed. The far infrared spectra (500–50 cm −1 ) of these compounds are also reported.

The electrochemical preparation of organo nickel and palladium halides

Abstract The electrochemical oxidation of a nickel or palladium anode in the presence of certain organic halides yields the unstable RMX species, which can be stabilised by both mono and bidentate phosphorus(III) ligands. Cyanide compounds of the general formula RNiCN.L 2 can also be synthesised. The advantages of the method are outlined.

Direct electrochemical synthesis of indium compounds

Cationic, neutral, and anionic complexes of indium can be prepared by the direct oxidation of the highly charged metal by the appropriate solute in an organic solvent.

Stepwise elimination of methane in the reaction of dimethylindium(III) compounds with dibasic acids

Abstract The reaction between acetato(dimethyl)indium(III) and toluene-3,4-dithiol (H2TDT) involves elimination of either one or two moles of methane, depending on experimental conditions; the unusual intermediate [CH3In(OAc)(HTDT)]2 has been identified. The stepwise elimination reaction appears to be common to other dimethylindium(III) species.