Dimethylarsinate

Concerning anthropogenic sources, methyl arsenic compounds such as methyl arsonic acid and dimethylarsinic acid have been used as herbicides, and were once a significant source of environmental residues. Dimethyl-arsinic acid (Agent Blue) was used as a defoliant during the Vietnam War. 

McBride BC, RS Wolfe (1971) Biosynthesis of dimethylarsine by a methanobacterium. Biochemistry 10 4312-4317. 

Uson, R., Laguna, A., Vicente, J., Garcia, J., Jones, P.G. and Sheldrick, G.M. (1981) Preparation of three- and four-coordinate gold(I) complexes crystal structure of bis [o-phenylenebis(dimethylarsine)]gold(I) bis(pentafluorophenyl)aurate. Journal of the Chemical Society, Dalton Transactions, (2), 655-657. 

The arsenic compounds most commonly found in environmental and biological materials, and in working places, are arsenite and arsenate ions [As(III) and As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsine, di- and tri-... 

Trivalent Co complexes of the mixed donor amino arsine emda (2-aminoethyl)dimethylarsine) have been synthesized.936 Examples include trans(X,X), cA(As,As)-[CoX2(edma)2]+ (X = C1, Br, and I), trans( As,As)- and trara(As,N)-[Co(acac)(edma)2]2+, trara(As,N)-[Co(C03)(edma)2]+, [Co(acac)2(edma)]+, and /ao[Co(edma)3]3+. The /ao[Co(edma)3]3+ complex was resolved and the absolute configuration of the (+)49o CD isomer was assigned as A on the basis of the CD spectrum. Racemization of this complex was first order in both complex and hydroxide ions. The crystal structure of [Co(acac)2(emda)]C104 has been reported.937... 

Zinc complex formation with 1,3-diketones in aqueous solution has been investigated with pentane-2,4-dione, l,l,l-trifluoropentane-2,4-dione, and 4,4,4-trifluoro-l-(2-thienyl)butane-l, 3-dione. The buffer dimethylarsinic acid was shown to have a catalytic effect on complex formation with pentane-2,4-dione and the proton transfer reactions were affected.471,472 High-resolution solid state 13C NMR studies of bis(2,4-pentanedionato) zinc complexes have been carried out.473... 

In 1933 Challenger et al. discovered that trimethylarsine was synthesized from inorganic arsenic compounds by molds (93). Recently, McBride and Wolfe (94), have reported the synthesis of dimethylarsine from arsenate by cell extracts of the methanogenic bacterium M. O. H. Methylcobalamin is the alkylating coenzyme for this synthesis which requires reduction of arsenate to arsenite, methylation of arsenite to methylarsonic acid, reduction and methylation of methylarsonic acid to dimethylarsinic acid, and finally a four electron reduction of dimethylarsinic acid to dimethylarsine (Fig. 13). 

Fig. 13. Mechanism for the synthesis of dimethylarsine from arsenate and methyl-cobalamin...

The bidentate ligand o-phenylenebis(dimethylarsine) (DAS) was first prepared by Chatt and Mann.1 A wide variety of... 

A 50% dispersion of sodium in paraffin, which was obtained from Alfa Inorganics, Inc., can be used successfully instead of the freshly prepared sodium sand, t Faster addition of dimethylarsine causes aggregation of sodium. 

MMAA monomethylarsonic acid [(CH3)AsO(OH)2] DMAA dimethylarsinic acid [(CTbhAsOfOH)] MexSn MeSn3+, Me2Sn2+, Me3Sn+... 

---