Trimethylarsine complexes

The compounds MMA, DMA, and TMAO are reduced in acidic aqueous media by borohydride solutions to methylarsine (MeAsH2, bp 2°C), dimethylarsine (Me2AsH, bp 35°C), and trimethylarsine (Me3As, bp 55°C), respectively. These products are useful derivatives for speciation analysis of arsenic because they are readily separated from complex sample matrices and may be further separated from each other by distillation (41) or by gas chromatography (42) prior to their determination by element-specific detectors. Consequently, arsine generation techniques are the most commonly used methods for determining MMA, DMA, and TMAO in marine samples. 

The complex [Pd(AsMe3)2Cl2] loses trimethylarsine on heating to afford the dinuclear, chloride bridged, complex [Pd(AsMe3)Cl2]2. ... 

Trimethylarsine, (CH3)3 As (78), has been synthesized from CH3MgI and Asl3. The product 78 is stable when kept in benzene solution. 78 forms with mercury(II) chloride a complex Me3 As-HgCl2 (79) soluble in water. 78 can be liberated from 79 by reduction of the Hg(II) with zinc powder or by addition of an excess of potassium iodide. 

Methylarsines and methylstibines are subject to a number of reactions such as oxidation, quaternization and complex formation, which could facilitate or inhibit their dispersal in the environment . It has been reported that environmentally important concentrations of halocarbons (Mel, MeBr and MeCl) are produced naturally and accumulate in the oceans and the atmosphere. Parris and Brinckman reported quantitative measurements of the rate of quaternization of trimethylstibine and trimethylarsine by alkyl halides in polar solvents. 

Complexes of the type M(CO)sL, where L is arsine (AsHj) and stibine (SbH,) and M is Cr, Mo, and W, have been prepared by fischer el al. i (AsH) and S(AsHj) are near 2200 and 900 cm, respectively. Complexes of trimethylarsine (AsMc3) have been studied by several investigators. 

Although marine animals contain many arsenic compounds, most species contain arsenobetaine as the major arsenical. Fish tend to have a simple pattern of arsenic compounds dominated by arsenobetaine. The silver drummer Kyphosus sydney-anus, however, contains trimethylarsine oxide as its major arsenical (25). Crustaceans also generally contain arsenobetaine as a high percentage of their total arsenic. It should be noted, however, that most work on fish and crustaceans has examined the muscle tissue, and the pattern of compounds may be more complex in other tissues (88). 

Molecular dimensions (ed) As—C 193.7, As—O 163.1 pm. Synth, by oxidn. of Trimethylarsine, T-02786 with H2O2. Ligand for many heavy metals. Solid. Mp 191.2-195.2°. Reacts with NaBH4 - Mc3As. Metab. to Mc3As by microbial action, or to Mc2As02H in the mouse. Metab. of Arsenobetaine, A-02808 in many marine microorganisms. Forms complexes with HI, BF3, HBr, HCl etc. 

Marine organisms are known to contain, in addition to inorganic arsenic compounds and simple methylated arsenic compounds, the more complex arsenic derivatives arsenobetaine and ribosyldimethylarsine oxides [46, 47], These two complex derivatives are converted upon treatment with 2 M aqueous sodium hydroxide for three hours at 95 C to reducible arsenic compounds, arsenobetaine to trimethylarsine oxide (eqn. 2) and ribosyldimethylarsine oxides probably to dimethylarsinic acid (eqn. 3) ... 

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