Sodium selenocarboxylates were found to react with organoarsanyl chlorides Ph_,, _,, AsCln 1-3 (n= 1, 2, 3) to give the corresponding Se-organoarsanyl esters RCOSeAsPh2 (5),(RCOSe) 2AsPh (6) and (RCOSe)-_., As (7) in good yields. The reaction of Se- diphenylarsanyl 4-methylbenzenecarboselenoate 5g with phenylselenenyl bromide and phenyltellurenyl iodide afforded the corresponding Se-phenylselenenyl 13 and Se~ ...