2,5-Diphenyl-1-R-arsoles (R = Ph, PhCH 2, CH 3) react with phenyliodide dichloride to give the 1,1-dichloro-2,5-diphenyl-1-R-λ 5-arsoles (V), which decompose, depending on the nature of R, even under mild conditions (R PhCH 2) or at higher temperatures (R = CH 3) to form 1-chloro-2,5-diphenylarsole. The reaction of this chloroarsole with organolithium compounds (RLi) gives the 2,5-diphenyl-1-R-arsoles (R = Ph, C(CH 3) 3) and with sodium methanolate a mixture of 2,2′,5,5′-tetraphenyl-diarsolyl (XVI) and oxygen-containing derivatives of XVI is formed; the expected 1-methoxy-2,5-diphenylarsole cannot be detected. 1,1-Dichlor-2,5-diphenyl-1-R-λ 5-arsoles (V) react with sodium methanolate, under elimination of methyl chloride, to give the 2,5-diphenyl-1-R-arsoloxides; the 1-R-arsoles are reformed by organolithium compounds. 1-t-Butoxy-1-chloro-2,5-diphenyl-1-R-λ 5-arsoles (XII), formed by reaction of 2,5-diphenyl-1-R-arsole with t-butyl hypochlorite, disproportionate to give the 1,1-dichloro-2,5-diphenyl-1-R-λ 5-arsoles and the 1,1-di-t-butoxy-2,5-diphenyl-1-R-λ 5-arsoles; when R = PhCH 2 the 1-chloro-2,5-diphenyl-arsole is formed immediately. 1-t-Butoxy-1-chloro-1,2,5-triphenyl-λ 5-arsole (XII) reacts with organolithium compounds (RLi) and gives by a S N2′-like reaction, the 1,2,5-triphenyl-3-R-arsoles (XIII). 1-Chloro-2,5-diphenylarsole undergoes a substitution reaction with 2,5-diphenyl-arsolyl lithium to give the 2,2′,5,5′-tetraphenyldiarsolyl (XVI). The tendency of formation of XVI is very large. XVI is formed, e.g., by reaction of 1-methoxymethyl-2,5-diphenylarsole with Fe(NO 3) 3, by oxidation of the 1,2,5-triphenylarsolyl radical anion with air or with trityl perchlorate; the 2,5-diphenyl-arsolyl anion is also oxidized by trityl perchlorate to give XVI. The diarsolyl XVI forms 2,5-diphenylarsolyl potassium by cleavage reaction with metallic potassium; with organolithium compounds a mixture of 2,5-diphenyl-1-R-arsole and 2,5-diphenylarsolyl lithium is formed.