Arsaalkyne

In chemistry, a arsaalkyne is an organoarsenic compound containing a triple bond between arsenic and carbon with the general chemical formula. Arsaalkynes are rare, especially in comparison with the phosphaalkynes. The parent has been characterized spectroscopically, otherwise the only arsaalkynes have bulky organic substituents.

Synthesis and isolation

Arsaalkynes are produced by dehydrohalogenation or related base-induced elimination reactions. The case of HCAs is illustrative:
Owing to the principles of the double bond rule, arsaalkynes tend to oligomerize more readily than the phosphorus analogues. Thus attempts to prepare produce the tetramer, which has a cubane structure. The very bulky substituent -2,4,6- does however allow the crystallization of the monomeric arsaalkyne. Its As-C bond length is 1.657 Å.