In chemistry, an arsaalkyne is chemical compound with a triple bond between carbon and arsenic. These organoarsenic compounds are rare, especially in comparison with the phosphaalkynes. The parent HCAs has been characterized spectroscopically, otherwise the only arsaalkynes have bulky organic substituents.[1]

Chemical structure of the arsaalkyne AsCC6H2-2,4,6-(t-Bu)3.

Synthesis and isolation edit

Arsaalkynes are produced by dehydrohalogenation or related base-induced elimination reactions. The case of HCAs is illustrative:

H2ClCAsH2 + 2 Na2CO3 → HCAs + 2 NaHCO3 + 2 NaCl

Owing to the principles of the double bond rule, arsaalkynes tend to oligomerize more readily than the phosphorus analogues. Thus attempts to prepare AsCCMe3 produce the tetramer, which has a cubane structure.[2] The very bulky substituent C6H2-2,4,6-(t-Bu)3 does however allow the crystallization of the monomeric arsaalkyne. Its As-C bond length is 1.657(7) Å.[3]

See also edit

References edit

  1. ^ Guillemin, Jean-Claude; Chrostowska, Anna; Dargelos, Alain; Nguyen, Thi Xuan Mai; Graciaa, Alain; Guenot, Pierre (2008). "Methylidynearsine (HC≡As): Synthesis and Direct Characterization by UV-Photoelectron Spectroscopy and Mass Spectrometry". Chemical Communications (35): 4204–4206. doi:10.1039/B806771F. PMID 18802530.
  2. ^ Hitchcock, Peter B.; Johnson, Julian A.; Nixon, John F. (1993). "Synthesis and Structure of the Arsaalkyne Tetramer (AsCtBu)4 and its Fe(CO)4 Derivative". Angewandte Chemie International Edition in English. 32: 103–104. doi:10.1002/anie.199301031.
  3. ^ Hitchcock, Peter B.; Jones, Cameron; Nixon, John F. (1994). "Synthesis, Crystal and Molecular Structure of the First Metal Complex [Pt(PPh3)22-As≡C(C6H2But3)}] Derived from an Arsaalkyne". J. Chem. Soc., Chem. Commun. (18): 2061–2062. doi:10.1039/C39940002061.