Electrophilic terminal arsinidene-iron(0) complexes with a two-coordinated arsenic atom

The first terminal arsinidene complexes [{(NHC)C(Ph)}As]Fe(CO)(4) (NHC = IPr = C{(NDipp)CH}(2)5, Me-IPr = C{(NDipp)CMe}(2)6; Dipp = 2,6-iPr(2)C(6)H(3)) with a two-coordinated arsenic atom have been reported as crystalline solids. Calculations suggest that 5 and 6 are electrophilic, which has been demonstrated by the reaction of 5 with an NHC nucleophile (IMe4), affording the Lewis adduct [{(IPr)C(Ph)}As(IMe4)]Fe(CO)(4) (7) (IMe4 = C(NMeCMe)(2)).