The addition of the Ph 3 PAu + electrophile to deprotonated Fischer-type alkoxy(methyl)carbene complexes of pentacarbonyl group 6 metals leads to the formation of novel vinyl ether complexes of gold coordinated to the pentacarbonylmetal moiety. X-ray structures and DFT calculations show that the greatest bonding contribution in the vinyl coordination to the M(CO) 5 fragment comes from the terminal, partially negatively charged, CH 2 carbon atom via partial end-on η 1 -bonding rather than the usual η 2 -bonding of olefins. The corresponding positive charge from the asymmetric vinyl coordination is mainly delocalized onto the Ph 3 PAu fragment, stabilizing this coordination mode. The use of W instead of Cr in the M(CO) 5 fragment, in otherwise isostructural compounds, results in somewhat greater asymmetry in the vinyl coordination, with the difference in the two M(CO) 5 -η 2 -vinyl carbon bond lengths increasing from 0.252( 11) Å (M ) Cr) to 0.307( 5) Å (M ) W) in the solid state.

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Deprotonated Fischer-type aminocarbene complexes, (CO)5M=C(NR2)CH3 (M = Cr or W; R = Me or propyl), react with Ph3PAu+ by metal group substitution - (CO)5M for Ph3PAu+--and attachment of the extricated M(CO)5 to the deprotonated methyl group. (The products may also be seen as aminovinylgold compounds coordinated to M(CO)5 moieties.) DFT calculations at the B3LYP level of theory using model compounds indicate a clear preference of the gold unit for central C to terminal coordination in the ligand [NMe2CCH2]-, whereas the Cr(CO)5 has a 7 kcal mol(-1) preference for C(vinyl) coordination compared to N-coordination. In related thiocarbenes, the sulfur donor atom should be the preferred point of attachment for the metal carbonyl unit. The latter prediction is borne out in practice, and in the three products isolated, including Ph3PAu{C(=CH2)SPh}Cr(CO)5 in a mixed crystal with [Ph3PAuSPh]Cr(CO)5, precisely this coordination mode is present. The latter component of the mixed crystal has also been prepared independently of the vinyl one.