title: Is the phosphaethynolate anion, (OCP)(-), an ambident nucleophile? A spectroscopic and computational study.
abstract: The reactivity of Na(OCP) was investigated towards triorganyl compounds of the heavier group 14 elements (R3EX R = Ph or (i)Pr; E = Si, Ge, Sn, Pb; X = Cl, OTf). In the case of E = Si two constitutional isomers were formed and characterised in situ: R3Si-O-C[triple bond, length as m-dash]P is the kinetic and R3Si-P[double bond, length as m-dash]C[double bond, length as m-dash]O is the thermodynamic product, representing experimental evidence of the ambident character of the (OCP)(-) anion. Applying theoretical calculations and spectroscopic methods, the compound previously reported as (i)Pr3Si-O-C[triple bond, length as m-dash]P can now unambiguously be identified as (i)Pr3Si-P[double bond, length as m-dash]C[double bond, length as m-dash]O. The heavier analogues form exclusively the phosphaketene isomer R3E-P[double bond, length as m-dash]C[double bond, length as m-dash]O (E = Ge, Sn, Pb). DFT calculations were performed to gain deeper insight into the bonding and thermodynamic stability of these compounds.
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland. hgruetzmacher@ethz.ch benkoe@inorg.chem.ethz.ch.
authors.forename: Dominikus
authors.initials: D
authors.lastname: Heift
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Benkő
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Grützmacher