title: Density functional theory study of the binding capability of tris(pyrazol-1-yl)methane toward Cu(I) and Ag(I) cations.
abstract: Density functional theory (DFT) has been used to look into the electronic structure of [M(tpm)]+ molecular ion conformers (M = Cu, Ag; tpm = tris(pyrazol-1-yl)methane) and to study the energetics of their interconversion. Theoretical data pertaining to the free tpm state the intrinsic instability of its kappa3-like conformation, thus indicating that, even though frequently observed, the kappa3-tripodal coordinative mode is unlikely to be directly achieved through the interaction of M(I) with the kappa3-like tpm conformer. It is also found that the energy barrier for the kappa2-[M(tpm)]+ --> kappa3-[M(tpm)]+ conversion is negligible. As far as the bonding scheme is concerned, the tpm --> M(I) donation, both sigma and pi in character, is the main source of the M(I)-tpm bonding, whereas back-donation from completely occupied M(I) d orbitals into tpm-based pi* levels plays a negligible role.
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Padova 35131, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Casarin
authors.forename: Daniel
authors.initials: D
authors.lastname: Forrer
authors.forename: Federica
authors.initials: F
authors.lastname: Garau
authors.forename: Luciano
authors.initials: L
authors.lastname: Pandolfo
authors.forename: Claudio
authors.initials: C
authors.lastname: Pettinari
authors.forename: Andrea
authors.initials: A
authors.lastname: Vittadini