The missing entry in the agostic-anagostic series: Rh(I)-eta(1)-C interactions in P(CH)P pincer complexes

Christine Lepetit (1) , Jordi Poater (2) , Mohammad Esmaïl Alikhani (3) , Bernard Silvi (4) , Yves Canac (1) , J. Contreras-Garcia (4) , Miquel Sola (2) , Rémi Chauvin (1)

1 LCC - Laboratoire de chimie de coordination
2 UdG - Universitat de Girona
3 MONARIS - De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies
4 LCT - Laboratoire de chimie théorique

The missing entry, namely, the "C-anagostic" or eta(1)-C interaction, closing the agostic-anagostic series of metal-CH(aryl) interactions is found in a bis(amidiniophosphine) P(CH)P pincer rhodium complex. The three entries, namely, agostic eta(2)-(C,H), anagostic (related to hydrogen bonding, thus recoined here as "H-anagostic"), and C-anagostic interactions, are unambiguously characterized by electron localization function (ELF) topological analysis. Other theoretical tools Such as noncovalent interaction (NCI) analysis and Multicenter electron delocalization indices (MCIs) support the ELF characterization. A eta(2)-(C,H) agostic interaction is evidenced by a disynaptic V(C,H) or trisynaptic V(M,C,H) ELF basin with a significant quantum topological atoms in molecules (QTAIM) atomic contribution of the metal M and a large covariance (in absolute value) with the metal core basin C(M). The C-anagostic eta(1)-C interaction is Characterized by a disynaptic V(M,C) basin, a weak covariance (in absolute value) of V(C,H) and C(M) populations, and a negligible QTAIM atomic contribution of M to V(C,H). The relevance of these ELF signatures is evidenced in a selected series of related rhodium and osmium complexes.

Domaines: Chimie de coordination

Christine Lepetit, Jordi Poater, Mohammad Esmaïl Alikhani, Bernard Silvi, Yves Canac, et al.. The missing entry in the agostic-anagostic series: Rh(I)-eta(1)-C interactions in P(CH)P pincer complexes. Inorganic Chemistry, 2015, 54 (6), pp.2960-2969. ⟨10.1021/acs.inorgchem.5b00069⟩. ⟨hal-01916647⟩