RT journal article
T1 Counteranion-Dependent Reaction Pathways in the Protonation of Cationic Ruthenium−Vinylidene Complexes
A1 Jiménez Tenorio, Manuel
A1 Ortuño, Manuel A.
A1 Ujaque, Gregori
A1 Lledós, Agustí
A1 Puerta Vizcaino, María del Carmen
A1 Valerga Jiménez, Pedro Sixto
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
AB The tetraphenylborate salts of the cationic vinylidene complexes [Cp*Ru=C=CHR(iPr2PNHPy)]+ (R = p-C6H4CF3 (1a-BPh4), Ph (1b-BPh4), p-C6H4CH3 (1c- BPh4), p-C6H4Br (1d-BPh4), tBu (1e-BPh4), H (1f-BPh4)) have been protonated using an excess of HBF4·OEt2 in CD2Cl2, furnishing the dicationic carbyne complexes [Cp*Ru≡CCH2R(iPr2PNHPy)]2+ (R = p-C6H4CF3 (2a), Ph (2b), p-C6H4CH3 (2c), p-C6H4Br (2d), tBu (2e), H (2f)), which were characterized in solution at low temperature by NMR spectroscopy. The corresponding reaction of the chloride salts 1a-Cl, 1b-Cl, 1c-Cl, and 1d-Cl followed a different pathway, instead affording the novel alkene complexes [Cp*RuCl(κ1(N),η2(C,C)-C5H4N-NHPiPr2CH=CHR)][BF4] (3a−d). In these species, the entering proton is located at the α- carbon atom of the former vinylidene ligand, which also forms a P−C bond with the phosphorus atom of the iPr2PNHPy ligand. To shed light on the reaction mechanism, DFT calculations have been performed by considering several protonation sites. The computational results suggest metal protonation followed by insertion. The coordination of chloride to ruthenium leads to alkenyl species which can undergo a P−C coupling to yield the corresponding alkene complexes. The noncoordinating nature of [BPh4]− does not allow the stabilization of the unsaturated species coming from the insertion step, thus preventing this alternative pathway.
PB ACS Publications
YR 2014
FD 2014-05
LK http://hdl.handle.net/10498/20452
UL http://hdl.handle.net/10498/20452
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026