om051013u_si_002.pdf (802.27 kB)
Reactivity of a Phosphido-Niobocene Derivative toward CS2 and Alkyl Halides to Give Phosphinodithioformato- and Phosphino-Niobocene Complexes: X-ray Crystal Structures of [Nb(η5-C5H4SiMe3)2(κ1-S-SC(S)(PPh2))(CO)] and [Nb(η5-C5H4SiMe3)2(P(I)Ph2)(CO)]I3
journal contribution
posted on 2006-02-27, 00:00 authored by Antonio Antiñolo, Santiago García-Yuste, Antonio Otero, Juan C. Pérez-Flores, Rebeca Reguillo-Carmona, Ana M. Rodríguez, Elena VillaseñorThe reaction of the niobocene complex [Nb(η5-C5H4SiMe3)2(PHPh2)(CO)]Cl (1) with NaOH yielded
the corresponding phosphidoniobocene derivative [Nb(η5-C5H4SiMe3)2(PPh2)(CO)] (2) by deprotonation
of the P−H bond. The subsequent insertion reaction of carbon disulfide into the Nb−P bond yielded the
first examples of a diphenylphosphinodithioformato ligand coordinated to the niobocene system by giving
[Nb(η5-C5H4SiMe3)2(κ1-S-SC(S)(PPh2))(CO)] (3) and [Nb(η5-C5H4SiMe3)2(κ2-S,S-SC(S)(PPh2))] (4); the
latter compound can also be prepared by the corresponding CO elimination of 3. The cationic d2 species
[Nb(η5-C5H4SiMe3)2(PRPh2)(CO)]X (R = Me, X = I (5); CH2Ph, X = Br (6); CH2CH2Ph, X = Br (7))
were prepared by the reaction of alkyl halides RX (R = Me, X = I; CH2Ph, X = Br; CH2CH2Ph, X =
Br) with 2 by electrophilic attack on the phosphorus atom present in the phosphido terminal ligand. In
the same way, the reaction of 2 with ICH2CH2I yielded the complex [Nb(η5-C5H4SiMe3)2(P(I)Ph2)(CO)]I3 (8). The molecular structures of 3 and 8 were determined by single-crystal X-ray diffraction studies.