@article {4545, title = {Preparation and reactivity of zirconium(III), niobium(III), and molybdenum(III) complexes stabilized by a cyclopentadienyl unit with pendant phosphine donors}, journal = {Organometallics}, volume = {18}, number = {20}, year = {1999}, note = {ISI Document Delivery No.: 244CDTimes Cited: 14Cited Reference Count: 55}, month = {Sep}, pages = {4050-4058}, type = {Article}, abstract = {This paper deals with the organometallic chemistry of the trivalent second-row transition metals of groups 4-6, namely, Zr, Nb, and Mo, with the cyclopentadienyldiphosphine ligand [eta(5)-C5H3-1,3-(SiMe2CH2PR2)(2)], abbreviated as [(P2Cp)-P-R] (where R = i-Pr and Ph). The Zr(IV) complex [i-PrP2Cp]ZrCl3 undergoes reduction with Na/Hg to form the trivalent Zr derivative, [i-PrP2Cp]ZrCl2, which undergoes a metathetical reaction with MeMgBr to yield the monomethyl derivative [i-PrP2Cp]Zr(CH3)Cl. The reaction of the Zr(III) complex [i-PrP2Cp]ZrCl2 with excess carbon monoxide results in disproportionation to the Zr(IV) complex, [i-PrP2Cp]ZrCl3, and the Zr(II) compound [i-PrP2Cp]Zr(CO)(2)Cl. This reaction is reversible, and upon removal of CO the starting material, [i-PrP2Cp]ZrCl2 is formed. The preparation of the diamagnetic Nb(III) complex [(P2Cp)-P-R]NbCl2 is achieved by the reaction of NbCl3(DME) with [(P2Cp)-P-R]Li. [(P2Cp)-P-R]NbCl2 complexes react with excess CO to form the CO adducts whose solid-state structures have been determined. The Nb(IV) derivatives [(P2Cp)-P-R]NbCl3 are formed via the reaction of [(P2Cp)-P-R]NbCl2 with PbCl2. These complexes can also be produced when Nb(O)Cl-3(THF)(2) is allowed to react with excess [(P2Cp)-P-R]Li. These Nb(IV) derivatives are ESR active, and their solid-state molecular structures show distorted octahedral geometries around the Nb center. MoCl3(THF)(3) reacts with [(P2Cp)-P-R]Li to generate the corresponding Mo(III) complexes [(P2Cp)-P-R]MoCl2. These compounds are low-spin, paramagnetic complexes as evidenced by their ESR spectra.}, keywords = {CARBONYL, CHEMISTRY, CONVENIENT, DERIVATIVES, HALOGENO, LINKAGE, {BONDS}, isbn = {0276-7333}, url = {://000083033500018}, author = {Fryzuk,Michael D. and Jafarpour, L. and Rettig, S. J.} } @article {4051, title = {Different modes of reaction of lithium phosphides with Cp*M(NO)(X)Cl complexes of molybdenum tungsten}, journal = {Organometallics}, volume = {16}, number = {2}, year = {1997}, note = {ISI Document Delivery No.: WD812Times Cited: 15Cited Reference Count: 40}, month = {Jan}, pages = {190-196}, type = {Article}, abstract = {{Treatment of Cp*M(NO)(X)Cl complexes (M = Mo, W; X, = CH(2)SiMe(3), CH(2)CMe(3), NHCMe(3), OCMe(3), Cl) with lithium phosphides can result in one of three different types of reactions. Some reactions involve the starting material undergoing metathesis of a chloro ligand, and others effect reduction of the organometallic reactant, while a third class results in a scrambling of the ligands of the starting complex. Reactions of CP*M(NO)(X)Cl with LiPPh(2) lead to formation of the respective phosphido-containing complexes Cp*M(NO)(X)(PPh(2)) [M = W}, keywords = {ISOMERIZATION, LIGAND, {BONDS}, isbn = {0276-7333}, url = {://A1997WD81200008}, author = {Legzdins,Peter and Ross, K. J. and Sayers, S. F. and Rettig, S. J.} }