Ligand designs for polynuclear and heterometallic complexes

The tripodal amido ligands P(CH2NHArR) 3 can be utilized to produce mononuclear Ti, Zr, and Ta complexes, where ArR = 3,5-(CF3)2C6H3 , Ph, and 3,5-Me2C6H3. The mononuclear compound P(CH2N-3,5-Me2C6H3) 3TiNMe2 reacts with excess Ni(CO)4 to afford an early-late heterobimetallic complex (CO)3Ni[P(CH2N-3,5-Me 2C6H3)3]TiNMe2 or a trinuclear complex (CO)2Ni[P(CH2N-3,5-Me2C6H 3)3TiNMe2]2. The reactions of 4 equiv of the mononuclear early transition metal complexes P(CH2NArR) 3TiNMe2 or P(CH2NArR)3Ta=N tBu with [Rh(CO)2(mu-Cl)]2 produce the trinuclear trans-rhodiumcarbonylchlorobisphosphine complexes. The donor abilities of the phosphine complexes are affected by the direct interactions between the phosphine donors and Ti or Ta metal centers.;The reaction of phosphine ligand P(CH2NHPh)3 with nickelocene Cp2Ni produces a Ni(II) dimer [CpNiP(CH2NHPh) 2]2 with a bridging diamido-phosphido ligand. Ni[P(CH 2NHPh)3]4 is identified as an intermediate. The Ni(II) dimer can be used as a ligand to give the early-late transition tetranuclear heterometallic complex [CpNiP(CH2NPh)2Ti(NMe2) 2]2.;The reactions of P[CH2NArR]3ZrCl(THF) with cyclopentadienyl lithium (LiC5H5) or lithium salt of the fulvalene dianion (Li2C10H8) produce P(CH2NArR)3ZrCp and the bridged binuclear complexes trans-[P(CH2NArR) 3Zr]2(eta5:eta5-C 10H8), respectively, where ArR = Ph and 3,5-Me2C6H3. The mononuclear titanium complexes [P(CH2NArR)3]TiOC6H 4tBu and the binuclear species [P(CH 2NPh)3Ti]2-mu-4,4'{O[3,3 ',5,5'-(C6H2Me 2)2]O}, {[P(CH2NPh)3]Ti}2(mu-O), and [P(CH2N-3,5-Me2C6H3 )3]Ti-mu-O-Ti(NMe2)3, are prepared from [P(CH2NArR)3]TiNMe2 via protonolysis. One equiv of {[P(CH2NPh)3]Ti}2(mu-O) precipitates a polymer of {Cl(CO)Rh[P(CH2NPh)3Ti] 2O}n. A single CO stretch is observed in the IR spectrum of a KBr pellet at 1972.5 cm-1.;Se=P(CH2NHArR)3 are prepared by oxidation of [P(CH2NHArR)3], which can react with AlMe3 to afford [P(CH2NArR) 2Se](AlMe2)3 or Me3AlP(CH2NAr R)2Se(AlMe2)3 with the unanticipated diamidoselenophosphinito ligands, where ArR = 3,5-(CF 3)2C6H3, Ph, and 3,5-Me2C 6H3. Comparing the reactions with P(CH2NHAr R)3, only P(CH2NArR)3Al 2Me3 or Me3Al·P(CH2NAr R)3Al2Me3 are produced without P-C bond cleavage.;Se=P[CH2NH-3,5-(CF3)2C6H 3]3 reacts with n-butylmagnesium to produce a binuclear magnesium complex bridging with a bisphosphine ligand {P 2[CH2N-3,5-(CF3)2C6H 3]4}(MgTHF2)2 by the cleavage of the P-C bond and the Se=P bond, with concomitant loss of [nBuCH 2N-3,5-(CF3)2C6H3] 2Mg. Byproducts include elemental selenium and SeMg. Se=P(CH2NHAr R)3 are efficiently reduced by Zr(NEt2) 4 to produce the mononuclear zirconium complexes [P(CH2NAr R)2SeZrNArRCH2NEt2], where ArR = Ph and 3,5-Me2C6H3.