Synthesis and characterisation of linear triphos {PhP(CH2CH2PPh2)(2)} bridged tri-, tetra- and pentametallic molybdenum(II) (pi-allyl)/tungsten(II) (alkyne) complexes

Equimolar quantities of [MoX(CO)(2)(NCMe)(2)(eta(3)-C3H4R")] and L, L' or L " {[WI2(CO){PhP(CH2CH2PPh2)(2)-P,P'} (eta(2)-RC2R')] (L, R = R' = Me; L', R = R' = Ph; L", R = Me, R' = Ph) react in CH2Cl2 at room temperature to giv e the tetrametallic linear triphos-bridged, halo-bridged complexes [{Mo(mu- X)(CO)(2)(L, L' or L")(eta(3)-C3H4R")}(2)] (for L, L' or L", X = Cl, R" = H , Me-2 or CH2Cl-2; X = Br, R" = H) (1-12) in high yield. Reaction of [MoX(C O)(2)(NCMe)(2)(eta(3)-C3H4R")] with two equivalents of L, L' or L" in CH,CI , at room temperature affords the trimetallic complexes [{Mo(mu-X)(CO)(2)(L , L' or L")(eta(3)-C3H4R")}(2)] (for L, L' or L", X = Cl, R" = H, Me-2, CH2 Cl-2; X = Br, R" = H) also in high yield. Reaction of [MoCl(CO)(2)(NCMe)(2) (eta(3)-C3H4(CH2Cl-2)}] with three equivalents of L' afforded the tetrameta llic complex cis-,mer-[Mo(CO)(2)(NCMe)(L')(3)] (25). Treatment of [MoCl(CO) (2)(NCMe)(2){eta(3)-C3H4(CH2Cl-2)}] with four equivalents of L or L" yielde d the zero-valent pentametallic complexes cis-[Mo(CO)(2)(L or L")(4)] (26 a nd 27). All the new complexes (1-27) described in this paper were character ised by elemental analysis, IR, H-1-NMR and in selected cased by P-31{H-1}- NMR spectroscopy. (C) 1999 Elsevier Science S.A. All rights reserved.