The synthesis and characterisation of a series of linear triphos {PhP(CH2CH2PPh2)(2)} bridged iron/tungsten or molybdenum bimetallic complexes

The reaction of [Fe-2(CO)(9)] with 2 equiv. of L-a,L-b,L-c {L-a,L-b,L-c = [ MX2(CO) {PhP(CH2CH2PPh2)(2)-P,P'}(eta(2)-RC2R')] {M = W, X = I; L-a, R = R' = Me; L-b= R = R' = Ph; L-c = R = Me, R' = Ph} in CH2Cl2 at room temperatu re gives the bimetallic linear triphos-bridged complexes [Fe(CO)(4)L-a,L-b, L-c] (1-3) in good yield. Equimolar quantities of [FeI(CO)(2)Cp or Cp'] and L-a,L-b,L-c,L-d,L-e,L-f (L-d, M = Mo, X = I, R = R' = Me; L-c, M = Mo, X = I, R = R' = Ph; L-f, M = W, X = Pr, R = R' = Ph) react in CH2Cl2 at room t emperature to afford the cationic phosphine-bridged complexes [Fe(CO)(2)(L- a,L-b,L-c,L-d,L-e,L-f)(Cp or Cp')]I (for L-a,L-b,L-c, Cp or Cp'; for L-d,L- e,L-f, Cp only) 4-12 in good yield. Treatment of [Fe(CO)(2)LaCp]I with 1 eq uiv, of Na[BPh4] in CH2Cl2 at room temperature yields the iodide exchanged product, [Fe(CO)(2)LaCp][BPh4] (13). Equimolar quantities of [Fe(CO)(4)L-a] and L {L = CNBut or P(OMe)(3)} gives the iron-carbonyl substituted product s [Fe(CO)(3)LLa] (14-15) in good yield. Complexes 1-15 have been characteri sed by elemental analysis (C, H and N), IR and H-1 and P-31 NMR spectroscop y. (C) 2000 Elsevier Science S.A. All rights reserved.