24859-91-4Relevant academic research and scientific papers
Chemistry of cis-Bis(2,2'-bipyridine)dicarbonyl-molybdenum(0) and -tungsten(0). Substitution Reactions with Phosphorus Donor Ligands and with Isocyanides
Connor, Joseph A.,Overton, Colin
, p. 2397 - 2402 (1982)
Nucleophilic substitution reactions of cis- (M=Mo or W; bipy=2,2'-bipyridine) by various unidentate (PR3; R=Ph, Bun, or OMe) and bidentate (Ph2PCH2CH2PPh2=dppe) phosphorus and carbon (CNR; R=Et or p-tolyl) donor ligands, L, result in displacement of bipy to produce cis, trans- (L=PR3), cis,cis- (M=Mo, L2=(CNEt)2 or dppe; M=W, L=CNEt>, cis- (M=Mo or W; L=CNC6H4Me-p), and fac- (L=PPh3) depending on the ligand L, temperature, and solvent.Trifluorophosphine reacts with cis- to displace CO and form cis-.Substitution in by isocyanides gives fac- (M=Cr; R=Et or p-tolyl; M=Mo, R=Et) or cis- (R=p-tolyl).The products are characterised by microanalysis and by i.r., (1)H and (31)P n.m.r., electronic, and mass spectroscopy.It is suggested that the formation of cis,trans- may involve a trigonal biprismatic intermediate structure which allows reorganisation to occur simply.The acceptor strength of L in indicated by i.r. , (1)H n.m.r. (bipy ring chemical shifts), and visible (MO -> bipy d?*) spectra, decreases in the order CO > P(OMe)3 > CNEt > PBu3 > bipy, which does not reflect geometrical differences in the disposition of these ligands.
