54111-73-8Relevant academic research and scientific papers
Rapid synthesis of Group VI carbonyl complexes by coupling borohydride catalysis and microwave heating
Birdwhistell, Kurt R.,Schulz, Brian E.,Dizon, Paula M.
, p. 69 - 71 (2013/01/15)
Several Group VI tetracarbonyl phosphine and tertiary amine complexes [M(CO)4 L2, M = Cr, Mo, W, L2 = 2PPh 3, dppm, dppe, dppp, dppb, bpy, phen, dppf] were synthesized in minutes in the microwave at moderate temperature, atmospheric pressure, and utilizing NaBH4 as a catalyst. The reactions were optimized by careful solvent selection. The octahedral complexes were isolated in percent yields ranging from 17 to 95. The lower temperatures, shorter reaction times, benign solvents, and lower pressures as compared to the traditional thermal syntheses provide a rapid, eco-friendly synthetic route to these common Group VI complexes.
Substitution and addition reactions of the (CO)3(η7-tropylium)M cations (M = Cr, Mo, W) with tertiary diphosphines
Brown, David A.,Burns, John,Glass, William K.,Cunningham, Desmond,Higgins, Tim,McArdle, Patrick,Salama, Mabrouk M.
, p. 2662 - 2667 (2008/10/08)
The reactions of the title compounds I-III, [(η7-C7H7)M(CO)3]BF4 (M = Cr, Mo, and W, respectively), with the diphosphines PPh2(CH2)nPPh2 (n = 1-4) at low temperatures (-40 to -60°C) form two new series of complexes which are quite different from previous carbonyl substitution products. The first series (IV-VI) formed by the diphosphines (n = 1-3) comprise 7-exo ring adducts involving the bonding of only one phosphorus atom of the diphosphine to ring carbon atom 7 of I. The second series (VII and VIII) are diphosphine ring linked dimers, e.g. [(7,7′-exo-dppb){η6-C7H7)Cr(CO) 3}2] [BF4]2, for which X-ray crystallography confirms a diphosphine linked ring-ring structure with the Cr(CO)3 moieties situated on opposite sides of the ring systems. The ring C-phosphorus bond length of 1.852 A? indicates a relatively weak bond, consistent with facile cleavage of these adducts on reaction with nucleophiles such as hydride.
