12128-26-6Relevant articles and documents
Phosphido-bridged heterodinuclear complexes of CrPd, MoPd, WPd, and MnPd. X-ray crystal structures of and
Braunstein, Pierre,Jesus, Ernesto de,Tiripicchio, Antonio,Camellini, Marisa Tiripicchio
, p. C5 - C10 (1989)
A series of phosphido-bridged heterodinuclear complexes has been prepared by the low temperature reaction of the labile chain complexes trans-2(PhCN)2> (m = Cr, Mo, W(CO)2Cp; Mn(CO)4) with 3 molar equivalents of PCy2H or PPh2H.The crystal struc
A structural study of [CpM(CO)3H] (M = Cr, Mo and W) by single-crystal X-ray diffraction and DFT calculations: Sterically crowded yet surprisingly flexible molecules
Burchell, Richard P. L.,Sirsch, Peter,Decken, Andreas,McGrady, G. Sean
, p. 5851 - 5857 (2009)
The single-crystal X-ray structures of the complexes [CpCr(CO) 3H] 1, [CpMo(CO)3H] 2 and [CpW(CO)3H] 3 are reported. The results indicate that 1 adopts a structure close to a distorted three-legged piano stool geometry, wh
Dimetallagermanes of molybdenum and tungsten: Synthesis, structure and reactions
Filippou, Alexander C.,Winter, Johannes G.,Kociok-Koehn, Gabriele,Hinz, Isolde
, p. 2029 - 2036 (1998)
Reaction of the trichlorogermyl complexes CpM(CO)3GeCl3 3a or 3b with Li[CpM(CO)3] 2a or 2b, which were obtained from CpM(CO)3H 1a or 1b and LiBun, afforded the dimetalladichlorogermanes [CpM(CO)3]2GeCl2 4a or 4b (Cp = C5H5; a M = Mo; b M = W). Similarly, treatment of Cp*Mo(CO)3GeCl3 3c with K[Cp*Mo(CO)3] 2c yielded selectively [Cp*Mo(CO)3]2GeCl2 4c (Cp* = C5Me5). Complex 3c was obtained from Cp*Mo(CO)3H 1c in two steps. The first step involved an insertion of GeCl2 into the molybdenum-hydrogen bond of 1c to give the dichlorogermyl complex Cp*Mo(CO)3GeCl2H 5c followed by chlorination of 5c with CCl4. The dimetalladichlorogermanes 4a-4c contain two reactive sites for further functionalization, the transition-metal centers and the germanium atom. This has been demonstrated by the CO/PMe3 ligand exchange reaction of 4a to give [Cp(CO)3Mo(μ-GeCl2){trans-Mo(CO)2(PMe 3)Cp}] 6a and the substitution reaction of 4a with LiAlH4 to afford the dimetallagermane [CpMo(CO)3]2GeH2 7a. The crystal structures of 4a, 4b and 6a have been reported.
Reactivity of 17-electron organometallic tungsten and molybdenum radicals: A laser flash photolysis study
Scott, Susannah L.,Espenson, James H.,Zhu, Zuolin
, p. 1789 - 1797 (1993)
Visible (460-490 nm) laser flash photolysis of [CpW(CO)3]2 or [CpMo(CO)3]2 induces homolysis of the metal-metal bond with formation of 17-electron radicals, CpM(CO)3. Radical dimerization results in quantitative recovery of the parent dimer and can be followed by the time-resolved increase in dimer absorbance. The reaction follows clean second-order kinetics, -d[CpM(CO)3]/dt = 2kc[CpM(CO)3]2; kc(W) = 6.2 × 109 and kc(Mo) = 3.9 × 109 L mol-1 s-1 in CH3CN at 23°C. The CpM(CO)3 radicals react with organic and inorganic halides and pseudohalides by an atom-transfer mechanism. In the presence of a large excess of the halide-containing substrate, the rate of loss of the radical, -d[CpM(CO)3]/dt, proceeds according to a mixed first- and second-order rate law. The pseudo-first-order rate constants for reactions with organic halides vary linearly with the concentration of the organic halide; bimolecular rate constants for CpW(CO)3 range from 3.9 × 102 L mol-1 s-1 with CH2Br2 to 1.34 × 109 L mol-1 s-1 for CBr4. The reactivity trends (RI > RBr > RCl) and (benzyl > allyl > 3° > 2° > 1° > CH3) are observed. The 7 orders of magnitude variation in bimolecular rate constants is attributed to a highly selective atom abstraction process. The range of rate constants for atom abstraction from halo- and pseudohalopentaamminecobalt(III) and halobis(dimethylglyoximato)cobalt(III) complexes is smaller (2 orders of magnitude, from 1.6 × 107 L mol-1 s-1 for NCCo(NH3)52+ to > 2 × 10- L mol-1 s-1 for BrCo(dmgH)2py), because of the upper limit imposed by diffusion. Transfer of the halogen atom from both organic and metal substrates to CpW(CO)3 was confirmed by the IR spectrum of the organometallic product, CpW(CO)3X (X = Cl, Br, or I). Dioxygen traps CpW(CO)3 with a rate constant k = 3.3 × 109 L mol-1 s-1. Light-initiated chain reactions were observed at high concentrations of RX, XCoL5nt, or O2. Hydroperoxides react with CpW(CO)3 by a radical mechanism. The reaction observed between CpW(CO)3 and (n-Bu)3SnH is not consistent with either outer-sphere electron transfer or a hydrogen atom abstraction mechanism; oxidative addition to the 17-electron radical is believed to occur in this case. The dimer [(C5H4COOCH3)W(CO)3]2 shows photoreactivity in organic solvents which is very similar to that of [CpW(CO)3]2.
Acid-base interaction between transition-metal hydrides: Dihydrogen bonding and dihydrogen evolution
Levina, Vladislava A.,Rossin, Andrea,Belkova, Natalia V.,Chierotti, Michele R.,Epstein, Lina M.,Filippov, Oleg A.,Gobetto, Roberto,Gonsalvi, Luca,Lledos, Agusti,Shubina, Elena S.,Zanobini, Fabrizio,Peruzzini, Maurizio
, p. 1367 - 1370 (2011/04/18)
Reaction of the acidic tungsten(II) hydride 2 with the nickel(II) pincer complex 1 in either THF or toluene after an initial dihydrogen bonding (DHB) interaction led to the formation of the Ni-W bimetallic species 3 (see picture). The first example of DHB between two metal hydrides with opposite polarity was analyzed by NMR and IR spectroscopy, X-ray crystallography, and DFT calculations.
Unbridged homo and hetero dinuclear complexes of Group 6 and 8 metals: Synthesis, characterization and comparison of X-ray crystallographic data
Straub, Thomas,Haukka, Matti,Pakkanen, Tapani A.
, p. 106 - 116 (2007/10/03)
Several novel compounds of the type Cp/Cp*(CO)3M-M′(CO)nCp/Cp* (M = Cr, Mo, W; M′ = Ru, n = 2; M′ = Mo, n = 3; Cp = C5H5, Cp* = C5Me5) were synthesized, characterized, their structures compared and preliminary reactivity studies were carried out. The main investigations were focused on the molybdenum and ruthenium containing heterobimetallic compounds Cp(CO)3Mo-Ru(CO)2Cp (1) as well as Cp(CO)3Mo-Ru(CO)2Cp* (2) and Cp*(CO)3Mo-Ru(CO)2Cp (3), the latter two representing a 'mixed-metal mixed-ligand' type of complexes with the former (1) having identical ligands on both metal cores. For the first time comparison of properties of unbridged bimetallic complexes with molybdenum and ruthenium metal cores was elaborated. The novel Cp(CO)3Mo-Mo(CO)3Cp* (4) consists of two identical metal cores and of 'mixed' ligands. 4 was prepared by treating NaMo(CO)3Cp with Cp*Mo(CO)3Br (5) after a route for the synthesis of the latter was established. 1 reacted with halides or AlCl3, respectively, under cleavage of the metal-metal bond to form Cp(CO)nMHal (M = Mo, n = 3; M = Ru, n = 2; Hal = Br, I, Cl) but was shown to be inert towards substrates such as CO2 CO, PPh3 or CS2 under the chosen conditions. The corresponding anionic species Cp(CO)nM- were obtained when 1 was reacted with alkali metal benzophenyl ketyl.
