16742-97-5Relevant academic research and scientific papers
Direct photolytic route to trans-Cr(CO)4(AsPh3)2 and crystal structures of cis-Mo(CO)4(AsPh3)2 and cis-W(CO)4(AsPh3)2
Bergstrom, Christina L.,Luck, Rudy L.
, p. 77 - 83 (2008/10/08)
The preparation of trans-Cr(CO)4(AsPh3)2 is accomplished in reasonable yield by the direct photolysis of a solution of Cr(CO)6 and an excess of AsPh3 in heptane. The structures of cis-Mo(CO)4(AsPh3)2 and cis-W(CO)4(AsPh3)2 are reported. These are found to be isostructural and consist of distorted octahedral geometries with As-M-As angles of 102.56(2) and 102.62(2)° for M = Mo and W, respectively. The Mo-As distances of 2.6428(9) and 2.6489(9) A? are significantly longer than those in the W analogue at 2.6384(6) and 2.6361(6) A?. On the basis of a comparison to literature data, the AsPh3 ligands in these molecules can be described as extremely compressed.
Triphenyl-phosphine and -arsine analogues which facilitate the electrospray mass spectrometric analysis of neutral metal complexes
Decker, Corry,Henderson, William,Nicholson, Brian K.
, p. 3507 - 3513 (2007/10/03)
The six triarylphosphines PPhn(C6H4OMe-p)3-n and PPhn(C6H4NMe2-p)3-n (n = 0-3) and the arsine As(C6H4OMe-p)3 (L) have been synthesized and examined for their use in the electrospray mass spectrometric (ESMS) study of metal complexes. This has been tested with selected examples of the complexes [Mo(CO)4L2], [Fe(CO)3L2], [Fe(CO)4L], [Ru3(CO)9L3], cis-[PtCl2L2], [PdCl2L2] and [AuCl(L)]. All of the metal carbonyl complexes of these ligands gave [M + H]+ ions in their spectra, while in contrast the analogous PPh3 complexes do not, suggesting that these electrospray-friendly ligands should be useful for the characterisation of a wide range of complexes by ESMS. The incorporation of the ligands into metal halide complexes however does not allow the observation of [M + H]+ ions, with ions formed by the previously reported halide-loss mechanism being the only ones observed. The Royal Society of Chemistry 1999.
Crystal Structures of , and (M = Mo or W): A Comparative Study of Structure and Bonding in Complexes (E = P, As or Sb; M = Cr, Mo or W)
Aroney, Manuel J.,Buys, Irmi E.,Davies, Murray S.,Hambley, Trevor W.
, p. 2827 - 2834 (2007/10/02)
Crystal structures have been determined for , and (M = Mo or W) as part of a systematic study of a series of nine complexes (M = Cr, Mo or W; E = P, As or Sb).Trends in bond lengths and angles are rationalised in terms of streric and electronic interactions between the bonded M(CO)5 and EPh3 fragments.Comparison is made between the solid-state geometry of the free and co-ordinated EPh3.Torsion angles defining the disposition of the EPh3 groups in relation to M(CO)5 show little variation within the series.For all nine complexes the EPh3 groups have propeller geometry with small deviations from symmetric C3 structures.The studies were extended to include other related complexes.Trends in the strutural parameters of 29 such compounds are related to the steric behaviour and ?-acceptor capacity of the ligands L.It is shown that M-P bond dimensions are not adequately explained by hybridisation changes of the phosphorus atom in the ligand L.
Molibdenum-95 nuclear magnetic resonance studies on disubstituted molibdenum(0) carbonyls
Alyea, Elmer C.,Somogyvari, Arpad
, p. 397 - 400 (2007/10/02)
Molibdenum-95 nmr spectral data are reported for 40 cis- and trans-Mo(CO)4LL' compounds and the chemical shifts discussed in relation to a simplified Ramsey expression for the paramagnetic shielding term.The identification of mixtures of products of the type Mo(CO)6-nLn is shown to be easily accomplished by 95Mo nmr spectroscopy.The 95Mo chemical shifts provide a sensitive probe of structural and electronic effects, as illustrated for several cyclic nitrogen ligands as well as a range of phosphine ligands in the Mo(CO)4LL' complexes.
Heat of reaction of (norbornadiene)molybdenum tetracarbonyl with monodentate and bidentate ligands. Solution thermochemical study of ligand substitution in the complexes cis-L2Mo(CO)4
Mukerjee, Shakti L.,Nolan, Steven P.,Hoff, Carl D.,Lopez De La Vega, Ramon
, p. 81 - 85 (2008/10/08)
The enthalpy of reaction of (NBD)Mo(CO)4 (NBD = norbornadiene) with a number of monodentate and bidentate ligands forming cis-L2Mo(CO)4 has been measured at 30°C in THF solution. The heats of reaction span a range of 33 kcal/mol. The order of stability for monodentate ligands is PCl3 6H5)3 6H5)3 3 6H5)3 6H5)2(CH3) 6H5)(CH3)2 3)3 3 6H11)NC 3 3. The series of chelating bidentate phosphines R2P-(CH2)nPR2 (n = 1-4, R = C6H5; n = 1, 2, R = CH3) and several related ligands were investigated. The chelating ring systems in the metallacycles show strain energies of about 8 kcal/mol for four-membered rings. The mixed ligand (C6H5)2PCH2CH2-As(C 6H5)2 shows a heat of binding midway between the heats of binding of (C6H5)2PCH2CH2P(C 6H5)2 and (C6H5)2AsCH2C-H2As(C 6H5)2, implying group additivity in this system. The complex (phen)Mo(CO)4 is some 5 kcal/mol more stable than (bpy)Mo(CO)4, presumably due to conformational effects in the free ligand. The ligand 1,5-cyclooctadiene forms a complex 2 kcal/mol less stable than that of norbornadiene. The influences of steric and electronic factors in determining the Mo-L bond strength are discussed.
Oxygen atom transfer reaction to metal carbonyls. Kinetics and mechanism of CO-substitution reactions of Mo(CO)5L in the presence of (CH3)3NO
Gao, Yi-Ci,Shi, Qi-Zhen,Kershner, David L.,Basolo, Fred
, p. 188 - 191 (2008/10/08)
Kinetic data are reported for the reactions of Mo(CO)5L (where L1 = P(c-Hx)3, P(n-Bu)3, NMe3, py, PPh3, AsPh3, P(OEt)3, or P(OMe)3) with L in the presence of Me3NO to form cis-Mo(CO)4L2. The rates of reactions are second order: first order in Mo(CO)5L concentration, first order in Me3NO concentration, and zero order in L concentration. For ligand L with cone angles less than 135°, the rates of reaction increase with increasing stretching frequency of the CO bands in the IR. This supports the proposed mechanism, which involves attack by the O atom of Me3NO on a C of a CO cis to L in Mo(CO)5L For L = PPh3 or AsPh3, the reactions are faster than expected on the basis of their νCO values, and this is discussed in terms of steric effects.
