16337-48-7

Upstream product

• 101-02-0 triphenyl phosphite 
• 19319-48-3 cis-{Mo(CO)4(MeSCH₂CH₂SMe)} 
• 13939-06-5 molybdenum hexacarbonyl 
• 12146-37-1 (bicyclo[2.2.1]hepta-2,5-diene)tetracarbonylmolybdenum⁽⁰⁾ 
• 12109-74-9 tetracarbonyl(1,5-cyclooctadiene)molybdenum 
• 65337-26-0 bis(piperidyl)tetracarbonylmolybdenum⁽⁰⁾ 
• 59967-36-1 cis-tetracarbonylbis(piperidine)molybdenum 

Downstream Products

• 15711-66-7 Mo(CO)5(P(OPh)3) 

Relevant academic research and scientific papers

Geometrical isomerization of fac/mer-Mo(CO)3(phosphite)3 and cis/trans-Mo(CO)4(phosphite)2 catalyzed by Me3SiOSO2CF3

Geometrical isomerization of fac-Mo(CO)3L3 (L = P(OPh)3, P(OMe)3, P(OEt)3) to the mer form and that of cis-Mo(CO)4L2 (L = P(OPh)3, P(OMe)3, PPh2(OMe)) to the trans form were observed in CH2Cl2 at room temperature in the presence of a catalytic amount of Me3SiOSO2CF3 (TMSOTf). Crossover experiments suggest that a ligand dissociation is not involved in the isomerization. A catalytic cycle involving an interaction of the silicon atom in Me3Si+ with one oxygen in P(OR)3 ligands has been proposed. The first isolation and the X-ray structure analysis were attained for mer-Mo(CO)3{P(OPh)3}3 through the TSMOTf-assisted isomerization of fac-Mo(CO)3{P(OPh)3}3.

What is the real steric impact of triphenylphosphite? Solid-state and solution structural studies of cis- and trans-isomers of M(CO) 4[P(OPh)3]2 (M = Mo and W)

The steric requirements for the triphenylphosphite ligand in several molybdenum and tungsten carbonyl derivatives have been shown by X-ray crystallography to exceed the original Tolman's cone angle of 128°. That is, due to various accessible conformers possible for P(OPh)3, solid-state data predict a considerably larger cone angle for the ligand of between 140° and 160°. Importantly, the solution behavior of cis-M(CO)4[P(OPh)3]2 (M = Mo or W), coupled with similarly reported observations on a series of cis-Mo(CO) 4[PR3]2 derivatives, support this conclusion, for these molecules both undergo thermal rearrangement to the more stable trans-isomers. On the other hand, the electronically similar but sterically much smaller cis-Mo(CO)4[P(OCH2)3CEt]2 complex is thermally stable under much harsher conditions. Furthermore, a comprehensive survey of structural data for transition-metal-triphenylphosphite derivatives available in the Cambridge Crystallographic Database reveals that most molecules display conformations that dictate cone angles much greater than that originally suggested by Tolman.

cis-Tetracarbonylbis(triphenyl phosphite)-molybdenum(0)

The coordination environment of the Mo atom in the title compound, 2>, is pseudooctahedral, with principle dimensions Mo-P 2.442 (1), 2.443 (2), Mo-C(trans to P) 2.003 (6), 2.016 (6), Mo-C(trans to C 2.032 (7), 2.042 (6) Angstroem, P-Mo

Influence of atomic size on mechanism: Displacement of chelating ligands coordinating through sulfur from their chromium and molybdenum carbonyl complexes

Variable-pressure kinetics studies (to 150 MPa) at various temperatures for chelate ring displacement from cis-(S2)M(CO)4 complexes (S2 = dithiaalkane, dithiaalkene (2,5-dithiahexane, 3,6-dithiaoctane, and cis-2,2,7,7-tetramethyl-3,6-dithiaoct-4-ene); M = Cr, Mo) by L (=Lewis base (P(OR)3, R = Me, Et, i-Pr, Ph)) in chlorobenzene (CB) and 1,2-dichloroethane (DCE) have been carried out. All reactions obey the rate law -d[(S2)M(CO)4]/dt = k[(S2)M(CO)4][L]. However, calculated volumes of activation (ΔV≠) and thermal activation parameters (ΔH≠, ΔS≠) indicate that ligand displacement in the Cr complexes takes place via initial, reversible Cr-S bond fission, while for Mo and S2 = 2,5-dithiahexane and 3,6-dithiaoctane an associative pathway involving significant initial L-Mo bond making is operative. For S2 = cis-2,2,7,7-tetramethyl-3,6-dkhiaoct-4-ene and M = Mo, activation parameters (the thermal data were taken over a 70°C temperature range) are equivocal as to whether the mechanism is best described as an interchange process or in terms of competing dissociative and associative pathways. It is concluded that the mechanistic differences observed in the Cr and Mo systems result from the differing atomic sizes of these metals. The results are also discussed in terms of the properties of the chelating rings.

Molibdenum-95 nuclear magnetic resonance studies on disubstituted molibdenum(0) carbonyls

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

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.

The Mechanism of Displacement of Diene from 4-diene)(CO)4> (M = Cr, Mo, or W, diene = norbornadiene; M = Mo, diene = cyclo-octa-1,5-diene) and the cis trans Isomerization of Complexes

Kinetic studies are reported of the displacement of the diene from 4-diene)(CO)4> by phosphorus ligands to give complexes .With the exception of , all reactions exhibit a bimolecular rate law of the type -d>/dt = Kobs.>, where A = which is interpreted mechanistically as a stepwise ligand-assisted dechelation of the diene; Kobs. may be seen to increase in the order Cr reflects the increasing order of ligand nucleophilicity. cis-trans Isomerization of (L = PBu3, P(OMe)3, or P(OPh)3; M = Cr, Mo, or W) has also been studied kinetically.With the exception of 2>, all isomerizations are intramolecular.Rates of isomerization increase in the order Mo eq (=/) increases in the order W ca.Mo Cr and in the order P(OPh)3 P(OMe)3 PBu3.These results are interpreted in terms of both steric and electronic factors.

Transition-metal Chemical Shifts in Complexes of Molybdenum(0) and Tungsten(0)

Molybdenum-95 and tungsten-183 n.m.r. spectra have been measured by direct observation and by multiple-resonance methods respectively for 65 related derivatives of and with (mainly) phosphorus ligands.The chemical shifts of the two nuclei are remarkably parallel, those for (183)W being ca. 1.7 times more sensitive to changes in chemical environment than those for (95)Mo.The chemical shifts are temperature-dependent, and trends in them can be largely accounted for by variations in the mean electronic excitation energy.The metal-phosphorus spin-coupling constants are very predictable.Molybdenum-95 linewidths in many cases are quite small, and can be broadly explained by the use of a point-charge model.