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Molybdenum complexes, photolysis

Another route to neutral bisalkyne complexes is from the trifluoro-methylacyl precursor which deinserts carbon monoxide to yield trifluoro-methyl molybdenum products. Photolysis of CpMo(CO)3[C(0)CF3] in the presence of CF3C=CCF3 forms CpMo(CF3C=CCF3)2(CF3) CpMo-(DMAC)2CF3 is formed without photolysis (98). Addition of hexafluoro-butyne to CpMo(CO)(MeC=CMe)(CF3) forms the mixed bisalkyne via CO substitution. [Pg.17]

Reviews have appeared of the photophysics of molybdenum complexes, primary and secondary processes in organometallic chemistry, flash photolysis of Pe(CO)5 and Cr(CO)g, dinuclear manganese carbonyl compounds, the photochemistry of metal complexes isolated in low temperature matrices, cluster complexes, diene complexes, photoproduction of coordinativeiy unsaturated species containing rhodium or iridium, and redox chemiluminescence of organometallic compounds.Synthetic and metal organic photochemistry in industry has also been reviewed. [Pg.103]

Molybdenum(IV).—Several reports have appeared dealing with the existence and properties of molybdenum(iv) in aqueous solutions. Kinetic studies, however, have been concentrated upon photolytic investigations of cyanides of molybdenum(iv). Photolysis of the [Mo(CN)8] ion in liquid ammonia and in O.lM-NaOH have been reported. The mechanism proposed for the latter study agrees with the results of Samotus (1971) in which a relatively short-lived intermediate [Mo(CN) -OH] and a longer-lived intermediate [Mo(CN)e] were observed. The complex ions [Mo(CN)70H] and [MoO(OH)(CN)4] , relevant to the photochemistry of the [Mo(CN)g] ion, have now been characterized. ... [Pg.172]

The photochemical studies of transition metal hydride complexes that have appeared in the chemical literature are reviewed, with primary emphasis on studies of iridium and ruthenium that were conducted by our research group. The photochemistry of the molybdenum hydride complexes Mo(tj5-C5H5)2M2] and [MoH4(dppe)2] (dppe = Ph2PCH2CH2PPh2), which eliminate H2 upon photolysis, is discussed in detail. The photoinduced elimination of molecular hydrogen from di-and polyhydride complexes of the transition elements is proposed to be a general reaction pathway. [Pg.188]

Photooxidation of the Mo2+ moiety has also been demonstrated for Mo2(aq)4, Mo2Clg , Mo2 Br (244), and Mo2Cl4(PR3)4 (245). Molyb-denum(III) products are observed upon 254 nm irradiation of these complexes as opposed to the molybdenum (2.5+) species formed upon photolysis of the Mo2(S04)4 dimer. Molecular hydrogen and a hydroxy bridged Mo3 dimer are... [Pg.291]

A number of readily reversible cr-7r rearrangements have been observed wherein a labile ligand such as carbon monoxide is lost by pyrolysis or photolysis, producing a coordinatively unsaturated metal center, which then regains coordinative saturation by means of a tr-n rearrangement. For example, irradiation of o--alkyl-7r-cyclopentadienyl-molybdenum tricarbonyl (15) produces the rr-allene complex (16) (25). These... [Pg.233]

Reduction of [Mo(CO)(Bu C=CH)2Cp] + BF4 with KBHBu3(s) at — 78°C in an atmosphere of carbon monoxide yields a complex of a vinyl substituted y-lactone linked tj3 t]2 (220). The allylidene ruthenium complex 64, obtained by photochemical addition of one alkyne molecule to a /x-carbene derivative, is transformed into pentadienylidene complexes 65 and 66 on photolysis with more alkyne substrate. These reactions show clearly the stepwise growth of chains in alkyne oligomerizations at dimetal centers [Eq. (31)] (221). Similar reactions are also known for dinuclear iron (222), molybdenum (223), and tungsten (224) complexes. [Pg.154]

The remarkable xenon complex Cr(CO)5(Xe) was also obtained by UV photolysis of Cr(CO)6 in liquefied xenon and found to have a lifetime of ca. 2 s at -98°C [117]. Later, the corresponding molybdenum and tungsten complexes Mo(CO)5(Xe) and W(CO)5(Xe) were generated in a similar way and characterized by time-resolved IR spectroscopy [118]. The bond energies Cr-Xe, Mo-Xe, and W-Xe were not as low as previously anticipated and determined to be 8-9 kcal/mol, independent of the group VI metal. [Pg.103]

The photolyses of a series of binuclear molybdenum carbonyl complexes containing alkyne ligands have been studied in frozen Nujol matrices at 77 K. IR spectra indicated the formation of two isomeric carbonyl-loss products in each case, one of which seems to be formed by photolysis into the... [Pg.311]

Molybdenum and Tungsten.—Flash photolysis and e.s.r. studies40 have been carried out on [Mo(CN)8]3- in solutions of varying pH, concentration, and solvent. The results are consistent with (11) as the primary reaction following excitation of the complex to an LMCT state. [Pg.157]


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See also in sourсe #XX -- [ Pg.1345 ]

See also in sourсe #XX -- [ Pg.3 , Pg.1345 ]




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Complex photolysis

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