12108-11-1Relevant articles and documents
Matrix effects and their role in the low-temperature photochemistry of (η-Aniline)Cr(CO)3
Alamiry, Mohammed H.,Long, Conor,Fidgeon, Padraig P.,Pryce, Mary T.
, p. 1634 - 1640 (2010)
The low-temperature chemistry and photochemistry of (η6- Aniline)Cr(CO)3 was investigated by matrix isolation techniques in frozen CH4 or N2. The spectroscopic properties of the matrix changed both during the de
Adduct-Mediated Photochemistry. Evidence for Excited-State Reordering in (Acetophenone)tricarbonylchromium(0) upon Adduct Formation with Tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)europium(III)
Schreiner, Rodney,Ellis, Arthur B.
, p. 3374 - 3381 (1982)
The electronic spectra of several (arene)tricarbonylchromium(0) complexes (arene = aniline, anisole, benzaldehyde, benzene, acetophenone, acenaphthene) and the photochemical reactivity of the latter three species have beeen investigated in isooctane solution in the absence and presence of the title europium(III) β-diketonate complex, Eu(fod)3.These complexes possess a band whose positional dependence on arene substituent leads to its assignment as predominantly Cr->arene charge transfer (MLCT).Addition of Eu(fod)3 produced spectroscopic changes only for the acetophenone and benzaldehyde complexes, red-shifting the λmax values of their MLCT bands by over 1000 cm-1 and shifting their IR terminal carbonyl stretching bands to higher energy by ca. 10 cm-1.These spectral changes are ascribed to adduct formation wherein the arene carbonyl oxygen atom, serving as a site of Lewis basicity, coordinates to the Lewis acid, Eu(fod)3.Spectrophotometric titrations support the presence of predominantly 1:1 adducts whose formation constants are ca. 103 M-1.Visible and near-UV photolysis of the benzene, acetophenone, and acenaphthene complexes in 1-pentene/isooctane solution results in the disappearance of the complexes, presumably through photosubstitution of CO by 1-pentene, with quantum efficiencies, φd, of ca. 0.7, 0.2, and 0.001, respectively.Addition of Eu(fod)3 affected φd for only the acetophenone complex: spectroscopic evidence indicates that the adduct undergoes the same photoreaction as the free complex but far less efficiently - φd is ca. 0.02.The decline in φd for the complexes examined roughly parallels the red-shift in their MLCT bands and is consistent with a model developed for other low-spin d6 systems: the MLCT excited state is believed to be inert toward substitution; as it is tuned to below a ligand field excited state whose population leads to substitution, φd diminishes.The adduct photoreactivity is readly subsumed in this excited-state reordering model.Implications of adduct-mediated perturbation of excited-state properties are discussed.
A laser flash photolysis, matrix isolation, and DFT investigation of (η6-C6H5Y)Cr(CO)3 (Y = NH2, OCH3, H, CHO, or CO2CH3)
Alamiry, Mohammed A.H.,Brennan, Peter,Long, Conor,Pryce, Mary T.
, p. 2907 - 2914 (2008)
The quantum yield for arene displacement from (η6-C6H5Y)Cr(CO)3 was measured in 1,1,2-trifluorotrichloroethane (Y = NH2, OCH3, H, CHO, or CO2CH3). Values of 0.24, 0.27, 0.15, 0.17, and 0.32 were obtained respectively (λexc. = 355 nm). These values are significantly higher than those measured for photoinduced arene loss in hydrocarbon solvents using the same excitation wavelength. Laser flash photolysis of (η6-C6H5Y)Cr(CO)3 in 1,1,2-trifluorotrichloroethane (λexc. = 355 nm) resulted in the rapid formation (6. Matrix isolation experiments on (η6-C6H5Y)Cr(CO)3 (Y = H or CHO) at 12 K in CH4 or CO-doped CH4 matrixes using monochromatic irradiation confirmed the presence of two discrete excited states, one leading to CO-loss and the other to arene-loss. The results correlate with the calculated electron drift in the excited state derived from density functional theory and time dependent density functional theory calculations.
Protodeboronation of arylboronic acids and triarylboroxines in Bu2O/THF
Beckett, Michael A.,Gilmore, Robert J.,Idrees, Khalid
, p. 47 - 49 (2007/10/02)
The arylboron compounds Ph3B3N3Me3, Ar3B3O3, or ArB(OH)2 (Ar = Ph, p-BrC6H4, p-MeC6H4, m-NH2C6H4) react with in refluxing Bu2O/THF (9:1) to afford the η6-arene)tricarbonylchromium(0) complexes of the protodeboronated substrates in yie
THE CONFORMATIONS OF SOME MONO-SUBSTITUTED DERIVATIVES OF (η6-BENZENE)TRICARBONYLCHROMIUM(0) FROM DIPOLE MOMENT AND ELECTRIC BIREFRINGENCE STUDIES
Aroney, M. J.,Cooper, M. K.,Englert, P. A.,Pierens, R. K.
, p. 99 - 108 (2007/10/02)
Experimental dipole moments and molar Kerr constants (at 589 nm) are reported for (η6-C6H5Y)Cr(CO)3, where Y=CHO, COCH3, COOCH3, OCH3, NH2, N(CH3)2 and NH(CH3), examined as solutes in dioxan at 298 K.Analysis of these data in conjunction with i
