Analysis of the vibrational spectra, force fields, and molecular structures of pentacarbonyl(methyl)manganese(I) and pentacarbonyl(methyl)rhenium(I)

Photochemistry of CH3Mn(CO)5: A multiconfigurational ab initio study

“…34 The CASPT2 reference weights range between 0.63 and 0.65. The same computational strategy has been used for building the state correlation diagrams, which connect the electronically ground and excited singlet states of CH 3 Mn(CO) 5 to those of the primary products CO þ CH 3 Mn(CO) 4 and CH 3 þ Mn(CO) 5 . The Cs symmetry has been retained along the channels corresponding to the axial CO loss and to the homolysis of the MnÀ ÀCH 3 bond, whereas the calculations have been performed without symmetry constraint along the path corresponding to the equatorial CO loss (cf.…”

“…The first intense bands are predicted at 37,760 cm À1 (264 nm), between 40,130 and 41,990 cm À1 (233-250 nm) and above 45,000 cm À1 at 46 800 (213 nm) and 48,510 cm À1 (206 nm) and correspond to MLCT states with a charge transfer from the manganese to the * of the carbonyls. The theoretical spectrum of CH 3 Mn(CO) 5 differs from the one of the complexes HMn(CO) 5 , HCo(CO) 4 , or CH 3 Co(CO) 4 by the absence of lowlying pure MSBCT states (3d M ? * M-R ; R¼ ¼H or CH 3 ) photoactive for the CO dissociation observed upon UV irradiation of the hydrides.…”

“…However, one strategy to generate and study reactive intermediates in catalytic carbonylations such as alkene hydroformylation or acetic acid synthesis from methanol is decarbonylation of the parent complex by means of laser irradiation. [8][9][10] Such migratory insertion of CO into a metal-alkyl bond is well illustrated by the reactivity of methylmanganese pentacarbonyl CH 3 Mn(CO) 5 , which has been the subject of a number of experimental 11,12 and computational studies. [13][14][15] The laser flash photolysis of this molecule has been studied using time resolved infrared (IR) (TRIR) and time-resolved opti-cal (TRO) detection techniques to probe structures and reactivities of unsaturated species formed via photolabilization of CO in condensed phase.…”

“…[13][14][15] The laser flash photolysis of this molecule has been studied using time resolved infrared (IR) (TRIR) and time-resolved opti-cal (TRO) detection techniques to probe structures and reactivities of unsaturated species formed via photolabilization of CO in condensed phase. 16,17 Early studies were devoted to UV photochemistry and IR spectroscopy of low-temperature matricesisolated RMn(CO) 5 (R¼ ¼H, CH 3 ) and unsaturated derivatives RMn(CO) 4 . 18,19 There has recently been a renewal of interest in transition metal carbonyls in two turns: (i) as generators of unsaturated neutral or ionized fragments using pump-probe multiphoton ionization (MPI) 20-23 ; and (ii) as precursors of thin metal or metal containing films via chemical vapor deposition (CVD).…”

Synthesis, spectroscopic characterization, X-ray structure and DFT calculations of rhenium(III) complex with bis(3,5-dimethylpyrazol-1-yl)methane

“…Recently, the electronic structures of nitrido, oxo, carbonyl, nitrosyl and nitrile rhenium complexes, as well as their spectroscopic properties, bonding and reactivity have been theoretically studied at the HF, MP2, EHT and DFT levels of theory using various basis sets [15][16][17][18][19][20][21][22][23][24]. Gancheff and co-workers [17] have performed extended tests of the ability of the B3LYP method in LANL2DZ basis set for rhenium compounds in a geometry optimization and calculation of spectral properties.…”