Activation parameters in flash photolysis studies of Mo(CO)6

Reported is a combined time-resolved optical (TRO) and infrared (TRIR) spectroscopic investigation of the flash photolysis of MO(CO)6 in cyclohexane solution. TRIR studies using 308 nm excitation led to transient bleaching of the strong v(CO) band at 1987 cm(-1) of Mo(CO)(6) and appearance of new bands at 1931 and 1964 cm(-1) attributed to Mo(CO)(5)(SOl). Using a high pressure/variable temperature flow cell, the kinetics of back reaction with CO (k(CO)) to regenerate the hexacarbonyl was studied over the P-CO range 1-20 atm and at five temperatures. These data gave k(CO) = 4.6 +/- 0.2 x 10(6) M-1 s(-1) (298 K) and the activation parameters DeltaH(CO)(double dagger) = 32.6 +/- 13 kJ/mol and AS -7.3 +/- 11 J mol(-1) K-1 from which an interchange mechanism was proposed. The analogous species seen in the TRO experiment displayed a transient absorbance at 420 nm and analogous kinetics properties although at lower P-CO self-trapping with Mo(CO())6 (to give Mo-2(CO)(11)) is a competitive process. The Mo(CO)(5)(SOl) transient could also be trapped by "PrBr (k(RBr) = 5.3 +/- 0.7 x 10(7) M-1 s(-1)). (C) 2003 Elsevier B.V. All rights reserved.


ISCI, HY; DAG, O; MASON, WR (American Chemical Society (ACS), 1993-09-01)
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Activation behavior of an AB(2), namely (Ti0.36Zr0.64) (V0.15Ni0.58Mn0.20Cr0.07)(2) Laves phase alloy, was investigated with regards to; particle size, ball milling and hot alkaline treatments. Galvanostatic cycling in open cells showed that an untreated alloy initially had almost no capacity, but reached a value of 220 mAh/g after 14 cycles. Experiments with different particle sizes showed that coarse particles activate faster yielding an improved capacity. In terms of activation more pronounced effect was...
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Hacaloğlu, Jale; Andrews, Lester (1990-12-01)
A Townsend discharge chemical ionization source has been used for matrix infrared studies of anions in the argon-N20 system. In addition to neutral products, the NO", N02", (NO)f, NN02", and 03" anions have also been isolated. Filtered visible photolysis shows different behaviors for these anions. The two isomers NN02" and (NO)2" have been identified by isotopic substitution and characterized by different 15N and 180 isotopic shifts and different structures. These matrix isolation experiments provide struct...
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Qasrawi, A. F.; Abd-Alrazq, Mariam M.; Hasanlı, Nızamı (Elsevier BV, 2014-01-15)
A new p-n interface made of p-type MgO as an optical window to the n-type Ga4Se3S crystals is investigated by means of optical reflectance, transmittance and absorbance in the incident light wavelength (k) range of 200-1100 nm. The reflectivity spectral analysis as a function of angle of incidence for MgO, Ga4Se3S and the Ga4Se3S/MgO layers revealed Brewster angles of 75 degrees, 80 degrees and 70 degrees with the corresponding dielectric constants of 13.93, 32.16 and eMgO 7: 55eGa(4)Se(3)S, respectively. T...
Molecular beam epitaxy growth of inp/ingaas structures for short wavelength infrared photodetectors
Temel, Oğuzhan; Beşikci, Cengiz; Parlak, Mehmet; Department of Micro and Nanotechnology (2014)
Indium Gallium Arsenide (In0.53Ga0.47As) is a suitable compound semiconductor for photodetector applications in the Short Wavelength Infrared (SWIR) band with its ~1.7 µm cut-off wavelength. In this work, lattice-matched InxGa1-xAs compounds (x~0.53) were grown on InP (001) substrates by the molecular beam epitaxy (MBE) method. Unintentional doping level as low as 1.96E15 cm-3 was obtained in the In0.53Ga0.47As epilayers. The X-ray diffraction full width at half maximum values were as low as 45 arc-sec disp...
Citation Formats
C. Kayran İşçi and P. Ford, “Activation parameters in flash photolysis studies of Mo(CO)6,” INORGANICA CHIMICA ACTA, vol. 357, no. 1, pp. 143–148, 2004, Accessed: 00, 2021. [Online]. Available: