16954-96-4Relevant articles and documents
Infrared Spectra of Diacetylene-Hydrogen Fluoride Complexes in Solid Argon
Patten, Kenneth O.,Andrews, Lester
, p. 3910 - 3916 (1986)
Diacetylene-hydrogen fluoride complexes and their deuterated counterparts have been characterized in solid argon at 10 K by infrared spectroscopy.The observation of two new sets of H-F stretching, C-H stretching, and C-H bending absorptions indicates that two primary product 1:1 complexes were trapped in the matrix.These absorption bands characterize a C4H2--HF ? complex and a C4H2--FH ? complex whose relative yields exhibit a deuterium substitution dependence consistent with a preference for deuterium in the bonding position.The relative values of the νs (H-F stretching) and ν1 (H-F librational) modes for the diacetylene--HF and acetylene--HF ? complexes reveal weaker hydrogen bonding in the diacetylene--HF complex.Annealing produced comparable increased yields of both 1:1 complexes, suggesting combarable stabilities, and a marked increase in a C4H2--(HF)2 complex.
Rate Constants (296-1700 K) for the Reactions C2H + C2H2 -> C4H2 + H and CD2 + C2D2 -> C4D2 + D
Shin, Kuan S.,Michael, J. V.
, p. 5864 - 5869 (1991)
Rate constants for the reactions C2H + C2H2 -> C4H2 + H and C2D + C2D2 -> C4D2 + D have been measured over the temperature range 296-1475 and 1226-1700 K, respectively.For the high-temperature experiments, the method was the laser photolysis-shock tube technique (LP-ST); however, for the room-temperature experiments, the laser photolysis-resonance absorption (LP-RA) technique was used.These techniques utilize the atomic resonance absorption spectroscopy (ARAS) method to monitor H or D atom formation.The results for C2H + C2H2 -> C4H2 + H may be represented by the Arrhenius expression k1H = 3.02*10-10exp(-235 K/T) cm3 molecule-1 s-1 or may be represented by the simple average of all values, k1H = (1.9 +/- 0.8)*10-10 cm3 molecule-1 s-1, over the temperature range 296-1475 K.The rate constant for the reaction C2D + C2D2 -> C4D2 + D can be represented by a simple average of the experimental values, k1D = 1.8 +/- 0.5)*10-10 cm3 molecule-1 s-1, over the temperature range 1226-1700 K.The primary quantum yield for H atom production from acetylene by single-photon absorption at 193.3 nm has also been determined to be 0.21 +/- 0.04.
THE HARMONIC FORCE FIELD AND ABSOLUTE INFRARED INTENSITIES OF DIACETYLENE
Koops, TH.,Visser, T.,Smit, W. M. A.
, p. 179 - 196 (1984)
The frequencies, harmonic force field and absolute IR intensities for C4H2 and C4D2 are reported.The experimental harmonized frequencies obey the Teller-Redlich product rule very well.An approximate harmonic force field was obtained from a refinement procedure in which the starting values are adjusted in order to fit the experimental harmonized C4H2 and C4D2 frequencies.The starting force constant values were taken from the harmonic force field of propyne.The integrated IR intensities were determined according to the Wilson-Wells-Penner-Weber method, using nitrogen as a broadening gas at a pressure of 60 atm.The results of the F-sum rule clearly reveal the internal consistency of the measurements.Two sets of values can be derived from the experimental intensities by use of an iterative least-squares fitting procedure.One final set can be selected by applying the isotopic invariance criterion and by comparing with the corresponding derivatives of propyne.The final values are reduced to bond-charge parameters and atomic charges.The bond-charge parameter values are compared with the corresponding values of some common set of intensity parameters recently reported for the series C2H2, CH3CCH and CH3CCCH3.
