Kinetic Laser Absorption Spectroscopy of Vibrationally Excited Hydroxyl Radicals on Infrared Transitions ν = 3 ← 1 and ν = 4 ← 2.

The kinetics of vibrationally excited OH(ν = 1) and OH(ν = 2) radicals was studied by time-resolved laser absorption in the overtone IR region. Two DFB laser diodes, 1509.3 and 1589 nm, were used.

Kinetics of the gas-phase reaction of hydroxyl radicals with trimethyl phosphate over the 273-837 K temperature range.

The kinetics of the reaction of hydroxyl radical (OH) with trimethyl phosphate (CHO)PO (TMP) (reaction (1)) OH + TMP → products (1) was studied at the bath gas (He) pressure of 1 bar over the 273-837 K temperature range. Hydroxyl radicals were produced in fast reactions of electronically excited oxygen atoms O(D) with either HO or H. Excited oxygen atoms O(D) were produced by photolysis of ozone, O, at 266 nm (4 harmonic of Nd:YAG laser) over the 273-470 K temperature range and by photolysis of NO at 193 nm (ArF excimer laser) over the whole temperature range including the elevated temperature range 470-837 K.

Kinetics of the Gas-Phase Reaction of Hydroxyl Radicals with Dimethyl Methylphosphonate (DMMP) over an Extended Temperature Range (273-837 K).

The kinetics of the reaction of hydroxyl radical (OH) with dimethyl methylphosphonate (DMMP, (CHO)CHPO) (reaction 1) OH + DMMP → products (1) was studied at the bath gas (He) pressure of 1 bar over the 295-837 K temperature range. Hydroxyl radicals were produced in the fast reaction of electronically excited oxygen atoms O(D) with HO. The time-resolved kinetic profiles of hydroxyl radicals were recorded via UV absorption at around 308 nm using a DC discharge HO/Ar lamp.

Magnetic field effect on the free induction decay of hydroxyl radicals (OH) in the terahertz region.

The effect of an external longitudinal magnetic field on the optical free induction decay from a free radical is observed for the first time. The experiments were performed on a rotational transition of the hydroxyl radical, OH (2Π3/2(J = 1) ← 2Π3/2(J = 0) at 83.8 cm-1), using a terahertz free electron laser.

Disproportionation Channel of the Self-reaction of Hydroxyl Radical, OH + OH → HO + O, Revisited.

The rate constant of the disproportionation channel 1a of the self-reaction of hydroxyl radicals OH + OH → HO + O (1a) was measured at ambient temperature as well as over an extended temperature range to resolve the discrepancy between the IUPAC recommended value ( = 1.48 × 10 cm molecule s, discharge flow system, Bedjanian et al. 1999, 103, 7017) and a factor of ca.

Intramolecular vibrational dynamics in free polyatomic molecules with C═O chromophore bond excited by resonant femtosecond IR laser radiation.

In nine polyatomic molecules, we have studied the intramolecular redistribution of vibrational energy from chromophore C═O group excited by a resonant femtosecond IR laser radiation at a wavelength of ∼5 μm. All experiments have been performed in the gas phase using the IR-IR pump-probe technique in combination with the spectral analysis of the probe radiation. For molecules with one C═O end group, characteristic times of intramolecular vibrational redistribution (IVR) lie in the range between 2.

Infrared multiple photon dissociation of chloromethyltrifluorosilane.

Infrared multiphoton absorption and dissociation of chloromethyltrifluorosilane molecules under the action of pulsed transversely excited atmospheric pressure CO2 laser were experimentally studied. Dissociation products were analyzed. The dissociation proceeds via chlorine atom transfer from carbon to silicone.