Photodissociation dynamics of benzoyl chloride at 235 nm: resonance-enhanced multiphoton ionization detection of Cl and HCl.
The photodissociation dynamics of benzoyl chloride at 235 nm has been investigated and compared with that of 2-furoyl chloride. Atomic Cl and molecular HCl channels have been detected in benzoyl chloride by employing resonance-enhanced multiphoton ionization technique and time-of-flight mass spectrometry. Both the Cl fragments, Cl((2)PJ=3/2, relative quantum yield 0.70 ± 0.15) and Cl*((2)PJ=1/2), show isotropic angular distribution and bimodal translational energy distributions. The predominant high kinetic energy channel contributes 72% to the C-Cl bond scission and arises from the S1 state having nπ* character of benzoyl chloride. However, the low-energy Cl and HCl channels originate from the ground electronic state. The most plausible mechanism of HCl formation is proposed based on molecular orbital calculations. In contrast to benzoyl chloride, the HCl channel is not observed in 2-furoyl chloride on excitation at 235 nm, and this is attributed to an energy constraint.
Radiation and Photochemistry Division, Bhabha Atomic Research Centre , Trombay Mumbai - 400 085, Maharashtra, India.
Ankur
A
Saha
Monali
M
Kawade
Sumana
S
SenGupta
Hari P
HP
Upadhyaya
Awadhesh
A
Kumar
Prakash D
PD
Naik
D000465:Algorithms; D016880:Anisotropy; D001565:Benzoates / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D005663:Furans / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry*; D007700:Kinetics; D007834:Lasers; D013058:Mass Spectrometry; D008958:Models, Molecular; D015394:Molecular Structure; D017785:Photons
D001565:Benzoates; D002712:Chlorides; D005663:Furans; C048252:2-furoyl chloride; D002244:Carbon; D006851:Hydrochloric Acid; C013409:benzoyl chloride