First direct detection of transient organic free radicals in solution by time-resolved infrared spectroscopy. Kinetic studies on some acyl radicals

1991 ◽  
Vol 113 (5) ◽  
pp. 1869-1870 ◽  
Author(s):  
A. G. Neville ◽  
C. E. Brown ◽  
D. M. Rayner ◽  
J. Lusztyk ◽  
K. U. Ingold
Keyword(s):  
Infrared Spectroscopy ◽  
Free Radicals ◽  
Direct Detection ◽  
Kinetic Studies ◽  
Time Resolved ◽  
Acyl Radicals ◽  
Time Resolved Infrared Spectroscopy

Time Resolved Infrared Spectroscopy: Kinetic Studies of Weakly Binding Ligands in an Iron–Iron Hydrogenase Model Compound

2012 ◽  
Vol 51 (13) ◽  
pp. 7362-7369 ◽  
Author(s):  
Sohail Muhammad ◽  
Salvador Moncho ◽  
Edward N. Brothers ◽  
Marcetta Y. Darensbourg ◽  
Donald J. Darensbourg ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Model Compound ◽  
Kinetic Studies ◽  
Time Resolved ◽  
Iron Hydrogenase ◽  
Iron Iron ◽  
Time Resolved Infrared Spectroscopy

Kinetic and Spectroscopic Studies on Acyl Radicals in Solution by Time-Resolved Infrared Spectroscopy

1995 ◽  
Vol 48 (2) ◽  
pp. 363 ◽  
Author(s):  
CE Brown ◽  
AG Neville ◽  
DM Rayner ◽  
KU Ingold ◽  
J Lusztyk
Keyword(s):  
Infrared Spectroscopy ◽  
Rate Constant ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Spectroscopic Studies ◽  
Kinetic Properties ◽  
Acyl Radical ◽  
Time Resolved ◽  
Acyl Radicals ◽  
Time Resolved Infrared Spectroscopy

A number of acyl radicals, RĊ=O, have been generated in hexane or di -t-butyl peroxide as solvent at room temperature by 308 nm laser flash photolysis, and their spectroscopic and kinetic properties have been examined by time-resolved infrared spectroscopy. The C=O stretching frequencies for the RĊ=O radicals are found to be higher than those of the corresponding aldehydes, RCHO, by between 108 and 128 cm-1, an effect attributed to a higher C=O bond order in the radicals. For the RĊ=O radicals some typical values of vC =O are: CH3Ċ=O, 1864 cm-1; (CH3)3CĊ=O, 1848 cm-1; and C6H5Ċ=O, 1828 cm-1, while the corresponding acylperoxyl radicals, RC(O)OO, formed by reaction with oxygen have vC =O values of 1838, 1840 and 1820 cm-1, respectively. The acyl radicals exhibit a reactivity towards a variety of substrates that is roughly comparable to that of simple alkyl radicals. For reactions of the benzoyl radical some typical rate constants/M-1 s-1 are: CCl4, 6.0x104; C6H5SH, 4.8×107; CCl3Br, 2.2×108; Tempo, 1.1×109; and oxygen, 1.8×109. Alkanoyl radicals have a rather similar reactivity to benzoyl. The propanoyl radical reacts with tributyltin deuteride with a rate constant of 3×105 M-1s-1. The hex-5-enoyl radical undergoes a 5-exo-trig cyclization to form the 2-oxocyclopentylmethyl radical with a rate constant of 2.2×105 s-1, a value which is almost identical to that for cyclization of the hex-5-enyl radical. It is hoped that our kinetic data will prove useful in the planning of organic synthetic strategies which involve acyl radical chemistry.

A quantum cascade laser setup for studying irreversible photoreactions in H2O with nanosecond resolution and microlitre consumption

2020 ◽  
Vol 22 (45) ◽  
pp. 26459-26467
Author(s):  
Jessica L. Klocke ◽  
Tilman Kottke
Keyword(s):  
Infrared Spectroscopy ◽  
Quantum Cascade Laser ◽  
Time Resolved ◽  
Quantum Cascade ◽  
Time Resolved Infrared Spectroscopy ◽  
Laser Setup

Flavin photoreduction in H2O is elucidated by developing a quantum cascade laser setup for time-resolved infrared spectroscopy on irreversible reactions.

Water Transport in Proton Exchange Membranes: Insights from Time-Resolved Infrared Spectroscopy

2019 ◽  
Vol 33 (1) ◽  
pp. 1029-1033 ◽  
Author(s):  
Daniel Hallinan ◽  
Maria Grazia De Angelis ◽  
Marco Giacinti Baschetti ◽  
Giulio Sarti ◽  
Yossef A. Elabd
Keyword(s):  
Infrared Spectroscopy ◽  
Water Transport ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Time Resolved ◽  
Time Resolved Infrared Spectroscopy
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