Direct Detection of Dimethylstannylene and Tetramethyldistannene in Solution and the Gas Phase by Laser Flash Photolysis of 1,1-Dimethylstannacyclopent-3-enes

2005 ◽  
Vol 127 (49) ◽  
pp. 17469-17478 ◽  
Author(s):  
Rosa Becerra ◽  
Peter P. Gaspar ◽  
Cameron R. Harrington ◽  
William J. Leigh ◽  
Ignacio Vargas-Baca ◽  
...  
1980 ◽  
Vol 73 (9) ◽  
pp. 4693-4694 ◽  
Author(s):  
Nobuaki Nakashima ◽  
Haruo Inoue ◽  
Minoru Sumitani ◽  
Keitaro Yoshihara

1989 ◽  
Vol 18 (9) ◽  
pp. 1615-1618 ◽  
Author(s):  
Ikuo Naito ◽  
Akito Ishida ◽  
Kazuki Yamamoto ◽  
Setsuo Takamuku ◽  
Kazuaki Isomura ◽  
...  

2015 ◽  
Vol 68 (11) ◽  
pp. 1707 ◽  
Author(s):  
H. Dushanee M. Sriyarathne ◽  
Kosala R. S. Thenna-Hewa ◽  
Tianeka Scott ◽  
Anna D. Gudmundsdottir

Laser flash photolysis of 2-methyl-1-phenylbut-3-en-1-one (1) conducted at irradiation wavelengths of 266 and 308 nm results in the formation of triplet 1,2-biradical 2 that has λmax at 370 and 480 nm. Biradical 2 is formed with a rate constant of 1.1 × 107 s–1 and decays with a rate constant of 2.3 × 105 s–1. Isoprene-quenching studies support the notion that biradical 2 is formed by energy transfer from the triplet-excited state of the ketone chromophore of 1. Density functional theory calculations were used to verify the characterization of triplet biradical 2 and validate the mechanism for its formation. Thus, it has been demonstrated that intramolecular sensitization of simple alkenes can be used to form triplet 1,2-biradicals with the two radical centres localized on the adjacent carbon atoms.


ChemInform ◽  
1990 ◽  
Vol 21 (26) ◽  
Author(s):  
I. NAITO ◽  
A. ISHIDA ◽  
K. YAMAMOTO ◽  
S. TAKAMUKU ◽  
K. ISOMURA ◽  
...  

2006 ◽  
Vol 84 (7) ◽  
pp. 934-948 ◽  
Author(s):  
William J Leigh ◽  
Ileana G Dumbrava ◽  
Farahnaz Lollmahomed

Photolysis of 1,3,4-trimethyl-1-phenylgermacyclopent-3-ene (5) in hydrocarbon solvents containing isoprene, methanol, or acetic acid affords 2,3-dimethyl-1,3-butadiene (DMB) and the expected trapping products of methyl phenylgermylene (GeMePh) in chemical yields exceeding 90%. The germylene has been detected in hexane solution by laser flash photolysis as a short-lived species (τ ~ 2 µs) exhibiting a UV-vis absorption spectrum centered at λmax = 490 nm. It decays with second-order kinetics and a rate constant close to the diffusion-controlled limit, with the concomitant growth of a second longer-lived transient (λmax = 420 nm) that is assigned to a mixture of (E)- and (Z)-1,2-dimethyl-1,2-diphenyldigermene (4). Absolute rate constants have been determined for the reactions of the germylene with primary and tertiary amines (n-BuNH2 and Et3N, respectively), acetic acid (AcOH), a terminal alkyne and alkene, isoprene, DMB, CCl4, and the group 14 hydrides Et3SiH and Bu3SnH. GeMePh is slightly more reactive than GePh2 towards all the reagents studied in this work; both are significantly less reactive than GeMe2 toward the same substrates. Absolute rate constants for the reactions of 4 have also been measured or assigned upper limits in every case and are compared to previously reported values for tetraphenyl- and tetramethyl-digermene with the same reagents.Key words: germylene, digermene, kinetics, laser flash photolysis, germirane, germirene, vinylgermirane, complex, UV–vis spectrum, insertion, addition.


2007 ◽  
Vol 129 (47) ◽  
pp. 14566-14567 ◽  
Author(s):  
Yue-Ting Wang ◽  
Jin Wang ◽  
Matthew S. Platz ◽  
Michael Novak

2017 ◽  
Vol 19 (34) ◽  
pp. 23345-23356 ◽  
Author(s):  
Michael K. M. Ward ◽  
David M. Rowley

The kinetics of the reaction between gas phase BrO and HO2 radicals, BrO + HO2 → HOBr + O2 (1), have been studied over the atmospherically relevant temperature range T = 246–314 K and at ambient pressure, p = 760 ± 20 Torr, using laser flash photolysis coupled with ultraviolet absorption spectroscopy.


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