Electron Localization in Liquid Acetonitrile

Autor:	Myran C. Sauer, Ilya A. Shkrob
Rok vydání:	2002
Předmět:	chemistry.chemical_compound Crystallography Electron transfer Reaction rate constant chemistry Analytical chemistry Physical and Theoretical Chemistry Absorption (chemistry) Solvated electron Acetonitrile Standard enthalpy of formation Electron localization function Ion
Zdroj:	The Journal of Physical Chemistry A. 106:9120-9131
ISSN:	1520-5215 1089-5639
Popis:	Time-resolved one- and two-pulse laser dc photoconductivity has been used to observe two kinds of reducing species, anion-1 and anion-2, in liquid acetonitrile. At 25 C, the standard enthalpy of conversion from anion-1 to anion-2 is -44.3 {+-} 3.6 kJ/mol and the conversion time is 3 ns. The high-temperature form, anion-1, absorbs in the IR and migrates >3.3 times faster than any other ion in acetonitrile. This rapid migration has a low activation energy of 3.2 kJ/mol (vs 7.6 kJ/mol for other ions). Anion-1 rapidly transfers the electron to acceptors with high electron affinity, with rate constant up to 10{sup 11} M{sup -1} s{sup -1}. The low-temperature form, anion-2, absorbs in the visible and exhibits normal mobility and electron-transfer rates, ca. 1.5 x 10{sup 10} M{sup -1} s{sup -1}. It reacts, by proton transfer, with two hydrogen-bonded molecules of water and/or aliphatic alcohols. Laser photoexcitation of these two solvent anions in their respective absorption bands leads to the formation of CH{sub 3} and CN{sup -}. We present arguments indicating that anion-2 is a dimer radical anion of acetonitrile, whereas anion-1 is a multimer radical anion that may be regarded as a 'solvated electron'.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f1347cdda5e970e097f2dd088898d44d https://doi.org/10.1021/jp0207580 Zobrazit plný text záznamu