Reaction of the transient species W(CO)5(cyclohexane) with cyclo-C4HnO (n = 4, 6, 8) studied by time-resolved infrared absorption spectroscopy

Alex Lugovskoy, Riki Paur-Afshari, Richard H. Schultz

פרסום מחקרי: פרסום בכתב עתמאמרביקורת עמיתים

22 ציטוטים ‏(Scopus)

תקציר

Time- and temperature-resolved infrared absorption spectroscopy is used to monitor the ligand substitution reaction of W(CO)5(cyclohexane) with a series of ligands L of the form cyclo-C4HnO (n = 4, 6, 8). Second-order rate constants for the formation of W(CO)5(L) are obtained over the temperature range 20-60 °C, and from these temperature-dependent rate constants, activation parameters for the ligand substitution reaction are obtained. We find that for L = furan, ΔH‡ = 7.1 ± 0.7 kcal mol-1 and ΔS‡ = -7.1 ± 5.1 eu; for L = 2,3-dihydrofuran, ΔH‡ = 5.9 ± 0.5 kcal mol-1 and ΔS‡ = -8.9 ± 7.3 eu; and for L = 2,5-dihydrofuran, ΔH‡ = 3.8 ± 0.2 kcal mol-1 and ΔS‡ = -14.0 ± 3.5 e.u. We find that as L becomes less strongly electron-donating, as determined by the trans C-O stretching force constant of W(CO)5L, ΔH‡rises and ΔS‡ becomes less negative. The correlation of the activation enthalpy with the properties of the products and the low activation enthalpies relative to the (CO)5W-cyclohexane bond dissociation energy are consistent with an associative interchange (Ia) mechanism for the ligand exchange.

שפה מקוריתאנגלית
עמודים (מ-עד)10587-10593
מספר עמודים7
כתב עתJournal of Physical Chemistry A
כרך104
מספר גיליון45
מזהי עצם דיגיטלי (DOIs)
סטטוס פרסוםפורסם - 16 נוב׳ 2000
פורסם באופן חיצוניכן

טביעת אצבע

להלן מוצגים תחומי המחקר של הפרסום 'Reaction of the transient species W(CO)5(cyclohexane) with cyclo-C4HnO (n = 4, 6, 8) studied by time-resolved infrared absorption spectroscopy'. יחד הם יוצרים טביעת אצבע ייחודית.

פורמט ציטוט ביבליוגרפי