The reactivity of the azidyl radical (N-3(.)) With olefins has been studied in acetonitrile solution using time-resolved UV-vis and infrared (TRIR) laser flash photolysis techniques. Azidyl radicals, formed by electron transfer from azide to excited state ketones, combine with excess azide in aceton...

Semianalytic perturbative approaches for investigating the spectroscopy, and the underlying dynamics, associated with fast time-resolved, two-photon, two-color, pump-probe, low intensity laser-molecule interactions are developed and discussed. In particular the perturbation theory is developed with ...

The S1 population decay times of azulene and 4,6,8-trimethylazulene have been measured in solvents with a wide range of viscosities using a two-photon, two-color, pump-probe method. The S, lifetimes vary as expected on the basis of the energy gap law. No effect of solvent viscosity is observed, cont...

The lifetimes of the S1 states of azulene, azulene-d8, 4,6,8-trimethylazulene, and guaiazulene (1,4-dimethyl-7-isopropylazulene) have been measured in three nonviscous solvents of different polarity and structure using a two-photon, two-color, pump-probe method with subpicosecond time resolution. A ...

This work describes the fluorescence enhancement of the anilinonaphthalene sulfonate probes 1,8-ANS, 2,6-ANS, and 2,6-TNS via complexation with PAMAM dendrimer hosts of Generation 4, 5 and 6. The use of this set of three very closely related probes allows for comparative binding studies, with specif...

Single-electron oxidation of the known Cr(II) bis(amidinate) Cr[(Me3SiN)2CPh]2 (1) provides synthetic access to neutral Cr(III) complexes. The complexes Cr[(Me3SiN)2CPh]2X were prepared by reaction of 1 with AgO2CPh (X = O2CPh, 2), of 1 with iodine in THF (X = I/THF, 3), or of 1 with iodine in penta...

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Abstract: Laser flash photolyses of 2-, 3-, and 4-diazoacetylpyridines 8 give the corresponding pyridylketenes 7 formed by Wolff rearrangements, as observed by time-resolved infrared spectroscopy, with ketenyl absorptions at 2127, 2125, and 2128 cm-1, respectively. Photolysis of 2-, 3-, and 4-8 in C...

Abstract: The title ketene 2 has been generated by laser flash photolysis and observed in solution for the first time, using time-resolved infrared spectroscopy. The kinetics of the reactivity of 2 with H2O, MeOH, and Et2NH with relative reactivities of 1.0, 2.0, and 73 have been measured. These are...

Abstract: A solid precipitate is formed immediately upon the mixing of aqueous salt solutions of the fluorescence probe 1-anilino-8-naphthalenesulfonate (1,8-ANS) and the cage compound cucurbituril. The resulting solid compound is highly fluorescent, with a maximum emission at ca. 478 nm. Single cry...

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Abstract: This work describes the fluorescence enhancement of the probes 2,6- and 1,8-ANS via complexation with the macrocyclic host cucurbit[7]uril (Q7). The association of these two guests with the Q7 host has been studied using fluorescence, 1H NMR spectroscopy, and molecular modeling. In the cas...

Abstract: Photolysis of N-nitrosamines in acidic acetonitrile produces aminium radical cations via protonation of the initially-formed aminyl radicals. The kinetics of these species can be monitored by transient UV spectroscopy via their absorption band which is found at ca. 300 nm in the case of th...

Abstract: The interconversion of cyclobutene-1,2-diones (1) and 1,2-bisketenes (RC=C=O)2 (2) has been surveyed for different combinations of substituents R = H, Me, t-Bu, Ph, Me3Si, CN, Cl, Br, R1O, alkynyl, and PhS. The bisketenes 2 have been generated by flash photolysis, and the kinetics of their...

Abstract: Laser flash photolysis with time-resolved infrared detection of transients (LFP-TRIR) has been used to study the IR spectroscopy and reactivity of a number of substituted ketenes, prepared by the 308-nm photolysis of -diazocarbonyl precursors in acetonitrile solution at room temperature. T...