The effect of the macrocyclic host compounds cucurbit[n]urils (Qn), with n = 5 - 7, on the fluorescence of the biologically active compound curcumin has been studied. Curcumin, the main constituent of the Indian spice turmeric, is of growing interest because of its wide-ranging pharmaceutical proper...

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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...

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...

Abstract: The molecular-recognition properties of the cucurbit[6]uril analogue (1) in aqueous buffer (sodium acetate, 50 mM, pH 4.74, 25 C) toward a variety of guests including alkanediamines (6-12), aromatics (14-32), amino acids (33-36), and nucleobases (37-42) were studied by fluorescence spectro...

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The macrocyclic ligand cyclam occurs as a 70:30 mixture of its trans-I and trans-II configurations, respectively, when included as its CuII complex inside the cavity of the macrocyclic host compound cucurbit[8]uril. This is the first report of an unsubstituted cyclam occurring in either of these two...

Azinphos-methyl (AZM) is a widely used organophosphate insecticide and acaricide, with demonstrated negative impacts on the environment. Upon absorption of UV-A radiation, this molecule undergoes photolysis to the highly fluorescent compound N-methylanthranilic acid, which undergoes subsequent photo...

Various methods for the enhancement of the fluorescence of the pesticide azinphos-methyl are reported. The addition of hydroxypropyl-beta-cyclodextrin was found to moderately enhance the fluorescence by a factor of three, presumably via inclusion of the pesticide into the cyclodextrin cavity. This c...

Fluorescence enhancement of a probe molecule in solution by the container molecule cucurbituril (CB) is reported for the first time. The fluorescence of the probe 2-anilinonaphthalene-6-sulfonate (2,6-ANS) in aqueous Na2SO4 solution is found to increase by a maximum factor of 5.0 upon addition of cu...

The ketene derived from diazoquinone 5 can be readily detected by laser photolysis techniques with IR detection and its behavior agrees with that observed with more conventional UV-visible detection. The ketene reacts with amines (e.g. k similar to 7 x 10(7) M-1 s(-1) for diethylamine) to give ylide...

The C=O stretching vibration appears in the infrared spectra of 2-naphthaldehyde (1), 2-acetonaphthone (2), 2-naphthoic acid (3), methyl 2-naphthoate (4) and 1,2-dihydro-3H-benz[e]inden-3-one (5) in the state T-1(pi pi*) between 1600 and 1700 cm(-1). There is a strong line in the Raman spectrum of 1...

The S-1 population decay times of azulene and 1,4-dimethyl-7-isopropylazulene (guaiazulene) in solution have been determined as a function of their initial vibrational energy content, E(vib)(i), using a pump-probe experiment with subpicosecond time resolution. The S-1 lifetime of azulene does not de...

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 ...