Acyl nitroso compounds have been generated by photolysis of several different classes of precursors including 9,10-dimethylanthracene adducts, nitrodiazo compounds, and 1,2,4-oxadiazole-4-oxides. Consideration of the nitronate-like resonance structure of nitrodiazo compounds led to an examination of the photochemistry of nitronates with α-leaving groups. Photolysis of such nitronates has been shown to generate an acyl nitroso species along with a carbene intermediate. Nanosecond time-resolved infrared (TRIR) spectroscopy has been used to detect photogenerated acyl nitroso compounds directly and to examine their reaction kinetics with amines and thiols. The mechanism of acyl nitroso aminolysis by primary amines involves general base catalysis, while the mechanism of aminolysis by secondary amines is strictly bimolecular. Thiols do not seem to be reactive with acyl nitroso compounds on the microsecond time scale, but thiolates are quite reactive. The reaction between benzoyl nitroside and an organic-soluble thiolate, tetrabutylammonium dodecanethiolate, proceeds via a proposed tetrahedral intermediate, which is observable by TRIR spectroscopy.

The solvatochromism and possible excited state deactivation pathways of benzo[a]fluorenone were investigated and compared with the related aromatic compounds 9‐fluorenone and benzo[b]fluorenone. These molecules can serve as molecular building blocks with application in light emitting diodes, catalysts, and dye‐sensitized solar cells. A study of the effect changes in aromatic structure might have on their relative photophysical responses is therefore of interest. Steady‐state absorption and emission spectra, Lippert‐Mataga plots, fluorescence lifetimes, and absolute quantum yields were used in tandem with time dependent density functional theory (TD‐DFT) calculations to investigate solvatochromism, excited state decay, and the relative energies of singlet and triplet excited states. It was found that changes in aromaticity affect the energetic order and character of the excited singlet and triplet states differently among these fluorenones as solvent polarity is varied. The observed fluorescence emission from all these molecules can be understood in terms of their relative ability to undergo intersystem crossing. Additional calculations on the related benzo[c]fluorenone predict that its solvatochromic behavior should resemble that of benzo[a]fluorenone.

In this organic chemistry laboratory experiment, students are guided through a series of exercises to understand the behavior of compounds during liquid–liquid extraction. Aspects of density, structure, solubility, acid–base theory, and pK a are all incorporated into activities that students complete in groups. After using their initial observations to make predictions about the two colored compounds, nile blue and 2,6-dichloroindophenol, students check the reliability of their predictions by carrying out liquid–liquid extractions of these compounds in the laboratory. The set of exercises culminates in the application of the procedures to a real-world situation.

A hetero-Diels−Alder reaction that proceeds rapidly and only requires a simple filtration to purify the product is presented. The dienophile, 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), is prepared by the heterogeneous oxidation of 4-phenylurazole by the bromenium ion, Br+, generated in situ by the oxidation of potassium bromide by Oxone. PTAD is reacted with both cyclopentadiene and 1,3,5-cycloheptatriene, and the resulting products are analyzed by NMR spectroscopy. PTAD reacts with cyclopentadiene in the expected fashion; however, it reacts exclusively with the norcaradiene valence tautomer of 1,3,5-cycloheptatriene to form a single cycloadduct. The speed of these reactions allows for more of a three-hour laboratory period to be devoted to spectral characterization and data analysis than in similar experiments. This laboratory experiment is suitable for second- or third-year organic chemistry courses.

The photochemistry of O2-naphthylmethyl- and O2-naphthylallyl-substituted diazeniumdiolates has been investigated. Electron-donating methoxy group substitution is shown to have a significant effect on the observed photochemistry, with the appropriate substitution pattern resulting in efficient diazeniumdiolate photorelease. Observed nitric oxide release rates from these photoprecursors are consistent with those expected for normal thermal dissociation of the diazeniumdiolate in aqueous solutions and show the same pH dependence.