Oxidation of diaryl, aryl alkyl, and dialkyl thioketones by singlet oxygen generated via self-sensitization and other independent methods yielded the corresponding ketone and sulfine in varying amounts. A zwitterionic/diradical intermediate arising out of the primary interaction of singlet oxygen with the thiocarbonyl chromophore is believed to be the common intermediate for the ketone and sulfine. While closure of the zwitterion/diradical to give 1,2,3-dioxathietane would lead to the ketone, competing oxygen elimination is believed to lead to the sulfine. This partitioning is governed by steric and electronic factors operating on the zwitterionic/diradical intermediate.

Rh(iii)-Catalyzed ortho-C–H amidation of ketones and aldehydes under cooperative metal organocatalysis has been utilized for synthesizing various ortho-amidocarbonyl analogs, and the reaction for the aldehyde proceeds >at ambient temperature.

High school students find reaction stoichiometry and the concept of the mole hard to comprehend. Teachers are well aware of the importance of teaching the mole concept and also the difficulty associated with it. In an attempt to improve the understanding of the mole concept with reduced difficulty, an atomic model kit that provides a hands-on learning experience has been developed and implemented in a class of 40 students. Each model atom consists of spherical neodymium magnets (acting as nucleons) of appropriate number (1 for hydrogen, 12 for carbon, 14 for nitrogen, and 16 for oxygen) enclosed in a hollow spherical Styrofoam casing (acting as an atom) that can be opened when required. These model atoms can be easily weighed using a laboratory balance, to obtain mass ratios of 1:12:14:16. This model kit provides an opportunity to have a hands-on learning experience of abstract concepts such as mass conservation in a balanced chemical reaction, excess and limiting reagents, and the mole and its relation to gram atomic/molecular mass. Herein, we provide a detailed description of the design criteria and the construction of the model atoms. We also provide the activity sheets with the necessary instructions to carry out the hands-on activities and the assessment sheets used for evaluation.

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