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Abstract The first reactions of thioimidates under radical‐mediated conditions are described along with the delineation of structural factors that impact radical reactivity and possible side reactions. Thioimidate‐containing copolymers with methylmethacrylate (MMA) are synthesized through radical‐mediated, chain‐growth polymerization. These materials serve as a synthetic branch point for facile conversion into amidines by treatment with a weak acid and an external amine. Our approach allows for more diverse amidine structures than have been previously reported in polymers. This chemistry also enables crosslinking to form novel hydrogels with finely tuned acid–base behavior. Subsequent examination of the acid–base properties revealed that these features are preserved across linear, soluble amidine polymers to cross‐linked amidine gel polymer architectures. 

Chemists are trained to recognize aromaticity semi-intuitively, using pictures of resonance structures and Frost-Musulin diagrams, or simple electron-counting rules such as Hückel's 4 n + 2/4 n rule. To quantify aromaticity one can use various aromaticity indices, each of which is a number reflecting some experimentally measured or calculated molecular property, or some feature of the molecular wavefunction, which often has no visual interpretation or may not have direct chemical relevance. We show that computed isotropic magnetic shielding isosurfaces and contour plots provide a feature-rich picture of aromaticity and chemical bonding which is both quantitative and easy-to-visualize and interpret. These isosurfaces and contour plots make good chemical sense as at atomic positions they are pinned to the nuclear shieldings which are experimentally measurable through chemical shifts. As examples we discuss the archetypal aromatic and antiaromatic molecules of benzene and square cyclobutadiene, followed by modern visual interpretations of Clar's aromatic sextet theory, the aromaticity of corannulene and heteroaromaticity.