Computations at the CASPT2, CBS-QB3, and B3LYP levels of theory demonstrate that beta-substitution of vinyl cations with pi-donors switches the ground state of these ions from the familiar closed-shell singlet state to a carbene-like triplet state similar to the electronic state of triplet phenyl cations. Although the parent vinyl cation is a ground-state singlet species with a very large energ...

BACKGROUND Nilaparvata lugens, a major pest in rice-growing areas, is extremely difficult to manage. Neonicotinoids have increasingly been used in crop protection and animal health care against N. lugens. To discover new bioactive molecules and pesticides, we combined the active structure of cyanoacrylates, aromatic aldehydes, and substituted pyridyl (thiazolyl) methyl-2-substituted-methylidene...

An intramolecular hydrogen bond between NH•••O2N in insecticide, imidacloprid (1), and its nitromethylene analog 15 was proved by NMR and IR spectra. That electron delocalization over their planar moieties was disrupted by alkylation at the imidazolidine nitrogen atom is demonstrated by the hypsochromic shifts in UV and deshielding effect in NMR spectra. Interestingly, the N-alkyl derivatives (...

The asymmetric synthesis of new chiral γ-chloro-α,β-diaminocarboxylamide derivatives by highly diastereoselective Mannich-type reactions of N-(diphenylmethylene)glycinamides across chiral α-chloro-N-p-toluenesulfinylaldimines was developed. The resulting (S(S),2S,3S)-γ-chloro-α,β-diaminocarboxylamides were formed with the opposite enantiotopic face selectivity as compared to the (S(S),2R,3R)-γ-...

Electron paramagnetic resonance (EPR) spectroscopy is a powerful and widely used technique for studying structure and dynamics of biomolecules under bio-orthogonal conditions. In-cell EPR is an emerging area in this field; however, it is hampered by the reducing environment present in cells, which reduces most nitroxide spin labels to their corresponding diamagnetic N-hydroxyl derivatives. To d...

In the title mol-ecule, C21H20BrClN6O2, the chloro-substituted benzene ring forms a dihedral angle of 77.84 (7)° with the tetra-zole ring and the bromo-substituted ring forms a dihedral angle of 43.95 (6)° with the imidazole ring. The dihedral angle between the tetra-zole and imidazole rings is 67.42 (8)°. The terminal methyl group of the butyl substituent is disordered over two sets of sites, ...