NMR Studies of Alkali Anions in Non-Aqueous Solvents

摘要: Publisher Summary This chapter describes the progress that has been achieved to date in study of alkali anions liquid 12-crown-4 and 15-crown-5 (15C5). It reviews chemistry elements is dominated by occurrence systems, involving cation M + . In anions, two electrons occupy ns 2 valence orbital, neutral atom having this orbital only singly occupied. Alkali metals dissolve anhydrous ammonia yield, at very low metal concentration, solvated electrons, cation. As content increased, these charged species aggregate form a stoichiometry whose spectral characteristics are remarkably insensitive particular metal. Thus it inferred from electron spin resonance (ESR) nuclear magnetic (NMR) studies metal–ammonia solutions (spin) density nucleus as 1% corresponding gaseous ground-state atom. The also focuses on use crown–ether solvents for preparation anions. known crown ethers strong complexes with cations. formation such cationic provides driving force dissolution crowns. This, coupled binary alkali–metal alloys, led production stable solutions, containing high concentrations