Methoxy and Methyl Group Rotation: Solid-State NMR H-1 Spin-Lattice Relaxation, Electronic Structure Calculations, X-ray Diffractometry, and Scanning Electron Microscopy

摘要

We report solid-state H-1 nuclear magnetic resonance (NMR) spin-lattice relaxation experiments, X-ray diffractometry, field-emission scanning electron microscopy, and both single-molecule and cluster ab initio electronic structure calculations on 1-methoxyphenanthrene (1) and 3-methoxyphenanthrene (2) to investigate the rotation of the methoxy groups and their constituent methyl groups. The electronic structure calculations and the H-1 NMR relaxation measurements can be used together to determine barriers for the rotation of a methoxy group and its constituent methyl group and to develop models for the two coupled motions.