H-1 nuclear magnetic resonance spin-lattice relaxation, C-13 magic-angle-spinning nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and x-ray diffraction of two polymorphs of 2,6-di-tert-butylnaphthalene

Polymorphism, the presence of structurally distinct solid phases of the sam e chemical species, affords a unique opportunity to evaluate the structural consequences of intermolecular forces. The study of two polymorphs of 2,6- di-tert-butylnaphthalene by single-crystal x-ray diffraction, differential scanning calorimetry (DSC), C-13 magic-angle-spinning (MAS) nuclear magneti c resonance (NMR) spectroscopy, and H-1 NMR spin-lattice relaxation provide s a picture of the differences in structure and dynamics in these materials . The subtle differences in structure, observed with x-ray diffraction and chemical shifts, strikingly affect the dynamics, as reflected in the relaxa tion measurements. We analyze the dynamics in terms of both discrete sums a nd continuous distributions of Poisson processes. (C) 2000 American Institu te of Physics. [S0021-9606(00)50229-3].