Crystal structure of 1,5-dimethylnaphthalene: a neutron diffraction study

Abstract

The crystal structure of the title compound has been examined at room temperature by neutron diffraction. Three-dimensional least-squares refinement of positional and anisotropic temperature parameters for all atoms gave R 0·041 over 437 independent neutron reflections. Aromatic bond lengths and angles are essentially the same as for the unsubstituted compound and C(methyl) atoms do not deviate significantly from the plane of the rings. The H(methyl) atoms are locked in fixed orientations in which one hydrogen of each is in the ring plane; closest approaches of out-of-plane H(methyl) atoms to adjacent α-hydrogen atoms are 2·35(4)–2·40(4)Å. Aromatic C–H and methyl C–H bond lengths do not differ significantly from their means (1·05 and 1·06 Å).