5-[(1R,2R,4R)-2-Meth-oxy-1,7,7-tri-methylbi-cyclo-[2.2.1]hept-2-yl]-1H-tetra-zole

Abstract

The title compound, C12H20N4O, undergoes a phase transition on cooling. The room-temperature structure is tetra-gonal (P43212, Z' = 1), with the meth-oxy-bornyl group being extremely disordered. Below 213 K the structure is ortho-rhom-bic (P212121, Z' = 2), with ordered mol-ecules. The two independent mol-ecules (A and B) have very similar conformations; significant differences only occur for the torsion angles about the Cborn-yl-Ctetra-zole bonds. The independent mol-ecules are approximately related by the pseudo-symmetry relation: xB = -1/4 + yA , yB = 3/4 - xA and zB = 1/4 + zA . In the crystal, mol-ecules are connected by N-H⋯N hydrogen bonds between the tetra-zole groups, forming a pseudo-43 helix parallel to the c-axis direction. The crystal studied was a merohedral twin with a refined twin fraction value of 0.231 (2).

Fig. 1.

The structure of molecule A, showing the atom-labelling. Displacement ellipsoids are drawn at the 50% probability level.

Fig. 2.

The structure of molecule B, showing the atom-labelling. Displacement ellipsoids are drawn at the 50% probability level.

Fig. 3.

A view along the c axis of the helical structure of the title compound [the C-bound H atoms have been omitted for clarity; hydrogen bonds are shown as dashed lines; see Table 1 for details; symmetry codes: (i) -x+1/2, -y+1, z+1/2; (ii) -x+1/2, -y+1, z-1/2].