SOLID-STATE POLYMERIZATION OF DIACETYLENES .3. CRYSTAL AND MOLECULAR-STRUCTURE OF 1,4-BIS(1-OXYL-2,2,6,6-TETRAMETHYL-4-HYDROXY-PIPERIDINE-4-YL)BUTADIYNE

An X-ray structural study (R= 0.040 for 1871 reflections)of the title compound has been carried out. Molecules in crystal are pseudocentrosymmetric, the piperidine cycle is in a chair conformation. The N atoms of both paramagnetic centers exhibit, in fact, the same degree of pyramidalization, their displacements from the planes of their bonded atoms being 0.111 and 0.119(2) Å. In crystal the molecules form two sets of infinite ribbons (along the [112] and [112] directions), which are linked with each other via the O—H…O hydrogen bonds a long the [001] direction. Although the packing of diacetylene rod-like groups does not correspond to the conditions of topo chemical polymerization of diacetylenes, compound Ipolymerizes in crystal. © by R. Oldenbourg Verlag