4-NITROINDANE AND 5-NITROINDANE

Mononitration of indane produces a mixture of 4- and 5- nitroindanes. Crystallization from mixtures occurs after distillation improves compo sition of a major component to above 80%. 4-Nitroindane: triclinic, sp ace group P1 (#2), a = 7.332(4) Angstrom, b = 8.304(4) Angstrom, c = 8 .358(4) Angstrom, alpha = 61.43(4)degrees, beta = 67.60(4)degrees, gam ma = 70.15(4)degrees, V = 405.4(4) Angstrom(3), Z = 2. Non-H-atoms are nearly planar, aliphatic H's are eclipsed. 5-Nitroindane: monoclinic, space group P2(1)/c (#14), a = 10.946(8) Angstrom, b = 15.643(10) Ang strom, c = 9.415(6) Angstrom, beta = 92.34(5)degrees, V = 1611(2) Angs trom(3), Z = 8. Non-H-atoms in the two molecules differ in torsion of the nitro group with respect to indane and fold of the nonbenzylic met hylene group. Semiempirical calculations (PM3) suggest that distorsion from planarity may be associated with the two lowest energy vibration al modes. Uv, ir, ms, proton, and C-13-nmr spectra are correlated with the solid state structures.