摘要

The high-resolution infrared absorption spectrum of spiropentane (C5H8) has been measured from 200 to 4000 cm(-1), and a detailed analysis is presented for eight bands in the region from 700 to 2200 cm(-1). Two fundamental perpendicular bands were analyzed, v(22) and v(24) near 1050 and 780 cm(-1), respectively, along with two fundamental parallel bands, v(14) and v(16) near 1540 and 990 cm(-1), respectively. Two other fundamentals, v(17) and v(23), are seen as intense overlapping bands near 880 cm(-1) and are Coriolis-coupled, producing a complex mixture in which only P-branch transitions could be tentatively assigned for v(17). In addition, three binary combination bands were fit at about 1570, 2082, and 2098 cm(-1) which are assigned as either 2v(24) or v(5) + v(16) in the first case, v(4) + v(22) in the second case, and 2v(22) in the latter case. The two l-type resonance constants, q(+) and q(-), were determined for each of the two perpendicular fundamentals v(22) and v(24). Those two constants were also responsible for splittings observed in the K = 3 levels of v(24). For the ground state the order of the split K = 2 B-1/B-2 levels has been reversed from that reported previously, based on the measurements and assignments for the v(24) band. Rovibrational parameters deduced from the analyses are compared with those obtained from density functional Gaussian calculations at the anharmonic level.

  • 出版日期2015-6