The High-Resolution Absorption Spectrum of Nitrogen from 1060 TO 1520 Å. II. The α'¹Σᵤ <- Χ¹Σg⁺ System.

Twenty bands (v' = 0 - 19) of the forbidden a' X + system of nitrogen have been observed in absorption at high resolution from 1060 to 1480 A. Observation of these bands indicates that this transition borrows (or "steals") intensity from higher neighboring 111 + transitions, suggested, on the basis of new calculations, to be either the m H" X + or p 111 X + transitions with "oo'S at 105000 and 108000 , respectively. Rotational selection rules show that only a branch (AJ = 0) can be expected. The rotational intensity distribution, as determined experimentally, is in agreement with an earlier theoretical derivation. Rotational and vibrational analyses have been performed on all twenty bands. The molecular constants obtained for the a' state are: T00 = 66977.18 Yio( w.) = 1530.254 cm-2 Y20( - cox.) = -12.0747 Y2o( co.y) = 0.041292 Y40( - w.z) = -0.()() 1 Y01( B) = 1. Y11( - a) = 2 Y21( ) = 0.00002408a r = 1.2707 A. The lifetime of the a' state has been determined to be 0.7 sec.