The Millimeter Wave Spectrum of DCNO: An Example of Current Measurements in the Frequency Range from 60 to 350 GHz

An efficient system for preliminary data reduction is described which completes a recently developed data acquisition and reduction system for the measurement of millimeter wave absorption lines with the help of a dedicated computer. A simple method of automatically determining the absorption line centers is given. Rotational transitions of DCNO, measured with the above system, are reported for the ground state and the first excited state of each of the two bending modes ν4 and ν5. The rotational and rotation-vibration constants obtained for these states are B0 = 10,292.48340 (31) MHz, D0 = 3.5418 (10) kHz, Bν4 = 10,306.00780 (45) MHz, Dν4 = 3.6409 (22) kHz, Bν5 = 10,338.65942 (32) MHz, Dν5 = 3.6208 (16) kHz. The l-type doubling constants q.t 0) and qt (1) agree with the values obtained previously from direct l-type doubling transitions.