Experimental Study of the Nuclear-Quadrupole and Spin—Rotation Interactions of 17O in Formaldehyde

Abstract

The microwave spectrum of ¹⁷O¹²CH₂ has been observed using high‐resolution microwave spectroscopy. The ¹⁷O nuclear‐quadrupole coupling constants and spin—rotation constants have been obtained. The results are X_aa=−1.89±0.01, X_bb=12.37±0.01, X_cc=−10.48±0.01, M_aa=0.371±0.01, M_bb=0.025±0.01, and M_cc=−0.002±0.01 Mc/sec. The K=1 and K=2 series of rotational transitions were studied in an attempt to observe a K‐dependent field gradient with no success. The ¹⁶O¹³CH₂ spectra were also observed under high resolution with no splitting observed due to the ¹³C spin—rotation interaction. An upper limit on M_aa for ¹³C in ¹⁶O¹³CH₂ can be given as | 10.170 | Mc/sec. The spin—rotation constants are interpreted by a localized theory and the change in the average value of 1/r³ with ionic character is discussed.