Timothy C. STEIMLE (Arizona State Univ. and IMS), Kei-ichi NAMIKI (Grad. Univ. for Advanced Studies), Mitsutoshi TANIMOTO (Shizuoka Univ. and IMS) and Shuji SAITO
[J. Chem. Phys. 107, 6109 (1997)]
As discussed in the former Annual Review,1) spectra of the 3d metal bearing oxides are a good probe in assessing the chemical bonds dependent on the 3d orbital of the metal and the 2p orbital of oxygen, and we reported preliminary results on four microwave spectroscopic studies: MnO(6(SIGMA)+),2) CoO(4(DELTA)i), CuO(2(PI)i), and TiO(3(DELTA)r). Results on the CuO radical have been published in the Journal of Chemical Physics, reporting the determination of the hyperfine coupling constants of the 63Copper nucleus of I=3/2: a=214.1(35), bF=-483.6(94), c=72.5(95), d=134.5(34), and eQq0=-16.9(54) MHz. These observed parameters are interpreted by using a plausible molecular orbital configuration made up of a linear combination of atomic orbitals.
Recently we also detected the microwave spectrum of AgO in the X2(PI)i state by dc-discharging a mixture of oxygen and a large amount of helium over a silver-plate cathode. The spectral lines of AgO in the 2(PI)3/2 state were detected in the frequency region higher than that of the 2(PI)1/2 state lines, though the 2(PI) ground electronic state of AgO is claimed to be inverted. This anomalous behavior was explained by a large value of the centrifugal distortion term of the spin-orbit interaction term, AD, which cancels the change of the rotational constants for both the substates by spin-orbit interaction. A similar anomaly was also found in the case of CuO. The result on the AgO radical will be reported separately.