... 33 levels observed in our previous single vibronic level (SVL) emission study (Fan et al., J. Chem ... between 1 1 and 2 1 3 1 and an unusually small anharmonic C−H stretching frequency ... 2 (Aldrich, 99.9%) in argon (BOC gases, 99.999%) that was premixed in a 1 L stainless steel ...