THE IDENTIFICATION OF INOH IN THE GAS-PHASE AND DETERMINATION OF ITS GEOMETRIC STRUCTURE

The first gas phase observation of the species InOH is reported throug h the detection of its electronic spectrum in the near ultraviolet reg ion, between 345 and 377 nm. The molecule was generated by the high te mperature reaction between H2O and In metal or between H-2 and In2O3, and cooled in a free jet expansion. Two separate electronic transition s have been identified and are tentatively assigned as alpha(1)A'<--($ ) over tilde X(1)A' and beta(1)A''<--($) over tilde X(1)A'. Values for the vibrational wavenumbers nu(2) (bending vibration) and nu(3) (In-O stretching vibration) have been determined for InOH and InOD in all t hree electronic states involved. There is evidence that the molecule i s quasilinear in its ground electronic State which somewhat complicate s the values determined for nu(2) in this state. Rotational structure was easily resolved at the lowest temperature achieved in this work (T (rot)approximate to 12 K). Analysis of this structure shows that the m olecule is bent in all of the electronic states studied, with a bond a ngle of about 132 degrees in the ($) over tilde X state and about 105 degrees in the alpha and beta states.