Structure of Metastable Molecules The Microwave Spectra of BH(OH), and BHF(OH)

Abstract

Various isotopic species of cis, trans-BH(OH)₂ and cis-BHF(OH) produced as reaction intermediates between diborane and water, and between BHF₂ and water, respectively, have been observed by microwave spectroscopy. The r_s and r₀ structures have been derived f rom the rotational constants obtained. Since the Kraitchman's equation gives imaginary va lues for some coordinates, the double substitution method is applied to the determination of these coordinates. The r_s structural parameters thus determined are in good agreement with the r₀ parameters determined by least squares fitting of all the observed rotational constants. The dipole moments and their directions have been obtained from the measurements of the Stark effect. These molecular parameters show good agreement with those predicted by ab initio MO calculations.