The microwave spectrum of the furan-HCl complex in the ground vibrational state has been measured and assigned using a Fourier-transform microwave spectrometer employing a Fabry-Perot cavity and a pulsed supersonic nozzle as a molecular source. Furan-HCl is planar, with the axis of the HCl subunit oriented along the a axis of furan, bisecting the oxygen-carbon angle. A hydrogen bond is formed between the HCl proton and the lone electron pair of oxygen. The spectroscopic constants for furan-H35Cl in MHz are A″=9421.3(39), B″=1004.2001(27), C″=904.5526(26), τT 1=-0.9392(12), τ2=-0.0751(2), τbbbb=-0. 004 01(19), τcccc=-0.002 17(17), χaa=-52.803(17), χbb=25.626(54), and χcc=27.177(54). Rotational transitions for the isotopic species furan-H 37Cl and furan-D 35Cl were also measured and assigned. The oxygen-chlorine distance is 3.26(1) Å. The binding of the HCl to oxygen, rather than to the π bonds between the âcarbon atoms, was confirmed by measurements on the 2-D furan-H 35Cl complex.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry