Effects of Fluorine Substitution on the Microsolvation of Aromatic Azines: The Microwave Spectrum of 3‑Fluoropyridine-Water

The rotational spectra of the parent species and of four water isotopologues (−DOH, −HOD, −DOD, and −H¹⁸OH) of the adduct 3-fluoropyridine-water have been investigated using pulsed supersonic-jet Fourier-transform microwave spectroscopy. From the rotational constants, the structure of the adduct was deduced where the water is linked to the aromatic ring through an intermolecular O–H···N hydrogen bond with a bond distance of 1.9961(5) Å and an O–H···N angle of 156.8(1)°. The shape of the complex is such that the water oxygen is in the plane of the aromatic ring, on the opposite side of fluorine, and forming a C–H···N weak hydrogen bond with the adjacent aromatic hydrogen