Microwave Structure Measurements on the Furan-Argon Complex

Rotational transitions were measured for furan-argon and [2-D]furan-argon using a pulsed nozzle Fourier transform spectrometer. Analysis of the data indicates that the argon atom is above the plane of furan, a distance of 3.54 Ä from the furan center of mass. The line between the argon and furan center of mass makes an angle of 11 º with the furan c axis with the displacement toward the oxygen atom of furan. Measured rotational constants for argon-furan are A = 4802.340 (3), B = 1362.612 (2), and C= 1360.289 (2) MHz. For argon-[2-D]furan, A = 4591.442 (18), B = 1358.191 (4), and C= 1338.736 (2) MHz. An analysis of the centrifugal distortion and interaction potential is given for this complex. The stretching force constant is ks = 0.27 mdyn/Á and the approximate well depth is e = 236 cm″1.