A FTIR STUDY OF THE VAN-DER-WAALS COMPLEXES BETWEEN BORON-TRIFLUORIDEAND CARBON-MONOXIDE IN LIQUEFIED ARGON

The mid-infrared spectra (4000-500 cm(-1)) of several boron trifluorid e/carbon monoxide mixtures, dissolved in liquefied argon, were examine d. Concentration studies prove the existence of 1:1 (BF3 . CO) and of 1:2 (BF3(. CO)(2)) Van der Waals complexes. Also, indications were fou nd for the presence of a minor amount of the BF3 . OC complex. Using s pectra recorded in the temperature interval between 85 K and 115 K, th e stabilities of the complexes were determined. The complexation entha lpy was found to be -7.6+/-0.3 kJ mol(-1) for the 1:1 complex, and -14 .5+/-1.0 kJ mol(-1) for the 1:2 complex. The results of a structural a b initio study at the MP2/6-31+G level are reported.