Positionally dependent N-15 fractionation factors in the UV photolysis of N2O determined by high resolution FTIR spectroscopy

Positionally dependent fractionation factors for the photolysis of isotopom ers of N2O in natural abundance have been determined by high resolution FTI R spectroscopy at three photolysis wavelengths. Fractionation factors show clear N-15 position and photolysis wavelength dependence and are in qualita tive agreement with theoretical models but are twice as large. The fraction ation factors increase with photolysis wavelength from 193 to 211 nm, with the fractionation factors at 207.6 nm for (NNO)-N-14-N-15-O-16, (NNO)-N-15- N-14-O-16 and (NNO)-N-14-N-14-O-18 equal to -66.5 +/- 5 parts per thousand -27.1 +/- 6 parts per thousand and -49 +/- 10 parts per thousand, respectiv ely.