A study of the vibration–rotation and fine structure energy levels of the NSe radical by laser magnetic resonance

Abstract
Vibration–rotation and fine structure transitions of the NSe radical in its X 2Π state have been studied by CO2 laser magnetic resonance at 11 μm. Transitions involving the five most abundant naturally occurring isotopes of selenium have been detected. These data were all analyzed together by invoking the appropriate isotopic relationships between molecular parameters. The vibrational band origin for N80Se is determined to be 944.542 16(9) cm1 and the spin–orbit coupling constant à is 891.891 32(11) cm1. From a consideration of the likely sign of the lambda doubling parameter (p+2q), it is suggested that B electronic state may be 2+ rather than 2.