The infrared spectrum of the van der Waals complex CO-N2O has been rec
orded in the region of the nu(3)N(2)O monomer vibrational band using a
diode laser absorption spectrometer which incorporates a multipass ce
ll and a pulsed jet. The spectrum has been completely analyzed using a
normal asymmetric rotor Hamiltonian and the effective molecular const
ants are accurately determined for both ground and excited vibrational
states. The band origin of CO-N2O is observed to shift toward higher
wavenumber from the N2O monomer by 2.90540 cm(-1). With the aid of an
intermolecular potential calculation, we are able to determine that th
e complex has a T-shaped configuration with the CO forming the leg of
the T and the C atom of the CO molecule pointing to N2O. The structura
l parameters are R-cm'' = 3.8707(3) Angstrom, theta(N2O) = 80 degrees
+/- 5 degrees, and theta(CO) = 20 degrees +/- 5 degrees. (C) 1997 Acad
emic Press.