S. Coussan et al., MATRIX-ISOLATION INFRARED-SPECTROSCOPY AND DFT CALCULATIONS OF COMPLEXES BETWEEN WATER AND NITROGEN, Journal of molecular structure, 471(1-3), 1998, pp. 37-47
The mid-infrared spectra of water-nitrogen mixtures in argon matrices
have been investigated. Evidence for the existence of several (H2O)(m)
(N-2)(n), or m:n, complexes has been obtained from the appearance of m
any absorptions in the nu OH, nu NN and delta OH spectral regions whic
h are not present in the spectra of H2O/Ar binary matrices. Concentrat
ion effects allow identification of the four (seven) intramolecular fu
ndamentals of the 1:1 (2:1) species. The structural properties of thes
e two complexes are discussed on the basis of ab initio calculations c
arried out within the framework of the density functional theory (DFT)
. The comparison of the calculated and observed vibrational properties
of the 1:1 complex does not allow us to confidently deduce its struct
ure because of the weakness of the perturbations. In the case of the 2
:1 heterotrimer it is clearly established that the nitrogen molecule i
s fixed on the proton acceptor molecule of (H2O)(2), in a hydrogen-bon
d type interaction. The frequency shifts with respect to the water dim
er are accounted for in terms of cooperative effects. (C) 1998 Elsevie
r Science B.V. All rights reserved.