Microwave spectrum and molecular structure of the N2–H2O complex

Abstract

The a-type, K=0 microwave spectrum of the N2–H2O complex has been observed using a pulsed molecular beam Fabry–Perot cavity microwave spectrometer. Seven isotopic species have been studied in the range of 5–23 GHz.The N2–H2O complex exhibits tunneling motions similar to the 1→2 tunneling motion of the H2O–DOD complex which gives rise to four components for each rotational transition. The molecular constants obtained for the ground tunneling (A1) state of 14N2–HOH are: B̄=2906.9252(2) MHz, DJ =0.043 486(15) MHz, and eQq(14N)=−4.253(2) MHz. The structure has a nearly linear N–N–HO geometry with a N–H distance of 2.42(4) Å and an OHN angle of 169° [RO–N=3.37(4) Å]. The electric dipole moment along the a principal axis of inertia was determined for the 15N2–HOH species with μa =0.833(3) D.

H 2 O−N 2 collision-induced absorption band intensity in the region of the N 2 fundamental: ab initio investigation of its temperature dependence and comparison with laboratory data

“…• gives rise to a computed value of m z = 1.07 D. The experimental value determined in Leung et al [1] equals 0.833 D. Ab initio calculations by Kjaergaard et al [5] resulted in the value of 1.04 D. For the total dipole of a complex at equilibrium, Kjaergaard et al [5] obtained the value 2.08 D, which is also close to our calculated 1.96 D. …”

“…Quite reasonable results can be reached in this context with the use of relatively simple second order Møller-Plesset perturbation theory (MP2). 1 The latter does not permit, however, quantitatively accurate electronic energy for intermolecular pairs to be obtained. An alternative way for the calculation of electron correlation energy is due to coupled clusters method which is presently quite feasible on a level of CCSD(T), i.e.…”

“…On the experimental side, the microwave spectroscopic probe [1] of the low-temperature H 2 O−N 2 complex made it possible to characterize its equilibrium structure in much detail. Planar equilibrium structure of a dimer was found with a nearly collinear arrangement of the N 2 bond and one of the OH bonds in the H 2 O molecule.…”

Perspective: Water cluster mediated atmospheric chemistry

“…4,9,25 Water can form open and closed shell molecular complexes with low binding energies (van der Waals interactions) and more strongly bound complexes (dipolar interactions and hydrogen bonding) with atmospheric species (e.g., O 2 , N 2 , Ar, OH, HO 2 , RO 2 , O 3 , OCS, SO 2 , SO 3 , NO, SH, ClO, NH 3 , HNO 3 , HCl, H 2 SO 4 , organic acids, aldehydes, and ketones, etc.). 19,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] We illustrate results of calculations of the abundance of water complexes with altitude in Figure 1, pointing out that while the temperature minimum at the tropopause enhances the equilibrium constant, it also reduces the partial pressure of water and other monomeric condensable species leading to an overall decrease of the complex abundance with altitude. 4,8,10,12,29 Nevertheless, even low concentrations of weakly bound complexes can have a significant effect on atmospheric chemistry.…”

A molecular beam scattering study of the weakly bound complexes of water and hydrogen sulphide with the main components of air

“…Experimental information on the present case studies is limited to a microwave spectroscopic characterization of gas phase H 2 O-N 2 [9] and low temperature investigations on solid matrix of H 2 O-N 2 [10,11] and H 2 O-O 2 [12,13].…”