Combined High Resolution UV and Microwave Results: Structure of the Benzonitrile•Water Complex

Abstract

High resolution ultraviolet (UV) and molecular beam Fourier transform microwave (MB FTMW) spectroscopy of the benzonitrile-water (BZNW) cluster were performed to measure cluster structures in the So and Si states. The MW experiments provide additional information on the structure and the 14 N-nuclear quadrupole coupling in the ground state So, the UV experiments on the dynamics in Si.The rotationally resolved sub-Doppler UV spectra of BZNW were measured by mass-selective resonance-enhanced two-photon ionization. For the first time this UV technique has been applied to hydrogen-bonded clusters. From the UV spectra the rotational constants are obtained by Correlation Automated Rotational Fitting. The MW spectra were analyzed with the model of a centrifugally distorted rotor including nuclear quadrupole coupling. A r 0 -fit of the water position within the cluster is performed. The water is found to be located with its oxygen nearly in the plane of benzonitrile (BZN). For So (Si), the distance of the oxygen to the ortho hydrogen is r 0 = 2.477(4) Ä (2.457(2) A) and the angle to the ortho carbon-hydrogen bond 143.34(2)° (141.91(3)°). The structure differences in Si and So can be explained by the structure changes of the BZN molecule. A line broadening, which points to a faster decay in Si upon clustering with the polar solvent, is observed for the BZNW cluster.

Mode dependent intracluster vibrational energy redistribution rate in size-selected benzonitrile–(CHCl3)n=1–3 clusters

“…Though the high resolution electronic spectra of bare BN and some of its clusters were also reported by several groups, 20,24 there has been no report for BN-͑CHCl 3 ) 1 . Figure 4 shows the high resolution LIF spectrum of the origin band of bare BN, and the simulated spectrum by assuming the rotational temperature of 5 K. The inset of Fig.…”

“…BN has three different sites capable to form a hydrogenbond, that is, ͑1͒ the -electrons of the CN triple bond, ͑2͒ nonbonding electrons of nitrogen atom of the CN group, and ͑3͒ the -electrons of the phenyl ring. Structures of clusters containing BN have been investigated by several groups with electronic and microwave spectroscopy, [20][21][22][23][24][25][26] while our group employed double resonance vibrational spectroscopy for the determination of the cluster structures. In a previous paper, we determined the structures of BN-͑H 2 O) nϭ1 -3 and -(CH 3 CN) nϭ1 -3 by measurements of the vibrational spectra and by ab initio MO calculations.…”

High-Resolution Electronic Spectrum of the p-Difluorobenzene−Water Complex: Structure and Internal Rotation Dynamics

“…[31][32][33][34] In both complexes, the oxygen is bound to an ortho hydrogen and one hydroxy hydrogen is bound to the fluorine or the cyano group. In the electronic ground-state S 0 , the structures of these complexes are very similar.…”

Phenylacetylene: A Hydrogen Bonding Chameleon

“…On the other hand, the 4-ethynylbenzonitrile-water complex is characterized by the presence of a OÀH···p hydrogen bond to the p-electron density of the CN group accompanied by CÀH···O hydrogen bonding between the CÀH group in the ortho-position of benzene and the oxygen atom of the water molecule. The intermolecular structure of the 4-ethynylbenzonitrile-water complex is similar to the benzonitrile-water complex [18,114] indicating a higher propensity of the CN group to form hydrogen bonds compared to the acetylenic CC group.…”