. Resonance-enhanced two-photon ionization spectra of benzotriazole, benzimidazole and their water clusters have been taken in a molecular beam. The tautomerism of the benzotriazole and benzimidazole monomers is studied. In order to obtain an assignment of the vibronic bands of the benzotriazole- and benzimidazole-water clusters, ab initio calculations have been performed, which allow the assignment of the intermolecular vibrations and the determination of the most stable cluster structures. In the case of benzotriazole the cyclic cluster of the 2H-tautomer has been found to be the most stable one, whereas for benzimidazole the most stable cluster could be shown to have a linear arrangement, with the benzimidazole moiety acting as proton donor.

$^{a}$G. Berden, W.L. Meerts, M. Schmitt and K. Kleinermanns J. Chem. Phys. 102, 972 (1996)

The intermolecular vibrations of jet-cooled phenol(H2O)(2-5) and phenol(D2O)(2-5)-d(1) were investigated in the S-0 and S-1 electronic states by using mass-selective UV spectral hole burning (SHB) and single vibronic level dispersed fluorescence (DF) spectroscopy. Phenol(H2O)(2) shows broad bands with congested structure. We succeeded in obtaining its intermolecular vibrations via double-resonance spectroscopy. Previous studies of phenol(H2O)(3) were completed. By employing soft two-color ionization and spectral hole burning, the vibronic spectra of phenol(H2O)(4) and phenol(H2O)(5) were unambiguously assigned according to cluster size and discriminated for possible isomers. An essentially complete picture of the vibronically active intermolecular vibrations was obtained. This was possible because SHB proves to be sensitive to the higher frequency intermolecular vibrations which tend to fast intramolecular Si vibrational relaxation in the larger clusters and therefore are of low intensity or absent in the two-color ionization spectra. The experimental results are compared to normal mode calculations based on fully optimized cluster structures obtained from ab initio studies at the Hartree-Fock level. Phenol(H2O)(2-4) exhibit cyclic structures of the water moiety, while in case of phenol(H2O)(5) the cyclic and a bridged "double-donor" structure are of comparable energy. The 6n - 6 intermolecular vibrations of the cyclic clusters with n greater than or equal to 3 monomers can be classified into three small amplitude mutual rotations of the phenyl ring and the oxygen moiety, 2n - 6 oxygen ring deformation vibrations, n intermolecular stretch vibrations, and 3n - 3 hindered rotations of the water molecules in the cluster. The "double-donor" clusters exhibit a strong coupling of some of these modes. Many of the intermolecular vibrations, especially the mutual ring motions and the stretch vibrations, are optically active and can be assigned in the S-0 state by comparison with the calculated vibrational frequencies and deuteration shifts. The propensity rule helps to assign the corresponding vibrations in the S-1 state.

Phenol(H2O)n clusters have been studied in the electronic ground state by dispersed fluorescence spectroscopy and in the electronically excited state by means of two-color resonant two-photon ionization (R2PI), spectral hole burning and rotationally resolved laser-induced fluorescence. Resonant spectra up to a cluster size of n=12 have been obtained by two-color R2PI under `soft' ionization conditions. The analysis of spectral shifts and of the intermolecular vibrations in both electronic states is used to assign structures for these bi-, tri- and (partially) tetracoordinated hydrogen bonded systems, which may be comparable to H-bond-deficient water structures at the surface of liquid water and ice.

$^{a}$G. Berden, W.L. Meerts, M. Schmitt and K. Kleinermanns J. Chem. Phys. 102, 972 (1996)

Author Institution: Institut f\""ur Physikalische Chemie und Elektrochemie 1, Heinrich-Heine-Universit\""at D\""usseldorf

Author Institution: Institut f\""ur Physikalische Chemie und Elektrochemie, Universit\""at D\""usseldorf

The inter- and intramolecular vibrations in the S-0 and S-1 state of catechol, d2-catechol, catechol(H2O)(1), and d2-catechol (D2O)(1) have been investigated experimentally by resonant two photon ionization (R2PI), spectral hole burning (SHB), and dispersed fluorescence spectroscopy (DF). The experimental frequencies are compared to the vibrational frequencies obtained from ab initio normal mode calculations using the 6-31G(d,p) basis set. In order to get a complete interpretation of the S-0 state spectra of d2-catechol the strong coupling of the two OD torsional motions has been taken into account. A two-dimensional calculation of the torsional eigenvalues based on an ab initio potential [-31G(d,p) basis] obtained from single point calculations is presented. Due to these calculations all vibrations in the S-0 state can be assigned. Furthermore a new assignment of the vibrations in the S-1 state of d2-catechol is given. In the case of catechol (H2O)(1) [d2-catechol(D2O)(1)] different structural isomers are discussed. Using HF ab initio calculations (including MP2, BSSE, and ZPE corrections) a trans-linear hydrogen bonding arrangement turns out to be more stable by an amount of 840 cm(-1) compared to a cyclic structure which is also a minimum of the PES. Normal mode calculations have been carried out for both structures and anharmonic corrections are calculated for the tau and beta(2) mode of the trans-linear arrangement. The prediction of the ab initio calculations is supported by the vibrational transitions observed in the spectra of the S-0 and S-1 state, which can be assigned on the basis of the vibrations calculated for the trans-linear structure. The most important feature of the R2PI spectrum of catechol(H2O)(1) [d2-catechol(D2O)(1)] is the occurrence of intermolecular vibrations of very low frequencies (14, 37 cm(-1)). These vibrations and the low frequency torsional modes in the spectra of the S-1 state of the catechol monomer strongly support the assumption that catechol is nonplanar in the S-1 state with respect to the OH groups. Due to this nonplanarity a double minimum potential for the intermolecular rho(1) mode of catechol(H2O)(1) is postulated. Using this assumption the low frequency vibrations of the R2PI spectra as well as the vibrations observed in the spectra of the S-0 state can be assigned. (C) 1996 American Institute of Physics.

It has long been known1–3 that there were considerable differences in diagnostic rates generated by mental hospitals in America and Britain. However, Kramer4 was the first to systematically calculate the rates of various psychiatric diagnostic categories for the two countries. He found that the frequency in England and Wales for schizophrenia was one third lower, and for manic-depressive illness nine times higher, than the rates in the United States. At this point the U.S.-U.K. Diagnostic Project5 was designed to discover why such discrepancies existed.

Most earlier studies and all recent studies on national samples have shown that compared with live births in the control population, schizophrenic patients have a significant excess of birth rates in the winter or early months of the year. In contrast, only some of the early research efforts and only some of the national studies (in England and Wales as well as for certain decades in Sweden) have demonstrated that the same holds true for patients with affective psychosis. The present German study, carried out on affective disorder diagnosed in a strongly Kurt Schneider-oriented clinic, found (as did most Scandinavian research on national samples) that there was no significant overrepresentation of births in the winter or early months of the year for all types of affective disorder, neurotic as well as psychotic. Thus, the findings on Schneider-diagnosed affective disturbances were similar to those on Schneider-diagnosed schizophrenia reported elsewhere.

The inter‐ and intramolecular vibrations in the S0 and S1 state of catechol, d2‐catechol, catechol(H2O)1, and d2‐catechol (D2O)1 have been investigated experimentally by resonant two photon ionization (R2PI), spectral hole burning (SHB), and dispersed fluorescence spectroscopy (DF). The experimental frequencies are compared to the vibrational frequencies obtained from ab initio normal mode calculations using the 6‐31G(d,p) basis set. In order to get a complete interpretation of the S0 state spectra of d2‐catechol the strong coupling of the two OD torsional motions has been taken into account. A two‐dimensional calculation of the torsional eigenvalues based on an ab initio potential [6‐31G(d,p) basis] obtained from single point calculations is presented. Due to these calculations all vibrations in the S0 state can be assigned. Furthermore a new assignment of the vibrations in the S1 state of d2‐catechol is given. In the case of catechol (H2O)1 [d2‐catechol(D2O)1] different structural isomers are discussed....