Herpetic laryngitis is extremely rare in healthy adults. The local factors that increase susceptibility to herpes simplex virus include irradiation on the head and neck area. A 66-year-old man who had history of supraglottic cancer had voice change 4 years after the radiotherapy. On laryngscopic examination, the erosive mucosal lesion was found on his left vocal fold. A pathologic examination of the lesion by suspension laryngoscopy revealed that the lesion was herpetic laryngitis, which was confirmed by immunohistochemical stain as herpes simplex virus. Her petic laryngitis should be in the index of differential diagnosis in patients with laryngitis who have the history of irradiation on the neck.

The sensing behavior of SnO2-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO2 [SnO2(C)] and nano-SnO2 prepared by the precipitation method [SnO2(P)] were used to prepare the SnO2 sensor in this study. In the case of DCM and acetonitrile, the SnO2(P) sensor showed higher sensor response as compared with the SnO2(C) sensors. In the case of DMMP and DPGME, however, the SnO2(C) sensor showed higher responses than those of the SnO2(P) sensors. In particular, the response of the SnO2(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO2-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1–0.5 ppm).

E-mail: kimhs@knu.ac.krReceived August 26, 2011, Accepted September 15, 2011Key Words : One-pot reductive amination, Chlorotriisopropoxytitanium(IV), 1,1'-Diacetylferrocene, Sodiumtriacetoxyborohydride1,1'-Disubstituted-ferrocenes, especially bearing chelatingnitrogen atoms, are an important class of ligands in organicsynthesis.

Fluorescence excitation and resonance two-photon ionization spectra in the range of 285 302 nm were measured for fluorene (FR)-h10 and -d10 molecules cooled in pulsed supersonic expansion of He. The vibrational bands above the electronic origin were assigned on the basis of the S1 state vibrational frequencies evaluated with the RCIS/6-31G(d) method. We observed a sizable discrepancy between the 0-0 band observed in the present study for FR-h10, 33,791 cm 1 , and the vertical excitation energy of 44,209 cm 1 evaluated with the RCIS/6-31G(d) method. However, the experimental frequency ratios of H/ D populated in the range from 1.05 to 1.09 were found to be consistent with the theoretical ratios spanning 1.03 1.17. The findings are quite informative as to the assignment of the vibronic peaks.

The Al-27 multiple quantum magic angle spinning (MQMAS) nuclear magnetic resonance (NMR) spectra of mordenite zeolites were simulated using the point charge model (PCM). The spectra simulated by the PCM considering nearest neighbor atoms only (PCM-n) or including atoms up to the 3(rd) layer (PCM-m) were not different from those generated by the Hartree-Fock (HF) molecular orbital calculation method. In contrast to the HF and density functional theory methods, the PCM method is simple and convenient to use and does not require sophisticated and expensive computer programs along with specialists to run them. Thus, our results indicate that the spectral simulation of the Al-27 MQMAS NMR spectra obtained with the PCM-n is useful, despite its simplicity, especially for porous samples like zeolites with large unit cells and a high volume density of pores. However, it should be pointed out that this conclusion might apply only for the atomic sites with small quadrupole coupling constants.

For Abstract see ChemInform Abstract in Full Text.

The structures and energies of Li2C2 and Li4C4 have been reexamined by DFT and MP2 methods using a variety of basis sets of 6-311+G(3df) and cc-pVXZ(X=T,Q,5). Two low-lying isomers are found as the local minima on the potential energy surfaces of Li4C4. The lowest energy structure is shown to be multiply bridged D2h form. A newly found quadruply bridged Ci form is found to be a local minimum, lying in energy above D2h form by 22kJ/mol in the energy. Also the energetics of high-lying isomers such as tetralithiotetrahedrane isomers were evaluated and discussed.

The enthalpies of formation of OXO (X = Cl, Br, and I) and their anions were calculated using the Hartree-Fock, the second-order Moller-Plesset perturbation theory, the density functional theory with the B3LYP hybrid functional, and the coupled cluster theory using single and double excitation with a perturbational treatment of triplet excitation methods with two basis sets of triple-zeta plus polarization quality by employing several isodesmic (or congeneric) reactions. The weighted averages and their associated uncertainties for the enthalpies of formation were derived for these molecules using Irikura's procedure. The calculated standard enthalpies of formation at 0 K are 102.2 +/- 6.5, 163.9 +/- 7.1, 113.9 +/- 10.3, -104.8 +/- 6.5, -76.0 +/- 7.0, and -135.0 +/- 10.3 kJ/mol for OClO, OBrO, OIO, OCIO-, OBrO-, and OIO-, respectively. The derived values are in excellent agreement with the available experimental values.

The molecular geometries and harmonic vibrational frequencies of biphenyl in the ground and the first excited triplet states have been calculated using the Hartree-Fock and Becke-3-Lee-Yang-Parr (B3LYP) density functional methods with 6-31G* basis set. Structural change occurs from a twisted benzene-like to a planar quinone-like form upon the excitation to the first excited state. Scaled harmonic vibrational frequencies for the ground state obtained from the B3LYP calculation show good agreement with the available experimental data. A few vibrational fundamentals for both states are newly assigned based on the B3LYP results.

We have modified a Dirac–Fock program package, MOLFDIR [L. Visscher et al., Comput. Phys. Commun. 81, 120 (1994)], to perform two-component molecular spinor calculations based upon the relativistic effective core potentials (REPs) incorporating effective spin–orbit operators. The modified MOLFDIR can be used to perform two-component REP calculations instead of four-component all-electron calculations at various levels of theory including the configuration interaction (CI) level. As a test case for the multireference CI methods, the low-lying states of Tl2 are calculated with the two-component CI method and the more conventional spin–orbit CI method. Results indicate that the two-component method has some advantages in describing the ground state of Tl2 while excited states are similarly described by both methods.

The photoionization of SiBr4 in the valence shell, and the Br(3d) and Si(2p) inner shell excitation/ionization regions, has been studied by using a time-of-flight mass spectrometer and synchrotron radiation over the range 30-133 eV. The photoionization efficiency curve of SiBr4 has been recorded as a function of the incident photon energy. Dissociation processes of SiBr4 have also been investigated by photoelectron-photoion coincidence and photoion-photoion coincidence (PIPICO) techniques. Various monocations of Br-n(+) (n = 1, 2) and SiBrn+ (n = 0-4) are detected along with dications of Br2+ and SiBrn2+ (n = 0, 1, 3) in the energy range. Various dissociation patterns are proposed based on the measurements of the ion time-of-flight differences in the PIPICO mode. The dominant dissociation pattern is found to be Si+-Br+ and SiBr+-Br+ in the whole energy examined. In the Br(3d) excitation region, however, a fragmentation leading to ion pair such as SiBr3+-Br+ also plays an important role in the dissociation of the core-excited SiBr4. With the help of ab initio Hartree-Fock and previous CI calculations, we estimate the term values and symmetries of the discrete core-excited states. This study of the specific excitation and dissociation of molecules provides information on energy dissipation processes of the core-excited states.

The Kramers' restricted Hartree-Fock (KRHF) and second-order Moller-Plesset perturbation (KRMP2) methods using relativistic effective core potentials (RECP) with spin-orbit operators and two-component spinors are extended to the unrestricted forms, KUHF and KUMP2. As in the conventional unrestricted methods, the KUHF and KUMP2 methods are capable of qualitatively describing the bond breaking for a single bond. As a result, it is possible to estimate spin-orbit effects along the dissociation curve at the HF and MP2 levels of theory as is demonstrated by the test calculations on the ground states of HI and CH3I. Since the energy lowering due to spin-orbit interactions is larger for the I atom than for the closed-shell molecules, dissociation energies are reduced and bond lengths are slightly elongated by the inclusion of the spin-orbit interactions. (C) 1998 John Wiley & Sons, Inc.

Unusually large discrepancies exist between the reported values of the experimental geometries of hexafluorocyclobutene determined from microwave (MW) spectroscopy and those from electron diffraction (ED). In an attempt to explain the origin of the difference, the geometries of cyclobutene, 1,2-difluorocyclobutene, 3,3,4,4-tetrafluorocyclobutene, hexafluorocyclobutene and 1,2-dichloro-3,3,4,4-tetrafluorocyclobutene are optimized by ab initio calculations at the Hartree-Fock, second-order Møller-Plesset perturbation levels of theory and configuration interaction with single and double substitutions. Comparison of the calculated results with available MW and ED parameters imply that MW geometrical parameters are probably more accurate for hexafluorocyclobutene than ED ones. The difficulty associated with vibrational corrections for hexafluorocyclobutene appears to be responsible for the unusual pattern of the difference between MW and ED structures.

We have implemented geometry optimization using an analytic gradient to a two-component Kramers' restricted Hartree-Fock (KRHF) method for polyatomic molecules with closed-shell configurations, The KRHF method is a Hartree-Fock method based on relativistic effective core potentials with effective spin-orbit operators. The derivatives of spin-orbit integrals are obtained by numerical differentiation. Geometries for the various forms of polyatomic hydrides containing row 6 p-block elements are optimized with and without spin-orbit interactions. The structural changes due to spin-orbit interactions are small, but show definite trends, which correlate well with the p(1/2) spinor population. Atomization energies are reduced significantly by incorporating spin-orbit interactions for all molecules considered. The KRHF calculations of several methylhalides demonstrate that the spinor energies from the KRHF method can be useful for the interpretation of experimental photoelectron spectra of molecules exhibiting spin-orbit splittings. (C) 1998 John Wiley & Sons, Inc. J Comput Chem 19: 1526-1533, 1998.

IR and Raman spectra are measured to elucidate both the conformation and vibrational modes of bis(4,4-dimethyl-2,5-cyclohexadien-1-ylidene) in the fundamental state. It is found that the rule of mutual exclusion holds for the IR and Raman spectra. Ab initio Hartree-Fock and density functional theory (DFT) calculations with scaling were carried out to study the molecular structure and vibrational spectra. The HF and DFT calculations predict that the molecule has a planar D-2h structure, showing a little discrepancy between theory and experiment. In the Raman spectra, the most intense line is observed at 1640 cm(-1), which is consistent with the DFT value of 1647 cm(-1) and is found to be a totally symmetric ring stretching along the lone axis and in-plane C-H bending. In the IR spectra, however, the most outstanding line is 780 cm(-1), in excellent agreement with the theoretical value of 775 cm(-1) and also found to be a z-polarized out-of-plane C-H and C-C-C bending (b(1u)). The results of analysis have been confirmed by measuring the depolarization ratios from the solution Raman scattering. Comparison of the calculated and experimental vibrational spectra reveals that the DFT calculations are quite accurate in predicting the fundamental frequencies and intensities in the region below 1700 cm(-1).