Potential morphing has been applied to the investigation of proper blue frequency shifts, Δν0 in CO, the hydrogen acceptor complexing in the hydrogen bonded series OC-HX (X= F, Cl, Br, I, CN, CCH). Linear correlations of morphed hydrogen bonded ground dissociation energies D0 with experimentally determined Δν0 free from matrix and solvent effects demonstrate consistency with original tenets of the Badger-Bauer rule (J. Chem. Phys. 1937, 5, 839-51). A model is developed that provides a basis for explaining the observed linear correlations in the range of systems studied. Furthermore, the generated calibration curve enables prediction of dissociation energies for other related but different complexes. The latter include D0 for H2O-CO, H2S-CO, and CH3OH-CO which are predicted by interpolation and found to be 355(13), 171(11), and 377(14) cm(-1) respectively from available experimentally determined proton acceptor shifts. Results from this study will also be discussed in relation to investigations in which CO has been used as a probe of heme protein active sites.

Rovibrational transitions associated with tunneling states in the n 5 (water bending) vibration of the OC-H 2 O complex have been recorded using a supersonic jet mode-hop free quantum cascade laser spectrometer at 6.2 µm. Analysis of the resulting spectra is facilitated by incorporating fits of previously recorded microwave and submillimeter data accounting for Coriolis coupling to confirm assignment of the n 5 vibration. The theoretical basis of morphing a 5-D frozen monomers potential was initially developed and then extended to two 6-D morphed potentials. A combination of these spectroscopic results and previous rovibrational data for the n 5 vibration in OC-D 2 O are then used to generate a 6-D morphed potential surface for the intermolecular and the water bending vibrations. An alternative 6-D morphed potential of the intermolecular and the

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SynopsisMolecular mechanical simulations on base-paired deoxyhexanucleoside phosphates, (dAdT), .(dAdT),, (dTdA), . (dTdA),, (dGdC), . (dGdC),, and (dCdG), . (dCdG),, have been carried out to assess their energetic stabilities in left-and right-handed forms. These hexamers have also been simulated with alternating sugar-puckering profiles with the combinations (purine : C2'-endo-pyrimidine : C3'-endo) and (purine : C3'-e&pyrimidine C2'-endo). The right-handed models have been found to be the energetically most stable structures and the left-handed structures are significantly destabilized. This instability has been rationalized in terms of competition between stabilizing stacking interactions on one hand, and distortions in the bond angles and torsion angles in the sugar-phosphate backbone on the other.