Ab initio studies on hydrogen-bonded chains. III. The linear,infinite chain of hydrogen cyanide molecules

Ab initio crystal-orbital calculations have been performed on the linear, infinite chain of HCN molecules applying basis sets from minimal to double-zeta-plus-polarization quality. From computed potential surfaces many properties of the electronic ground state of (HCN)_∞ could be deduced. Equilibrium structure, hydrogen-bond energy, dipole moment per molecule, dipole-moment derivatives, harmonic force constants, vibrational frequencies and electronic band structure are reported. Results on the polymer are compared with monomer, dimer and crystal data.     

Molecular orbital study of co chemisorption and oxidation on a Pt(111) surface

A molecular orbital study was made, using an atom superposition and electron delocalization (ASED) technique, of the structures and energy levels of CO on Pt(111) surface. CO is predicted to be preferentially adsorbed at a height of 2.05 Å from the surface at a 1-fold position with the carbon end down. The calculated binding energy (1.7 eV) is in good agreement with the recent experimental result (1.5 eV) of Campbell et al. Calculated binding energies for bridging (1.3 eV) and high coordinate (1.1 eV) sites are predicted to be smaller in magnitude. Calculated results are used to discuss the ordering of energy levels of adsorbed CO. The interaction between CO (adsorbed) and O (adsorbed) has been studied to estimate the energy of activation for the oxidation of CO on Pt(111) surface. The calculated activation energy (1.6 eV) is in reasonable agreement with the recent experimental result (1 eV) of Campbell et al. The Langmuir-Hinshelwood mechanism is found to be favored. We predict CO₂ bonds vertically.     

Palladium-promoted Cyclization of Tetra-alkylated 1-Arylazonaphthalenes to 2-Aryl-benzo[g]indazoles

1-Arylazonaphthalenes with all the potential cyclopalladation sites (one peri- and three ortho-positions) substituted by methyl or ethyl groups react with stoicheiometric or catalytic amounts of sodium tetrachloropalladate(II) to the corresponding 2-arylbenzo[g]indazoles. Possible mechanisms for the catalytic cyclization reaction are proposed.     

Zum IR-Spektrum des Nitrosodicyanmethanid-Ions [ONC(CN)2]−

The infrared spectrum of [ONC(CN)₂]^? is described and an assignment is given. In order to facilitate this assignment, ₁₅N is used. Complexes, formed by this anion, are also investigated by means of IR spectroscopy. The shift of the bands of the anion are reported and a discussion concerning the bonding relations of the complexes is given. Some remarkable isotopic effects are mentioned.