Tables of accurate STF HF wavefunctions from B to Ca

Accurate Slater type function (STF) Hartree-Fock (HF) wavefunctions are calculated and tabled from B to Ca. The STF's have a form of r ⁿ e ^-r and the powers (n) of r are carefully determined. The total atomic energies agree with those of numerical HF (NHF) within the error of 4×10^–6 a.u. and 1×10^–5 a.u. for B to F and for Ne to Ca, respectively. The STF HF basis sets given will be useful to benchmark calculations for the molecular, solid, and atomic electronic states. Applications of the STF HF basis to molecular calculations are given and briefly discussed. Sample calculations are performed on the N₂ and P₂ molecules.     

Insertion reactions of difluorocarbene generated by pyrolysis of hexafluoropropene oxide to OH bond

ROCHF₂-type fluorinated ethers were synthesized by the reaction of hexafluoropropene oxide (HFPO) with alcohol or phenol. In this reaction, although the insertion reaction of difluorocarbene to OH bond and the nucleophilic attack of alcohol or phenol to HFPO were competition, the insertion reaction proceeded predominantly to give fluorinated ether in the case of low nucleophilic alcohol or phenol. In addition, high reaction pressure is advantageous to the selectivity of the fluorinated ethers in the reaction of HFPO with (CF₃)₂CHOH or C₆F₅OH.     

Analysis of the intermolecular interactions between CH3OCH3, CF3OCH3, CF3OCF3, and CH2F2, CHF3

The intermolecular interaction energy curves of CH(3)OCH(3)-CH(2)F(2), CF(3)OCH(3)-CH(2)F(2), CF(3)OCF(3)-CH(2)F(2), CH(3)OCH(3)-CHF(3), CF(3)OCH(3)-CHF(3), and CF(3)OCF(3)-CHF(3) complexes were calculated by the MP2 level ab initio molecular orbital method using the 6-311G** basis set augmented with diffuse polarization functions. We investigate the fluorine substitution effects of both methane and dimethyl ether on intermolecular interactions. In addition, orientation dependence of intermolecular interaction energies is also studied with utilizing eight types of orientations. Our analyses demonstrate that partial fluorinations of methane make electrostatic interaction dominant, and consequently enhance attractive interaction at several specific orientations. On the contrary, fluorine substitutions of dimethyl ether substantially decrease the electrostatic interaction between ether and CH(2)F(2) or CHF(3); thus, there is no such characteristic interaction between the C-H of fluorinated methane and ether oxygen of CF(3)OCF(3) as conventional hydrogen bonding, due to reduced polarity of fluorinated ether. The combination of different pairs of the electrostatic interaction is therefore responsible for the intermolecular interaction differences among the complexes investigated herein and also their orientations.     

Synthesis of trifluoromethyl amines,CF3N(X)H,from CF3N(X)C(O)F.

A new general synthesis of trifluoromethyl amines of the type, CF₃N(X)H, is reported. The amines are prepared in excellent yield by the hydrolysis CF₃N(X)C(O)F in the presence of NaF. The N-acyl fluorides are now available in considerable variety from the reaction of nucleophiles with the oxaziridine CF₃$\text{NCF}{}_2\text{O}$. Six new amines have been prepared and characterized [(X=CF₃O, (CF₃)₂CFO, CH₃O, C₂H₅O, (CH₃)₂CHO and (CH₃)₃CO)] and improved syntheses of CF₃NHF and CF₃NHOC(O)CH₃ are reported. The new compounds are thermally stable at 22° and are characterized by IR, NMR and physical properties.     

Photodissociation spectrum of cyanobenzene dimer cation. Absence of intermolecular resonance interaction

Electronic spectra of a homo-molecular dimer cation, (C₆H₅CN)₂ ⁺, are measured by photodissociation spectroscopy in the gas phase. Broad features appeared in the 450–650 nm region are characteristic of π₃ → π_CN transitions of the C₆H₅CN⁺ chromophore. No intense band is observed in the 650–1300 nm region, where other aromatic dimer cations usually show charge resonance bands. Two component molecules of (C₆H₅CN)₂ ⁺ cannot take a parallel sandwich configuration suitable for the resonance interaction, because of geometrical constraints due to other stronger interactions.     

The reaction of 2-trifluoromethyl-3,3-difluorooxaziridine with nucleophiles.

The facile reactions of CF₃$\text{NCF}{}_2\text{O}$ with a variety of non-fluorinated nucleophiles are discussed. CF₃$\text{NCF}{}_2\text{O}$ + Nu^- → CF₃N(Nu)C(O)F + F^- Reactions with alcohols, carboxylic acids, mercaptans, amines, KSCN, KCN, NaN₃ and NaOCN were carried out. All except NaN₃ and NaOCN were reactive and the expected compounds were isolated in most cases. Subsequent reaction of CF₃N(Nu)C(O)F with additional nucleophile was observed in many cases forming CF₃N(Nu)C(O)Nu. With CH₃CO₂H, the latter reaction forms CH₃C(O)F and the novel amine CF₃N(H)OC(O)CH⁶₃. Ten new compounds are reported with characterization by IR, NMR and physical properties.     

Photochemical aerosol formation from organic gases

It is found that many kinds of organic gases, which belong to aromatics, terpenes, and cycloalkanes, produce aerosols when irradiated by a deuterium lamp with spectrum ranging from 180 to 400 nm in wavelength, and by a krypton-fluoride excimer laser operated at 249 nm. Two initial processes are important, direct excitation of organic molecule by the ultraviolet light, and reaction of organic molecule with ozone produced photochemically by the ultraviolet light. It depends on compounds which process is dominant. For some compounds, both are possible.