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Discusses how the journal "Internet Journal of Chemistry" is designed to take advantage of newly available technologies. Describes the development of the concept of an electronic journal, decision-making on the scope and coverage of the journal, financial logistics, and how the journal will be implemented. Includes perspectives on how this new medium compares with traditional print publication. (Author/AEF)

A series of gas-phase nucleophilic substitution reactions at sulfur of methanesulfinyl derivatives by small anions is examined by Hartree-Fock, MP2, and DFT computations. In most cases, substitution is found to follow an addition-elimination mechanism, resulting in a triple-well potential energy surface with small barriers of activation on either side of the central, tetracoordinate-sulfur minimum.

B3LYP/6-31+G optimizations for prototype thiolate-disulfide exchange reactions were performed including one to four explicit water molecules, followed by single-point free energy calculations with B3LYP/6-31+G and the polarized continuum model. Solvation increases the stability of the transition states relative to the intermediates and hence reduces the depths of wells associated with the intermediates.

Research has been conducted on the reactions of HS (super)- with small cyclic disulfides. The study of this reaction carried out via B3LYP/aug-cc-pVDZ and MP2/6-31+G* calculations in the effort to determine the reaction mechanism is described.

Research has been conducted on dilithio-, tetralithio-, pentalithio- and hexalithiobenzenes. The geometries of these compounds have been investigated and the results demonstrate that the lowest energy structures can be studied via electrostatic interactions between carbanions and lithium cations.

Research has been conducted on the nucleophilic substitution reactions which involve simple species such as nucleophile and leave group in methylsulfenyl derivatives. Results indicate that the reactions involving hydroxide and amide correspond to deprotonation and not substitution and that the substitution reactions follow the addition-elimination pathway.

Research has been conducted on the Diels-Alder reaction of substituted selenoaldehydes or selenoketones with 1,3-butadiene or 2-methoxy-1,3-butadiene. Results indicate the yield of 3,6-dihydro-2H-selenopyrans examined by means of B3LYP with a modified 6-31G basis set.

A flowing afterglow tandem mass spectrometer and ab initio calculations were used to investigate the potential energy surface to protonated sulfuric acid. Results indicated that water can catalyze the dissociation of H3SO4+. Moreover, the overall energy surface was found to be similar to that for the addition of water to sulfuric acid, indicating that the reaction is not greatly affected by the additional proton.

Research was conducted to examine the lithium and sodium salts of doubly deprotonated benzene using ab initio molecular orbital calculations. Calculations were performed using the GAUSSIAN-94 code. Results indicate that phenyllithium is more acidic than benzene and that phenylsodium has almost the same acidity as benzene. Findings also suggest that both conjugate bases are apt to be stable in the gas phase.

The gas-phase basicity of sulfuric acid was determined using several mass spectrometric techniques. The flow rate of sulfuric acid was estimated by calculating absolute rate constants and obtaining the relative rate constants to provide reasonable assumptions on the rate of calibration reactions. A kinetic method involving collision-induced dissociation of a proton-bound dimer in a tandem mass spectrometry (MS) was used to eliminate the inefficiencies of the flowing afterglow-tandem MS technique.

The ene reaction between propene and different kinds of enophiles such as ethene, methanal, methanethial, ethanethial and cyanomethanethial were analyzed at the MP4/6-31G*//MP2/6-31G* level. The transition structures were all cyclic and concerted. The activation barriers for the thiocarbonyls were substantially lower than for ethene or methanal. This trend including the trend in activation energies among the substituted thials was in total agreement with the FMO theory.

A multistep process is involved in the trigger mechanism for the activation of calichaemicin and related enediyne antitumor agents. It starts with a displacement at the terminal sulfur of the trisulfide, followed by nucleophilic substitution of a disulfide. These findings found theoretical support from the results of an evaluation of the nucleophilic substitution reactions of three trisulfides by thiolate. These three reactions indicate that nucleophilic substitution at both the central and terminal sulfurs of a trisulfide proceed via an addition-elimination mechanism. A kinetic preference for attack at the terminal sulfur is also noted.

Ab initio calculations concerning the chemistry and activation energy of the Diels-Alder and Staudinger reactions between ketene and cyclopentadiene were carried out. According to the results, which were in good agreement with experimental observations, the Diels-Alder reaction occurs simultaneously unlike the Staudinger reaction which occurs sequentially. The cycloadditions were also found to be exothermic, kinetically controlled reactions that produce cyclobutanone exclusively.

The phospha-Cope rearrangement of 1,6-diphospha-1,5-hexadiene into 3,4-diphospha-1,5-hexadiene was examined. The results showed that the rearrangement involves the three isomers of 1,6-diphospha-1,5-hexadiene undergoing chairlike concerted transition states. Both 1,6-diphospha-1,5-hexadiene and 3,4-diphospha-1,5-hexadiene exhibit configurations and conformations with relative energies within 1 kcal mol-1.

The keto-enol tautomerization in formyl- and diformylphosphine are examined by measuring the energetics of the (1,3)-hydrogen shift at MP4SDQ/6-31**//MP2/6-31G** + ZPE(HF/6-31G**). The results were compared with the hydrocarbon analogues acetaldehyde and malonaldehyde. The results showed that the keto-enol tautomerization of diformylphosphine is exothermic by 0.80 kcal mol -1 as a result of the intramolecular hydrogen bond that stabilizes the enol form.

Ab initio analysis of Diels-Alder reaction of cyclopropenone and furan at the MP4SDQ/6-31G*//MP2/6-31G* level shows that the reaction mechanism favors the formation of exo isomer which is a thermodynamic and kinetic product. The stability of exo product is 6.35 kcal/mol below the endo product and the activation energy is 1.81 kcal/mol less than the activation energy to obtain endo isomer.

Ab initio calculations of the reactions of ethyne with cyclopentadiene and ethyne with 1H-, 2H- and 3H-phosphole help determine activation energies of the reactions. The calculated activation energy, geometry and electron distribution suggest a concerted (4+2) cycloaddition pathway for all the reactions. The studies support the mechanism proposed by Mathey for reactions between substituted 1H-phosphole and alkynes.

Ab initio calculations determine the enthalpies associated with reactants, products and transition states of phosphaketene and ketene dimerization reactions. Ketene dimerizes to products through concerted transition states having partial charge separation while exothermic phosphaketene dimerization involves a (2 pi-s + 2 pi-a) pathway. The change in mechanism is due to reduced ring strain and steric interaction associated with phosphaketene dimerization than due to ketene dimerization.

Energies of eleven methylphosphole isomers and three vinylphospholes are analyzed. Lowest energy in the unsubstituted phosphole is observed in the 2H isomer. Steric interactions favor substitutions more at phosphorus than carbon. Aromatic character is absent in 1H-phosphate. The calculations predict a mechanism which involves Diels-Alder reaction of phospholes.

The chemistry of pyrroles and phosphole are examined computationally. The analytical examination of 2H- and 3H-pyrroles reveal interconversion, which is proved by the close energy levels of the two, with an obstacle of 26.3 kcal mol (-1). A low barrier of 16.0 kcal mol (-1) is observed in the process of transforming 1H-phosphole to a 2H-phosphole. The conformation and electron density diffusions of various transition states, through which the (1,5) hydrogen translocation of cyclopentadiene, pyrrole, and phosphole take place, resemble one another. A concerted (1,5) hydrogen shift is observed as the common mechanism for all the migrations by this deduction.