Sulfur-containing derivatives of thiolan-1,1-dioxide 3. Reactions of salts of 2-(n,n-dialkyl)iminio-5,5-dioxoperhydrothieno[3,4-d]-1,3-dithiolans with bases

Salts of condensed 2-(N,N-dialkyl)iminio-1,3-dithiolan and 1,1-dioxothiolan rings are converted in alkaline media to 1,1-dioxothiolen esters of N,N-dialkyldithiocarbamic acids and into unsaturated bicyclic compounds. The latter are formed when the initial salts contain a bromine atom to the sulfonyl group.For Communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 40–47, January, 1993.     

Dispersity and kinetic characteristics of dissociation of mono- and hemiaquo adducts of copper N,N′-ethylenebis(acetylacetoniminate) under nonisothermal conditions

Using optical microscopy and thermogravimetry, we have established that determination of the kinetic characteristics of dissociation for the monoaquo adduct of copper N,N-ethylene-bis(acetylacetoniminate) with particle size 0.5–2 mm is hindered by self-dispersal processes. Using a piezoquartz microbalance, we have obtained the kinetic parameters for thermolysis for a phase whose crystal sizes are substantially smaller than the minimal size after self-dispersal of a block of a large crystal (0.5–2 m). For thermolysis of the hemiaquo adduct not accompanied by self-dispersal, the kinetic characteristics of the process for phases of dispersity 0.5–2 mm and 0.5–2 m are comparable.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 3, pp. 226–231, May–June, 1992.     

Diol-diisocyanate polymerization by gamma irradiation

Gamma irradiation has been used as an alternative way of curing diol-diisocyanate by means of specific catalysts and/or elevated temperatures. A mixture of toluene diisocyanate (TDI) and hydroxy terminated polybutadiene (HTPB) oligomer were irradiated over a dose range of 0–720 kGy using a 5 kCi⁶⁰Co -source. Various compositions were formulated and also suitable additives were incorporated. Disappearance of the isocyanate peak in the IR spectra was considered as a measure of its consumption. The conversion characteristics showed a profound influence of irradiation. A suitable mechanism is envisaged.     

Substituent effects in the fragmentation reactions of acetanilides and phenyl acetates

The mass spectra of a group of m- and p-substituted acetanilides were measured to determine the effect of the substituents, if any, on the rate of C₂H₂O expulsion (rearrangement) vs. the rate of [CH₃CO]⁺ formation (simple cleavage). Our results agree with observations of others in that substituents which raise the ionization potential of the aromatic ring appear to localize, on the average, less charge density on this locus, and conversely. The atomic composition of the substituent, however, irrespective of its position, seems to determine the relative rates of the competing reaction. Although in several cases Z_m/Z_p values were close to unity, rearrangement of isomeric molecular ions to a common species is shown not to occur.