AM1 study of photoelectron spectra.

The -orbital structure of the monomeric form of the 2,2,4,6-tetrachloro-2,2-dihydro-1,5,2-diazaphosphorinine has been studied by photoelectron spectroscopy and using quantum-chemical calculations by the semiempirical AM1 method. It has been concluded that the electronic and energy characteristics of four higher -MOs (frontier and three next orbitals) of this compound may be interpreted in terms of semipolar bonds formed by three atoms (C, P, and N). For describing two low-lying -MOs of the ⁴,⁵-phosphorine studied, it is necessary to take into account the --interaction.For Part 8, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 827–831, April, 1996.     

以硫醚为主链的螯合树脂研究Ⅳ．含硫代硫酸根、叠氮基树脂的合成及吸附性能

聚环硫氯丙烷或环硫氯丙烷与环氧氯丙烷共聚物，在少量二乙烯三胺存在下制得交联预聚物，将交联预聚物分别与硫代硫酸钠，叠氮化钠反应，制得四种侧链带有硫代硫酸根或叠氮基的新型螯合树脂。它们对贵金属离子具有较高的吸附容量和较好的吸附选择性。     

Organosilicon compounds containing carbofunctional biguanidine group

The reaction of triethoxysilylpropylamine (AGM-9) with dicyanodiamide was studied. The condensation of AGM-9 with dicyanodiamide occurs in the presence of a catalytic amount of CuCl₂ at 125–145°C within 5–24 h; it involves both the amino group of AGM-9 and ethoxy substituents at the Si atoms, with an unusual exchange of a Si-O bond for a Si-N bond. The final reaction product is 1-N-(3-triethoxysilylpropyl)-2-N-[3-aminopropylsilyl(diethoxy)]biguanidine. Its hydrolytic polycondensation yields an organosilicon polymer, a polycondensate of AGM-9 with 1-N-(3-triethoxysilylpropyl)biguanidine, which is a highly efficient sorbent for Ag(I) (static sorption capacity 544 mg g^?1).     

Reactions of 1,1,4,4-tetramethylsemicarbazide with prop-2-ynyl bromide, allyl bromide, and 1,3-dibromoprop-1-yne

1,1,4,4-Tetramethylsemicarbazide readily undergoes alkylation with prop-2-ynyl bromide and allyl bromide at the tertiary nitrogen atom of the hydrazine fragment to give 1-(prop-2-yn-1-yl)-and 1-(prop-2-en-1-yl)-1,1-dimethyl-2-(dimethylaminocarbonyl)hydrazinium bromides, respectively. A new procedure was proposed for the synthesis of 6-bromomethylidene-2-dimethylamino-4,4-dimethyl-5,6-dihydro-4H-1,3,4-oxadiazin-4-ium bromide by reaction of 1,1,4,4-tetramethylsemicarbazide with 1,3-dibromoprop-1-yne in acetonitrile.     

Addition of 1,2- and 1,3-Dithiols to 2-alkoxypropenals - a New Method for the Production of Substituted Dithiacycloalkanes

The reaction of 2-alkoxypropenals with ethane-1,2-dithiols and propane-1,3-dithiols under various conditions was studied by ¹H NMR and chromato-mass spectrometry. Under kinetically controlled conditions at 20° in the absence of catalysts the addition of dithiols takes place according to the Markovnikov rule. The primary adducts are unstable and are quickly converted into the corresponding substituted 1,4-dithiacycloheptane or 1,4-dithiane. The latter in turn can be converted under the reaction conditions or at high temperature into a thiolane derivative. The reaction of 2-ethoxypropenal with a twofold excess of ethane-1,2-dithiol at 60°C in the presence of p-toluenesulfonic acid leads to 2-methyl-2,2'-bi(dithiolane)     

Radical-anions in the vicarious C-amination reactions of N-substituted nitrotriazoles

The vicarious nucleophilic substitution of hydrogen in symmetrical and vicinal nitrotriazoles by 1,1,1-trimethylhydrazinium iodide in t-BuOK/DMSO was studied by ESR. In the ESR monitoring of the reactions the primary radical-anions of 4-nitro-2-phenyl-1,2,3-triazole and 1-methyl-3-nitro-1,2,4-triazole were detected and characterized. It was shown by NMR that the amination of 4-nitro-2-phenyl-1,2,3-triazole takes place exclusively in the triazole ring with the formation of 5-amino-4-nitro-2-phenyl-1,2,3-triazole. 1-Methyl-3-nitro-1,2,4-triazole, like 3-nitro-1,2,4-triazole, does not form amination products. A possible mechanism for the vicarious C-amination of nitrotriazoles and the formation of the radical-anions of the substrates is discussed. Dedicated to Academician M. G. Voronkov on his 85th birthday. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1662–1670, November, 2006.     

Rearrangements in methanolysis of bis(2-bromoalkyl)selenides

Addition of selenium dibromide to 1-hexene, 1-octene, and allylic ethers occurs through the formation of intermediate kinetic anti-Markovnikov adducts that further transform into more thermodynamically stable Markovnikov adducts presumably via seleniranium intermediates. The methanolysis of both Markovnikov and anti-Markovnikov adducts leads to the formation of the same products in approximately the same ratio thus showing that the reaction proceeds through seleniranium intermediates.