Field-desorption mass-spectrometric investigation of photolysis products of phosphonates

Field-desorption mass spectrometry was used to study the photolysis of phosphonates (afos and butonat) used as plant-protection agents. Field-desorption mass spectra of the starting compounds were obtained, as well as of compounds that were phosphonate-decomposition products; some products of phosphonate decomposition under the effect of UV irradiation were identified. It was observed that association complexes could be formed between the solvents and the starting compounds with irradiation of the substances in alcohol and hexane. It was shown that compounds more toxic than the starting ones could be formed during photolysis of the phosphonates.Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 22, No. 5, pp. 632–635, September–October, 1986.     

1-Aryl-5-carboxymethylhydantoin derivatives. structure of 1-phenyl-2-thio-5-carbomethoxymethylhydantoin

The reaction of aromatic amines with maleic acid or its diethyl ester with subsequent hydrolysis gave N-arylaspartic acids, which were converted to 1-aryl- and 1-aryl-2-thio-5-carboxymethylhydantoins by the action of urea, cyanates, or thiocyanates in an acidic medium. Esterification of the acid products with methanol gave the corresponding carbomethoxymethylhydantoins, which were converted by reduction to tetrahydroimidazole derivatives and by acetylation to acetyl derivatives. Alkylation of the carboxymethylhydantoins with dimethyl sulfate gave 3-methyl derivatives of hydantoins, while alkylation with formaldehyde gave 3-hydroxymethyl derivatives of hydantoins. Data from the x-ray diffraction analysis of 1-phenyl-2-thio-5-carbomethoxymethylhydantoin are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1669–1674, December, 1981.     

Kinetics and mechanism of 1-phenyl-5-methyltetrazole nitration in HNO3–H2SO4 system

Russian Journal of Organic Chemistry - At nitration of 1-phenyl-5-methyltetrazole with nitric acid in aqueous solutions of sulfuric acid of 84–96% concentration a mixture forms of...     

Simultaneous electron diffraction and mass-spectrometric study of the structure of the MoF5 molecule

Electron diffraction data for the MoF₅ molecule are analyzed in terms of an r_a structure. Three models of the geometrical structure, which have D_3h, C_4v, and C_2v symmetry, are considered. It is confirmed that a distorted bipyramid of C_2v symmetry is the best model that is in agreement with experimental electron diffraction data. The model has three different types of nuclear Mo-F distances: r_α(Mo-F_1eq) = 1.720(5) Å, r_α(Mo-F_2eq) = 1.826(7) Å, r_α(Mo-F_ax) = 1.825(7) Å. The bond angle between the pseudoaxial bonds is 168.1(0.6)?, and the angle between the Mo-F_2eq pseudoequatorial bonds is 122.6(0.8)?. The r_a(Mo-F_leq) and r_a(Mo-F_2eq) distances differ significantly. Possible reasons for this are discussed.     

Vibrational assignments and theoretical calculations of 1-phenyl-5-mercaptotetrazole and 1-phenyl-5-mercaptotetrazolate

The infrared and Raman spectra of 1-phenyl-5-mercaptotetrazole (PMT) and 1-phenyl-5-mercaptotetrazole sodium salt in the solid state and in solution have been measured. Detailed vibrational assignments of PMT and 1-phenyl-5-mercaptotetrazolate (PMTA) have been performed. In order to give a firmer basis to the interpretation of the vibrational spectra, harmonic wavenumbers of PMT and PMTA have been calculated by means of MP2 and DFT/BPW91 calculations. The DFT calculations provide a satisfactory agreement between the calculated and observed wavenumbers without using scaling factors. Experimental evidence shows that PMT is present in the thione tautomer both in the solid state and in solution of polar solvents.     

Orientation in the nitration of 3-phenyl-4-substituted furazans

The nitration of 3-phenyl-4-substituted furazans with various nitrating agents was investigated. It is shown that the orientation of the nitro group that is incorporated in the phenyl ring is determined by the substituent in the 4 position of the furazan ring, whereas the introduction of a furazan substituent in the phenyl ring lowers the reactivity of the latter. The corresponding dinitro derivatives can be obtained by means of acid mixtures.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 27–29, January, 1982.     

Conformation-specific spectroscopy of 4-phenyl-1-butyne and 5-phenyl-1-pentyne

4-Phenyl-1-butyne and 5-phenyl-1-pentyne were studied by a combination of methods including resonance-enhanced-two-photon ionization, UV-UV hole-burning spectroscopy, and rotational band contour studies. There are two conformations of 4-phenyl-1-butyne observed in the expansion with their S1<-- S0 origins occurring at 37617 and 37620 cm(-1). MP2 and DFT calculations identify these two low energy conformations (with the acetylenic group anti or gauche with respect to the ring) and confirm that these are the only two low energy conformations anticipated to have population in them. The experimental rotational band contours of the origin bands were compared to simulations based on transition moment directions and rotational constants predicted by CIS calculations. This comparison leads to definitive assignments for the bands, with the gauche and anti conformations assigned to the red and blue-shifted conformers, respectively. Three conformations of 5-phenyl-1-pentyne were observed in the expansion with their S1<-- S0 origins occurring at 37538, 37578, and 37601 cm(-1). MP2 and DFT calculations predict four low energy structures arising from gauche or anti conformations about each of the Calpha-Cbeta and Cbeta-Cgamma bonds. Rotational band contour analysis was used to assign the above transitions to gauche-anti (ga), gauche-gauche (gg), and anti-gauche (ag) structures, respectively.     

The structure of 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one

Crystal and molecular structure of 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one as a product of the benzoylation of 1-phenyl-3-benzoylaminopyrazol-2-in-5-one was characterised by X-ray single crystal diffraction. It is shown that 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one exists in the solid phase in an NH-tautomeric form, which is stabilised by two intramolecular hydrogen bonds and one intermolecular bond with the solvate dioxane molecule, the latter being used as a solvent for recrystallisation.     

Synthesis and nitration of 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one

Analysis of the UV spectra of the reaction products shows that in the nitration of 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one the nitro group is directed to the benzodiazepine ring rather than to the phenyl ring to give a 7-nitro derivative.Translated from Khimiya Geterotsiklieheskikh Soedinenii, No. 4, pp. 525–528, April, 1977.     

The structure of the diazonium coupling products of phenacyl thiocyanate and phenacyl selenocyanate with diazotized 3-phenyl-5-aminopyrazole

The reaction of diazotized 3-phenyl-5-aminopyrazole with phenacyl thiocyanate 1a and phenacyl selenocyanate 1b afforded directly 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-thiadiazole monohydrate 9a and 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-selenadiazole monohydrate 9b , respectively. The products 9a and 9b were also obtained from the reaction of C-benzoyl-N-(3-phenyl-5-pyrazolyl)formohydrazidoyl bromide 10 with potassium thiocyanate and potassium selenocyanate, respectively. Acetylation, benzoylation, and nitrosation of 9 afforded the corresponding diacetyl, dibenzoyl, and nitroso derivatives 11-13 , respectively. Cyclization of C-benzoyl-N-(3-phenyl-5-pyrazolyl)-nitrilimine 6 was shown to give the pyrazolo [5,1-d]triazole 8 and not the pyrazolo[5,1-c]-as-triazine derivative 7 , as previously reported.     

Thermal isomerization of 1-phenyl-5-hydrazinotetrazole

A new example of isomerization of a tetrazole derivative(1-phenyl-5-hydrazinotetrazole to 1-amino-5-anilinotetrazole) is described. A convenient method for preparing 1-phenyl-5-hydrazinotetrazole is described.     

Formation and structure of 1-Amino-4-methyl-4-(4-methyl-5-phenyl-1H-pyrazol-3-ylamino)-3-phenyl-4,5-dihydro-1H-pyrazol-5-one

The title compound 3 was obtained during the rearrangement of isoxazol-5-yl hydrazine 1 to 1-aminopyrazolone 2 at 115°. X-ray analysis of the corresponding benzylidene derivative allowed us to achieve the structure assignment.