Synthesis and Structure of 2-tert-Butylphenoxytetraphenylantimony

2-tert-Butylphenoxytetraphenylantimony Ph₄SbOC₆H₄(Bu-t)-2 was prepared by the reaction of pentaphenylantimony with 2-tert-butylphenol in toluene at 20°. The structure of the obtained compound was determined by X-ray diffraction. The Sb atom in this compound has a distorted trigonal-bipyramidal coordination with the aroxy group in the axial position. The Sb–C(Ph)_eqand Sb–C(Ph)_axdistances are 2.111(7)–2.138(7) and 2.180(7) Å the Sb–O and O–C_Ardistances are 2.143(4) and 1.363(8) Å, respectively. The C(Ph)_axSbO_Araxial angle is 174.1(2)°, while the SbOC angle is 126.7(4)°.     

The separation of the alkaloids of Anabasis aphylla

Summary 1. The optimum conditions for the extraction of the high-boiling alkaloids from technical anabasine sulfate by dilution with water and at various pH values of the medium have been established.2. A method for removing anabasine and lupinine from a mixture of the high-boiling alkaloids ofAnabasis aphylla has been developed which is based on the formation of the carbonates of the strong bases.V. I. Lenin Tashkent State University. Dzerzhinskii Chimkent Pharmaceutical Chemicals Factory. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 468–472, July–August, 1974.     

Synthesis and Acid-Base Properties of α-Aminophosphoryl Compounds

-Aminophosphoryl compounds of the phosphonate, phosphine oxide, and ,-bis(phosphine oxide) series and some of their thiophosphoryl analogs were synthesized. Potentiometric measurements of the pK_a of the conjugate acids revealed an insignificant effect of variation of substituents on the phosphorus, nitrogen, and -carbon atoms on the basicity of the phosphorylated amines. The latter are weak bases. Organophosphorus groups decrease the basicity of the amines by almost 5 pK _a units. The role of the hydrophobic effect and intramolecular H-bonding in the obtained substances was discussed.     

H-, C-NMR and ethylene polymerization studies of zirconocene/MAO catalysts: effect of the ligand structure on the formation of active intermediates and polymerization kinetics

Using ¹H- and ¹³C-NMR spectroscopies, cationic intermediates formed by activation of L₂ZrCl₂ with methylaluminoxane (MAO) in toluene were monitored at Al/Zr ratios from 50 to 1000 (L₂ are various cyclopentadienyl (Cp), indenyl (Ind) and fluorenyl (Flu) ligands). The following catalysts were studied: (Cp-R)₂ZrCl₂ (R=Me, 1,2-Me₂, 1,2,3-Me₃, 1,2,4-Me₃, Me₄, Me₅, n-Bu, t-Bu), rac-ethanediyl(Ind)₂ZrCl₂, rac-Me₂Si(Ind)₂ZrCl₂, rac-Me₂Si(1-Ind-2-Me)₂ZrCl₂, rac-ethanediyl(1-Ind-4,5,6,7-H₄)₂ZrCl₂, (Ind-2-Me)₂ZrCl₂, Me₂C(Cp)(Flu)ZrCl₂, Me₂C(Cp-3-Me)(Flu)ZrCl₂ and Me₂Si(Flu)₂ZrCl₂. Correlations between spectroscopic and ethene polymerization data for catalysts (Cp-R)₂ZrCl₂/MAO (R=H, Me, 1,2-Me₂, 1,2,3-Me₃, 1,2,4-Me₃, Me₄, Me₅, n-Bu, t-Bu) and rac-Me₂Si(Ind)₂ZrCl₂ were established. The catalysts (Cp-R)₂ZrCl₂/AlMe₃/CPh₃⁺B(C₆F₅)₄⁻ (R=Me, 1,2-Me₂, 1,2,3-Me₃, 1,2,4-Me₃, Me₄, n-Bu, t-Bu) were also studied for comparison of spectroscopic and polymerization data with MAO-based systems. Complexes of type (Cp-R)₂ZrMe⁺←Me⁻-Al≡MAO (IV) with different [Me-MAO]⁻ counteranions have been identified in the (Cp-R)₂ZrCl₂/MAO (R=n-Bu, t-Bu) systems at low Al/Zr ratios (50-200). At Al/Zr ratios of 500-1000, the complex [L₂Zr(μ-Me)₂AlMe₂]⁺[Me-MAO]⁻ (III) dominates in all MAO-based reaction systems studied. Ethene polymerization activity strongly depends on the Al/Zr ratio (Al/Zr=200-1000) for the systems (Cp-R)₂ZrCl₂/MAO (R=H, Me, n-Bu, t-Bu), while it is virtually constant in the same range of Al/Zr ratios for the catalytic systems (Cp-R)₂ZrCl₂/MAO (R=1,2-Me₂, 1,2,3-Me₃, 1,2,4-Me₃, Me₄) and rac-Me₂Si(Ind)₂ZrCl₂/MAO. The data obtained are interpreted on assumption that complex III is the main precursor of the active centers of polymerization in MAO-based systems.     

Synthesis of 9-diazo-4-azafluorenes

Stable diazo compounds of the azafluorene series, viz., 9-diazo-4-azafluorenone and 1,3-diphenyl-4-azafluorene, were obtained from 4-azafluorenone and 1,3-diphenyl-4-azafluorene tosylhydrazones. 1,2-Dicarbomethoxyspiro(4-azafluorene-9,3-cyclopropane) was obtained from 4-azafluorenone tosylhydrazone, and 4,5-dicarbomethoxyspiro(4-azafluorene-9,3-pyrazolenine) was obtained from 9-diazo-4-azafluorene. It is assumed that the product in the latter case is obtained as a result of reaction of a carbene, viz., 4-azafluorenylidene carbene, which is formed from 9-diazo-4-fluorene, with dimethyl acetylenedicarboxylate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 951–953, July, 1979.     

Dissociative ionization of substituted piperideines

The fragmentation of different alkyl(aryl) substituted piperideines [tetrahydro-pyridines] was studied by analyzing high-resolution mass spectra and DADI [Direct Analysis of Daughter Ions] spectra. It was shown that the retrodiene decomposition of the ring is suppressed by competing processes of elimination of ring substitutents. The nature of the substituents and their mutual disposition on the ring have a substantial influence on the extent of their cleavage from the ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 795–800, June, 1988.     

Substrate oxidation by copper-dioxygen adducts: mechanistic considerations

A series of copper-dioxygen adducts [{Cu(II)(MePY2)(R)}(2)(O(2))](B(C(6)F(5))(4))(2) (1(R)()), systematically varying in their electronic properties via ligand pyridyl donor substituents (R = H, MeO, and Me(2)N), oxidize a variety of substrates with varying C-H or O-H bond dissociation enthalpies. Detailed mechanistic studies have been carried out, including investigation of 1(R)() thermodynamic redox properties, 1(R)() tetrahydrofuran (THF) and N,N'-dimethylaniline (DMA) oxidation kinetics (including analyses of substrate dicopper binding equilibria), and application of mechanistic probes (N-cyclopropyl-N-methylaniline (CMA) and (p-methoxyphenyl)-2,2-dimethylpropanol (MDP)), which can distinguish if proton-coupled electron-transfer (PCET) processes proceed through concerted electron-transfer proton-transfer (ETPT) or consecutive electron-transfer proton-transfer (ET/PT) pathways. The results are consistent with those of previous complementary studies; at low thermodynamic driving force for substrate oxidation, an ET/PT is operable, but once ET (i.e., substrate one-electron oxidation) becomes prohibitively uphill, the ETPT pathway occurs. Possible differences in coordination structures about 1(Me)()()2(N)()/1(MeO)() compared to those of 1(H)() are also used to rationalize some of the observations.     

Micellization and catalytic activity of the cetyltrimethylammonium bromide-Brij 97-water mixed micellar system

Surface tension measurements and the kinetic study of the basic hydrolysis of ethyl p-nitrophenyl chloromethyl phosphonate were used to examine the structural behavior and catalytic activity of the cethyltrimethylammonium bromide (CTAB)-polyoxyethylene (10) oleyl ether, C(18)H(35)(OCH(2)CH(2))(10)OH (Brij 97)-water mixed micellar system. Application of the regular solution model to the experimental data yields the value of the interaction parameter beta as -4.6, which indicates an attractive interaction of the surfactants in the mixed micelle and reflects synergistic solution behavior of the mixture. The mixed micellar composition is found to be enriched in the surfactant with the lower critical micelle concentration (cmc). In the kinetic study a nonmonotonic change in the pseudo-first-order rate constant of basic hydrolysis of the substrate is observed with increasing mole fraction of nonionic surfactant. The pseudophase micellar model reveals that the concentration factor mainly contributes to the catalytic effect, while the microenvironmental factor plays a negative role.     

1,3-diphenyl-2-azaanthracene and 8-aza-7-phenylbenzo[a]fluoranthene in the diene synthesis

The diene condensation of 1,3-diphenyl-2-azaanthracene with maleic anhydride proceeds under more severe conditions than the analogous condensation with anthracene. On the basis of an analysis of the PMR data for the adduct obtained it was assumed that isomers of ,-[9,10-dihydro-2-aza-1,3-diphenylanthrylene(9,10)]succinic anhydride with respect to the position of the anhydride bridge relative to the pyridine ring are formed in this condensation. 9,10-Dihydro-2-aza-1,3-diphenyl-9, 10-(1-cyanoethylene)anthracene was obtained in the condensation of the same azaanthracene with acrylonitrile. ,-[5H-8-Aza-7-phenylbenzo[a]fluoranthrylene (5,12b) ]succinic anhydride is formed as a result of the similar condensation of 8-aza-7-phenylbenzo[a]fluoranthene with maleic anhydride, while isomeric (with respect to the position of the nitrile group in the ethylene bridge) 5H-8-aza-7-phenyl-5,12b-(cyanoethylene)benzo[a]fluoranthenes were isolated in its condensation with the acrylonitrile. Data from the PMR and IR spectra were used to prove the structures of the adducts of the diene synthesis obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1647, December, 1980.