Reaction of 4,4′-dimethyldiphenyl ether with phosphorus trichloride in the presence of anhydrous aluminum chloride

The reaction of 4,4mg src="/content/x2m7215863766042/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-dimethyldiphenyl ether with phosphorus trichloride in the presence of anhydrous aluminum chloride was studied. This reaction affords 2,8-dimethyl-10H-10mg src="/content/x2m7215863766042/xxlarge955.gif" alt="lambda" align="BASELINE" BORDER="0">⁵-phenoxaphosphine 10-oxide as virtually the only product. In air, the latter in an alkaline solution is quantitatively transformed into 10-hydroxy-2,8-dimethyl-10H-10mg src="/content/x2m7215863766042/xxlarge955.gif" alt="lambda" align="BASELINE" BORDER="0">⁵-phenoxaphosphine 10-oxide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2762–2765, December, 2004.     

双峰倍增配平法用于同步、导数-同步荧光法同时测定邻羟基苯甲酸和间羟基苯甲酸

邻羟基苯甲酸（ｏＨＢＡ）和间羟基苯甲酸（ｍＨＢＡ）荧光光谱严重重叠，同步及导数技术虽使选择性有所改善，但仍不能完全分辨开重叠谱。用双峰倍增配平计算法结合同步、一阶导数－同步荧光法对双组分体系（邻羟基苯甲酸／间羟基苯甲酸，ｐＨ１２介质）同时测定。结合计算的两种测定方法精密度、回收率和不同组分间浓度比范围均优于一阶导数－同步荧光法。     

Organoruthenaborane Chemistry. X. The SM2-catalysed formation of [ l-(η6-C6Me6)-isocloso-RuB9H9], and some B-phenylamino derivatives. NMR and X-ray diffraction studies

The action of SMe₂ on the ten-vertex nido-ruthenaborane [6-(η⁶-C₆Me₆)RuB₉H_l3] ( 1 ) provides a high-yield route to the unsubstituted isocloso-ruthenaborane [1-(η⁶-C₆Me₆)RuB₉H₉] (2). The benzene analogue [1-(η⁶-C₆Me₆)RuB₉H₉] is prepared similarly. By contrast, reaction of (1) with PhNH₂ gives a variety of B-phenylamino isocloso derivatives, including orange crystals of [1-(η⁶-C₆Me₆)-2-(PhNH)-isocloso-1-RuB 9 H₈] ( 3 ), red-orange [1-(η⁶-C₆Me₆)-2,3-(PhNH)₂-isocloso-1-RuB₉H₇] ( 4 ) and dark-red [1-(η⁶-C₆Me₆)-5,6,7-(PhNH)₃-isocloso-1-RuB₉H₆] ( 5 ). Detailed ¹H and ¹¹B nmr properties of these various compounds are described. The structure of ( 3 ) has been established by a single-crystal X-ray diffraction study of the solvate [1-(η⁶-C₆Me₆)-2-(PhNH)-isocloso-1-RuB₉H₈] · 1/2 CH₂Cl₂; the crystals were monoclinic, space group C2/c, with a = 1895.1(3), b = 1556.6(3), c = 1716.4(3) pm, β = 104.37(1)° and z = 8.     

About a minimax theorem of Matthies,Strang and Christiansen

We give a new minisup theorem for noncompact strategy sets. Our result is of the type of the Matthies-Strang-Christiansen minimax theorem where the hyperplane should be replaced by any closed convex set. As an application, we derive a slight generalization of the Matthies-Strang-Christiansen minimax theorem.     

Fluoroaliphatic esters of fluorosulfonic acid. 6. Interaction of fluorine-containing α,β-bis-fluorosulfatocarbonyl compounds with nucleophilic reagents

Fluorine-containing mg src="/content/m4q542807943535u/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">,mg src="/content/m4q542807943535u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-fluorosulfatocarbonyl compounds interact with halides of alkali metals with the formation of mg src="/content/m4q542807943535u/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-halogeno-mg src="/content/m4q542807943535u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-dicarbonyl derivatives.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 177813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 715–719, March, 1992.     

2,6-Di-tert-butylphenols and phenoxyl radicals with metal—metal bonds

mg src="/content/k0m10183r3350v12/xxlarge963.gif" alt="sgr" align="BASELINE" BORDER="0">-Aryl trans-bistriphenylphosphine complexes based on 2,6-di-tert-butylphenol containing Pt—SnCl₃, Pt—GeCl₃ groups were synthesized. Oxidation of these compounds gives the corresponding phenoxyl radicals, which were studied by ESR spectroscopy. The transformation of the diamagnetic complexes to the paramagnetic state is accompanied by cleavage of the Pt—Sn, Pt—Ge bonds and by elimination of SnCl₂, GeCl₂.     

On the affinity of cytosine towards electrophiles

Ab initio SCF computations on the intrinsic preferences of the H⁺, CH ₃ ⁺ and C₂H ₅ ⁺ cations towards the two principal sites of protonation or alkylation on cytosine, N₃ or O₂, show that this preference undergoes a continuous modification with the increase in size and complexity of the cation. N₃ is the preferred site of fixation of H⁺, O₂ the preferred site of C₂H ₅ ⁺ , while CH ₃ ⁺ has no marked preference. The exchange repulsion term of the binding energy appears responsible for the preference of C₂H ₅ ⁺ for O₂.This work was supported by the Ligue Francaise contre le Cancer and the National Foundation for Cancer Research (USA)     

1H-NMR Investigation of the Binding of 2-Methylnaphthalene to α-Cyclodextrin in D2O Solutions

As mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-cyclodextrin (mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD) was added to D₂Osolutions of 2-methylnaphthalene, its proton signals shifted to lower fieldsat low concentrations of mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD. At 2.0 × 10^-2 moldm^-3 of mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD, however, a reverse, higher-field shift wasobserved for the H-8 signal, indicating the formation of 1 : 1 and 2 : 1mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD–2-methylnaphthalene inclusion complexes. Intrinsic chemicalshift differences of all the protons in 2-methylnaphthalene have beenevaluated for both the 1 : 1 and the 2 : 1mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD–2-methylnaphthalene inclusion complexes. These intrinsicchemical shift differences suggest that the first mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD molecule has noselectivity in accommodating one end of uncomplexed 2-methylnaphthalene;mg src="/content/u58542m405152705/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-CD binds to a methyl group, as well as a naphthalene ring-end havingno methyl group, to form the 1 : 1 inclusion complex, resulting in theformation of two kinds of 1 : 1 complexes.     

Ab-initio-Berechnungen des π-Bindungsbeitrages in BF3 und BCl3

Ab initio gradient calculations were performed on BF₃ and BCl₃ to evaluate the mg src="/content/m62j6p2276634018/xxlarge960.gif" alt="pgr" align="BASELINE" BORDER="0">-contribution in these compounds. The influence of the basis set on the results is studied for borontrifluoride. For the chlorine compound the mg src="/content/m62j6p2276634018/xxlarge960.gif" alt="pgr" align="BASELINE" BORDER="0">-contribution is smaller than for the fluorine compound.