New methodology for tosylation of hydroxylic supports as exemplified by the immobilization of micrococcal endonuclease on agarose

Improvement have been made in a simplified procedure we previously reported (J.Mol.Catal. (1986),38,227 for the activation of tosyl chloride of supports possessing primary hydroxyl groups. The method is simple, can be completed in less than 90 min, yields a broad range of activation degrees, and, since it involves no toxic reagents, may be used for preparing immobilized enzymes to be utilized in food manufacturing and processing. The immobilization ofStophylococcal Nuclease has been carried out by this method. The insolubilized derivatives are more active than the native enzyme in the hydrolysis of DNA. The thermal stability of nuclease derivatives is greater than that of the native enzyme. These derivatives remain active at 50°C, and the native enzyme, 39°C. The insolubilized nuclease is more stable against organic solvents such as, dimethylsulfoxide (DMSO) or tetrahydroduran (THF) than the native enzyme.     

Kinetics of radical polymerization—XXXII. Determination of the rate of initiation in bulk polymerization of acrylonitrile

A study was made of the possibility of applying three chemically different types of free radicals for determination of the rate of initiation in the heterogeneous polymerization of acrylonitrile (AN) initiated by AIBN. The Banfield-Kenyon radical showed accelerating decay in acrylonitrile. Between triphenylverdazyl (TPV) and AN a thermal reaction occurs. The rate of initiation however can be determined by taking account of this reaction. By photometric and kinetic investigations, no thermal reaction between 1,1-diphenyl-2-(2,6-dinitrophenyl)-hydrazyl (DPDH) and AN could be observed at 60° or lower temperatures. The rate of initiation was determined also with DPDH by inhibition kinetic method. The values obtained with TPV and with DPDH are in very good agreement.     

The crystal and molecular structure of bis(indazol-1-yl)pyridin-2′-ylmethane (BIPM) and [Rh(BIPM)(NBD)]PF6

The syntheses of a new tripodal ligand bis(indazol-1-yl)pyridin-2′-ylmethane (BIPM) and of a cationic complex (Rh(BIPM)(NBD)]PF₆, (NBD = 2,5-norbornadiene) are reported. Both compounds were characterized by infrared, ¹H, and ¹³C NMR spectroscopy and by single crystal X-ray analysis. BIPM crystallizes in the monoclinic system in space group P2₁/n with an β helical conformation. The [Rh(BIPM)(NBD)]PF₆ complex crystallizes in the monoclinic space group C/2c, the rhodium atom being pentacoordinate with a distorted trigonal bipyramidal geometry.     

Effects of Pretreatments on the Structure of Palladium-Containing Amorphous Alloys Followed by DSC

Amorphous PdZr, PdCuZr and PdCuSi alloy ribbons and powders are characterized by DSC, XRD and XPS in the as-received state and after treatments with oxygen, hydrogen or dilute hydrogen fluoride solution. Zr-containing alloys are shown to undergo substantial structural changes resulting in palladium enrichment on their surface, whereas no apparent changes in the bulk structure are found for PdCuSi. Catalytic activity and selectivity of the pretreated samples were tested in the hydrogenation of phenylacetylene. This revised version was published online in July 2006 with corrections to the Cover Date.     

Convenient Synthesis of 7,8‐Dimethoxytetralin‐2‐one

7,8‐Dimethoxytetralin‐2‐one (1), an important intermediate for the synthesis of compounds possessing biological activity, was synthesized by simple reaction steps from commercially available starting materials.     

Simultaneous Extensions Revisited

After an introduction presenting the problem of simultaneous extensions, some concrete examples show the difficulties in examining this problem.     

Addition theorems for the Appell polynomials and the associated classes of polynomial expansions

Various interesting and potentially useful properties and relationships involving the Bernoulli, Euler and Genocchi polynomials have been investigated in the literature rather extensively. Recently, the present authors (Srivastava and Pinter in Appl Math Lett 17:375–380, 2004) obtained addition theorems and other relationships involving the generalized Bernoulli polynomials ${B_n^{(\alpha)}(x)}$ and the generalized Euler polynomials ${E_n^{(\alpha)}(x)}$ of order α and degree n in x. The main purpose of this sequel to some of the aforecited investigations is to give several addition formulas for a general class of Appell sequences. The addition formulas, which are derived in this paper, involve not only the generalized Bernoulli polynomials ${B_n^{(\alpha)}(x)}$ and the generalized Euler polynomials ${E_n^{(\alpha)}(x)}$ , but also the generalized Genocchi polynomials ${G_n^{(\alpha)}(x)}$ , the Srivastava polynomials ${\mathcal{S}_{n}^{N}\left( x\right)}$ , several general families of hypergeometric polynomials and such orthogonal polynomials as the Jacobi, Laguerre and Hermite polynomials. Some umbral-calculus generalizations of the addition formulas are also investigated.