Aţ Ţafīlah, Tafilah, Jordan

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    ABSTRACT: A series of mono- and disubstituted O-ferrocenoyl conjugates of 3-trans- and 4-trans-hydroxy-L-proline amino acids are synthesized. These conjugates are protected by tert-butloxycarbonyl (Boc) group at the N-terminus. The Boc removal of the ferrocene (Fc) hydroxy-L-proline conjugates affords a series of mono- and disubstituted Fc conjugates containing free amine at the N-terminus. These conjugates are characterized by NMR and IR spectroscopies as well as mass (MS) spectrometry. The catalytic properties of the free amine Fc conjugates toward aldol addition reaction are studied. The enantioselectivity of the aldol reaction products in acetone solvent is determined by the position of the N-atom in the proline residue with respect to the proline point of attachment to the Fc scaffold. The 4-trans-hydroxy-L-proline containing Fc catalyst favors the production of the R-isomer, while Fc catalysts containing 3-trans-hydroxy-L-proline favors the production of the S-isomer.
    Inorganica Chimica Acta 08/2014; 394:176–183. DOI:10.1016/j.ica.2012.07.015
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    ABSTRACT: This article examines the relationship between some components (i.e. risk assessment, control environment and control activities) of internal control system and the effectiveness of audit program in Jordan. Based on 43 usable questionnaires, the results of the study show that the risk assessment does contribute significantly toward an effective audit program. On the other hand, the results of analysis indicate that control environment and control activities do not contribute significantly toward an effective audit program. These results give an indicator that Jordanian companies lack the necessary experience to deal with the current tools of internal control evaluation. Some applications and recommendations were suggested for both management of companies and external auditors.
    International Business Research 07/2012; 5(9). DOI:10.5539/ibr.v5n9p128
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    ABSTRACT: Self-assembled monolayers (SAMs) of pentafluorobenzenethiol (PFBT) on Au(111) substrates, prepared with different immersion times (ITs) at room temperature, were studied using scanning tunneling microscopy (STM) and infrared reflection-absorption spectroscopy (IRRAS). In the present study, the focus was on several important points of interest in the field of SAMs. First, the gold islands formed upon adsorption of PFBT molecules on the gold surface were monitored at different ITs in terms of their size, density, and shape. After short ITs (5 to 30 min), small gold islands with rounded shape were formed. These gold islands were arranged in a rather regular fashion and found to be quite mobile under the influence of the STM-tip during the scanning. When the IT was increased to 16 h, the results revealed the formation of highly ordered and orientated gold islands with very unusual shapes with straight edges meeting at 60° or 120° running preferentially along the [11(-)0] substrate directions. The density of the gold islands was found to decrease with increasing IT until they almost disappeared from the SAMs prepared after 190 h of IT. On top of the gold islands, the PFBT molecules were found to adopt the closely packed (10√3 × 2) structure. Second, a number of structural defects such as disordered regions at the domain boundaries and dark row(s) of molecules within the ordered domains of the PFBT SAMs were observed at different ITs. The SAMs prepared after 190 h of IT were found to be free of these defects. Third, at low and moderate ITs, a variation in the PFBT molecular contrast was observed. This contrast variation was found to depend mainly on the tunneling parameters. Finally, our results revealed that the organization process of PFBT SAMs is IT-dependent. Consequently, a series of structural phases, namely, α, β, γ, δ, and ε were found. The α-, β-, γ-, and δ-phases were typically accompanied by the ε-phase that appeared on top of gold islands. With increasing IT, the α→β→ γ→δ→ε phase transitions took place. The resulting ε-phase, which covered the entire gold surface after 190 h of IT, yielded well-ordered self-assembled monolayers with large domains having a (10√3 × 2) superlattice structure.
    Langmuir 06/2012; 28(27):10192-208. DOI:10.1021/la301601c


  • Address
    Aţ Ţafīlah, Tafilah, Jordan
  • Head of Institution
    Prof. Dr. Shtaiwi al-Abdullah
  • Website
  • Phone
    +962- 32250326
  • Fax
    +962- 32250002
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