التفاصيل البيبلوغرافية
| العنوان: |
Conformational mobility of 7,16-bis(4-methoxybenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane in molecular and proton-transfer complexes: X-ray and DFT studiesElectronic supplementary information (ESI) available: Overlapping diagram (Fig. S1) for 1and 2in the relative complexes, table of torsion angles (Table S1) along with the macrocyclic framework of 2in the complexes parent to those discussed herein. The coordinates for all optimized conformers are available from the authors. CCDC reference numbers 717101–717107. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/b902953b |
| المؤلفون: |
Marina S. Fonari, Eduard V. Ganin, Yurii M. Chumakov, Mark M. Botoshansky, Kinga Suwinska, Stepan S. Basok, Yurii A. Simonov |
| المصدر: |
New Journal of Chemistry; Aug2009, Vol. 33 Issue 8, p1646-1656, 11p |
| مصطلحات موضوعية: |
PROTON transfer reactions, CONFORMATIONAL analysis, DENSITY functionals, CROWN ethers, HYDROGEN bonding, INORGANIC acids, MACROCYCLIC compounds, QUANTUM chemistry |
| مستخلص: |
For the first time the bibracchial-crown ether 7,16-bis(4-methoxybenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (1) and its molecular and proton-transfer complexes were isolated and characterized by X-ray single-crystal diffraction. Hydrogen bonding between the neutral molecules is present in the binary complex 1·(H2NCS)2(3) giving rise to a tape structure. The proton migration from an inorganic acid to a macrocyclic molecule results in doubly protonated cations (1-H2)2+and (2-H2)2+(where 2is the parent 7,16-dibenzyl-1,4,10,13-tetraoxo-7,16-diazacyclooctadecane) giving rise to the ionic complexes (1-H2)·[ClO4]2·2H2O (4), (1-H2)·[NbF6]2·2H2O (5), (1-H2)·[TaF6]2·2H2O (6), (1-H2)·[BF4]2(7) and (2-H2)·[ClO4]2·2H2O (8) sustained by a system of charge-assisted hydrogen bonding. The macrocyclic entities in 1–8differ by the conformation of the crown ring and the arrangement of the pendant arms. To rationalize the different conformations of 1in comparison with the relative compounds based on 2, the theoretical quantum chemical calculations on the DFT (B3LYP) level were performed. The contribution of the methoxy group that provides the C–HO(OCH3) hydrogen bonding to the overall system of intermolecular interactions has been estimated by comparison with the complexes based on 2. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
