Supramolecular Ammine-Copper rac-BINOLAT Salts through in-situ R- or S-BINOL Racemization |
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| Authors: | Barbara Wisser Andreas Labahn Christian Näther Christoph Janiak |
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| Institution: | 1. Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany;2. Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany;3. Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, 24098 Kiel, Germany;4. Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, 40204 Düsseldorf, Germany |
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| Abstract: | The molecule rac-1,1'-binaphthalene-2,2'-diol (rac-1,1'-bi-2-naphthol, rac-BINOL) shows a propensity for supramolecular, charge-assisted O–H ··· O– hydrogen-bonded strand formation when crystallized with its deprotonated form BINOLAT2– and Cu2+ in conc. ammonia. The naphthyl-paneled cavities in the {(rac-BINOLAT2–)(rac-BINOL)2} strands host the Cu(NH3)5]2+-guest cation through second-sphere N–H ··· O hydrogen bonding in the structure of Cu(NH3)5]2+(rac-BINOLAT2–)(rac-BINOL)2. Decreasing the copper(II) and ammonia concentrations in the crystallization leads to {(rac-BINOLAT2–)(rac-BINOL)} strands, in which rac-BINOLAT2– coordinates to two copper(II) atoms in the structure of Cu(NH3)2(μ-rac-BINOLAT2–-κ2O,O':κO)]2(rac-BINOL)2. In the {Cu2+(NH3)2} moiety two BINOLAT-oxide atoms act as bridging ligands. Both copper structures could be obtained by using the racemic rac-BINOL or the enantiomeric R- or S-BINOL, through an in-situ racemization of the latter. |
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| Keywords: | 1 1'-Binaphthalene-2 2'-diol 1 1'-Bi-2-baphthol BINOL Racemization Copper |
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