Engle Keary M, Pfeifer Lukas, Pidgeon George W, Giuffredi Guy T, Thompson Amber L, Paton Robert S, Brown John M, Gouverneur Véronique
Chemistry Research Laboratory , Department of Chemistry , Oxford University , OX1 3TA , UK . Email:
Chem Sci. 2015 Sep 1;6(9):5293-5302. doi: 10.1039/c5sc01812a. Epub 2015 Jun 22.
The nucleophilic reactivity of fluoride ion is altered in the presence of hydrogen-bond donors, including alcohols. Relatively little is known about the coordination involved; to rectify this, the X-ray structures of fourteen novel fluoride-alcohol complexes with tetrabutylammonium as the counterion have been determined. The coordination number varies from two to four depending on the steric bulk of the alcohol and is closely linked to trends in reactivity. This diversity in coordination stoichiometry is unprecedented but significant, as it implies differences in the ability of the fluoride-alcohol complexes to dissociate in solution with release of a more active and/or selective fluoride source.
在存在氢键供体(包括醇类)的情况下,氟离子的亲核反应活性会发生改变。关于其中涉及的配位情况,人们了解得相对较少;为了纠正这一点,已确定了十四种以四丁基铵为抗衡离子的新型氟化物 - 醇配合物的X射线结构。配位数根据醇的空间位阻从2到4不等,并且与反应活性趋势密切相关。这种配位化学计量的多样性是前所未有的,但意义重大,因为这意味着氟化物 - 醇配合物在溶液中解离并释放出更具活性和/或选择性的氟源的能力存在差异。