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Small‐Molecule Anion Recognition by a Shape‐Responsive Bowl‐Type Dodecavanadate
Author(s) -
Kuwajima Sho,
Kikukawa Yuji,
Hayashi Yoshihito
Publication year - 2017
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201700489
Subject(s) - chemistry , halide , crystallography , dissociation (chemistry) , ion , molecule , nuclear magnetic resonance spectroscopy , spectroscopy , bent molecular geometry , stereochemistry , inorganic chemistry , physics , organic chemistry , quantum mechanics
A dodecavanadate, [V 12 O 32 ] 4− , is an inorganic bowl‐type host with a cavity entrance with a diameter of 4.4 Å in the optimized structure. Linear, bent, and trigonal planar anions are tested as guest anions and the formation of host–guest complexes, [V 12 O 32 (X)] 5− (X=CN − , OCN − , NO 2 − , NO 3 − , HCO 2 − , and CH 3 CO 2 − ), were confirmed by X‐ray crystallographic analyses and a 51 V NMR spectroscopy study. The degree of distortion of the bowl from a regular to an oval shape depends on the type of guest anion. In 51 V NMR spectroscopy, all chemical shifts of the host–guest complexes are clearly shifted after guest incorporation. The incorporation reaction rates for OCN − , NO 2 − , HCO 2 − , and CH 3 CO 2 − are much larger than those of NO 3 − and halides. The incorporated nonspherical molecular anions in the dodecavanadate host are easily dissociated or exchanged for other anions, whereas spherical halides in the host are preserved without dissociation, even in the presence of the tested anions.