Enhancement of anion recognition exhibited by a zinc-imidazole-based ion-pair receptor composed of C-H hydrogen- and halogen-bond donor groups.
Dalton Trans
; 47(44): 15941-15947, 2018 Nov 13.
Article
in En
| MEDLINE
| ID: mdl-30376013
ABSTRACT
A 2-haloimidazole-tetraphenylethylene ion-pair receptor 1 is shown to recognise only HSO4- anions in the presence of a cobound Zn2+ cation guest species, which induced a remarkable increase with concomitant blue shift of the emission band of the complex [1·2Zn]4+ whereas no affinity of the free receptor 1 by the anions is observed. In addition, the downfield shifts observed by 1H NMR of the Ha, Hb and Hc protons of the complex [1·2Zn]4+ upon the addition of HSO4- anions indicate their participation in the recognition event. According to DFT studies, upon chelating a Zn2+ cation with two imidazole nitrogen atoms, receptor 1 adopts a conformation ideally fitted to recognise HSO4- through a combination of C(sp2)-HO and C(sp3)-HO hydrogen bondings, C+(sp2)-BrO halogen bonding and C(sp2)O tetrel bonding.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Dalton Trans
Journal subject:
QUIMICA
Year:
2018
Document type:
Article
Publication country:
ENGLAND
/
ESCOCIA
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GB
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GREAT BRITAIN
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INGLATERRA
/
REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM