Enantiopure Alleno-Acetylenic Helicages Containing Multiple Binding Sites.
Chemistry
; 22(45): 16172-16177, 2016 Nov 02.
Article
em En
| MEDLINE
| ID: mdl-27723155
ABSTRACT
Enantiopure alleno-acetylenic ligands, containing two chiral allene moieties, assemble diastereoselectively with zinc(II) ions to form trinuclear triple-stranded helicates, featuring two internal cavity binding sites ("helicages"). The addition of cycloalkanes or heteroalicycles results in inclusion complex formation with two guest molecules bound in one helicate. While no positive allosteric effects were observed, the chiroptical responses increased strongly upon complexation, with guest-induced circular dichroism (ICD) signals reaching up to ΔΔϵ=205 m-1 cm-1 . The highest binding affinity was observed for six-membered 1,4-dichalcogens, with binding constants (K1 ) of up to 2400 m-1 for 1,4-oxathiane in CD3 OD. The X-ray co-crystal structure of 1,4-dioxane bound to a dinuclear triple-stranded helicate confirmed the previously predicted guest orientation inside the helicage, with the two oxygen atoms facing towards the electropositive zinc(II) metal centers.
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MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2016
Tipo de documento:
Article
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