The Host-Guest Chemistry of Proflavine with Cucurbit[6,7,8]urils

Kemp, Sharon; Wheate, Nial J.; Stootman, F.; Aldrich‐Wright, Janice R.

doi:10.1080/10610270601124019

Cited by 43 publications

(29 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For this purpose, we first measured the K a for CB [7]·12 as (1.12 AE 0.17) 10 7 m À1 in water by direct fluorescence titration (see the Supporting Information). [23] Next, we performed 1 H NMR competition experiments (see the Supporting Information) with a series of guests of gradually increasing K a ( Table 2), which allowed us to determine K a for CB [7]·6 in D 2 O as (2.2 AE 0.7) 10 17 m À1 and K d = 4.5 10 À18 m ! The agreement between the K a values measured for CB[7]·6 (7.2 10 17 m À1 and (2.2 AE 0.7) 10 17 m À1 ) by the two sets of competition experiments is reasonable given the multistep nature of the competition experiments and the possible influence of pH and solvent isotope effects.…”

Section: Methodsmentioning

confidence: 99%

Cucurbit[7]uril⋅Guest Pair with an Attomolar Dissociation Constant

et al. 2014

View full text Add to dashboard Cite

Host⋅guest complexes between cucurbit[7] (CB[7]) or CB[8] and diamantane diammonium ion guests 3 or 6 were studied by (1) H NMR spectroscopy and X-ray crystallography. (1) H NMR competition experiments revealed that CB[7]⋅6 is among the tightest monovalent non-covalent complexes ever reported in water with Ka =7.2×10(17) M(-1) in pure D2 O and 1.9×10(15) M(-1) in D2 O buffered with NaO2 CCD3 (50 mM). The crystal structure of CB[7]⋅6 allowed us to identify some of the structural features responsible for the ultratight binding, including the distance between the NMe3 (+) groups of 6 (7.78 Å), which allows it to establish 14 optimal ion-dipole interactions with CB[7], the complementarity of the convex van der Waals surface contours of 6 with the corresponding concave surfaces of CB[7], desolvation of the CO portals within the CB[7]⋅6 complex, and the co-linearity of the C7 axis of CB[7] with the N(+) ⋅⋅⋅N(+) line in 6. This work further blurs the lines of distinction between natural and synthetic receptors.

show abstract

Section: Methodsmentioning

confidence: 99%

Cucurbit[7]uril⋅Guest Pair with an Attomolar Dissociation Constant

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Because the K a value determined above for CB[7]⋅ 6 is so extreme and relies on the K a values for CB[7]⋅ 4 and CB[7]⋅ 5 determined by a different technique (isothermal titration calorimetry) in another laboratory, we decided to determine the K a for CB[7]⋅ 6 by an independent series of competitions. For this purpose, we first measured the K a for CB[7]⋅ 12 as (1.12±0.17)×10 7 M −1 in water by direct fluorescence titration (see the Supporting Information) 23. Next, we performed 1 H NMR competition experiments (see the Supporting Information) with a series of guests of gradually increasing K a (Table 2), which allowed us to determine K a for CB[7]⋅ 6 in D 2 O as (2.2±0.7)×10 17 M −1 and K d =4.5×10 −18 M !…”

Section: Binding Constants (Ka M−1) Measured For the Host–guest Compmentioning

confidence: 99%

Cucurbit[7]uril⋅Guest Pair with an Attomolar Dissociation Constant

et al. 2014

View full text Add to dashboard Cite

Host⋅guest complexes between cucurbit[7] (CB[7]) or CB[8] and diamantane diammonium ion guests 3 or 6 were studied by 1H NMR spectroscopy and X‐ray crystallography. 1H NMR competition experiments revealed that CB[7]⋅6 is among the tightest monovalent non‐covalent complexes ever reported in water with Ka=7.2×1017 M−1 in pure D2O and 1.9×1015 M−1 in D2O buffered with NaO2CCD3 (50 mM). The crystal structure of CB[7]⋅6 allowed us to identify some of the structural features responsible for the ultratight binding, including the distance between the NMe3+ groups of 6 (7.78 Å), which allows it to establish 14 optimal ion‐dipole interactions with CB[7], the complementarity of the convex van der Waals surface contours of 6 with the corresponding concave surfaces of CB[7], desolvation of the CO portals within the CB[7]⋅6 complex, and the co‐linearity of the C7 axis of CB[7] with the N+⋅⋅⋅N+ line in 6. This work further blurs the lines of distinction between natural and synthetic receptors.

show abstract

“…up to 10 15 M À1 [27][28][29]. A variety of organic drugs and biologically relevant molecules have been encapsulated in CB[n] including: ranitidine [30], proflavine [31], cucurmin [32], amino anthracene [33], anthraquinones [34], amino acids [35], DNA bases [35] and anticancer titanocene and molybdocene compounds [36].…”

Section: Cucurbit[n]urilsmentioning

confidence: 99%