Design and recognition of cucurbituril-secured platinum-bound oligopeptides

Abstract

Platinum terpyridyl complexes, stacked on top of one another and secured as dimers with cucurbit[8]uril (CB[8]) in aqueous medium, were functionalized quantitatively and in situ with a pair of pentapeptides...

Enhanced photoreduction of water catalyzed by a cucurbit[8]uril-secured platinum dimer

“…A ternary binding constant β for complex 1c towards CB[8] of 1.9 (±0.6) × 10 13 M −2 (see equilibrium 1) was extracted. In other terms, dimer 1c 2 (and most likely dimer 1b 2 ) can be considered as a standalone guest forming a very tight 1 : 1 complex with CB[8], with a binding affinity K ′ of 5 (±2) × 10 8 M −1 , obtained from eqn (2) , in excellent agreement with one of our recent studies 26 on a parent system. 1c + 1c + CB[8] ⇄ CB[8]·1c 2 …”

Tunable White-Light Emissions of Azapyrene Derivatives with Cucurbit[n]uril Hosts in Aqueous Solution

“…Indeed, in a ROESY NMR spectrum (Figure S7), we observed the relevant signals between H b and H g and between H e and H a on diazapyrene and biphenyl units, suggesting the formation of a 2:2 complex (Figure b). DOSY experiments afforded a diffusion coefficient for the CB[10] 2 · G2 2 complex of 1.53 × 10 –10 m 2 /s, which is quite close to the D value of 2:3 complex CB[10] 2 · VPI 3 (1.78 × 10 –10 m 2 /s) and some of 2:2 complex CB[8] 2 · G 2 . , Relatively, a higher D value for free G2 was measured as 3.30 × 10 –10 m 2 /s (Figure S8). When more CB[10] was added (∼1.82 equiv), in addition to the H a signal on the N-substituted methyl representing the 2:2 binding mode (marked as H a′ in Figure g), two new signals of H a were observed (marked as H a″ and H a″′ ).…”

Ultramacrocyclization in water via external templation

“…In addition, cucurbit[8]uril (CB[8]) 7 c , e , g , i , k was observed as a host that is able to accommodate a two π-electron guest, driven by the hydrophobic effect and dipole–cation interactions in the case of cationic guests such as pyridinium derivatives. We thus envision that by taking advantage of the marriage of dynamic covalent chemistry 5,6,8 and external templation based on CB[8] rings, 7 we might be able to self-assemble an ultra-large macrocycle. Here, by condensing a dihydrazide and a dicationic bisaldehyde containing a poly-methylene chain in water, rings with medium sizes containing fifty to sixty atoms in their framework were self-assembled in a [1 + 1] manner as the major products.…”