A water soluble tetramethyl-substituted cucurbit[8]uril obtained from larger intermediates?

Supramolecular chemistry of substituted cucurbit[n]urils

“…39 The synthetic procedure involved the diether of dimethylglycoluril and the glycoluril dimer. Using similar strategies and appropriate building blocks, the Tao group later prepared a series of partially methyl-substituted Q[n]s, such as the symmetrical octamethyl-substituted cucurbit [6]uril 40 (OMeQ [6]), ortho-tetramethyl-substituted cucurbit [6]uril 41 (o-TMeQ [6]), meta-tetramethyl-substituted cucurbit [8]uril 42 (m-Me 4 Q [8]). Moreover, the same group has recently synthesized a series of hemimethyl-substituted cucurbit[n]urils (HMe n Q[n]s, n = 5, 6, 7) using the precursor 3α-methylglycoluril.…”

Alkyl-Substituted Cucurbit[6]uril Bridged β-Cyclodextrin Dimer Mediated Intramolecular FRET Behavior

“…In order to study the binding and photophysical behaviors of functionalized SCB [n]s, we utilized SCB [n]s possessing the OH group at a designated position to yield a special oxidation product, which was inspired by the complementary molecular binding behaviors of CB [n]s and cyclodextrins (CDs). 23 In this work, we designed and synthesized a novel macrocyclic dimer H (Figures S4−S6, Supporting Information) consisting of a symmetrical octamethylcucurbituril (OMeCB [6]) and β-C D , i n w h i c h t w o m a c r o c y c l i c m o l e c u l e s , (propargyl) 1 OMeCB [6] (Figures S1−S3, Supporting Information) and mono-6-azido-β-CD, were convalently conjugated via click reaction. In our case, given that β-CD can incorporate neutral guest molecules possessing an adamantyl end with high binding affinity, the adamantyl tetraphenylethylene (G1) (Figures S7−S9, Supporting Information) was accordingly synthesized.…”

“…In our case, given that β-CD can incorporate neutral guest molecules possessing an adamantyl end with high binding affinity, the adamantyl tetraphenylethylene (G1) (Figures S7−S9, Supporting Information) was accordingly synthesized. Meanwhile, OMeCB [6] is capable of encapsulating cationic guests in its hydrophobic cavity and the binding c o n s t a n t b e t w e e n O M e C B [ 6 ] a n d t r a n s -4 -[ 4 -(dimethylamino)styryl]-1-methylpyridinium chloride (G2) can reach up to 10 6 M −1 order of magnitude. Further spectroscopic studies have shown that H has the larger binding affinity for these two guest molecules (G1 and G2) than individual macrocycle molecules (CB and CD moieties) (Scheme 1).…”

“…To confirm the formation of the host−guest complexes between the OMeCB [6] moiety of H and G2 as well as free OMeCB [6] and G2, 1 H NMR spectroscopic titrations were first performed by using G2 as a guest compound and free OMeCB [6] as a model host compound. As shown in Figure S10 (Supporting Information), upon the gradual addition of G2, the proton signals of the guest appeared to shift upfield (Δδ = −0.22, −0.83, −0.09, for H 1 , H 2 , H 3 , respectively), suggesting that these protons of the guest were included in the cavity of the OMeCB [6] and were shielded by the OMeCB [6]. In contrast, the signal of H 4 , H 5 moved downfield by 0.13 and 0.56 ppm, suggesting that these protons on the guest were excluded at the portals of the OMeCB [6].…”

“…As shown in Figure S10 (Supporting Information), upon the gradual addition of G2, the proton signals of the guest appeared to shift upfield (Δδ = −0.22, −0.83, −0.09, for H 1 , H 2 , H 3 , respectively), suggesting that these protons of the guest were included in the cavity of the OMeCB [6] and were shielded by the OMeCB [6]. In contrast, the signal of H 4 , H 5 moved downfield by 0.13 and 0.56 ppm, suggesting that these protons on the guest were excluded at the portals of the OMeCB [6]. Additionally, the NMR assignments were made through 1 H− 1 H COSY experiment (Figure S11, Supporting Information).…”