This year marks the 50th anniversary of the invention of crown ethers by Pedersen and the 30th year anniversary of the Nobel Prize awarded to supramolecular chemistry. Since the seminal research works in mid 1960s, the macrocyclic and supramolecular chemistry has been evolved into an interdisciplinary research area across chemistry, materials, biology, nano-science and technology. One of the most exciting developments is the advancement of the study of molecular machines, which won the last year’s Nobel Prize in chemistry, indicating a new era of macrocyclic and supramolecular chemistry. To echo the dynamic research activity and the new trends in the field, the topics of this series will include design and construction of synthetic macrocycles, molecular recognition and self-assembly, supramolecular polymers and materials, molecular devices and machines, noncovalent interaction patterns and their applications, supramolecules for biological and biomedical applications.
Graphical Abstract
Scheme 1: (a) Chemical structures of ZB4 and the guests involved in this research. The counterions are PF6−. ...
Figure 1: X-ray single crystal structure of ZB4 and the host–guest complexes. a) ZB4, b) 2+@ZB4-IV, c) 3+@ZB4...
Figure 2: Parabolic free-energy relationship between log(KR/KH) and Hammett parameter σp. KR: guests 11+–21+; ...
Figure 3: X-ray single crystal structures of 14+@ZB4-III, 16+@ZB4-III, 18+@ZB4-III and 21+@ZB4-III. Butyl gro...
Figure 4: X-ray single crystal structures of 18+@ZB4-III and 18+ in 18+@ZB4-III.
Figure 5: Linear relationships of ΔH with temperature (left, slope = −0.13, R2 = 0.9956) and TΔS (right, slop...
Graphical Abstract
Scheme 1: Synthesis of pillar[5]arene mono(oxyalkoxy)benzoic acids 3a–c.
Figure 1: single crystal structure of pillar[5]arene 2a.
Figure 2: Single crystal structure of pillar[5]arene 2f.
Scheme 2: Synthesis of diamido-bridged bis-pillar[5]arenes 5a–d.
Figure 3: The 2D NOSEY spectrum of bis-pillar[5]arene 5d.
Scheme 3: Synthesis of pillar[5]arene di(oxyalkoxy)benzoic acid 8.
Figure 4: Single crystal structure of pillar[5]arene 7.
Scheme 4: Synthesis of diamido-bridged tris-pillar[5]arenes 9a–d.
Figure 5: The 2D NOSEY spectra of tris-pillar[5]arene 9d.
Graphical Abstract
Figure 1: The chemical structures of C-ethyl-2-bromoresorcinarene (BrC2), C-propyl-2-bromoresorcinarene (BrC3...
Figure 2: X-ray crystal structures of (a) 3@BrC6, (b) 4@BrC6, (c) 5@BrC6, (d) 6@BrC6, (e) 7@BrC6, (f) 8@BrC6,...
Figure 3: Comparison of X-ray crystal structures (a) 3@BrC2, (c) 3@BrC3, and (e) 3@BrC6 and their DFT-based o...
Figure 4: (a) The negative potential localised on the N-oxide oxygen in 3@BrC6 and, (b) the positive charge d...
Figure 5: An expansion of the 1H NMR (6.6 mM at 298 K, 500 MHz) of BrC6 complexes with 3. Spectra are produce...
Graphical Abstract
Figure 1: Targeted multivalent phototherapeutic agent and its calix[4]arene-based precursor. RGD = Arg–Gly–As...
Scheme 1: Synthesis of RuII-calix[4]arene complex 7.
Scheme 2: Synthesis of RuII-calix[4]arene-[c-(RGDfK)]4 conjugate 9.
Figure 2: MD snapshot showing an optimized model of conjugate 9. RGDfK units are depicted in orange ribbons, ...
Figure 3: Absorption and emission spectra of RuII-calix[4]arene-[c-(RGDfK)]4 conjugate 9 in water.
Figure 4: Luminescence intensity and excited state lifetime of conjugate 9 in the presence of GMP measured in...
Figure 5: Transient absorption spectra of RuII-calix[4]arene-[c-(RGDfK)]4 conjugate 9 (in 10 mM Tris·HCl buff...
Figure 6: MALDI–MS analysis of a solution containing conjugate 9 and GMP after continuous light irradiation. ...
Graphical Abstract
Scheme 1: The chemical structures of (a) bisphosphonates (BPs) and (b) guanidinium-modified calix[5]arene (GC...
Scheme 2: Schematic illustration of the binding between BPs and GC5A and the operating IDA principle of fluor...
Scheme 3: The chemical structures of the selected BP drugs.
Figure 1: (a) Fluorescence competitive titration of GC5A·Fl (0.9/1.0 μM) with risedronate (up to 29.6 μM) in ...
Figure 2: The set-up calibration lines of the fluorescence intensities for quantitatively determining the con...
Graphical Abstract
Scheme 1: Diazide and dialkyne building blocks used in this study.
Scheme 2: Synthesis of Cat-1 by CBAAC. aAssembly yield by HPLC; bisolated yield as PF6− salt.
Scheme 3: Synthesis of [3]catenanes by CBAAC. aAssembly yield by HPLC; bisolated yield by precipitation as PF6...
Figure 1: 1H NMR (500 MHz, D2O, 298 K) of Cat-2. The signal at ca. 8.3 ppm is the residual formate from prepa...
Figure 2: (a) ESIMS, (b) HRMS, and (c) MS2 spectrum (parent ion at m/z = 887.8) of Cat-2.
Scheme 4: Synthesis of the [4]catenane Cat-11. aAssembly yield by HPLC; bisolated yield by preparative HPLC.
Graphical Abstract
Scheme 1: Synthesis of 1.
Figure 1: 1H NMR spectrum of 1 (400 MHz, CDCl3).
Figure 2: X-ray molecular structure of 1. Hydrogen atoms are omitted for clarity; dashed lines represent hydr...
Figure 3: (a) Structure of compound 6. (b) 1H NMR of 6 (CDCl3, 400 MHz). (c) 1H NMR of 1 (CDCl3, 400 MHz).
Graphical Abstract
Scheme 1: Catalysts synthesized and screened in this study.
Scheme 2: Synthetic routes for organocatalysts 1–4.
Figure 1: Asymmetric Michael addition of acetylacetone with different nitroolefins catalyzed by organocatalys...
Scheme 3: Possible proposed reaction mechanism.
Graphical Abstract
Figure 1: Two [2]rotaxane molecular shuttles with both bis(pyridinium)ethane and benzylanilinium recognition ...
Figure 2: A [3]catenane containing two identical bis(pyridinium)ethane recognition sites on a large macrocycl...
Scheme 1:
Step-wise synthesis of [2]catenane [8DB24C8]6+ containing benzylanilinium and bis(pyridinium)ethane...
Figure 3:
1H NMR spectrum of [2]catenane [8DB24C8]6+ (500 MHz, 298 K, CD2Cl2) showing the assigned proton che...
Figure 4:
a) The [2]catenane [8DB24C8]6+ can be protonated to yield [8-H
DB24C8]7+ in two different co-conform...
Figure 5:
UV–visible spectra of [8DB24C8]6+ (orange trace) and [8-H
DB24C8]7+ (black trace) in CH3CN solution ...
Graphical Abstract
Figure 1: Chemical structures of (a) tri(ethylene oxide)-substituted pillar[n]arenes (1, n = 5; 2, n = 6), (b...
Figure 2: 1H NMR spectra of (a) model compound 4 (2 mM at 25 °C in CDCl3), (b) 3 (2 mM at 25 °C in CDCl3), (c...
Figure 3: Temperature dependence of light transmittance at 650 nm of an aqueous solution of (a) 3 (2 mM) upon...
Figure 4: Photographs of (a) 3 and (c) a mixture of 3 (2 mM) and 1,4-dicyanobutane (20 mM) in aqueous media a...
Scheme 1: Synthesis of the bicyclic compound 3.
Graphical Abstract
Scheme 1: Synthesis of “earring” subporphyrin and its Pd complex. Synthetic procedure: (i) Diboryltripyrrane ...
Figure 1: Partial 1H NMR spectrum of 3.
Figure 2: X-ray crystal structures of 3: a) top view; b) side view. Thermal ellipsoids are drawn at the 50% p...
Figure 3: Partial 1H NMR spectrum of 3Pd.
Figure 4: X-ray crystal structures of 3Pd: a) top view; b) side view. Thermal ellipsoids are at the 30% proba...
Figure 5: UV–vis/NIR spectra of 3 and 3Pd.
Graphical Abstract
Figure 1: a) The “anchor group” approach for a rational design of CB–dye pairs involving a thermodynamic cycl...
Scheme 1: Synthesis of BODIPY derivatives.
Figure 2: a) Normalized absorption (solid line) and normalized fluorescence emission spectrum (dotted line) o...
Figure 3: a) Fluorescence spectral changes (λexc = 470 nm) upon addition of CB7 to 50 nM 1 in 10 mM citrate b...
Figure 4: Fluorescence pH titration of 2 and the respective complex (in presence of 3 mM CB7) in 30% (v/v) AC...
Figure 5: Fluorescence displacement titrations (λex = 470 nm, λem = 510 nm). a) 5 µM 2 and 2.5 µM CB7 with cy...
Figure 6: FCS autocorrelation curves obtained with 10 nM 2 in the absence (red fitted line) and presence (blu...
Figure 7: Fluorescence microscopy images of 1 mg/mL polymer microspheres a) with or b) without surface-bound ...
Graphical Abstract
Scheme 1: The general structure of triazolylcalix[4]arene derivatives.
Scheme 2: Synthesis of di- (4a,b) and tetraazido (8a,b) calix[4]arene derivatives. Conditions: Ia: AlkBr, K2CO...
Figure 1: Molecular structure of 8a (50% ellipsoids). The dashed line indicates the alternative position of t...
Scheme 3: Synthesis of polyammonium macrocycles 10a,b and 12a,b.
Figure 2: 2D NOESY H1-H1 NMR spectra of 10b in DMSO-d6.
Figure 3: The optical response (OR) of the calixarene/EY systems toward adenosine phosphates. Concentration (...
Figure 4: Supramolecular binding motif of diphosphate (a) and triphosphate (b) groups of nucleotides with the...
Figure 5: UV spectra of EY (1), 10b–EY (2), and 10b–EY in the presence of 0.005 (3), 0.05 (4), 0.5 (5) and 2 ...
Scheme 4: Structure of AEPDA and the corresponding AEPCDA–10b polydiacetylene vesicle.
Figure 6: UV spectra of the AEPCDA polydiacetylene vesicles in the presence of different amounts of 10b; conc...
Figure 7: Photographs of a portion of a 96-well plate containing AEPCDA–10b polydiacetylene vesicles in the a...
Graphical Abstract
Scheme 1: The preparation of compound 3.
Figure 1: The chemical structure and the schematic representation of compound 3 as well as the proposed assem...
Figure 2: UV–vis absorbance spectra of a) compound 3 and b) irradiated by a light source of 365 nm and c) the...
Figure 3: CD spectrum of compound 3 in solutions of a) benzene, toluene, p-xylene, chloroform, tetrachloromet...
Figure 4: SEM images of the microstructure a) obtained by the self-assembled compound 3 in CHCl3 on the surfa...
Figure 5: a) The gel-to-sol transformation of the samples via different routes. b) Dynamic frequency sweep of...
Graphical Abstract
Scheme 1: Synthesis of half-sandwich rhodium metallarectangles via three different methods. Method A: coordin...
Figure 1: Partial 1H NMR spectra (400 MHz, DMSO-d6, ppm) of (a) L1; (b) the sample of metallarectagle 3a obta...
Figure 2: Partial 1H NMR spectra (400 MHz, DMSO-d6, ppm) of (a) L2; (b) a sample of metallarectangle 3b obtai...
Figure 3: Calculated (bottom) and experimental (top) ESI-MS spectra of the tetracationic half-sandwich rhodiu...
Figure 4: Optimized structures of the charged metallarectangles 3a (top) and 3b (bottom), optimized with the ...
Graphical Abstract
Scheme 1: Chemical structures and acid-base stimuli responsiveness of target [2]rotaxane R1 and deprotonated ...
Scheme 2: Syntheses of key intermediates 5, 8 and target [2]rotaxane R1.
Figure 1: Partial 1H NMR spectra (400 MHz, CDCl3, 298 K). (a) Compound 5, (b) target [2]rotaxane R1, (c) azid...
Figure 2: Partial 1H NMR spectra (400 MHz, CDCl3, 298 K). (a) [2]Rotaxane R1, (b) deprotonation by the additi...
Figure 3: Partial 2D ROESY NMR spectra (500 MHz, CDCl3, 298 K). (a) [2]Rotaxane R1, (b) deprotonation with ad...
Graphical Abstract
Figure 1: Cartoon representation of the chiral rotaxane of the Goldup group [15,16] (I and I*) and of the chiral pse...
Figure 2: Cartoon representation of the rotaxane sequence isomers reported by Leigh [17] (III and IV) and of the ...
Figure 3: The possible 8 discrete conformations of a calix[6]arene macrocycle [26].
Figure 4: Diastereoisomeric pseudorotaxanes obtained by threading a directional calixarene wheel with directi...
Scheme 1: Synthesis of threads 2+ and 3+. Reagents and conditions: a) hexamethyldisilazane, LiClO4, 30 min, 6...
Figure 5:
Possible mechanism for the formation of the two atropoisomeric pseudo[2]rotaxanes 2+1cone and 2+
11,...
Figure 6: 1H NMR spectra (600 MHz, CDCl3, 298 K) of, from bottom to top: hexahexyloxycalix[6]arene 1; a 1:1 m...
Figure 7:
DFT-optimized structures of the: (left) 2+1cone and (right) 2+
11,2,3-alt pseudorotaxane atropoisome...
Figure 8: The two pseudorotaxane atropoisomers obtained by threading hexahexyloxycalix[6]arene 1 with monosto...
Figure 9: The two pseudorotaxane atropoisomers obtained by threading penta-O-methyl-p-tert-butylcalix[5]arene ...
Figure 10: 1H NMR spectra (600 MHz, CDCl3, 298 K) of, from bottom to top: hexahexyloxycalix[6]arene 1; a 1:1 m...
Graphical Abstract
Figure 1: The two one-electron oxidation reactions of tetrathiafulvalene (TTF, 1) and the corresponding prope...
Figure 2: UV–vis spectra and photographs of TTF 2 in its three stable oxidation states (black line = 2, orang...
Figure 3: Structure and conformations of two TTF dimers in solution, the mixed-valence and the radical-cation...
Figure 4: (a) The isomerism problem of TTF. (b)–(d) Major synthetic breakthroughs for the construction of TTF...
Figure 5: (a) Host–guest equilibrium between π-electron-poor cyclophane 3 and different TTFs with their corre...
Figure 6: TTF complexes with different host molecules.
Figure 7: Stable TTF (a) radical-cation and (b) mixed-valence dimers in confined molecular spaces.
Figure 8: A “three-pole supramolecular switch”: Controlled by its oxidation state, TTF (1) jumps back and for...
Figure 9: Redox-controlled closing and opening motion of the artificial molecular lasso 12.
Figure 10: Graphical illustration how a non-degenerate TTF-based shuttle works under electrochemical operation....
Figure 11: The first TTF-based rotaxane 13.
Figure 12: A redox-switchable bistable molecular shuttle 14.
Figure 13: The redox-switchable cyclodextrin-based rotaxane 15.
Figure 14: The redox-switchable non-ionic rotaxane 16 with a pyromellitic diimide macrocycle.
Figure 15: The redox-switchable TTF rotaxane 17 based on a crown/ammonium binding motif.
Figure 16: Structure and operation of the electro- and photochemically switchable rotaxane 18 which acts as po...
Figure 17: (a) The redox-switchable rotaxane 19 with a donor–acceptor pair which is stable in five different s...
Figure 18: Schematic representation of a molecular electronic memory based on a bistable TTF-based rotaxane. (...
Figure 19: Schematic representation of bending motion of a microcantilever beam with gold surface induced by o...
Figure 20: TTF-dimer interactions in a redox-switchable tripodal [4]rotaxane 22.
Figure 21: (a) A molecular friction clutch 23 which can be operated by electrochemical stimuli. (b) Schematic ...
Figure 22: Fusion between rotaxane and catenane: a [3]rotacatenane 24 which can stabilize TTF dimers.
Figure 23: The first TTF-based catenane 25.
Figure 24: Electrochemically controlled circumrotation of the bistable catenane 26.
Figure 25: A tristable switch based on the redox-active [2]catenane 27 with three different stations.
Figure 26: Structure of catenane-functionalized MOF NU-1000 [108] with structural representation of subcomponents. ...
Figure 27: (a) [3]Catenanes 29 and 30 which can stabilize mixed-valence or radical-cation dimers of TTF. (b) S...
Graphical Abstract
Figure 1: Chemical structures of octaacid 1 and positand 2 showing the anionic binding sites of the two hosts...
Figure 2: Representative plots of the volume-weighted distribution obtained by DLS for salts titrated into 2....
Figure 3: Representative plots of the volume-weighted distribution obtained by DLS for salts titrated into 2....
Scheme 1: Visualization of the competitive equilibrium between iodide binding to host 2 or associating with i...
Graphical Abstract
Scheme 1: Synthesis of 2,2’-CBP4 and the chemical structures of P and B.
Figure 1: 1H NMR spectra (500 MHz, 293 K) of (A) B (2.0 mM), (B) B (2.0 mM) + 2,2’-CBP4 (2.0 mM) and (C) 2,2’...
Figure 2: Fluorescence spectra of P in the absence and presence of 2,2’-CBP4 in aqueous phosphate buffer solu...
Figure 3: Visible emission observed from samples of P and B in the absence and presence of 2,2’-CBP4 under a ...
Graphical Abstract
Scheme 1: Self-assembly of the heterometallic prismatic cages.
Scheme 2: Synthesis of the platinum metalloligand 2.
Figure 1: 1H NMR of 3b in CD3OD.
Figure 2: UV–vis spectra of the metalloligand 2 and heterometallic prismatic cages 3a and 3b in methanol (1.0...
Figure 3: ESIMS spectrum of 3a in methanol. Inset: experimentally observed isotopic distribution patterns of ...
Figure 4: Energy-minimized structure of heterometallic trigonal prismatic cage 3a. Hydrogen atoms are omitted...
Graphical Abstract
Figure 1: Examples of calix[n]arenes 1 and calix[4]azulenes 2–5.
Figure 2: Three major computed conformers of OPC4A; a: 1,2-alternate; b: cone and c: saddle.
Figure 3: Geometry-optimized (ωB97xD/6-31G(d)) and (ωB97xD/GenECP) structures, respectively, computed for lef...