163750-99-0Relevant academic research and scientific papers
Calix[4]arenes with 1,2- and 1,3-upper rim tetrathiafulvalene bridges
Dueker, Matthias H.,Kutter, Felix,Duelcks, Thomas,Azov, Vladimir A.
, p. 552 - 560 (2014)
Herein we report the synthesis of several calix[4]arene derivatives with tetrathiafulvalene bridges at the upper rim. Calix[4]arene-tetrathiafulvalene (TTF) conjugates 4a-d, fixed in cone conformation and comprising two smaller 1,2-bridges, were prepared
Structure impact in antenna effect of novel upper rim substituted tetra-1,3-diketone calix[4]arenes on Tb(III) green and Yb(III) NIR-luminescence
Zairov, Rustem,Shamsutdinova, Nataliya,Podyachev, Sergey,Sudakova, Svetlana,Gimazetdinova, Gulnaz,Rizvanov, Ildar,Syakaev, Victor,Babaev, Vasily,Amirov, Rustem,Mustafina, Asiya
, p. 2447 - 2455 (2016/04/26)
Two novel calix[4]arene macrocyclic ligands functionalized with four 1,3-diketone groups at the upper and hydroxyl (3) or propyloxy-groups (6) at the lower rims were synthesized and characterized using NMR, IR spectroscopy, mass spectrometry, and elemental analysis. UV-vis spectrophotometry and ESI mass spectrometry studies indicate 1:1 complex formation of ligands 3 and 6 with Ln(III) (Ln=Tb, Yb) in alkaline DMF solutions resulted from coordination of Ln(III) with 1,3-diketonate groups. Luminescence study of Ln(III) complexes with 3 and 6 reveals significant difference in antenna effects of their deprotonated forms on both Tb(III)- and Yb(III)-centered luminescence. Comparison of ligand-centered emission for ligands 3 and 6 points to the latter as more efficient antenna for Tb(III) and Yb(III). Different conformational behavior of ligands 3 and 6 in alkaline media is assumed as a reason for the experimentally observed difference in sensitization pathways in Ln(III) complexes with 3 and 6.
Cationic amphiphilic calixarenes to compact DNA into small nanoparticles for gene delivery
Rodik, Roman V.,Anthony, Anne-Sophie,Kalchenko, Vitaly I.,Mély, Yves,Klymchenko, Andrey S.
, p. 1654 - 1664 (2015/03/18)
Macrocycles have been attracting increasing attention as scaffolds for preparation of non-viral vectors for gene delivery. Here, following our earlier report, a series of amphiphilic calixarenes bearing cationic choline or N-(2-aminoethyl)-N,N-dimethylammonium groups at the upper rim and alkyl chains at the lower rim were synthesized. The effect of the length of aliphatic chains and the structure of the head group on their self-assembly, interaction with DNA, properties of their DNA complexes, transfection efficiency and cytotoxicity was studied. It was found that longer alkyl chains favor formation of small virus-sized DNA nanoparticles with low polydispersity. Moreover, longer alkyl chains, such as dodecyl groups, significantly improved the transfection efficiency, so transfection was observed in the presence of fetal bovine serum as well as with or without a helper lipid. Finally, we observed that the cytotoxicity of these calixarenes clearly decreased with increase of the chain length. On the other hand, the presence of four additional amino groups, which could be protonated at pH 7, affected only the stoichiometry of the complexes with DNA without influencing their transfection efficiency or cytotoxicity. The results obtained provide new insights for designing non-viral vectors based on macrocyclic molecules.
A stimulus-responsive shape-persistent micelle bearing a calix[4]arene building block: Reversible pH-dependent transition between spherical and cylindrical forms
Fujii, Shota,Sanada, Yusuke,Nishimura, Tomoki,Akiba, Isamu,Sakurai, Kazuo,Yagi, Naoto,Mylonas, Efstratios
scheme or table, p. 3092 - 3101 (2012/06/01)
A series of cationic calix[4]arene-based lipids with alkyl chains of varying length were newly synthesized, and the ones with propyl and hexyl tails, denoted by CaL[4]C3 and C6, respectively, were found to form spherical micelles at low pH (protonated state of the amine headgroup). Upon deprotonation with increasing pH, CaL[4]C3 showed a sphere-to-cylinder transition, while CaL[4]C6 changed from sphere, to cylinder, to monolayer vesicle. Synchrotron small-angle X-ray scattering (SAXS) patterns from both spherical and cylindrical CaL[4]C3 micelles exhibited a sharp intensity minimum, indicating shape monodispersity. The monodispersity of the CaL[4]C3 spherical micelles was further confirmed by analytical ultracentrifugation (AUC). SAXS, AUC, and static light scattering agreeingly indicated an aggregation number of 6. In contrast, CaL[4]C6 exhibited polydispersity with an average aggregation number of 12. When the number of carbons of the alkyl chain was increased to 9 (CaL[4]C9), cylinder formed at low pH, while at high pH, no clear morphology could be observed. The present results indicate that a very precise combination of tail length, head volume, and rigidity of the building block is required to produce shape-persistent micelles and that the shape-persistence can be maintained upon a structural transition. An attempt to reconstruct a molecular model for the spherical CaL[4]C3 micelle was made with an ab initio shape determining program.
Upper rim tetrathiafulvalene-bridged calix[4]arenes
Düker, Matthias H.,Gómez, Rafael,Vande Velde, Christophe M.L.,Azov, Vladimir A.
supporting information; experimental part, p. 2881 - 2884 (2011/06/21)
The synthesis of novel upper rim calix[4]arene-tetrathiafulvalene conjugates 1a-d has been performed by bridging the tetrachloromethylated calix[4]arene derivative 4 with the corresponding tetrathiafulvalene- dithiolates. The cyclic voltammetry of 1a-d sh
Synthesis and metal extraction behavior of pyridine and 1,2,4-triazole substituted calix[4]arenes
Kumar, Ashok,Sharma, Pratibha,Kalal, Bhagwan Lal,Chandel, Lal Kumar
experimental part, p. 369 - 379 (2011/12/14)
Three series of heterocycle substituted calixarenes, derivatized at lower and upper rim, were synthesized and successfully evaluated for metal extraction towards alkali, alkaline, transition and heavy metal ions. The presence and placement of sulfur, heterocycle functionality at upper/lower rim played a crucial role toward the extractability and selectivity of metal ions. The lower rim substituted calixarenes have shown high extractability and poor selectivity. In contrast to this, upper rim substituted calixarenes exhibited good selectivity. Moreover, sulfur functionalized calixarenes have shown better selectivity for heavy metal ions than alkali and alkaline metal ions. Among upper rim substituted calixarenes, 17 and 18 were found to be suitable for Na+, K+ and Ag+, 19,13 for heavy metal ions i. e., Pb2+, Hg+, Hg2+ and Ag+, and 11,12 for Pb2+ and Ag+ only.
Synthesis and optical resolution of naphthalene-containing inherently chiral calix[4]arenes derived by intramolecular ring closure or stapling of proximal phenyl units
Ikeda, Atsushi,Yoshimura, Makoto,Lhotak, Pavel,Shinkai, Seiji
, p. 1945 - 1950 (2007/10/03)
New methods for the preparation of inherently chiral calix[4]arenes have been developed. The molecular asymmetry in these calix[4]arenes is created by an asymmetrical disposition of naphthalene rings on the upper rim. In compound 1, monoformylcalix[4]arene 5 was transformed into naphthalene-containing calix[4]arene by ring closure. In compound 2, p-chloromethyl groups are intramolecularly cross-linked with 3-hydroxymethyl-2-naphthol. This 'stapling reaction' results in a syn isomer 2a and an anti isomer 2b, the latter being classified into an inherently chiral calix[4]arene. Racemic anti 2 could be 'perfectly' optically resolved by an HPLC method with a chiral-packed column. The chiral products were thoroughly characterized by various spectroscopic methods. These results indicate that the naphthalene skeleton is very useful for creating molecular asymmetry in calix[4]arenes.
On the origin of high ionophoricity of 1,3-alternate calix[4]arenes: π-Donor participation in complexation of cations and evidence for metal-tunneling through the calix[4]arene cavity
Ikeda, Atsushi,Shinkai, Seiji
, p. 3102 - 3110 (2007/10/02)
Nine conformationally-immobilizedcalix[4]arenes (including two doubly-bridged 1,3-alternate calix[4]arenes) and several reference calix[4]arenes with other conformations were synthesized. Two-phase solvent-extraction of and determination of association constants by 1H NMR spectroscopy for alkali metal cations established that, surprisingly, 1,3-alternate and partial-cone conformers show an ion affinity higher than the corresponding cone conformers. Detailed examination with 1H NMR spectroscopy presented unambiguous evidence that in the 1,3-alternate conformers the metal cation is bound asymmetrically to one of two metal-binding sites composed of two phenolic oxygens and two benzene rings, whereas in the partial-cone conformers the metal cation is bound to the upper rim composed of a phenolic oxygen in the inverted phenyl unit and two benzene rings in the proximal phenyl units. These metal-binding modes were rationalized in terms of the "cation-π interaction". The contribution of the cation-π interaction was further confirmed by the finding that these conformers all show high Ag+ affinity without exception. The X-ray crystallographic study of the partial-cone-2·Ag+ complex established that Ag+ is bound to a phenolic oxygen in the inverted phenyl unit and two benzene rings in the proximal phenyl units. Dynamic 1H NMR spectroscopy at the low-temperature region showed that Ag+ alternates intramolecularly between the two binding sites through a π-basic hole of 1,3-alternate calix[4]arenes. To the best of our knowledge, this is the first example for Ag+-tunneling across an aromatic cavity and has important implications with regard to the metal cation-π interaction expected for metal transport through ion channels, metal inclusion in fullerenes, intercalation of metal cations into graphites, etc.
Unusually high ionophoricity of 1,3-alternate-calix[4]arenes: π-Donor participation in the complexation of cations?
Ikeda, Atsushi,Shinkai, Seiji
, p. 7385 - 7388 (2007/10/02)
It was found that 1,3-alternate-calix[4]arenes having cavities composed of two oxygens and two benzene rings show the metal affinity much higher than cone-calix[4]arenes having a cavity composed of four oxygens. The unexpected finding is most likely rationalized in terms of the "π-donor participation" in the metal complexation.
