نتایج جستجو برای: calix 4 arene
تعداد نتایج: 1305219 فیلتر نتایج به سال:
Stable pi-dimers are formed upon oxidation of the model units of proposed calix[4]arene-based molecular actuators in a solvent of low dielectric constant (CH 2Cl 2) at room temperature. Evidence from UV-vis, EPR, and DPV are all in agreement with the pi-dimer formation. In addition, pi-dimer formation is dependent upon the conformational flexibility of the calix[4]arene hinge.
A fluorescent poly(phenylene ethynylene) containing calix[4]arene-based receptor units has a sensitivity to quenching by the N-methylquinolinium ion that is over three times larger than that seen in a control polymer lacking calix[4]arenes.
The binding efficiency of a series of monotopic () and heteroditopic () calix[4]arene-based receptors has been evaluated in chloroform solution toward N-methylpyridinium ion pairs using NMR and UV/vis spectroscopic techniques. These experiments provided evidence that, due to a positive cooperative effect, the presence of a phenylurea H-bond donor group on the upper rim of the calix[4]arene macr...
Calixarenes are a readily available and important class of macrocycles in supramolecularchemistry. Calixarenes have generated considerable interest due to their basket shaped structureand as useful building blocks to synthesize selective receptors for the guest species, notably alkali,alkaline earth, lanthanide and transition metal cations. In this work studied on the complexingproperties of a ...
the adsorption of pyrazolone(hpmsp), calix[4]-arene,cu and cs, on carbon nanotube(cnt) atroom temperature has been investigated using spectroscopy.uv spectroscopy indicated that pyrazolone molecules adsorbed on carbon nanotube at roomtemperature in compared calix[4]- arene molecules adsorbed approximately same.the amount ofpyrazolone(hpmsp) adsorb 3.8. le mol/g and amount calix[4]-arene adsorbe...
In the title compound, C(90)H(120)O(18)·2CH(3)CN, the calix[6]arene has a 1,2,3-alternate conformation and possesses inversion symmetry. It crystallizes as an acetonitrile disolvate, with a half-mol-ecule of calix[6]arene and one mol-ecule of solvent in the asymmetric unit. In the crystal, the two solvent mol-ecules are enclosed in voids between the calix[6]arene mol-ecules. They form weak C-H⋯...
We describe the calixarene-cyclodextrin-coupling via click reaction starting from 5,11,17,23-tetra-tert-butyl-25,27-dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-dipropargylether) (2) onto 6I-azido-6I-deoxycyclomaltoheptaose (3) under microwave assisted conditions. The coupling was proven by MALDI-TOF mass spectrometry, ¹H NMR and IR-spectroscopy. The pH dependent supramolecular c...
An amphiphilic calix[4]arene bearing branched 3,4,5-tris(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzamide groups at the upper rim was synthesized and could increase the solubility of naproxen and ibuprofen in water through hydrogen bonding and π-π stacking interactions. The interactions between amphiphilic calix[4]arene and carboxylic acids such as naproxen and ibuprofen could reverse the directio...
siilver tetrafluoroborate complex of 5.11.17.23-tetra-tert-butyl-25-26,27,28-tetrakis (diphenylphosphinoylmethoxy)calyx[4]arene (l) has been synthesized by reaction of silver tetrafluoroborate and l in dichloromethane at room temperature. the complex formed has a 1:1 metall/ligand ratio. 1h and 31p nmr data support an encapsulated structure of the complex in which silver ion is located inside t...
SYNTHESIS OF CALIX[4]ARENES WITH FIXED CONFORMATION AS POTENTIAL INHIBITORS OF FIBRIN POLYMERIZATION
Aim. The purpose of the present study was to develop a method for fixation ‘fixed’ conformation estimation impact calix[4]arene structure on efficacy its anticoagulant activity. This achieved by substitution lower rim C-145 analogue. Methods.Calix[4]arene C-145F (compound 6) obtained in 4 steps starting with Duff reaction. Calix[4]arene methylene-bis-phosphonic ester 3 prepared via addition dii...
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