Functionalized Luminescent Silica Nanoparticles with Chelate Groups on Interface: Synthesis and Characterization

Design, synthesis and characterization of luminescent silica nanoparticles with chelate groups on surface as well as the synthesis of new organosilanes with amino and carboxyl groups for silica surface functionalization is presented. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3512

Synthesis of Bifunctional Derivatives of Calix[4]arene Bearing Azidoalkyl Fragments in Cone Stereoisomeric Form

© 2020, Pleiades Publishing, Ltd. Abstract: A procedure for the chloromethylation of lipophilic distally di-O-substituted calix[4]arene derivatives has been developed to prepare dichloromethyl derivatives of calix[4]arenes with long-chain alkyl fragments in cone configuration in high yields. From the chloromethylated derivatives, ammonium/imidazolium salts containing azidopropyl moieties have been synthesized in high yields. The structure of all obtained compounds has been established by 1D and 2D NMR, IR spectroscopy, and MALDI spectrometry. They can be further used as precursors of polytriazole/polyimidazole polymer species as promising carriers for metal-complex catalysis

Synthesis of Water-Soluble Polyammonium Thiacalix[4]arene Derivative and Its Interaction with Calf Thymus DNA

© 2020, Pleiades Publishing, Ltd. A water-soluble thiacalix[4]arene derivative containing four diethylenetriamine fragments in 1,3-alternate stereoisomeric form has been obtained for the first time. Using ethidium bromide, it has been found that the macrocycle can interact with calf thymus DNA. The macrocycle has been found to interact with DNA via groove binding. The presence of four diethylenetriamine fragments on the calixarene platform leads to multivalent interactions with DNA, resulting in an increase in the binding constant by two orders of magnitude compared to individual diethylenetriamine

Comparative study of the vibrational spectra of carboxylate azocalix[4]arenes and azothiacalix[4]arenes

The vibrational spectra of calix[4]arene (p-CAC) and thiacalix[4]arenes with azobenzene units having carboxylate groups in the para (p-CATC) and meta position (m-CATC) were recorded and analyzed. The calculated structures of molecules p-CAC, p-CATC, and m-CATC are consistent with experimental X-ray data. The most stable and polar is the cone conformation with four intramolecular cooperative hydrogen bonds. In classical calixarenes, the hydrogen bonds are shorter and, therefore, more durable than in thiacalixarenes. The cone conformation retains for all the studied calixarene molecules. The energy differences between E- and Z-forms of azobenzene groups in p-CAC, p-CATC, and m-CATC are 254.4, 260.2, and 249.4 kJ/mol, respectively. The shape of the molecules changes noticeably upon isomerization of azobenzene groups. Upon passing from thiacalixarenes to classical calixarenes, the dipole moment of the molecule increases. The polarity of calixarene molecules changes upon isomerization of azobenzene units. Ionization energy electron affinity and electrophilicity are higher in classical calixarenes compared to thiacalixarenes. There are active sites of reaction and interaction in the narrow and wide rims of the calixarene molecules. Carboxylate groups are most active in the formation of complexes with metals

Amphiphilic n-oligoethyleneglycol-imidazolium derivatives of p-tert-butylthiacalix[4]arene: Synthesis, aggregation and interaction with dna

New water-soluble derivatives of p-tert-butylthiacalix[4]arene have been synthesized in the stereoisomeric form 1,3-alternate with butyl and tetradecyl groups on one side of the macrocyclic platform and tri/tetraethylene glycol substituents on the other. The aggregation characteristics of macrocycles in the aquatic environment (CAC, aggregate size, zeta potential) have been studied. It has been demonstrated that the resulting aggregates have the ability to solubilize the lipophilic azo dye Orange OT, and the solubilizing ability significantly increases on going from butyl to tetradecyl derivatives. Using the methods of dynamic and electrophoretic light scattering and fluorimetry with ethidium bromide as a probe, it was shown that the obtained macrocycles interact with the DNA of the calf thymus. It was found that the efficiency of the interaction is greatly influenced by the length of the oxyethyl fragments: macrocycles containing tetraethylene glycol fragments are more effective than triethylene glycol analogs, causing a 2-fold compaction of DNA

Photocatalytic properties of hybrid materials based on a multicharged polymer matrix with encored TiO<inf>2</inf>and noble metal (Pt, Pd or Au) nanoparticles

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2020. In this study, we report a synthesis of new nanocomposites, wherein TiO2is introduced into multicharged polymeric matrix and covered with noble metals (Pt, Pd or Au) for the photocatalytic application. A photocatalytic activity investigation was performed by studying the degradation of methylene blue. It revealed that all obtained nanocomposites demonstrate enhanced photocatalytic ability when compared to pure TiO2, under both UV (24 °C) and solar light (−2 °C). The morphology and catalytic properties of the composites depend on the noble metals. The kinetic speed value of photodegradation was found to increase in the following sequence: TiO2< TiO2-NPst ≈ Pd-TiO2@NPSt < Pt-TiO2@NPSt ≈ Au-TiO2@NPSt

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

The synthesis of new calix[4]arenes adopting a cone stereoisomeric form bearing two or four azide fragments on the upper rim and water-soluble triazolyl amphiphilic receptors with two or four polyammonium headgroups via copper-catalyzed azide-alkyne cycloaddition reaction has been performed for the first time. It was found that the synthesized macrocycles form stable aggregates with hydrodynamic diameters between 150-200 nm and electrokinetic potentials about +40 to +60 mV in water solutions. Critical aggregation concentration (CAC) values were measured using a micelle method with pyrene and eosin Y as dye probes. The CAC values of tetraalkyl-substituted macrocycles 12a,b (5 mu M for both) are significantly lower than those for dialkyl-substituted macrocycles 10a,b (790 and 160 mu M, respectively). Premicellar aggregates of macrocycles 10a,b and 12a,b with the dye eosin Y were used for nucleotides sensing through a dye replacement procedure. It is unusual that disubstituted macrocycles 10a,b bind more effectively a less charged adenosine 5'-diphosphate (ADP) than adenosine 5'-triphosphate (ATP). A simple colorimetric method based on polydiacetylene vesicles decorated with 10b was elaborated for the naked-eye detection of ADP with a detection limit of 0.5 mM

Amphiphilic Pd^II-NHC Complexes on 1,3-Alternate p-tert-Butylthiacalix[4]arene Platform: Synthesis and Catalytic Activities in Coupling and Hydrogenation Reactions

© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Herein we report the first example of amphiphilic PdII–NHC complexes on the thiacalix[4]arene backbone in 1,3-alternate configuration. Relative catalytic activity of synthesized PdII–NHC complexes in Suzuki–Miyaura coupling of haloarenes with phenylboronic acid was studied. A combination of micellar and metallocomplex catalysis was observed in Suzuki–Miyaura coupling upon going from pure DMF to water/DMF 3:1: the 2-fold increase of conversion of 4-bromoanisole unlike pure DMF was found. Interesting feature was found using chloroarene in DMF/water: the reaction selectivity changed from heterocoupling to homo coupling of phenylboronic acid. PdII–NHC complexes demonstrated a high activity in model hydrogenation reaction of p-nitrophenol using sodium borohydride. The most lipophilic PdII–NHC complex was found to be most active, which can be attributed with additional p-nitrophenol preconcentration in the aggregates due to larger hydrophobic capacity of macrocycle

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

The synthesis of new calix[4]arenes adopting a cone stereoisomeric form bearing two or four azide fragments on the upper rim and water-soluble triazolyl amphiphilic receptors with two or four polyammonium headgroups via copper-catalyzed azide-alkyne cycloaddition reaction has been performed for the first time. It was found that the synthesized macrocycles form stable aggregates with hydrodynamic diameters between 150-200 nm and electrokinetic potentials about +40 to +60 mV in water solutions. Critical aggregation concentration (CAC) values were measured using a micelle method with pyrene and eosin Y as dye probes. The CAC values of tetraalkyl-substituted macrocycles 12a,b (5 mu M for both) are significantly lower than those for dialkyl-substituted macrocycles 10a,b (790 and 160 mu M, respectively). Premicellar aggregates of macrocycles 10a,b and 12a,b with the dye eosin Y were used for nucleotides sensing through a dye replacement procedure. It is unusual that disubstituted macrocycles 10a,b bind more effectively a less charged adenosine 5'-diphosphate (ADP) than adenosine 5'-triphosphate (ATP). A simple colorimetric method based on polydiacetylene vesicles decorated with 10b was elaborated for the naked-eye detection of ADP with a detection limit of 0.5 mM

Single excited dual band luminescent hybrid carbon dots-terbium chelate nanothermometer

The report introduces hybrid polyelectrolyte-stabilized colloids combining blue and green-emitting building blocks, which are citrate carbon dots (CDs) and [TbL]+ chelate complexes with 1,3-diketonate derivatives of calix[4]arene. The joint incorporation of green and blue-emitting blocks into the polysodium polystyrenesulfonate (PSS) aggregates is carried out through the solvent-exchange synthetic technique. The coordinative binding between Tb3+ centers and CD surface groups in initial DMF solutions both facilitates joint incorporation of [TbL]+ complexes and the CDs into the PSS-based nanobeads and affects fluorescence properties of [TbL]+ complexes and CDs, as well as their ability for temperature sensing. The variation of the synthetic conditions is represented herein as a tool for tuning the fluorescent response of the blue and green-emitting blocks upon heating and cooling. The revealed regularities enable developing either dual-band luminescent colloids for monitoring temperature changes within 25–50 °C through double color emission or transforming the colloids into ratiometric temperature sensors via simple concentration variation of [TbL]+ and CDs in the initial DMF solution. Novel hybrid carbon dots-terbium chelate PSS-based nanoplatform opens an avenue for a new generation of sensitive and customizable single excited dualband nanothermometers