9004-86-8Relevant academic research and scientific papers
Octahedral molybdenum cluster complexes with aromatic sulfonate ligands
Efremova, Olga A.,Vorotnikov, Yuri A.,Brylev, Konstantin A.,Vorotnikova, Natalya A.,Novozhilov, Igor N.,Kuratieva, Natalia V.,Edeleva, Mariya V.,Benoit, David M.,Kitamura, Noboru,Mironov, Yuri V.,Shestopalov, Michael A.,Sutherland, Andrew J.
, p. 15427 - 15435 (2016)
This article describes the synthesis, structures and systematic study of the spectroscopic and redox properties of a series of octahedral molybdenum metal cluster complexes with aromatic sulfonate ligands (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] (where X- is Cl-, Br- or I-; OTs- is p-toluenesulfonate and PhSO3- is benzenesulfonate). All the complexes demonstrated photoluminescence in the red region and an ability to generate singlet oxygen. Notably, the highest quantum yields (>0.6) and narrowest emission bands were found for complexes with a {Mo6I8}4+ cluster core. Moreover, cyclic voltammetric studies revealed that (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] confer enhanced stability towards electrochemical oxidation relative to corresponding starting complexes (nBu4N)2[{Mo6X8}X6].
The first water-soluble hexarhenium cluster complexes with a heterocyclic ligand environment: Synthesis, luminescence, and biological properties
Shestopalov, Michael A.,Zubareva, Kristina E.,Khripko, Olga P.,Khripko, Yuri I.,Solovieva, Anastasiya O.,Kuratieva, Natalia V.,Mironov, Yuri V.,Kitamura, Noboru,Fedorov, Vladimir E.,Brylev, Konstantin A.
, p. 9006 - 9013 (2014)
The hexarhenium cluster complexes with benzotriazolate apical ligands [{Re6(μ3-Q)8}(BTA)6] 4- (Q = S, Se; BTA = benzotriazolate ion) were obtained by the reaction of [{Re6(μ3-Q)8}(OH) 6]4- with molten 1H-BTA (1H-benzotriazole). The clusters were crystallized as potassium salts and characterized by X-ray single-crystal diffraction, elemental analyses, and UV-vis and luminescence spectroscopy. In addition, their cellular uptake and toxicity were evaluated. It was found that both clusters exhibited luminescence with high lifetimes and quantum yield values; they were taken up by the cells illuminating them under UV irradiation and, at the same time, did not exhibit acute cytotoxic effects.
MICRO-ORGANIZATIONAL CONTROL OF PHOTOCHEMICAL OXIDATIONS: ROSE BENGAL AND DERIVATIVES (XV)
Neckers, D. C.,Paczkowski, Jerzy
, p. 4671 - 4684 (1986)
We define a microheterogeneous photo-oxidation to be a photosensitized oxidation reaction whose efficiency is enhanced beyond that of diffusion control by the covalent bonding of a sensitizer to a ligand.The ligand is responsible for enhancing the local concentration of a specific substrate susceptible to reaction with an excited state derived from the proximate sensitizer.We illustrate the principle with several applications in singlet oxygen processes.
Azomethine dyes revisited. Photobleaching of azomethine dyes under photoreducing conditions
Kucybala, Zdzislaw,Pyszka, Ilona,Marciniak, Bronislaw,Hug, Gordon L.,Paczkowski, Jerzy
, p. 2147 - 2154 (1999)
This paper presents the results of a study on the bleaching process of azomethine dyes (AMDs) during their irradiation in the presence of an electron donor N-phenylglycine (NPG). The bleaching process and singlet oxygen formation for the dyes under study occurred with very low quantum yields. Experimental results showed that the bleaching of azomethine dyes may be due to both singlet and triplet states. The prominence of the triplet state was suggested by an analysis of double reciprocal plots for bleaching quantum yields and [NPG]. Additional support for this mechanism was given by results from laser flash experiments with a cyclized form of the dye. In these experiments, a transient optical absorption was attributed to a triplet state, and this state was quenched by NPG with a rate constant of 1.2 × 107 M-1 s-1. A similar experiment performed for a branched dye shows a broad, weak transient absorption which may also indicate a small amount of triplet-state formation. Changes in the dye structure affected the rate of photobleaching. The introduction of heavy atoms into a dye molecule only slightly increased the color-loss efficiency. The decrease or restriction of the freedom of the phenyl-group rotation did not increase the rate of the bleaching process. Significant influence of the azomethine dye structure on photobleaching rates was observed only when there was a strong electron withdrawing group in the R2 position. The most significant increase of the bleaching rate was observed when the branching of the dye was limited, especially when the rotation of substituents around the C=N bond was prevented by structural constraints.
Nanosized mesoporous metal–organic framework MIL-101 as a nanocarrier for photoactive hexamolybdenum cluster compounds
Cheplakova, Anastasia M.,Solovieva, Anastasiya O.,Pozmogova, Tatiana N.,Vorotnikov, Yuri A.,Brylev, Konstantin A.,Vorotnikova, Natalya A.,Vorontsova, Elena V.,Mironov, Yuri V.,Poveshchenko, Alexander F.,Kovalenko, Konstantin A.,Shestopalov, Michael A.
, p. 100 - 107 (2017)
Inclusion compounds of photoluminescent hexamolybdenum cluster complexes in the chromium terephthalate metal-organic framework, MIL-101 (MIL, Matérial Institut Lavoisier) were successfully synthesized in two different ways and characterized by means of powder X-Ray diffraction, chemical analysis and nitrogen sorption. Some important functional properties of hexamolybdenum cluster complexes for biological and medical applications, in particular singlet oxygen generation ability, luminescence properties, cellular uptake behavior and cytotoxicity were studied. It was revealed that the inclusion compounds possessed significant singlet oxygen generation activity. The materials obtained showed a low cytotoxicity, thus allowing them to be used in living cells. Confocal microscopy of human larynx carcinoma (Hep-2) cells incubated with the inclusion compounds showed that MIL-101 performed as a nanocarrier adhering to the external cell membrane surface and releasing the cluster complexes which that penetrated into the cells. Moreover, photoinduced generation of reactive oxygen species (ROS) in Hep-2 cells incubated with inclusion compounds was demonstrated. The cluster supported on MIL-101 was shown to possess in vivo phototoxicity.
Expanding the Tool Kit of Automated Flow Synthesis: Development of In-line Flash Chromatography Purification
Thomson, Christopher G.,Banks, Colin,Allen, Mark,Barker, Graeme,Coxon, Christopher R.,Lee, Ai-Lan,Vilela, Filipe
supporting information, p. 14079 - 14094 (2021/07/31)
Recent advancements in in-line extraction and purification technology have enabled complex multistep synthesis in continuous flow reactor systems. However, for the large scope of chemical reactions that yield mixtures of products or residual starting materials, off-line purification is still required to isolate the desired compound. We present the in-line integration of a commercial automated flash chromatography system with a flow reactor for the continuous synthesis and isolation of product(s). A proof-of-principle study was performed to validate the system and test the durability of the column cartridges, performing an automated sequence of 100 runs over 2 days. Three diverse reaction systems that highlight the advantages of flow synthesis were successfully applied with in-line normal- or reversed-phase flash chromatography, continuously isolating products with 97-99% purity. Productivity of up to 9.9 mmol/h was achieved, isolating gram quantities of pure product from a feed of crude reaction mixture. Herein, we describe the development and optimization of the systems and suggest guidelines for selecting reactions well suited to in-line flash chromatography.
Solvent-free synthesis of symmetric methylene diestersviadirect reaction of aromatic carboxylates with 1,n-dihaloalkanes
Bai, Lin,Ding, Shenglong,Ma, Xiaofang
, p. 28711 - 28715 (2021/09/22)
An efficient methodology for the synthesis of symmetrical methylene diesters was developed through direct reaction of various aromatic carboxylates with 1,n-dihaloalkanes under solvent-free conditions. This strategy offers a high product yield, facile work-up and purification, and an environmentally friendly approach to obtain long-chain methylene carboxylate scaffolds with increased diversity.
Synthesis and characterization of polyethylene terephthalate (PET) precursors and potential degradation products: Toxicity study and application in discovery of novel PETases
Djapovic, Milica,Milivojevic, Dusan,Ilic-Tomic, Tatjana,Lje?evi?, Marija,Nikolaivits, Efstratios,Topakas, Evangelos,Maslak, Veselin,Nikodinovic-Runic, Jasmina
, (2021/03/01)
Polyethylene terephthalate (PET) is widely used material and as such became highly enriched in nature. It is generally considered inert and safe plastic, but due to the recent increased efforts to break-down PET using biotechnological approaches, we realized the scarcity of information about structural analysis of possible degradation products and their ecotoxicological assessment. Therefore, in this study, 11 compounds belonging to the group of PET precursors and possible degradation products have been comprehensively characterized. Seven of these compounds including 1-(2-hydroxyethyl)-4-methylterephthalate, ethylene glycol bis(methyl terephthalate), methyl bis(2-hydroxyethyl terephtahalate), 1,4-benzenedicarboxylic acid, 1,4-bis[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl] ester and methyl tris(2-hydroxyethyl terephthalate) corresponding to mono-, 1.5-, di-, 2,5- and trimer of PET were synthetized and structurally characterized for the first time. In-silico druglikeness and physico-chemical properties of these compounds were predicted using variety of platforms. No antimicrobial properties were detected even at 1000 μg/mL. Ecotoxicological impact of the compounds against marine bacteria Allivibrio fischeri proved that the 6 out of 11 tested PET-associated compounds may be classified as harmful to aquatic microorganisms, with PET trimer being one of the most toxic. In comparison, most of the compounds were not toxic on human lung fibroblasts (MRC-5) at 200 μg/mL with inhibiting concentration (IC50) values of 30 μg/mL and 50 μg/mL determined for PET dimer and trimer. Only three of these compounds including PET monomer were toxic to nematode Caenorhabditis elegans at high concentration of 500 μg/mL. In terms of the applicative potential, PET dimer can be used as suitable substrate for the screening, identification and characterization of novel PET-depolymerizing enzymes.
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Electrochemical esterification via oxidative coupling of aldehydes and alcohols
Smeyne, Dylan,Verboom, Katherine,Bryan, Maria,LoBue, James,Shaikh, Abid
supporting information, (2021/03/26)
An electrolytic method for the direct oxidative coupling of aldehydes with alcohols to produce esters is described. Our method involves anodic oxidation in presence of TBAF as supporting electrolyte in an undivided electrochemical cell equipped with graphite electrodes. This method successfully couples a wide range of alcohols to benzaldehydes with yields ranging from 70 to 90%. The protocol is easy to perform at a constant voltage conditions and offers a sustainable alternative over conventional methods.
