29 research outputs found
New NIR-emissive tetranuclear Er(III) complexes with 4-hydroxo-2,1,3-benzothiadiazolate and dibenzoylmethanate ligands: synthesis and characterization
New tetranuclear heteroleptic complexes [Er4(dbm)6(O-btd)4(OH)2] (1) and [Er4(dbm)4(O-btd)6(OH)2] (2) (O-btd = 4-hydroxo-2,1,3-benzothiadiazolate and dbm = dibenzoylmethanide) and their solvates with toluene, THF and CH2Cl2 were prepared using two synthetic approaches. The structures of the products were confirmed by single-crystal X-ray diffraction. Magnetic properties of 1 and 2 are in good agreement with X-ray data. The effective magnetic moment (ΞΌeff) values at 300 K for 1 and 2 corresponds to a system of 4 non-interacting Er(III) ions in the ground state 4J15/2 with g = 6/5. At ambient temperature and upon excitation with Ξ»exc = 450 nm, complexes 1 and 2 exhibit luminescence at βΌ1530 nm, i.e. in the near infra-red (NIR) region. The luminescence intensity grows with increasing the number of the (O-btd)βligands in the complexes. This observation suggests (O-btd)β as a new efficient antenna ligand for the lanthanide-based NIR luminescence
NHC Polymeric Particles Obtained by Self-Assembly and Click Approach of Calix[4]Arene Amphiphiles as Support for Catalytically Active Pd Nanoclusters
A new polymeric NHC carrier was synthesized by sequential supramolecular self-assembly and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of amphiphilic imidazolium calix[4]arenes with octyl lipophilic fragments. Obtained polytriazole-imidazolium particles were found as monodisperse submicron particles, with the average diameter of 236 Β± 34 nm and average molecular weight of 1380 Β± 96 kDa. Successful CuAAC polymerization has been proved using IR spectroscopy and high-resolution ESI mass spectrometry. Polymeric particles, as well as aggregates made from precursor macrocycles, were decorated by Pd clusters (2 nm) for further catalytic investigations. Pd nanoclusters, supported on the polymeric surface, were found highly catalytically active in the model reduction of p-nitrophenol, giving reaction rates an order of magnitude higher compared to literature examples. The reaction was recycled using the same catalyst five times without any loss of activity
Organic chemistry laboratory experiments: ΡΡΠ΅Π±.-ΠΌΠ΅ΡΠΎΠ΄. ΠΠΎΡΠΎΠ±ΠΈΠ΅ Π΄Π»Ρ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΡ ΡΡΡΠ΄Π΅Π½ΡΠΎΠ² Π½Π° Π°Π½Π³Π»ΠΈΠΉΡΠΊΠΎΠΌ ΡΠ·ΡΠΊΠ΅
ΠΠΎΡΠΎΠ±ΠΈΠ΅ ΠΏΡΠ΅Π΄Π½Π°Π·Π½Π°ΡΠ΅Π½ΠΎ Π΄Π»Ρ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΡ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ°Π±ΠΎΡ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΠΌΠΈ ΡΡΡΠ΄Π΅Π½ΡΠ°ΠΌΠΈ ΠΏΠΎ ΠΊΡΡΡΡ ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ Ρ
ΠΈΠΌΠΈΠΈ2830.05.01ΠΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠ°Ρ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠ°Ρ Ρ
ΠΈΠΌΠΈΡΠ²ΡΡΡΠ΅Π΅ΡΠΏΠ΅ΡΠΈΠ°Π»ΠΈΡΡΠΎΡΠ½ΠΎΠ΅
Organic chemistry laboratory experiments: ΡΡΠ΅Π±.-ΠΌΠ΅ΡΠΎΠ΄. ΠΠΎΡΠΎΠ±ΠΈΠ΅ Π΄Π»Ρ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΡ ΡΡΡΠ΄Π΅Π½ΡΠΎΠ² Π½Π° Π°Π½Π³Π»ΠΈΠΉΡΠΊΠΎΠΌ ΡΠ·ΡΠΊΠ΅
2830.05.01ΠΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠ°Ρ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠ°Ρ Ρ
ΠΈΠΌΠΈΡΠ²ΡΡΡΠ΅Π΅ΡΠΏΠ΅ΡΠΈΠ°Π»ΠΈΡΡΠΎΡΠ½ΠΎΠ΅2ΠΠΎΡΠΎΠ±ΠΈΠ΅ ΠΏΡΠ΅Π΄Π½Π°Π·Π½Π°ΡΠ΅Π½ΠΎ Π΄Π»Ρ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΡ ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ°Π±ΠΎΡ ΠΈΠ½ΠΎΡΡΡΠ°Π½Π½ΡΠΌΠΈ ΡΡΡΠ΄Π΅Π½ΡΠ°ΠΌΠΈ ΠΏΠΎ ΠΊΡΡΡΡ ΠΎΡΠ³Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ Ρ
ΠΈΠΌΠΈ
DFT Quantum-Chemical Calculation of Thermodynamic Parameters and DSC Measurement of Thermostability of Novel Benzofuroxan Derivatives Containing Triazidoisobutyl Fragments
New derivatives of benzofuroxan containing triazidoisobutyl fragments, opening the way for the creation of highly effective compositions with an increased value of energy characteristics, were synthesized for the first time. Such compounds are also an excellent platform for further modification and for the preparation of new biologically-active compounds containing tetrazole and triazole fragments. Calculations of heats of formation performed with the DFT (density functional theory) method showed that the studied compounds are high-energetic density ones, the enthalpies of formation of which are comparable to the enthalpies of formation of similar benzofuroxan derivatives and exceeds experimental enthalpy of formation of CL-14 (5,7-diamino-4,6-dinitrobenzofuroxan). The analysis of DSC indicates a sufficiently high thermal stability of the synthesized azidobenzofuroxans, which are acceptable for their use as components in the creation of highly efficient compositions with an increased value of energy characteristics
NHC Polymeric Particles Obtained by Self-Assembly and Click Approach of Calix[4]Arene Amphiphiles as Support for Catalytically Active Pd Nanoclusters
A new polymeric NHC carrier was synthesized by sequential supramolecular self-assembly and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of amphiphilic imidazolium calix[4]arenes with octyl lipophilic fragments. Obtained polytriazole-imidazolium particles were found as monodisperse submicron particles, with the average diameter of 236 Β± 34 nm and average molecular weight of 1380 Β± 96 kDa. Successful CuAAC polymerization has been proved using IR spectroscopy and high-resolution ESI mass spectrometry. Polymeric particles, as well as aggregates made from precursor macrocycles, were decorated by Pd clusters (2 nm) for further catalytic investigations. Pd nanoclusters, supported on the polymeric surface, were found highly catalytically active in the model reduction of p-nitrophenol, giving reaction rates an order of magnitude higher compared to literature examples. The reaction was recycled using the same catalyst five times without any loss of activity
Novel PEPPSI-Type NHC Pd(II) Metallosurfactants on the Base of 1H-Imidazole-4,5-dicarboxylic Acid: Synthesis and Catalysis in WaterβOrganic Media
Carrying out organic reactions in water has attracted much attention. Catalytic reactions in water with metallosurfactants, which have both a metallocenter and the surface activity necessary for solubilizing hydrophobic reagents, are of great demand. Herein we proposed new approach to the synthesis of NHC PEPPSI metallosurfactants based on the sequential functionalization of imidazole 4,5-dicarboxylic acid with hydrophilic oligoethylene glycol and lipophilic alkyl fragments. Complexes of different lipophilicity were obtained, and their catalytic activity was studied in model reduction and SuzukiβMiyaura reactions. A comparison was made with the commercial PEPPSI-type catalytic systems designed by Organ. It was found that the reduction reaction in an aqueous solution of the metallosurfactant with the tetradecyl lipophilic fragment was three times more active than the commercially available PEPPSI complexes, which was associated with the formation of stable monodisperse aggregates detected by DLS and TEM
New Supramolecular Hypoxia-Sensitive Complexes Based on Azo-Thiacalixarene
Hypoxia accompanies many human diseases and is an indicator of tumor aggressiveness. Therefore, measuring hypoxia in vivo is clinically important. Recently, complexes of calix[4]arene were identified as potent hypoxia markers. The subject of this paper is new hypoxia-sensitive hostβguest complexes of thiacalix[4]arene. We report a new high-yield synthesis method for thiacalix[4]arene with four anionic carboxyl azo fragments on the upper rim (thiacalixarene L) and an assessment of the complexes of thiacalixarene L with the most widespread cationic rhodamine dyes (6G, B, and 123) sensitivity to hypoxia. Moreover, 1D and 2D NMR spectroscopy data support the ability of the macrocycles to form complexes with dyes. Rhodamines B and 123 formed hostβguest complexes of 1:1 stoichiometry. Complexes of mixed composition were formed with rhodamine 6G. The association constant between thiacalixarene L and rhodamine 6G is higher than for other dyes. Thiacalixarene L-dye complexes with rhodamine 6G and rhodamine B are stable in the presence of various substances present in a biological environment. The UV-VIS spectrometry and fluorescence showed hypoxia responsiveness of the complexes. Our results demonstrate that thiacalixarene L has a stronger binding with dyes compared with the previously reported azo-calix[4]arene carboxylic derivative. Thus, these results suggest higher selective visualization of hypoxia for the complexes with thiacalixarene L