65448-72-8Relevant academic research and scientific papers
Tetranuclear Lanthanide(III) Complexes Containing a Square-Grid Core: Synthesis, Structure, and Magnetism
Biswas, Sourav,Das, Sourav,Hossain, Sakiat,Bar, Arun Kumar,Sutter, Jean-Pascal,Chandrasekhar, Vadapalli
, p. 4683 - 4692 (2016)
The reactions of Ln(NO3)3·5H2O (Ln = Dy3+, Tb3+, Ho3+, Er3+) and a multidentate flexible ligand, (E)-N′-[2-hydroxy-3-(hydroxymethyl)-5-methylbenzylidene]-6-(hydroxymethyl)picolinohydrazide (LH4), in the presence of Et3N in a 1:1:3 molar ratio afforded a series of complexes [Ln4(LH2)4(μ2-OH)4]·xCH3OH·yH2O (Dy3+, x = 2, y = 2; Tb3+, x = 4, y = 5; Ho3+, x = 0, y = 13; Er3+, x = 4, y = 6). X-ray diffraction analysis revealed that all the complexes are neutral and possess a distorted [2 × 2] square-grid core [Ln4(μ2-O)4(μ2-OH)4] anchored by the concerted coordination of four doubly deprotonated ligands, (LH2)2–, and four μ2-OH groups. All the Ln centers adopt a distorted triangular dodecahedral coordination geometry. An ac magnetic susceptibility study revealed undulations of the out-of-phase (χM′′) component above 2 K for 1 with a quantum tunnelling of magnetization tail at zero dc field. Surprisingly, a field-induced temperature dependence of the ac frequencies at which the χM′′ maxima occur implies that the slow relaxation is a result of a mixed contribution from more than one Dy3+center.
Synthesis, structure, and magnetic properties of a family of heterometallic pentanuclear [Co4Ln] (Ln = GdIII, DyIII, TbIII, and HoIII) assemblies
Chandrasekhar, Vadapalli,Das, Sourav,Dey, Atanu,Hossain, Sakiat,Lloret, Francesc,Pardo, Emilio
, p. 4506 - 4514 (2013)
The reaction of 6-formyl-2-(hydroxymethyl)-4-methylphenol (LH2) with appropriate lanthanide salts followed by reaction with Co(OAc) 2·4H2O afforded the pentanuclear heterobimetalllic compounds [Co4Ln(L)4(OAc)2(S) 4](NO3)(S) [LnIII = GdIII, S = MeOH (1); LnIII = DyIII, S = H2O (2); Ln III = TbIII, S = MeOH (3); LnIII = Ho III, S = MeOH (4)] in good yields. All the compounds are stable in solution as confirmed by ESI-MS studies. These complexes contain a distorted Co4 tetrahedral core, which encapsulates a central lanthanide ion. The CoII and LnIII ions are in an all-oxygen environments. All the CoII ions possess a distorted octahedral geometry, and the LnIII ions are in a distorted square-antiprismatic geometry. The magnetic properties of 1-4 have been investigated in the temperature range 2-300 K. In addition, the magnetic properties of 1 were fitted by using a Hamiltonian of the type H = HSO + Haxial + Hexchange + HZeeman. A moderately strong antiferromagnetic interaction between the nearest-neighbour CoII ions was found, whereas the magnetic interaction between the CoII ions and the corresponding Ln III ions is negligible. The reaction of 6-formyl-2-(hydroxymethyl)-4- methylphenol with lanthanide salts followed by reaction with Co(OAc) 2·4H2O affords new pentanuclear heterobimetalllic compounds with a [Co4Ln] core. Magnetic studies on these compounds reveal a moderately strong antiferromagnetic interaction between the Co II ions, whereas the interactions between the CoII and LnIII ions are negligible. Copyright
Facile synthesis of 1,6-bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5- methylbenzyl)-2,5-diazahexane: A new dinucleating ligand
Sun, Gang-Chun,He, Zhan-Hang,Li, Zhong-Jun,Yuan, Xiao-Dong,Yang, Zhi-Juan,Wang, Guo-Xi,Wang, Liu-Fang,Liu, Chang-Rang
, p. 1001 - 1005 (2001)
A convenient three-step preparation of the dinucleating ligand, 1,6-bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5-methylbenzyl)-2,5-diazahexane (3) starting from 2,6-bis(hydroxymethyl)-4-methylphenol (4) is reported. Compound 4 was partially oxidized with preactivated manganese dioxide to form compound 5, which was converted to 2-hydroxy-3-chloromethyl-5-ethylbenzaldehyde (6) with conc.HCl/EtOH. Compound 6 in turn reacted with N,N′-bis (2-furyl)-1,2-diaminoethane (7) in the presence of K2CO3 in ethanol to give the title compound 3. No protecting groups were required in the whole process and the conditions were mild.
A rhodamine B-based "turn-on" fluorescent sensor for detecting Cu2+ and sulfur anions in aqueous media
Guo, Dan,Dong, Zhengping,Luo, Chao,Zan, Wenyan,Yan, Shiqiang,Yao, Xiaojun
, p. 5718 - 5725 (2014)
A novel selective fluorescent chemosensor L based on rhodamine B derivative has been designed and synthesized to optically detect Cu2+ and S2- in aqueous buffer solution. The fluorescence of L was excited by Cu2+ with a 1:1 binding ratio, and could be used as a "turn-on" type sensor. Otherwise, the emission band would undergo a slight red-shift. Once binding with Cu2+, the copper complex can exhibit high selectivity for S2-. Upon addition of Cu2+, the color of the chemosensor L changes from colorless to pink. Additionally, the resulting pink solution changes to colorless immediately upon the addition of S2-. However, no phenomenon change could be observed in the presence of other anions. Conclusively, the color changes suggest that sensor L could serve as a "naked-eye" sensor for Cu2+ and S2-.
Decanuclear Ln10 Wheels and Vertex-Shared Spirocyclic Ln5 Cores: Synthesis, Structure, SMM Behavior, and MCE Properties
Das, Sourav,Dey, Atanu,Kundu, Subrata,Biswas, Sourav,Narayanan, Ramakirushnan Suriya,Titos-Padilla, Silvia,Lorusso, Giulia,Evangelisti, Marco,Colacio, Enrique,Chandrasekhar, Vadapalli
, p. 16955 - 16967 (2015)
The reaction of a Schiff base ligand (LH3) with lanthanide salts, pivalic acid and triethylamine in 1:1:1:3 and 4:5:8:20 stoichiometric ratios results in the formation of decanuclear Ln10 (Ln=Dy(1), Tb(2), and Gd (3)) and pentanuclear Ln5 complexes (Ln=Gd (4), Tb (5), and Dy (6)), respectively. The formation of Ln10 and Ln5 complexes are fully governed by the stoichiometry of the reagents used. Detailed magnetic studies on these complexes (1-6) have been carried out. Complex 1 shows a SMM behavior with an effective energy barrier for the reversal of the magnetization (Ueff)=16.12(8) K and relaxation time (τo)=3.3×10-5 s under 4000 Oe direct current (dc) field. Complex 6 shows the frequency dependent maxima in the out-of-phase signal under zero dc field, without achieving maxima above 2 K. Complexes 3 and 4 show a large magnetocaloric effect with the following characteristic values: -ΔSm=26.6 J kg-1 K-1 at T=2.2 K for 3 and -ΔSm=27.1 J kg-1 K-1 at T=2.4 K for 4, both for an applied field change of 7 T. Homometallic complexes: The reaction of a multidentate flexible Schiff base ligand (LH3; see figure) with [LnCl3]6 H2O affords homometallic decanuclear complexes, [Ln10(LH)10(κ2-Piv)10] (Ln=Dy, Tb, and Gd), and homometallic pentanuclear complexes, [Ln5(LH)4(μ2-η1η1Piv)4(η1Piv)(S)] (Ln=Dy, Tb, and Gd). The Dy3+ analogues exhibit single-molecule magnet (SMM) behavior, whereas the Gd3+ complexes show a significant magnetocaloric effect (MCE).
Preparation method and application of fluorescent probe for ultrafast detection of biological mercaptan
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Paragraph 0036-0040, (2021/05/29)
The invention relates to the field of optical imaging, in particular to a preparation method and application of a fluorescent probe for ultrafast detection of biological mercaptan. According to the invention, a pink solid probe, namely [2-(7-diethylaminocoumarin)methylene-7-methyl-1-oxo-3,3a-dihydrocyclopenta[b]chroman-cycl-5-yl]-methyl-N,N-dimethyl-4(1H)-pyridylidene carbonic ester, is finally synthesized through a series of chemical reactions on the basis of 2,6-bis(hydroxymethyl)-p-cresol and 4-(diethylamino)salicylaldehyde. The fluorescent probe has the advantages of simple synthesis route, easily available raw materials, low cost and very short reaction time, can realize the detection of certain micromolecular biological mercaptans at a very high speed, and has very strong sensitivity and selectivity; and in addition, the probe can be targeted to and positioned in mitochondria, so rapid imaging at a specific position is realized.
Radix stemonae alkaloid analogue near-infrared fluorescent probe and preparation method thereof
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Paragraph 0027-0030, (2020/07/21)
The invention relates to the field of optical imaging, in particular to a radix stemonae alkaloid analogue near-infrared fluorescent probe and a preparation method thereof. The near-infrared fluorescent probe is applied to rapid detection of biological mercaptan, and is applied to imaging of the biological mercaptan in cells and living bodies. Existing reported fluorescent probes for detecting thebiological mercaptan have certain limitations, such as complex synthetic routes, long response time, short emission wavelength and the like. The preparation method of the near-infrared fluorescent probe comprises the following steps: 5-(hydroxymethyl)-7-methyl-3, 3 a-dihydrocyclopenta [ b ] chroman cyclo-1 (2H)-one and 3, 7-bis (dimethylamino)-10H-benzothiazine-10-carbonyl chloride react under the action of 4-dimethylamino pyridine and pyridine to generate (7-methyl-1-oxy-1, 2, 3, 3 a-tetrahydrocyclopenta [ b ] chroman cyclo-5-yl)-methyl-3, 7-bis (dimethylamino)-10H-benzothiazine-10-carboxylate.
Synthesis and structure-activity relationship studies of hydrazide-hydrazones as inhibitors of laccase from trametes versicolor
Giurg, Miros?aw,Maniak, Halina,Matyja, Konrad,Talma, Micha?,Trusek, Anna
supporting information, (2020/03/23)
A series of hydrazide-hydrazones 1-3, the imine derivatives of hydrazides and aldehydes bearing benzene rings, were screened as inhibitors of laccase from Trametes versicolor. Laccase is a copper-containing enzyme which inhibition might prevent or reduce the activity of the plant pathogens that produce it in various biochemical processes. The kinetic and molecular modeling studies were performed and for selected compounds, the docking results were discussed. Seven 4-hydroxybenzhydrazide (4-HBAH) derivatives exhibited micromolar activity Ki = 24-674 μM with the predicted and desirable competitive type of inhibition. The structure-activity relationship (SAR) analysis revealed that a slim salicylic aldehyde framework had a pivotal role in stabilization of the molecules near the substrate docking site. Furthermore, the presence of phenyl and bulky tert-butyl substituents in position 3 in salicylic aldehyde fragment favored strong interaction with the substrate-binding pocket in laccase. Both 3- and 4-HBAH derivatives containing larger 3-tert-butyl-5-methyl- or 3,5-di-tert-butyl-2-hydroxy-benzylidene unit, did not bind to the active site of laccase and, interestingly, acted as non-competitive (Ki = 32.0 μM) or uncompetitive (Ki = 17.9 μM) inhibitors, respectively. From the easily available laccase inhibitors only sodium azide, harmful to environment and non-specific, was over 6 times more active than the above compounds.
A chemically encoded timer for dual molecular delivery at tailored ranges and concentrations
Serra, Silvia,Alouane, Ahmed,Le Saux, Thomas,Huvelle, Steve,Plasson, Rapha?l,Schmidt, Frédéric,Jullien, Ludovic,Labruère, Rapha?l
supporting information, p. 6396 - 6399 (2018/06/22)
Spatiotemporal control of molecular distribution is much in demand in many fields of chemistry. To address this goal, we exploit a low molecular weight branched self-immolative architecture, which acts as a triggerable chemically encoded timer for autonomous sequential release of two chemicals. Using a light-activated model liberating two distinct fluorophores, we generated a tunable spatially contrasted molecular distribution.
Deprotonation in Mixed-Valent Diiron(II,III) Complexes with Aniline or Benzimidazole Ligands
Gouré, Eric,Carboni, Michae¨l,Troussier, Angélique,Dubourdeaux, Patrick,Clémancey, Martin,Gon, Nathalie,Balasubramanian, Ramachandran,Lebrun, Colette,Pécaut, Jacques,Blondin, Geneviève,Latour, Jean-Marc
supporting information, p. 6257 - 6266 (2015/07/15)
We have previously investigated cis/trans isomerization processes in phenoxido-bridged mixed-valent FeIIFeIII complexes that contain either one aniline or one anilide ligand. In this work, we compare the properties of similar complexes bearing one terminal protic ligand, either aniline or 1H-benzimidazole. Whatever the ligand, 1H NMR spectroscopy clearly evidences that the complexes are present in CH3CN as a mixture of cis- and trans-isomers in a close to 1:1 ratio. We show here that addition of NEt3 indeed allows the deprotonation of these ligands, the resulting complexes bearing either anilide or benzimidazolide that are coordinated to the ferric site. The latter are singular examples of a high-spin ferric ion coordinated to a benzimidazolide ligand. Whereas the trans-isomer of the anilide complex is the overwhelming species, benzimidazolide species are mixtures of cis- and trans-isomers in equal proportions. Moreover, cyclic voltammametry studies show that FeIIIFeIII complexes with 1H-benzimidazole are more stable than their aniline counterparts, whereas the reverse is observed for the deprotonated species. (Graph Presented).
