65448-72-8Relevant articles and documents
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.
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.
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).
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.
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.
