- Thermal-healable and shape memory metallosupramolecular poly(n-butyl acrylate-co-methyl methacrylate) materials
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A big challenge in developing stimuli-responsive materials is to integrate multiple functionalities such as shape memory property, healable ability, recyclability into a single-component material. With this purpose, we designed a novel poly(n-butyl acrylate-co-methyl methacrylate) bearing a side group 2,6-bis(1′-methylbenzimidazolyl)pyridine ligand, which is dynamically crosslinked by the metal salt zinc trifluoromethanesulfonate to obtain the metallosupramolecular polymer. The shape recovery and healing is achieved upon application of a thermal or light stimulus due to the specific metal-ligand interactions which not only serve as an "inert" crosslink network at low temperature to produce the shape recovery, but also dissociate at high temperature for healing. The healing rate is quick and the healing efficiently is close to ～90%. the Partner Organisations 2014.
- Wang, Zhenhua,Fan, Wenru,Tong, Rui,Lu, Xili,Xia, Hesheng
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- Ligand-Sensitized Near-Infrared to Visible Linear Light Upconversion in a Discrete Molecular Erbium Complex
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While the low-absorption cross section of lanthanide-based upconversion systems, in which the trivalent lanthanides (Ln3+) are responsible for converting low- to high-energy photons, has restricted their application to intense incident light, the emergence of a cascade sensitization through an organic dye antenna capable of broadly harvesting near-infrared (NIR) light in upconversion nanoparticles opened new horizons in the field. With the aim of pushing molecular upconversion within the range of practical applications, we show herein how the incorporation of an NIR organic dye antenna into the ligand scaffold of a mononuclear erbium coordination complex boosts the upconversion brightness of the molecule to such an extent that a low-power (0.7 W·cm-2) NIR laser excitation of [L6Er(hfa)3]+(hfa = hexafluoroacetylacetonate) at 801 nm results in a measurable visible upconverted signal in a dilute solution (5 × 10-4M) at room temperature. Connecting the NIR dye antenna to the Er3+activator in a single discrete molecule cures the inherent low-efficient metal-based excited-state absorption mechanism with a powerful indirect sensitization via an energy transfer upconversion, which drastically improves the molecular-based upconverted Er3+-centered visible emission.
- Alves, Filipe,Golesorkhi, Bahman,Guénée, Laure,Naseri, Soroush,Nozary, Homayoun,Piguet, Claude,Taarit, Inès
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supporting information
p. 15326 - 15334
(2021/09/30)
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- Bottom-Up Approach for the Rational Loading of Linear Oligomers and Polymers with Lanthanides
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The adducts between luminescent lanthanide tris(β-diketonate)s and diimine or triimine ligands have been explored exhaustively for their exceptional photophysical properties. Their formation, stability, and structures in solution, together with the design of extended metallopolymers exploiting these building blocks, remain, however, elusive. The systematic peripheral substitution of tridentate 2,6-bis(benzimidazol-2-yl)pyridine binding units (Lk = L1-L5), taken as building blocks for linear oligomers and polymers, allows a fine-tuning of their affinity toward neutral [Ln(hfa)3] (hfa = hexafluoroacetylacetonate) lanthanide containers in the [LkLn(hfa)3] adducts. Two trends emerge with (i) an unusual pronounced thermodynamic selectivity for midrange lanthanides (Ln = Eu) and (ii) an intriguing influence of remote peripheral substitutions of the benzimidazole rings on the affinity of the tridentate unit for [Ln(hfa)3]. These trends are amplified upon the connection of several tridentate binding units via their benzimidazole rings to give linear segmental dimers (L6) and trimers (L7), which are considered as models for programming linear Wolf-Type II metallopollymers. Modulation of the affinity between the terminal and central binding units in the linear multitridentate ligands deciphers the global decrease of metal-ligand binding strengths with an increase in the length of the receptors (monomer → dimer → trimer → polymer). Application of the site binding model shed light onto the origin of the variation of the thermodynamic affinities: a prerequisite for the programmed loading of a polymer backbone with luminescent lanthanide β-diketonates. Analysis of the crystal structures for these adducts reveals delicate correlations between the chemical bond lengths measured in the solid state (or bond valence parameters) and the metal-ligand affinities operating in solution.
- Besnard, Céline,Guénée, Laure,Mirzakhani, Mohsen,Naseri, Soroush,Nozary, Homayoun,Piguet, Claude
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supporting information
p. 15529 - 15542
(2021/10/20)
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- Pinene condensed chiral terpyridyl bidentate compound and preparation method thereof
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The invention discloses a pinene condensed chiral terpyridyl bidentate compound and a preparation method thereof. The compound has a structure formula shown in the description. Commercial diethyl oxalate and acetone are adopted as initial raw materials, the initial raw materials are subjected to a Suzuki coupling reaction with a boronic acid pinacol ester compound, and thus a chirally modified terpyridyl bidentate ligand is synthesized. The synthesis method disclosed by the invention is simple in operation, and the raw materials are low in price and easy to obtain. A terpyridyl compound can beused as the tridentate ligand to form a stable complex together with multiple transition metals and rare earth metal ions, and in addition, the complex has good catalysis performance and special redox, photophysical properties, and the like, and can be applied to fields such as material science, life science, supramolecular self assembling, molecular catalysis and DNA (deoxyribonucleic acid) chips.
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Paragraph 0023-0025; 0028-032
(2020/01/12)
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- Preparing method of 4-hydroxypyridine-2,6-dicarboxylic acid
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The invention relates to a preparing method of 4-hydroxypyridine-2,6-dicarboxylic acid, and belongs to the technical field of organic synthesis. According to the preparing method of the 4-hydroxypyridine-2,6-dicarboxylic acid, acetone and dimethyl oxalate are taken as raw materials, concentrated hydrochloric acid is taken as a cyclizing agent, and then an intermediate 4-pyrone-2,6-dicarboxylic acid is synthesized and reacts with ammonium hydroxide to prepare the 4-hydroxypyridine-2,6-dicarboxylic acid. In the condensation process, the temperature of a mixed liquor of acetone, dimethyl oxalateand ethyl alcohol is gradually increased until the mixed liquor is heated to 60-80 DEG C. The viscosity of a reaction mixture can be lowered, so that uniform mixing of the mixture is achieved, and theyield of the product is increased. The concentrated hydrochloric acid is added in the mixture system, after heating is conducted for a reaction, the system is cooled to 5 DEG C, and then stirring andfiltering are conducted under an ice-water bath condition. An intermediate product is prevented from being decomposed, and condensation reverse reactions are prevented. The preparing method is simplein process, the yield is 90.1 or above, the reaction time is short, the cost is low, and the economic benefit and the social benefit are obvious.
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Paragraph 0028-0062
(2019/10/01)
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- Implementing liquid-crystalline properties in single-stranded dinuclear lanthanide helicates
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The connection of flexible protodendritic wedges to the bis-tridentate rigid polyaromatic ligand L1 provides amphiphilic receptors L5 and L6; their reduced affinities for complexing trivalent lanthanides (Ln = La, Y, Lu) in organic solvent (by fifteen orders of magnitude!) prevent the formation of the expected dinuclear triple-stranded helicates [Ln2(Lk) 3]6+. This limitation could be turned into an advantage because L1 or L6 can be treated with [Ln(hfac)3] (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) to give neutral single-stranded [Ln2(Lk)(hfac)6] complexes with no trace of higher-order helicates. Whereas ligands L1 and L5 are not liquid crystals, L6 can be melted above room temperature (41°C) to give a nematic mesophase, and its associated dinuclear helical complex [Y2(L6)(hfac)6] self-organises at the same temperature into a fluidic smectic mesophase. The lipophilic dendritic ligand L6 selectively reacts with trivalent yttrium hexafluoroacetylacetonate (hfac) to give the liquid-crystalline single-stranded dinuclear helicate [Y2(L6)(hfac)6], which self-organises into an SmA mesophase. Copyright
- Terazzi, Emmanuel,Zaim, Amir,Bocquet, Bernard,Varin, Johan,Guenee, Laure,Dutronc, Thibault,Lemonnier, Jean-Francois,Floquet, Sebastien,Cadot, Emmanuel,Heinrich, Benoit,Donnio, Bertrand,Piguet, Claude
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supporting information
p. 3323 - 3333
(2013/07/26)
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- Scale-up of flow-assisted synthesis of C2-symmetric chiral PyBox ligands
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A series of PyBox ligands were prepared from commercially available chelidonic acid by a multistep flow sequence using mesoreactor technology. A chloro group introduced onto the ligand scaffold was subsequently exploited to give amine derivatives ready for immobilization through microencapsulation technologies. Georg Thieme Verlag Stuttgart · New York.
- Battilocchio, Claudio,Baumann, Marcus,Baxendale, Ian R.,Biava, Mariangela,Kitching, Matthew O.,Ley, Steven V.,Martin, Rainer E.,Ohnmacht, Stephan A.,Tappin, Nicholas D. C.
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experimental part
p. 635 - 647
(2012/04/17)
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- Synthesis, structural investigation and computational modelling of water-binding aquafoldamers
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Detailed studies on water-binding aquafoldamers are presented that illustrate the potential use of the elongated larger aquafoldamers for recognizing larger water clusters of diverse topologies. A novel self-trapping dimerization mode involving two tetramer molecules is proposed, which is consistent with the obtained varying experimental evidences. The Royal Society of Chemistry 2012.
- Zhao, Huaiqing,Ong, Wei Qiang,Fang, Xiao,Zhou, Feng,Hii, Meng Ni,Li, Sam Fong Yau,Su, Haibin,Zeng, Huaqiang
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scheme or table
p. 1172 - 1180
(2012/03/07)
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- Encapsulation of conventional and unconventional water dimers by water-binding foldamers
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Water-binding foldamers have been rarely studied. By orienting both H-bond donors and acceptors toward their interior, two pyridine-derived crescent-shaped folding oligoamides were found to be capable of trapping both conventional and unconventional water dimer clusters in their cavity (～2.5 A radius). In the unconventional water dimer cluster, the two water molecules stay in contact via an unusual H-H interaction (2.25 A) rather than the typical H-bond.
- Ong, Wei Qiang,Zhao, Huaiqing,Fang, Xiao,Woen, Susanto,Zhou, Feng,Yap, Weiliang,Su, Haibin,Li, Sam F. Y.,Zeng, Huaqiang
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supporting information; scheme or table
p. 3194 - 3197
(2011/08/06)
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- Synthesis of novel multifunctional pyridine-2,6-dicarboxylic acid derivatives
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Eleven novel multifunctional compounds with pyridine-2,6-dicarboxylic acid were synthesized by hydrolyzing of ester prepared by coupling of diethyl 4-hydroxypyridine-2,6-dicarboxylate to bis-halohydrocarbon or bis-halide. All of the new compounds were characterized by 1H NMR, MS, IR and EA.
- Yin, Xian-Hong,Tan, Min-Yu
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p. 1113 - 1119
(2007/10/03)
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- Synthesis and coordination chemistry of arene soluble 4-alkyl-2,6-bis[(diphenylphosphino)methyl]pyridine N,P,P′-trioxide ligands
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The trifunctional ligand 2,6-[(C6H5) 2P(O)CH2]2C5H3NO forms stable complexes with trivalent and tetravalent f-element cations and it acts as an effective liquid-liquid extraction reagent when it is dissolved in CHCl3. In a search for more hydrocarbon solvent soluble extraction reagents, derivative ligands having alkyl substituents in the 4-pyridyl ring position, 4-R′-2,6-[(C6H5)2P(O)CH 2]2C5H2NO (R′ = Et, Oct), have been prepared and characterized. A single crystal X-ray diffraction analysis for the Et derivative shows that the ligand molecular structure is closely related to the parent ligand, 2,6-[(C6H5) 2P(O)CH2]2C5H3NO. The coordination chemistry of the ligands with Nd(NO3)3 has been examined, and the molecular structures of two complexes obtained with 1 : 1 and 2 : 1 ligand : metal reactant ratios are reported. The Royal Society of Chemistry 2003.
- Gan, Xin-Min,Paine, Robert T.,Duesler, Eileen N.,Noeth, Heinrich
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p. 153 - 159
(2007/10/03)
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- Hydroformylation of olefins using azoxy-dentated ligands
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At a temperature in the range 100° C to 225° C the destructive dissociation of cobalt carbonyl compounds to cobalt metal and residue is inhibited by the action of one or more azoxy-dentated chelation ligands.
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