7703-74-4Relevant articles and documents
Free Amino Acid Recognition: A Bisbinaphthyl-Based Fluorescent Probe with High Enantioselectivity
Zhu, Yuan-Yuan,Wu, Xue-Dan,Gu, Shuang-Xi,Pu, Lin
, p. 175 - 181 (2019)
A novel fluorescent probe based on a bisbinaphthyl structure has been designed and synthesized. This compound in combination with Zn(II) has exhibited highly enantioselective fluorescence enhancement with 13 common free amino acids. For example, its enantiomeric fluorescent enhancement ratios (ef or δIL/δID) in the presence of the following amino acids are extremely high: 177 for valine, 199 for methionine, 186 for phenylalanine, 118 for leucine, and 89 for alanine. The observed high enantioselectivity and the extent of the substrate scope are unprecedented in the fluorescent recognition of free amino acids. This fluorescent probe can be applied to determine the enantiomeric composition of the structurally diverse chiral amino acids. NMR and mass spectroscopic investigations have provided clues to elucidate the observed high enantioselectivity.
A one dimensional coordination polymer composed of antiferromagnetically coupled disk-like [Mn7] units
Yang, En-Che,Huang, Han-Sheng,Huang, Shao-Yun,Huang, Shi-Yi,Chang, Yu-Ying,Lee, Gene-Hsiang,Sheu, Hwo-Shuenn,Chang, Chung-Kai
, p. 6963 - 6969 (2018)
The synthesis, characterization by X-ray analysis and magnetic properties of a one dimensional coordination polymer {[Mn7(OH)2(dhap)2(N3)3(MeCN)4(ClO4)2]·2(MeCN)·2(ClO4)}∞ (1) are reported. The ligand dhapH4 in the complex is 2,6-bis[N,N-di(hydroxyethyl)aminomethyl]pyridine. This compound crystallizes in the monoclinic space group C2/c. Each [Mn7(OH)2(dhap)2(N3)3(MeCN)4(ClO4)2] unit (abbreviated by Mn7) is linked end-to-end by azido ligands to its neighboring units to form a one dimensional polymer. Magnetic susceptibility measurements indicate that the polymer is composed of S = 8 units with inter-Mn7-unit antiferromagnetic coupling. The Jahn-Teller axes of the Mn7 units are arranged in a zigzag manner along the polymer chain which induces spin canting at low temperatures. The slow magnetization relaxation at low temperatures was evidenced by observing out-of-phase signals in ac magnetic susceptibility measurements that give Ueff = 47.5 K and Δ0 = 2.7 × 10-13 s. This phenomenon also indicates that this one dimensional coordination polymer functions as a single-chain magnet (SCM).
Synthesis, characterization and X-ray crystal structures of cyclam derivatives. Part VI. Proton binding studies of a pyridine-strapped 5,12-dioxocyclam based macrobicycle
Meyer, Michel,Fremond, Laurent,Tabard, Alain,Espinosa, Enrique,Vollmer, Guy Yves,Guilard, Roger,Dory, Yves
, p. 99 - 108 (2005)
The 14-membered cyclic diamide 1,4,8,11-tetraazacyclotetradecane-5,12-dione (5,12-dioxocyclam) can be considered as a trans-autodiprotected tetraazamacrocycle and provides a convenient starting material for the preparation of macrobicyclic receptors. As an example, the secondary amine nitrogen atoms located at the 1 and 8 positions were cross-bridged with a 1,3-pyridyl strap, affording the constrained ansa-dioxocyclam ligand 1,9,12,18,22-pentaazatricyclo[7.6.6.13,7]docosa-3,5,7(22)-triene-13, 19-dione (L1). The proton binding properties of this cage-type compound, which possesses a hemispherical cavity, were fully investigated by spectroscopic (IR, NMR, UV, MALDI-TOF MS), quantum chemical, and potentiometric methods. While both bridgehead tertiary amines have their free lone pairs oriented inside the cavity, intramolecular hydrogen bonding was found to play a key role in determining the structural features of the free base and its protonated forms. L1 behaves as a diprotic base in water with log K011 = 8.94(1) and log K012 = 2.32(9), but most interestingly shows slow proton-transfer rates on the NMR timescale.
Phosphonated chelates for nuclear imaging
Abada, Sabah,Lecointre, Alexandre,Christine, Cline,Ehret-Sabatier, Laurence,Saupe, Falk,Orend, Gertraud,Brasse, David,Ouadi, Ali,Hussenet, Thomas,Laquerrire, Patrice,Elhabiri, Mourad,Charbonnire, Loc J.
, p. 9601 - 9620 (2014)
A series of bis-, tris- and tetra-phosphonated pyridine ligands is presented. In view of their potential use as chelates for radiopharmaceutical applications, the physico-chemical properties of the ligands and of their Co(ii), Ni(ii), Cu(ii), and Zn(ii) complexes were studied by means of potentiometry and UV-Vis absorption spectroscopy. The pKa values of the ligands and of the complexes, as well as the stability constants for the formation of the complexes, are presented. The kinetic aspects of the formation of Cu(ii) complexes and of their dissociation in acidic media were studied by means of stopped flow experiments, and the stability of the Cu(ii) complex toward reduction to Cu(i) was investigated by cyclic voltammetry and by titration with different reducing agents. The different thermodynamic and kinetic aspects of the polyphosphonated ligands were compared with regard to the impact of the number of phosphonic acid functions. Considering the very promising properties for complexation, preliminary SPECT/CT imaging experiments were carried out on mice with 99mTc using the bis- and tetra-phosphonated ligands L2 and L1. Finally, a bifunctional version of chelate L1, L, was used to label MTn12, a rat monoclonal antibody with both specificity and relatively high affinity for murine tenascin-C. The labeling was monitored by MALDI/MS spectrometry and the affinity of the labeled antibody was checked by immunostaining experiments. After chelation with 99mTc, the 99mTc-L-MTn12 antibody was injected into a transgenic mouse with breast cancer and the biodistribution of the labeled antibody was followed by SPECT/CT imaging.
Synthesis of macrocyclic inclusion complexes using olefin metathesis
Ng, Po Ling,Lambert, John N.
, p. 1749 - 1750 (1999)
The ruthenium-catalysed synthesis of a macrocyclic chelate is described. The reaction proceeds at room temperature using 5% catalyst to afford 4 in 80% isolated yield.
COMPOUND, AMMONIA DETECTION MATERIAL CONTAINING THE SAME AND METHOD FOR PRODUCING THE SAME, AND METHOD FOR DETECTING AMMONIA USING THE SAME
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Paragraph 0046; 0059-0060, (2021/09/27)
PROBLEM TO BE SOLVED: To provide a novel compound that can detect the existence of ammonia with high sensitivity, an ammonia detection material including the same, and the like. SOLUTION: The present disclosure provides a compound represented by general formula (1). In the general formula (1), each R1 independently represent a hydrogen atom or R, each R independently represent an optionally branched, C8-35 alkyl group, alkyloxy group or alkylsilyloxy group, each Ar independently represent a substituent and/or an aromatic ring optionally having a hetero atom in a ring, each L independently represent -CR2=CR2-, -C≡C- or a single bond, each R2 independently represent a hydrogen atom or a C1-5 alkyl group, X- is any counter anion, each k independently represent an integer of 1-5, and m is an integer of 0-4. SELECTED DRAWING: Figure 2 COPYRIGHT: (C)2021,JPOandINPIT
Structural and Thermodynamics Studies on Polyaminophosphonate Ligands for Uranyl Decorporation
Ye, Gaoyang,Roques, Jérome,Solari, Pier-Lorenzo,Den Auwer, Christophe,Jeanson, Aurélie,Brandel, Jérémy,Charbonnière, Lo?c J.,Wu, Wangsuo,Simoni, éric
, p. 2149 - 2159 (2021/02/16)
The development of actinide decorporation agents with high complexation affinity, high tissue specificity, and low biological toxicity is of vital importance for the sustained and healthy development of nuclear energy. After accidental actinide intake, sequestration by chelation therapy to reduce acute damage is considered as the most effective method. In this work, a series of bis- and tetra-phosphonated pyridine ligands have been designed, synthesized, and characterized for uranyl (UO22+) decorporation. Owing to the absorption of the ligand and the luminescence of the uranyl ion, UV-vis spectroscopy and time-resolved laser-induced fluorescence spectroscopy (TRLFS) were used to probe in situ complexation and structure variation of the complexes formed by the ligands with uranyl. Density functional theory (DFT) calculations and X-ray absorption fine structure (XAFS) spectroscopy on uranyl-ligand complexes revealed the coordination geometry around the uranyl center at pH 3 and 7.4. High affinity constants (log K ~17) toward the uranyl ion were determined by displacement titration. A preliminary in vitro chelation study proves that bis-phosphonated pyridine ligands can remove uranium from calmodulin (CaM) at a low dose and in the short term, which supports further uranyl decorporation applications of these ligands.
Simple synthetic process of platelet aggregation inhibitor pirozadil intermediate 2,6-bis(bromomethyl)pyridine
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Paragraph 0017-0020, (2019/05/08)
The invention discloses a simple synthetic process of a platelet aggregation inhibitor pirozadil intermediate 2,6-bis(bromomethyl)pyridine. The simple synthetic process includes the following steps: taking 107-428 g of 2,6-lutidine, 5-20 g of AIBN and 20-80 ml of 65% of concentrated nitric acid as raw materials, taking 500-2000 ml of dichloromethane, placing the materials into a reaction bottle of1-5 L, and starting stirring; heating the reaction solution to reflux; taking 200-800 g of bromine and slowly dropping the bromine into the reaction solution; after the dropping is completed, performing the reflux reaction for 5 h at a maintained temperature, performing TLC until an intermediate state is completely reacted, cooling the reaction solution to room temperature, adding the reaction solution to 500-2000 ml ice water, and stirring for 20 min; and extracting a water phase once with 500-2000 ml of dichloromethane, combining organic phases, and performing vacuum concentration on the organic phases until the organic phases are dry to obtain 225-910 g of solid with the yield being 85.6-86.5% and liquid phase being 97%. The simple synthetic process takes the 2,6-lutidine as a raw material to synthesize the target product in one step. The raw material is easily available, the reaction can be easily controlled, and the post-treatment is simple.