- Rapid and high yield detosylation of linear and macrocyclic p-toluenesulfonamides
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Rapid and high yield detosylation of linear and macrocyclic p-toluenesulfonamides were achieved by heating their approximately 50% concentrated sulfuric acid solution at 170-180°C for 5-8 min.
- Lazar
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Read Online
- DINUCLEATING LIGAND OR DINUCLEAR METAL COMPLEX
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To provide a dinuclear metal complex that can be synthesized simply and easily and has a proper anticancer action.SOLUTION: The present disclosure provides a dinucleating ligand represented by the following formula (I) and a dinuclear metal complex thereof (where X is H or a substituted carbamoyl group, R1, R2, R3, and R4 independently represent H or a C1-8 linear or branched alkyl group).SELECTED DRAWING: None
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Paragraph 0048; 0054-0055
(2021/03/19)
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- METHOD FOR PREPARING NOTA DERIVATIVE
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The present invention discloses Method for preparing NOTA derivative. Firstly, take 4-methylsulfonyl chloride and diethylenetriamine in tosyl group reaction to obtain the first product. And, take the first product and sodium methoxide in the first substitution reaction to obtain the second product. Further, take 4-methylsulfonyl chloride and ethylene glycol in tosyl group reaction to obtain a third product. The second product is coupled to the third product to obtain a fourth product. Take the fourth product and sulfuric acid in the second substitution reaction. Finally, a final product is obtained by a bonding reaction with hydrochloric acid. The preparation method improves the water absorption issue of the benzene ring structure compound (TACN) of the NOTA derivative.
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Paragraph 0046
(2019/08/14)
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- METHOD FOR PREPARING NOTA DERIVATIVE
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A method for preparing a NOTA derivative is revealed. The method includes a plurality of steps. First take 4-toluenesulfonyl chloride and diethylenetriamine to carry out tosylation reaction and obtain a first product. Then the first substitution reaction takes place upon addition of the first product with sodium methoxide to get the second product. Next take 4-toluenesulfonyl chloride to react with ethylene glycol for preparing a third product by tosylation reaction therebewteen. Then a coupling reaction between the third product and the second product is carried out to produce a fourth product. The second substitution reaction occurs involving the fourth product in the presence of sulfuric acid. Lastly take the reaction product and hydrochloric acid to have bonding reaction and obtain a final product. The method solves the water-absorption problem of the cyclic organic compound TACN, a NOTA derivative.
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Page/Page column 0024; 0033; 0041; 0042; 0043; 0048
(2019/09/20)
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- Comparative studies of the electronic, binding and photophysical properties of a new nona-dentate hemi-cage tripodal HQ pendant trizaza-macrocycle with unfilled, half-filled and completely filled lanthanide ions
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The present paper describes the comparative studies of the electronic, photophysical and binding properties of a new C3-symmetric polydentate ligand, 1,4,7-tris-{(5-methylene-8-hydroxyquinoline)-1,4,7-triazacyclononane} (9N3Me5Ox), and its complexes with 4f0, 4f7, and 4f14 metal ions (La3+, Gd3+, and Lu3+) by experimental and theoretical methods using DFT, TDDFT, TDDFTB, ETS-NOCV, NBO and Ligand Field DFT (LFDFT). The ligand and the complexes were synthesized and characterized through elemental analysis, molar conductance, TGA, FT-IR, FT-NMR, 1H-1H COSY and ESI-mass spectrometry techniques. The spectral data and structural studies revealed the formation of nine-coordinate compounds with the general formula [Ln(9N3Me5Ox)(H2O)3], in which the nonadentate chelator acted as a trinegative hexadentate ligand coordinating to the metal ions through three sets of O,N-donors of 8-hydroxyquinoline groups and three coordinated water molecules. The molecular modeling studies suggest that the metal ion can be easily encapsulated in its central cavity forming hemi-cage complexes without altering the basic metal-ligand coordination sphere. The nature of the bonding between the lanthanide ions and 9N3Me5Ox3?, elucidated by means of the natural bond orbital (NBO), Morokuma-Ziegler energy decomposition analysis (ETS-NOCV) scheme, suggests that the Ln-L bonds are more electrostatic (~82percent) than covalent (~18percent). The covalent character of the complexes increases in the order Lu > La > Gd. The photoluminescence spectral studies of the metal complexes revealed that the observed luminescence of the compounds in the solid state and solution is of different origin. The vibrational, 1H and 13C NMR spectral data obtained from the DFT optimized structures showed good agreement with the experimental results. The excitation and emission behaviours of the ligand and the complexes were established by molecular orbital analysis of the ground state DFT geometry as well as of the excited state optimized geometry using TD-DFT and TD-DFTB orbital analysis, excitation and emission properties.
- Baral, Minati,Kanungo, B. K.,Rohini
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p. 16040 - 16059
(2018/10/04)
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- A Bis-Triazacyclononane Tris-Pyridyl N9-Azacryptand “Beer Can” Receptor for Complexation of Alkali Metal and Lead(II) Cations
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A new bis-triazacyclononane tris-pyridyl N9-azacryptand ligand is prepared via a convenient one-pot [2+3] condensation reaction between triazacyclononane and 2,6-bis(bromomethyl) pyridine in the presence of M2CO3 (M=Li, Na, K). The proton, lithium, sodium, potassium and lead(II) complexes of the ligand are characterised in the solid state. Preliminary solution-phase competition experiments indicate that the cryptand ligand preferentially binds lead(II) in the presence of sodium, calcium, potassium and zinc cations in methanol solution.
- Brown, Asha,Bunchuay, Thanthapatra,Crane, Christopher G.,White, Nicholas G.,Thompson, Amber L.,Beer, Paul D.
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supporting information
p. 10434 - 10442
(2018/07/31)
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- Synthesis of Previously Inaccessible Derivatives of 1,4,7-Tri-R-1,4,7-Triazacyclononane, Including Chiral Examples, and a Rapid Synthesis of the HCl Salts of H3tacn and H4dtne
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The synthesis of 1,4-di-tert-butyl-7-R-1,4,7-triazacyclononane (tBu2Rtacn) derivatives through a “crab-like” cyclization is reported. The tert-butyl groups were cleavable with concentrated hydrochloric acid, allowing for a facile and convenient synthesis of the HCl salt of H3tacn and the most direct route to its industrially relevant binucleating N-ethylene bridged derivative, H4dtne. In addition, the synthesis of chiral tacn derivatives with both one and two stereocenters in non-annulet, alpha-N positions is reported.
- Pickel, Thomas C.,Karahalis, Gregory J.,Buru, Cassandra T.,Bacsa, John,Scarborough, Christopher C.
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p. 6876 - 6889
(2019/01/04)
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- Using iSUSTAIN to validate the chemical attributes of different approaches to the synthesis of tacn and bridged (bis)tacn ligands
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Using green chemistry principles, alternative approaches for the synthesis of commercially important aza-macrocyclic tacn and (bis)tacn derivatives have been investigated to determine the step average and overall efficiency of these synthetic methods. Based on analytical metrics derived from the iSUSTAIN toolkit, the Richman-Atkins route for the synthesis of tacn (1) was found to be the more efficient; however an alternate route was shown to be preferable for the synthesis of (bis)tacn (2) compounds. The outcome of this study documents the importance of rigorous analysis of synthetic procedures for such aza-macrocyclic compounds in terms of their green chemistry attributes, in order to delineate how alternative synthetic methods can be ranked, more innovative procedures selected to improve productivity and yield, and synthetic methods deployed to achieve greater levels of waste reduction, reduced use of hazardous chemicals and lower environmental impact.
- Coghlan,Campi,Jackson,Hearn
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supporting information
p. 5477 - 5484
(2016/10/21)
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- A high-nuclearity metal-cyanide cluster [Mo6Cu14] with photomagnetic properties
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A high-nuclearity metal-cyanide cluster [Mo6Cu14] has been prepared and its photomagnetic properties investigated. The photoswitchable magnetic phenomenon observed is thermally reversible (T ≈ 230 K). In the field of photomagnetism, [Mo6Cu14] represents a unique example of a nanocage and the highest nuclearity observed so far.
- Bridonneau,Chamoreau,Gontard,Cantin,Von Bardeleben,Marvaud
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supporting information
p. 9412 - 9418
(2016/07/06)
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- Phosphate diester cleavage, DNA interaction and cytotoxic activity of a bimetallic bis(1,4,7-triazacyclononane) zinc complex
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The dinuclear zinc complex [Zn2{bcmp(-H)}(μ-Cl)](ClO 4)2·H2O {bcmp = 2,6-bis(1,4,7- triazacyclonon-1-ylmethyl)-4-methylphenol} has been synthesized and structurally characterized. The DNA binding affinity was assessed by ethidium bromide fluorescence quenching experiments. The complex relaxes supercoiled pUC19 DNA into the nicked form at low micromolar concentration. Mechanistic studies were carried out using the DNA and RNA models bis(2,4-dinitrophenyl) phosphate (BDNPP) and 2-hydroxypropyl p-nitrophenyl phosphate (HPNP). A detailed kinetic analysis suggested that the bridging OH group of the solution species [Zn 2{bcmp(-H)}(μ-OH)]2+ acts as the nucleophile in the hydrolysis of BDNPP, while in the case of HPNP, the bridging OH group acts as a general base and seems to shift to a terminal position upon substrate coordination. Finally, the cytotoxicity profile of the dinuclear zinc(II) complex was assessed. The complex showed promising in vitro antitumour activity against pancreatic and lung cancers cell lines. A new bimetallic Zn complex with a phenolate scaffold ligand with two aza-crown binding sites has been synthesized and characterized. DNA binding, cleavage and cytotoxicity results are reported.
- Montagner, Diego,Gandin, Valentina,Marzano, Cristina,Erxleben, Andrea
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supporting information
p. 4084 - 4092
(2014/12/09)
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- Phosphate diester cleavage, DNA interaction and cytotoxic activity of a bimetallic bis(1,4,7-triazacyclononane) Zinc Complex
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The dinuclear zinc complex [Zn2{bcmp(-H)}(μ-Cl)](ClO4)2·H2O {bcmp = 2,6-bis(1,4,7-triazacyclonon-1-ylmethyl)-4-methylphenol} has been synthesized and structurally characterized. The DNA binding affinity was assessed by ethidium bromide fluorescence quenching experiments. The complex relaxes supercoiled pUC19 DNA into the nicked form at low micromolar concentration. Mechanistic studies were carried out using the DNA and RNA models bis(2,4-dinitrophenyl) phosphate (BDNPP) and 2-hydroxypropyl p-nitrophenyl phosphate (HPNP). A detailed kinetic analysis suggested that the bridging OH group of the solution species [Zn2{bcmp(-H)}(μ-OH)]2+ acts as the nucleophile in the hydrolysis of BDNPP, while in the case of HPNP, the bridging OH group acts as a general base and seems to shift to a terminal position upon substrate coordination. Finally, the cytotoxicity profile of the dinuclear zinc(II) complex was assessed. The complex showed promising in vitro antitumour activity against pancreatic and lung cancers cell lines.
- Montagner, Diego,Gandin, Valentina,Marzano, Cristina,Erxleben, Andrea
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supporting information
p. 4084 - 4092
(2015/04/27)
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- Triamidetriamine bearing macrobicyclic and macrotricyclic ligands: Potential applications in the development of copper-64 radiopharmaceuticals
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A versatile and straightforward synthetic approach is described for the preparation of triamide bearing analogues of sarcophagine hexaazamacrobicyclic cage ligands without the need for a templating metal ion. Reaction of 1,1,1-tris(aminoethyl)ethane (tame) with 3 equiv of 2-chloroacetyl chloride, yields the tris(α-chloroamide) synthetic intermediate 6, which when treated with either 1,1,1-tris(aminoethyl)ethane or 1,4,7-triazacyclononane furnished two novel triamidetriamine cryptand ligands (7 and 8 respectively). The Co(III) and Cu(II) complexes of cryptand 7 were prepared; however, cryptand 8 could not be metalated. The cryptands and the Co(III) complex 9 have been characterized by elemental analysis, 1H and 13C NMR spectroscopy, and X-ray crystallography. These studies confirm that the Co(III) complex 9 adopts an octahedral geometry with three facial deprotonated amido-donors and three facial amine donor groups. The Cu(II) complex 10 was characterized by elemental analysis, single crystal X-ray crystallography, cyclic voltammetry, and UV-visible absorption spectroscopy. In contrast to the Co(III) complex (9), the Cu(II) center adopts a square planar coordination geometry, with two amine and two deprotonated amido donor groups. Compound 10 exhibited a quasi-reversible, one-electron oxidation, which is assigned to the Cu2+/3+ redox couple. These cryptands represent interesting ligands for radiopharmaceutical applications, and 7 has been labeled with 64Cu to give 64Cu-10. This complex showed good stability when subjected to L-cysteine challenge whereas low levels of decomplexation were evident in the presence of L-histidine.
- Tan, Kel Vin,Pellegrini, Paul A.,Skelton, Brian W.,Hogan, Conor F.,Greguric, Ivan,Barnard, Peter J.
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supporting information
p. 468 - 477
(2014/01/23)
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- Paramagnetic palladacycles with PdIII centers are highly active catalysts for asymmetric aza-Claisen rearrangements
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A combination of spectroscopic and electrochemical methods - XANES, EXAFS, X-ray, 1H NMR, EPR, Moessbauer, and cyclic voltammetry - demonstrate that the most efficient Pd catalysts for the asymmetric rearrangement of allylic trifluoroacetimidates unexpectedly possess in the activated oxidized form a PdIII center bound to a ferrocene core which remains unchanged (FeII) during the oxidative activation. These are the first recognized PdIII complexes acting as enantioselective catalysts.
- Eitel, Simon H.,Bauer, Matthias,Schweinfurth, David,Deibel, Naina,Sarkar, Biprajit,Kelm, Harald,Krueger, Hans-Joerg,Frey, Wolfgang,Peters, Rene
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supporting information; experimental part
p. 4683 - 4693
(2012/05/05)
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- Significant relaxivity gap between a low-spin and a high-spin iron(II) complex of structural similarity: An attractive off-on system for the potential design of responsive MRI probes
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We have identified a pair of structurally similar iron complexes in the oxidation state ii that exist in a low-spin and a high-spin electronic spin state in aqueous media, respectively. The low-spin, diamagnetic complex (LS, 1) is mute in MRI while the high-spin, paramagnetic complex (HS, 2) generates considerable contrast in MRI. These results demonstrate that iron(ii) complexes, hitherto neglected for contrast enhancement in MRI, have potential for the design of an MRI probe that suffers passage from one state to the other under the influence of a targeted biochemical activity and thus operates in an off-on mode. At 300 MHz (proton resonance frequency at 7 T field strength) and in phosphate buffer, we found a longitudinal relaxivity (r1) of 1.29 mM -1 s-1 for 2 that, in light of the difference in unpaired electrons of the central metal atoms (4 for FeII; 7 for Gd III), comes remarkably close to that of gadolinium(iii)-DOTA (2.44 mM-1 s-1), a commercialized MRI contrast agent. Since gadolinium complexes are always paramagnetic and can therefore not be muted in MRI, the here presented Fe(ii)-based system offers an alternative strategy to develop responsive MRI probes. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Stavila, Vitalie,Allali, Mustapha,Canaple, Laurence,Stortz, Yvon,Franc, Cecile,Maurin, Philippe,Beuf, Olivier,Dufay, Olivier,Samarut, Jacques,Janier, Marc,Hasserodt, Jens
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p. 428 - 435
(2008/09/17)
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- Ligand and complex for catalytically bleaching a substrate
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The invention relates to ligands or complexes useful as catalysts for catalytically bleaching substrates with atmospheric oxygen, and as catalysts in the of treatment of textiles such as laundry fabrics whereby bleaching by atmospheric oxygen is catalysed after the treatment. The ligand is of the general formula: wherein R1, R2, and R3independently represent a group selected from methyl, pyridin-2-yl, quinolin-2-yl, pyrazol-1-yl, 3,5-dimethylpyrazol-1-yl, N-methyl-amido, and N-isopropyl-amido; provided at least two of R1, R2and, R3represent a coordinating group, the ligand being selected from: 1,4-bis(pyridin-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(quinolin-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(pyrazol-1-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(3,5-dimethylpyrazol-1-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(N-methylimidazol-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4,7-tris(quinolin-2-ylmethyl)-1,4,7-triazacyclononane; 1,4-bis(N-isopropylacetamido)-7-ethyl-1,4,7-triazacyclononane; and 1,4-bis(N-methylacetamido)-7-ethyl-1,4,7-triazacyclononane.
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Page/Page column 7
(2010/01/31)
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- Simulation Strategies for Unusual EPR Spectra of Binuclear Mixed-Valence Manganese Complexes: Synthesis, Properties, and X-ray Structures of the MnIIMnIII Complexes (ClO4)2*H2O and (ClO4)2*CH2Cl2
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The preparation, single-crystal X-ray structures, variable-temperature magnetic susceptibility, and novel EPR data are presented for two mixed-valence MnIIMnIII complexes. (ClO4)2*H2O (1), where bpmp(1-) is the monoanion of 2,6-bis-4-methylphenol, crystallizes in the monoclinic space group P21/n with a=12.493 (1) Angstroem, b=21.583 (2) Angstroem, c=16.631 (2) Angstroem, β=95.31 (1) deg, Z=4, RF=0.061 and RwF=0.085 for 4298 unique reflections 3?(I)> at 297 (1) K. (ClO4)2*CH2Cl2 (2),where bcmp(1-) is the monoanion of 2,6-bis(1,4,7-triazacyclonon-1-ylmethy)-4-methylphenol, crystallizes in the orthorhombic space group Pca21, with a=19.273 (1) Angstroem, b=15.155 (1) Angstroem, c=13.749 (3) Angstroem, Z=4; RF=0.074 and RwF=0.085 for 2324 unique reflections 3?(I)> at 296 (1) K.Trapped-valence MnIIMnIII descriptions are appropriate for both 1 and 2, where in each case the two Mn atoms are bridged by two bidentate acetate ions and by the phenoxide O atom of the bpmp(1-) or bcmp(1-) ligand.In the case of either 1 or 2 both Mn ions show pseudooctahedral coordination, and the MnIII ion is Jahn-Teller distorted along the "z" direction.Two one-electron quasi-reversible cyclic voltammogram waves (MnIIMnIII --> MnII2 and MnIIMnIII III2, respectively) are seen for both 1 (+0.067 and +0.597 V vs Fc(1+)/Fc) and 2 (-0.133 and +0.347 V).Moderately well-resolved (1)H NMR signals are seen at room temperature for 1 in CD2Cl2 and 2 in CD3CN.Magnetic susceptibility data are presented for polycrystalline samples of 1 in the 2.2-298 K range and 2 in the range 5-301.2 K.Fitting these data to the theoretical susceptibility equation for an isotropic exchange interaction (H=-2JS1*S2) gave exchange parameters of -6.0 and -7.7 cm-1 for 1 and 2, respectively.X-band EPR spectra for polycrystalline 1 and 2 in the 7.5-90 K range are illustrated and discussed.In addition to several other transitions the signals at g ca.4 and g ca.2 are associated with complexes in the S=3/2 excited and S=1/2 ground states, respectively.In a frozen glass (2:1:2 acetone/toluene/ethanol) at temperatures below ca.15 K the X-band spectra of 1 and 2 exhibit a g ca.2 signal structured with a 29-line manganese hyperfine pattern.It was necessary to run ca.20 K Q-band EPR spectra of glasses of 1 and 2 to understand these hyperfine patterns.Through detailed computer simulation it was concluded that only the manganese hyperfine structure for the z component of the g tensor is resolved in the X- and Q-band spectra and that hyperfine structure for the gx and gy components is broad to the point of not contributing significantly to the observed EPR spectra.The absence of resolved structure from the gx and gy components is attributed to some combination of strain effects (i.e., distributions) associated with the g, A, or J values.
- Diril, Habibe,Chang, Hsiu-Rong,Nilges, Mark J.,Zhang, Xiaohua,Potenza, Joseph A.,et al.
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p. 5102 - 5114
(2007/10/02)
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