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1.
Three new mercury(II) coordination polymers, [Hg2(μ-bpa)(μ-SCN)2(μ-CH3COO)2]n (1), [Hg2(μ-4-bpdb)1.5(μ-CH3COO)(μ1,1- SCN)(μ1,3-SCN)(SCN)]n · CH3CN (2) and [Hg(μ-3-bpdb)(CH3COO)2]n (3) {(bpa = 1,2-bis(4-pyridyl)ethane, 4-bpdb) = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, have been synthesized and characterized by CHN elemental analysis and IR spectroscopy. The single crystal X-ray data show the compound 1 is two-dimensional coordination polymer as a result of simultaneously bridging 1,2-bis(4-pyridyl)ethane, acetate and thiocyanate ligands. The single-crystal X-ray data of the compound 2 show that the complex to be a two-dimensional polymer, one of Hg atoms has four-coordinate and one of them has seven-coordinate. Three SCN anions show three different coordination modes with terminal, μ1,1-bridge and μ1,3-bridge fashions. The structural studies of compound 3 show the structure may be considered a one-dimensional coordination polymer of mercury(II) consisting of linear chains formed by a bridging 3-bpdb ligand. The thermal stabilities of these compounds were studied by thermal gravimetric (TG) and differential thermal analyses (DTA).  相似文献   

2.
Six new coordination polymers based on V-shaped linkage 2,5-bis(4-pyridyl)-1,3,4-thiadiazole (bpt) and transition metal ions, [Co(bpt)(pm)0.5(H2O)]n · 3nH2O (1), [Cu2(bpt)(pm)(H2O)4]n (2), [Co(bpt)(pydc)]n · 2nCHCl3 · nH2O (3), [Cu2(bpt)(pydc)2(H2O)2]n (4), [Cu2(bpt)(pydco)2(H2O)2]n · nH2O (5) and [Cd(bpt)(pydco)]n (6) (H4pm = pyromellitic acid, H2pydc = pyridine-2,6-dicarboxylic acid, H2pydco = pyridine-2,6-dicarboxylic acid N-oxide), have been synthesized under the intervention of various polycarboxylate ligands. Complex 1 exhibits a 3-D 4-connected structure with 1-D nanosized open channels encapsulated lots of water molecules. Complex 2 represents a 2-D grid containing two types of rectangular windows. When pydc and pydco instead of pm, complexes 3 and 6 were obtained with highly undulated 2-D layers. The interlayers of 3 are filled with two kinds of solvent molecules, whereas 6 is a double-layered framework without free molecules. Complexes 4 and 5 consist of two distinct 1-D infinite chains held together to form different 2-D supramolecular networks. Importantly, bpt spacer shows changeful conformational geometries and generates complicated crystalline architectures with the introduction of polycarboxylate ligands. Additionally, thermal stability of complexes 1, 3 and 5, fluorescent properties of 6 and X-ray powder diffraction of 1 have also been investigated.  相似文献   

3.
Three new 2D PbII coordination polymers containing 4,4′-bipyridine (4,4′-bipy), 1,2-bis(4-pyridyl)ethane (bpa) and 1,2-bis(4-pyridyl)ethene (bpe) with bromide anions, [Pb(μ-4,4′-bipy)(μ-Br)2]n (1), [Pb(μ-bpa)(μ-Br)2]n (2) and [Pb(μ-bpe)(μ-Br)2]n (3) have been synthesized and characterized by elemental analysis, IR spectroscopy and their structures studied by X-ray crystallography. The thermal stability of compounds 1-3 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The single-crystal X-ray data shows that the Pb2+-ions have coordination numbers of six and contain the rarely holodirected geometries.  相似文献   

4.
Assemblies of an angular dipyridyl ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) with a series of metal perchlorate afford five new supramolecular complexes with the general formula of [M(4-bpo)2(H2O)4] · (4-bpo)2 · (anion) · (solvent), in which M = MnII for 1, FeII for 2, CoII for 3, ZnII for 4, and FeIII for 5. Although similar molecular structures and compositions are found for these mononuclear complexes, they display two types of supramolecular lattices. Complexes 1, 4 and 5 similarly crystallize in space group P2/n or P2/c. The complex cations, free 4-bpo and lattice water are linked to generate 2D layered frameworks with the aid of hydrogen bonding, and the counter anions are located within and between (also methanol in 5) these 2D arrays. However, complexes 2 and 3 are isostructural in space group . Two types of alternate 2D layers consisting of complex cations and free 4-bpo components, respectively, are observed with the anions and lattice water locating between them. These motifs are interlinked by complicated hydrogen-bonding to form a 3D intercalated network. Moreover, when Co(NO3)2 is used instead of Co(ClO4)2 in the assembly of 3, a 1D polymeric chain complex {[Co(4-bpo)(H2O)2(NO3)2](H2O)3}n (6) is generated. These results indicate that the choice of metal ion and anion exerts a significant influence on governing the target complexes. A comparison of the structural features for all metal perchlorate complexes with 4-bpo is also briefly discussed.  相似文献   

5.
The complexes of Cu(I), Cu(II), Ni(II), Zn(II) and Co(II) with a new polypyridyl ligand, 2,3-bis(2-pyridyl)-5,8-dimethoxyquinoxaline (L), have been synthesized and characterized. The crystal structures of these complexes have been elucidated by X-ray diffraction analyses and three types of coordination modes for L were found to exist in them. In the dinuclear complex [Cu(I)L(CH3CN)]2·(ClO4)2 (1), L acts as a tridentate ligand with two Cu(I) centers bridged by two L ligands to form a box-like dimeric structure, in which each Cu(I) ion is penta-coordinated with three nitrogen atoms and a methoxyl oxygen atom of two L ligands, and an acetonitrile. In [Cu(II)L(NO3)2]·CH3CN 2, the Cu(II) center is coordinated to the two nitrogen atoms of the two pyridine rings of L which acts as a bidentate ligand. The structures of [Ni(II)L(NO3)(H2O)2]·2CH3CN·NO3 (3), [Zn(II)L(NO3)2 (H2O)]·2CH3CN (4) and [Co(II)LCl2(H2O)] (5) are similar to each other in which L acts as a tridentate ligand by using its half side, and the metal centers are coordinated to a methoxyl oxygen atom and two bipyridine nitrogen atoms of L in the same side. The formation of infinite quasi-one-dimensional chains (1, 4 and 5) or a quasi-two-dimensional sheet (2) assisted by the intra- or intermolecular face-to-face aryl stacking interactions and hydrogen bonds may have stabilized the crystals of these complexes. Luminescence studies showed that 1 exhibits broad, structureless emissions at 420 nm in the solid state and at 450 nm in frozen alcohol frozen glasses at 77 K. Cyclic voltammetric studies of 1 show the presence of an irreversible metal-centered reduction wave at approximately −0.973 V versus Fc+/0 and a quasi-reversible ligand-centered reduction couple at approximately −1.996 V versus Fc+/0. The solution behaviors of these complexes have been further studied by UV-Vis and ESR techniques.  相似文献   

6.
Two tellurium ligands 1-(4-methoxyphenyltelluro)-2-[3-(6-methyl-2-pyridyl)propoxy]ethane (L1) and 1-ethylthio-2-[2-thienyltelluro]ethane (L2) have been synthesized by reacting nucleophiles [4-MeO-C6H4Te] and [C4H3S-2-Te] with 2-[3-(6-methyl-2-pyridyl)propoxy]ethylchloride and chloroethyl ethyl sulfide, respectively. Both the ligands react with HgBr2 resulting in complexes of stoichiometry [HgBr2 · L1/L2] (1/4), which show characteristic NMR (1H and 13C{1H}). On crystallization of 1 from acetone-hexane (2:1) mixture, the cleavage of L1 occurs resulting in 4-MeOC6H4HgBr (2) and [RTe+→HgBr2]Br (3) (where R = -CH2CH2OCH2CH2CH2-(2-(6-CH3-C5H3N))). The 2 is characterized by X-ray diffraction on its single crystal. It is a linear molecule and is the first such system which is fully characterized structurally. The Hg-C and Hg-Br bond lengths are 2.085(6) and2.4700(7) Å. The distance of four bromine atoms (3.4041(7)-3.546(7) Å) around Hg (cis to C) is greater than the sum of van der Waal’s radii 3.30 Å. This mercury promoted cleavage is observed for an acyclic ligand of RArTe type for the first time and is unique, as there appears to be no strong intramolecular interaction to stabilize the cleavage products. The 4 on crystallization shows the cleavage of organotellurium ligand L2 and formation of a unique complex [(EtS(CH2)2SEt)HgBr(μ-Br)Hg(Br)(μ-Br)2Hg(Br)(μ-Br)BrHg(EtS(CH2)2SEt)] · 2HgBr2 (5), which has been characterized by single crystal structure determination and 1H and 13C{1H} NMR spectra. The elemental tellurium and [C4H3SCH2]2 are the other products of dissociation as identified by NMR (proton and carbon-13). The cleavage appears to be without any transmetalation and probably first of its kind. The centrosymmetric structure of 5 is unique as it has [HgBr3] unit, one Hg in distorted tetrahedral geometry and one in pseudo-trigonal bipyramidal one. The molecule of 5 may also be described as having [(EtSCH2CH2SEt)HgBr]+ [HgBr3] units, which dimerize and co-crystallize with two HgBr2 moieties. There are very weak Hg?Br interactions between co-crystallized HgBr2 units and rest of the molecule. [Hg(3)-Br(1)/Hg(3)-Br(4) = 3.148(1)/3.216(1) Å]. The bridging Hg?Br distances, Hg(2)-Br(4)′, Hg(2)′-Br(4) and Hg(1)-Br(2), are from 2.914(1) to 3.008(1) Å.  相似文献   

7.
Two new lead(II) nitrate coordination polymers from ligand 1,2-di-(4-pyridyl)-ethylene (bpe), [Pb2(μ-bpe)3(μ-NO3)2(NO3)2]n (1) and {[Pb(μ-bpe)(μ-NO3)2(NO3)(H2O)]·(Hbpe)·0.5(bpe)}n (2), were synthesized. The compounds 1 and 2 were characterized by IR spectroscopy, elemental analyses and X-ray crystallography. The structures of 1 and 2 may be considered coordination polymers of lead(II) consisting of metallocyclic chains formed by bridging bpe ligands, making two- and one-dimensional array of Pb(NO3)2 and bpe, respectively. Pure phase PbO nano-particles were obtained by thermolyses of compounds 1-2 in oleic acid as surfactant at 180 and 200 °C under air atmosphere. The PbO nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).  相似文献   

8.
Polydentate nitrogen heterocycle ligand 2,3-bis(2-pyridyl)pyrazine (2,3-dpp) reacted with M(NO3)x (M = Ag, x = 1; M = Cd, x = 2) to give two new complexes [Ag(2,3-dpp)(NO3)]2 (1) and [Cd(2,3-dpp)(NO3)2]n (2). Both complexes have been characterized by single-crystal X-ray diffraction, elemental analyses, IR and 1H NMR spectroscopy. Single-crystal X-ray analyses showed that complex 1 crystallized in monoclinic, space group P21/n is a dimmer containing penta-coordinated Ag+ ion. While compound 2 has 1D chain-like structure with repeat unit Cd(2,3-dpp)(NO3)2, in which the Cd(II) presents octa-coordinated N4O4 donor set with two four-membered chelating rings and two five-membered chelating rings around Cd(II) ion. Meanwhile, every neutral chain [Cd(2,3-dpp)(NO3)2]n is mutually connected by face-to-face π?π packing interactions to form a two dimensional layer. Furthermore, antibacterial activities of compound 1 and luminescent property of the compound 2 are also investigated.  相似文献   

9.
The crystalline compounds [LnCl2(L)(thf)2] [Ln = Ce (1), Tb (2), Yb (3)], [NdI2(L)(thf)2] (4), [LnCl(L′)2] [Ln = Tb (5), Yb (6) (a known compound)] and [YbCl(L′′)(μ-Cl)2Li(OEt2)2] (7) have been prepared [L = {N(C6H3Pri2-2,6)C(H)}2CPh, L′ = {N(SiMe3)C(Ph)}2CH, L′′ = {N(SiMe3)C(C6H4Ph-4)}2CH]. The X-ray molecular structures of 2-7 have been established; in each, the monoanionic ligand L, L′ or L′′ is N,N′-chelating and essentially π-delocalised. Each of 1-7 was prepared from the appropriate LnCl3, or for 4 [NdI3(thf)2], and an equivalent portion of the appropriate alkali metal [Li for 7, Na for 2, 3 and 5, or K for 1, 4 and 6] β-diiminate in thf; the isolation of exclusively 5 and 6 (rather than the L′ analogues of 2 or 3) is noteworthy, as is the structure of 7 which has no precedent in Group 3 or 4f metal β-diiminato chemistry.  相似文献   

10.
The synthesis, structure and characterization of the dinuclear Mn(II) complex [Mn2(LO)(μ-OAc)2](ClO4) (1) where LOH = 2,6-bis{bis(2-(2-pyridyl)ethyl)aminomethyl)}-4-methylphenol are reported. The reaction of Mn(ClO4)2 · 6H2O with the dinucleating ligand LOH and H3CCOONa in the presence of NEt3 in dry, degassed methanol and under an argon atmosphere, yields 1 as a colorless powder. The crystal structure of 1, determined by X-ray diffraction methods, shows a dinuclear Mn(II) complex in which two Mn(II) ions, each in six-coordinate approximate octahedral coordination, are bridged by the phenolate oxygen of LO and by two acetate ions in a syn,syn-1,3-bridging mode. The Mn-Mn distance is 3.557(1) Å and Mn-Ophenolate-Mn angle is 112.50(9)°. Cyclic voltammetry of 1 in acetonitrile solution shows a quasi-reversible wave at E1/2 = 0.65 V, for the Mn2(II,II)/Mn2(II,III) redox process, and an irreversible oxidation peak at Ep,c = 1.22 V versus Ag/AgCl for the Mn2(II,III) to Mn2(III,III) oxidation process. Controlled potential electrolysis of 1 in acetonitrile solution at 0.85 V (versus Ag/AgCl) takes up 1 F of charge per mole of 1 to yield a brown solution of the Mn2(II,III) state of the complex, which, however, is unstable and reverts back to the Mn2(II,II) state in solution at room temperature. Least square fitting of the variable temperature magnetic susceptibility measurements on powdered sample of 1 is obtained with g = 1.888, J = −2.75 cm−1, Par = 0.008, TIP = 0. The low −J value and the room temperature calculated magnetic moment of the complex (5.30 BM per Mn(II)), which is less than the spin-only moment of Mn(II), show that the two Mn(II) ions are weakly antiferromagnetically coupled.  相似文献   

11.
Three coordination complexes of formula [Ni(L1)2(H2O)4].4H2O (1), [Mn(L2)2(H2O)4] (2) and [Mn(L2)2(H2O)2]n (3) [L1H = 6-methylpyridine-3-carboxylic acid, L2H = 3-(3-pyridyl)acrylic acid] have been synthesized and structurally characterized by X-ray single crystal analysis. A 3D network is achieved through H-bonding in 1 and 2, while crystal packing of complex 3 shows a 3D supramolecular coordination polymer. Thermal properties have been investigated by thermogravimetric analysis. Luminescence study features the presence of LMCT and metal purterbed ligand centered emission bands.  相似文献   

12.
The reaction of AgX with the diphosphazane ligand, PriN(PPh2)2 (L) gives the polymeric complexes, [Ag2(μ-X)2(μ-L)]n (X = NO31a or OSO2CF31b). Single crystal X-ray analysis of 1a reveals a novel structural motif formed by interlinking of giant 40-membered rings; the diphosphazane ligand L adopts a unique ‘Cs’ geometry. These polymeric complexes exhibit a completely reversible ring-opening polymerization-depolymerization relationship with the dinuclear and mononuclear complexes, [{Ag(μ-L)(X)}2] (X = NO32a, X = OSO2CF32b) and [Ag(κ2-L)2]X (X = NO33a, X = OSO2CF33b).  相似文献   

13.
The complexes [Cu(DPS)(H2O)Cl2] · H2O (1a) and [{Cu(DPS)Cl}2μ-(Cl)2] (1b) where DPS = Di(2-pyridyl)sulfide have been synthesized and characterized using elemental analysis, thermal analysis (TG/DSC), vibrational and electronic spectroscopies as well as electron paramagnetic resonance (EPR). Additionally, the crystal and molecular structures of both compounds have been determined by X-ray diffraction techniques.  相似文献   

14.
Synthesis and single crystal X-ray structures of H2L1 and VO(L1)(HL) [H2L1 = N,N-bis(2-hydroxy-3,5-ditertiarybutyl)-N′,N′-dimethylethylendiamine) or simply aminebis(phenol) and H2L = salicylic acid) are reported here. The complex [VO(L1)(HL)] is in distorted octahedral geometry under O4N2 donor environment where the basal core is defined by O(1), O(3), O(2) and N(5) atoms and two axial coordinates are occupied by O(4), an alkoxo-group and N(1), an imino-nitrogen atom. The electron spray mass spectrometric study on [VO(L1)(HL)] in MeCN clearly points out the existence of single species in solution. Again, the 51V NMR of the bulk polycrystalline sample reveals that the complex [VO(L1)(HL)] mainly exists in three out of four possible isomers. The formation of [VO(L1)(HL)] from both [VO(L1)(OMe)] and [VO(L1)(OEt)] was followed kinetically by reacting with salicylic acid in MeCN. The presence of isosbestic point indicates a clean conversion of the reactants to product.  相似文献   

15.
The reaction of MCl2 · 2H2O (M = Cu, Zn) with 2,3,5,6-tetra(2-pyridyl)pyrazine (tppz) (referred hereafter as L) in 2:1 molar ratio in acetonitrile at room temperature afforded binuclear complexes [M23-L)Cl4] [Cu (1), Zn (2)] where the ligand is bis-tridentate manner. The complexes have been characterized by elemental analyses, FAB-MS, IR, EPR, NMR and electronic spectral studies. Solid state structures of both the [Cu23-L)Cl4] · 5H2O (1), [Zn23-L)Cl4] · H2O (2) have been determined by single crystal X-ray analyses. A well-resolved uudd cyclic water tetramer and water monomer were reported in the crystal host of [Cu23-L)Cl4] · 5H2O (1) and [Zn23-L)Cl4] · H2O (2) showing the contribution of the water cluster to the stability of the crystal host 1 and 2.  相似文献   

16.
A new pyridyl-carboxylate ligand, the anion of trans-4-cotininecarboxylic acid, HL, 1, has been used to prepare a new polymeric copper(II) complex, [CuLN3]2n, 2, based on a [CuLN3]2 dimeric building block. The single crystal structures of both 1 and 2 have been determined and 1 has been found to be in its zwitterionic configuration. The structure of 2 is a one-dimensional tape-like polymeric structure based on an end-on azido-bridged binuclear [Cu2N3]2 backbone moiety. Magnetic studies reveal that 2 is close to paramagnetic from 2 to 300 K with a Curie constant of 1.094 emu K/mol, a Weiss temperature of 0.73 K and a corresponding μeff of 2.09 μB. A fit of χMT for 2 with S1 = S2 = ½, yields g = 2.441(6), J = −0.49(3) cm−1, zJ = −0.38(2) cm−1 and N(α) = 0.00053(12) emu/mol, a fit that indicates the presence of both very weak intramolecular intrachain antiferromagnetic exchange coupling within the one-dimensional tape-like chains and very weak interchain antiferromagnetic exchange coupling between these chains.  相似文献   

17.
The reaction of dioxygen with the copper(I) complex of the tridentate ligand 1,1,4,7,7-pentamethyldiethylenetriamine (Me5dien) has been investigated using low-temperature stopped-flow techniques. The formation of a bis(μ-oxo)copper(III) complex as a reactive intermediate could be detected spectroscopically at low temperatures and a quantitative kinetic analysis was performed for this system. Crystal structures of the copper(II) complexes [(Me-bpa)Cu(Cl)2] (1), [{(Me-bpa)Cu(Cl)(ClO4)}2] (2), [{(MeL)Cu(Cl)(ClO4)}2] (3), and [(MeL)Cu(NCS)2] (4) (Me-bpa = N-methyl-[bis(2-pyridyl)methyl]amine; MeL = N-methyl-[(2-pyridyl)ethyl(2-pyridyl)methyl]amine) are reported.  相似文献   

18.
In air, hydrated ethanolic (95%) solution of 2-(aminomethyl) substituted pyridine and quinoline, on stirring with half equivalent of Cu(OAc)2·H2O, respectively afforded [Cu(bpca)(OAc)(H2O)]·H2O (1) and [Cu(bqca)(OAc)(H2O)] (2) {bpca = bis(2-pyridylcarbonyl)diimide ion and bqca = bis(2-quinolylcarbonyl)diimide ion} in good yields. These reactions involve oxidation of the methylene group and formation of the bond between nitrogen and carbon in N-C(O) through coupling. The complex [Cu(pqca)(OAc)(H2O)]3[Cu2(OAc)4(EtOH)2]1.5 (3) {pqca = (2-pyridylcarbonyl)(2-quinolylcarbonyl)diimide ion} was synthesized by stirring an ethanolic solution of the Schiff base [(2-pyridyl)-N-((2-quinolyl)methylene)methanamine] (L1) and with one equivalent of Cu(OAc)2·H2O. A plausible mechanism for the conversion has been proposed. The free ligands were isolated as crystalline solids from compounds 1-3, by extrusion of Cu2+ ion using EDTA2−. The molecular structures of 1-3 and bqcaH were established by X-ray crystallography and compounds having quinolyl group have π-stacking interactions.  相似文献   

19.
Four new zinc(II) cyclams of the composition {Zn(L)(tp2−) · H2O}n (1), {Zn(L)(H2bta2−) · 2H2O}n (2), [Zn2(L)2(ox2−)] 2ClO4 · 2DMF (3), and Zn(L)(H2btc)2 · 2DMF (4), where L = cyclam, tp2− = 1,4-benzenedicarboxylate ion, H2bta2− = 1,2,4,5-benzenetetracarboxylate ion, ox2− = oxalate ion, DMF = N,N-dimethylformamide, and H2btc = 1,3,5-benzenetricarboxylate ion, have been synthesized and structurally characterized by a combination of analytical, spectroscopic and crystallographic methods. The carboxylato ligands in the complexes 1-4 show strong coordination tendencies toward zinc(II) cyclams with hydrogen bonding interactions between the pre-organized N-H groups of the macrocycle and oxygen atoms of the carboxylato ligands. The macrocycles in 1, 2, and 4 adopt trans-III configurations with the appropriate R,R,S,S arrangement of the four chiral nitrogen centers, respectively. However, the complex 3 shows an unusual cis V conformation with the R,R,R,R nitrogen configuration. The finding of strong interactions between the carboxylato ligands and the zinc(II) ions may provide additional knowledge for the improved design of receptor-targeted zinc(II) cyclams in anti-HIV agents.  相似文献   

20.
Six copper(I) complexes {[Cu2(L1)(PPh3)2I2] · 2CH2Cl2}n (1), {[Cu2(L2)(PPh3)2]BF4}n (2), [Cu2(L3)(PPh3)4I2] · 2CH2Cl2 (3), [Cu2(L4)(PPh3)4I2] (4), [Cu2(L5)(PPh3)2I2] (5) and [Cu2(L6)(PPh3)2I2] (6) have been prepared by reactions of bis(schiff base) ligands: pyridine-4-carbaldehyde azine (L1), 1,2-bis(4′-pyridylmethyleneamino)ethane (L2), pyridine-3-carbaldehyde azine (L3), 1,2-bis(3′-pyridylmethyleneamino)ethane (L4), pyridine-2-carbaldehyde azine (L5), 1,2-bis(2′-pyridylmethyleneamino)ethane (L6) with PPh3 and copper(I) salt, respectively. Ligand L1 or L2 links (PPh3)2Cu2(μ-I)2 units to form an infinite coordination polymer chain. Ligand 3 or 4 acts as a monodentate ligand to coordinate two copper(I) atoms yielding a dimer. Ligand 5 or 6 chelates two copper(I) atoms using pyridyl nitrogen and imine nitrogen to form a dimer. Complexes 1-4 exhibit photoluminescence in the solid state at room temperature. The emission has been attributed to be intraligand π-π* transition mixed with MLCT characters.  相似文献   

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