The title compound [Cu(HSSA)(py)3H2O]n (H3SSA = 5-sulfosalicylic acid, py = pyridine) I has been synthesized and structurally determined by single-crystal X-ray diffraction. I was further characterized by elemen...The title compound [Cu(HSSA)(py)3H2O]n (H3SSA = 5-sulfosalicylic acid, py = pyridine) I has been synthesized and structurally determined by single-crystal X-ray diffraction. I was further characterized by elemental analyses, thermogravimetric analyses, IR and UV-visible spectroscopy. The crystal belongs to the monoclinic system, space group P21/c with a = 9.4564(10), b = 18.2679(19), c = 15.7284(12) A,β= 126.045(4)°, V= 2196.9(4)A^3, Z= 4, Dc = 1.618 g/cm^3, Mr = 535.02,μ = 1.141 mm^-1, F(000) = 1100, 2(MoKα) = 0.71073 A, the final R = 0.0429 and wR = 0.1044 for all observed reflections. In the structure, every two Cu(II) atoms are bridged by a bivalent 5-sulfosalicylic anion to form a 1D chain-like coordination polymer. Lattice waters between chains link them to form 2D layers which are further linked by C-H…O hydrogen bonds to form a three-dimensional supramolecular network.展开更多
Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclin...Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclinic, space group C2/c, with a = 24.144(5), b = 7.1622(14), c = 17.283(4) ?, C16H24Cu2N4O12, Mr = 591.47, β = 131.73(3)o, V = 2230.3(8) ?3, Z = 4, Dc = 1.761 g/cm3, F(000) = 1208, μ = 1.978 mm?1, R = 0.0400 and wR = 0.1099. The copper (II) ion is five- coordinated with a distorted square pyramidal geometry. The complex can be viewed as a one- dimensional chain structure by carboxylic bridges among copper atoms. In the complex there exist hydrogen bonding interactions to stabilize the structure.展开更多
A mononuclear copper(II) complex CuL with a Schiff-base L (H2L = N,N(- cyclohexanebis(3-formyl-5-tert-butyl-salicylaldimine)) has been synthesized and characterized. X-ray diffraction analysis at room temperature indi...A mononuclear copper(II) complex CuL with a Schiff-base L (H2L = N,N(- cyclohexanebis(3-formyl-5-tert-butyl-salicylaldimine)) has been synthesized and characterized. X-ray diffraction analysis at room temperature indicates that the complex (Cu C30H36N2O4, Mr = 552.15) crystallizes in tetrahedral system, space group P41 with a = 13.4685(6), c = 31.326(2) ?, V = 5682.5(5) ?3, Z = 8, Dc = 1.291 g/cm3, F(000) = 4656, μ(MoK() = 0.805 mm-1. The final R and Rw factors are 0.0421 and 0.0815, respectively with 4435 observed reflections. The title complex is a neutral molecule in which the ligand is doubly deprotonated, forming a four-coordinated Cu(II) complex by nitrogen and oxygen donors of the ligand and the coordination geometry of Cu(II) could be considered as an approximately planar configuration. There are two independent molecules, having a transoid arrangement in this structure.展开更多
The title complex [CuL3](ClO4)2·2H2O·2CH3CN (L = 1,10-phenanthroline-5,6-dione) has been synthesized and characterized by elemental analysis, conductivity, infrared and UV-Vis spectra. X-ray diffraction ...The title complex [CuL3](ClO4)2·2H2O·2CH3CN (L = 1,10-phenanthroline-5,6-dione) has been synthesized and characterized by elemental analysis, conductivity, infrared and UV-Vis spectra. X-ray diffraction analysis at room temperature indicates that the complex (C40H28Cl2CuN8O16, Mr = 1011.14) crystallizes in orthorhombic system, space group P212121 with a=13.983(1), b=14.310(1), c= 20\^890(2) , V = 4179.7(6) 3, Z = 4, Dc = 1.607 g/cm3, F(000) = 2026,μ(MoKα) = 0.736 mm-1. The final R and wR factors are 0.0446 and 0.1212 respectively with 8545 independent reflections. The title complex is composed of a discrete [CuL3]2+ cation, uncoordinated ClO4- anions, H2O and CH3CN molecules. The central Cu(II) atom is six-coordinated by six nitrogen donors of three ligands. The coordination geometry of Cu(II) could be considered as an approximately ideal octahedral configuration with little static Jahn-Teller distortion (the longest and shortest Cu-N bonds are 2.102 vs 2.139 with the mean length of 2.122 ), which is very rare for a six-coordinated Cu(II) complex.展开更多
The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H1...The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?展开更多
A new copper complex 2{Cu(C10H8N2)[C8H11O2(COO)](H2O)3}·(H2O)5 with bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid(H2L) [C7H8(COOH)2], basic copper carbonate and 2,2'-bipyridine has been synthesized i...A new copper complex 2{Cu(C10H8N2)[C8H11O2(COO)](H2O)3}·(H2O)5 with bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid(H2L) [C7H8(COOH)2], basic copper carbonate and 2,2'-bipyridine has been synthesized in the mixed solvents of methanol and water. It crystallizes in the triclinic system, space group P1, with a = 7.4626(5), b = 11.9779(8), c = 12.9841(8)A, α = 109.7040(10), β = 98.7550(10), γ = 90.6240(10)°, V = 1077.50(12)A3, Dc = 1.538 g/cm^3, Z = 1, F(000) = 520, GOOF = 1.065, R = 0.0360 and wR = 0.0950. The copper ion is coordinated with four oxygen atoms from one H2 L molecule and three water molecules together with two nitrogen atoms from the 2,2'-bipyridine molecule, forming a distorted octahedral coordination geometry. The thermal stability and electrochemical properties were also studied.展开更多
A new complex [Cu2(sala)2(H20)2(4,4'-bipy)]'H20 (sala = N-(2-hydroxybenzyl)- D,L-alaninate, 4,4'-bipy = 4,4'-bipyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy, the...A new complex [Cu2(sala)2(H20)2(4,4'-bipy)]'H20 (sala = N-(2-hydroxybenzyl)- D,L-alaninate, 4,4'-bipy = 4,4'-bipyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. The complex crystallizes in monoclinic system, space group C2/c with a = 42.44(3), b = 10.416(8), c = 15.487(13) ./k, fl = 97.455(14)°, C30H36Cu2N4O9, Mr = 723.71, V = 6789(9) A3, Dc = 1.416 g/cm3, Z = 8, F(000) = 2992, μ(MoKa) = 1.308 mm-1, R = 0.0493 and wR = 0.1004 for 4878 observed reflections (I 〉 2σ(I)). Structural analysis shows that each copper(II) atom displays a distorted square-based pyramidal coordination geometry with two oxygen atoms and one nitrogen atom from one N-(2-hydroxybenzyl)-D,L-alaninate, one nitrogen atom from 4,4'-bipyridine ligand and one water molecule. 4,4'-Bipyridine ligand bridges two Cu(II) ions to form a dinuclear compound. The molecular structure is extended into a one-dimensional wavy chain through hydrogen bonds. These 1D chains are further expanded into 2D networks through hydrogen bonds.展开更多
The complex [Cu(phen)2py](ClO4)2 was obtained by the reaction of 1,10-phenanthroline with Cu(ClO4)2·6H2O in water and by recrystallization from pyridine. A single-crystal X-ray study shows that the complex is a ...The complex [Cu(phen)2py](ClO4)2 was obtained by the reaction of 1,10-phenanthroline with Cu(ClO4)2·6H2O in water and by recrystallization from pyridine. A single-crystal X-ray study shows that the complex is a square pyramidal arrangement of five nitrogen atoms from the two 1,10-phenanthroline ligands and one pyridine ligand, respectively. The compound is orthorhombic, C29H21N5Cl2O8Cu, Mr = 701.958, with space group Pbcn, a = 29.9593(3), b = 16.1240(3), c = 11.9183(6) ?, V = 5757.3(3) ?3, Z = 8, Dc = 1.409g/cm3, μ =1.121 mm-1, F(000) = 2465, R = 0.0539, Rw = 0.1380 for 4293 reflections with I >2σ(I). The bond lengths of Cu(1)-N(1), Cu(1)-N(2), Cu(1)-N(3) and Cu(1)-N(4) are 2.223(3), 2.017(3), 2.013(3) and 2.038(3) ?, respectively. The distance from copper to pyridine N(5) is 2.012(3) ?. The angles N(2)-Cu(1)-N(3) and N(4)-Cu(1)-N(5) are 176.1(1) ° and 160.9(1)°, respectively. The angles between axial position nitrogen atom N (1) and four square position nitrogen atoms N(2), N(3), N(4), N(5) are 79.3(1), 98.3(1), 90.7(1), 108.4(1)°, respectively.展开更多
The complex [Cu2L2(Py)2] (H2L=2-aminobenzoic alcohol condensation salicylaldehyde) was obtained. A single-crystal X-ray study shows that the complex is a binuclear compound (Cu2C38H32N4O4). The coordination geometry a...The complex [Cu2L2(Py)2] (H2L=2-aminobenzoic alcohol condensation salicylaldehyde) was obtained. A single-crystal X-ray study shows that the complex is a binuclear compound (Cu2C38H32N4O4). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2L2(Py)2] belongs to monoclinic system with space group P21, lattice constants: a = 10.3881(1), b = 17.9724(1), c = 17.5800(2) ? b =90.4880(1), V= 3282.05(5) 3, Z= 4, Mr =735.75, Dc=1.489 g/cm3, m= 1.344mm-1, F(000) = 1512, R=0.0519, wR=0.1092 for 6725 reflections with I >2s(I). The distances between Cu(II) and O atoms are range from 1.898(6) to1.976(5)? between Cu(II) and N atoms are range from 1.990(6) to 2.369(7)? The Cu(1)Cu(2) bond length is 3.024(4) ?展开更多
The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.6...The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.展开更多
A new chain-like coordination polymer, namely, [CuL]n (1, Na2L = 2-[(2-hydroxy- benzylidene)-amino]-benzenesulfonic acid sodium salt), has been synthesized and characterized by single-crystal X-ray diffraction, IR...A new chain-like coordination polymer, namely, [CuL]n (1, Na2L = 2-[(2-hydroxy- benzylidene)-amino]-benzenesulfonic acid sodium salt), has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 9.2296(16), b = 10.4754(18), c = 12.200(2) A, β = 102.392(2)°, V = 1152.0(3)A3, CI3H9CuNOaN, Mr = 338.83, Dc = 1.953 g/cm3, Z = 4, F(000) = 684, p = 2.089 mm-1, the final R = 0.0376 and wR = 0.0956. X-ray diffraction analyses indicate that 1 displays a square-pyramidal metal center with NO4 donor sets. The sulfonate-derived Schiff base serves as a common N,O,O'-tridentate and a unique O-bridged ligand connecting the metals. Dinuclear copper complexes serve as secondary building blocks (SBUs) to construct an unusual 2D coordination network. In the crystal, the components form a stable 3D supramolecular architecture by C-H...O interactions and to-stacking展开更多
A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic...A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.展开更多
The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2?-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was det...The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2?-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was determined by single-crystal X-ray diffraction method. It crys- tallizes in triclinic, space group P1, C44H31ClCu2N4O12, Mr = 970.26, a = 8.175(2), b = 16.254(4), c = 16.946(4) ?, α = 62.966(6), β = 84.833(8), γ = 84.348(8)°, V = 1993.4(8) ?3, Z = 2, Dc = 1.616 g/cm3, F(000) = 988 and μ = 1.207 mm-1. The final R = 0.0429 and wR = 0.0843 for 5682 observed reflections with I > 2σ(I). Each copper(II) atom displays a distorted square-pyramidal geometry with two nitrogen atoms of one chelate 2,2?-bipy molecule, two oxygen atoms from two different bridging carboxylate groups of Hpht- and one bridging chloride atom occupying the apical position. The two copper(II) atoms are connected by a μ2-Cl atom and two bridging Hpht- ligands in a syn-syn coordination mode to form an isolated dinuclear unit. The molecular structure is extended to a one-dimensional wavy chain through hydrogen bonds. The title complex exhibits blue fluorescent emission at 443 nm (λex = 372 nm) in the solid state at room temperature.展开更多
A planar transition metal complex Cu(L)2 (L = (E)-benzyl-2-(4-nitrobenzylidene)-hydrazinecarbodithioate) has been prepared and determined by X-ray single-crystal diffraction. The crystal belongs to the monocli...A planar transition metal complex Cu(L)2 (L = (E)-benzyl-2-(4-nitrobenzylidene)-hydrazinecarbodithioate) has been prepared and determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system,space group P21/c with a = 6.7101(11),b = 16.952(3),c = 13.962(3) ,β = 92.458(4)°,V = 1586.7(5) 3,Z = 4,Mr = 724.33,Dc = 1.516 g·m-3,μ = 0.998 mm-1,F(000) = 742,S = 1.021,R = 0.0634 and wR = 0.1077 for 813 observed reflections with Ⅰ〉 2σ(Ⅰ) and 205 parameters. In the molecular structure of the title complex,the copper atom exhibits a slightly distorted square-planar geometry in which the basal plane is defined by two N and two S atoms from two bidentate ligands. The complex was evaluated for its antitumor activity against two kinds of cell lines (MKN45 and HepG2) by MTT method. The preliminary bioassay indicates that the complex exhibits weak antitumor activity.展开更多
A new copper(II) complex Cu2(L)a(2,2'-bipy)2(H2O)2 (1) has been synthesized with 2-benzoylbenzoic acid (HL) and 2,2'-bipyridin as ligands. The crystal belongs to a monoclinic system with space group Cc, ...A new copper(II) complex Cu2(L)a(2,2'-bipy)2(H2O)2 (1) has been synthesized with 2-benzoylbenzoic acid (HL) and 2,2'-bipyridin as ligands. The crystal belongs to a monoclinic system with space group Cc, a = 13.9979(II), b = 15.9888(13), c = 30.306(3) A, β = 100.8700(10)°, V= 6661.1(10) A3, Dc= 1.372 g/cm3, Z = 8, F(000) = 2840, the final GOOF = 1.018, R= 0.0685, and wR= 0.1731. There are two mononuclear Cu(L)2(2,2'-bipy)(H20) units in the crystal of 1. Each Cu(II) cation is coordinated by five atoms. The magnetic and fluorescent properties of 1 were studied. The results show that 1 exhibits weak paramagnetism, and when the excitation wavelength is at 616 nm, it has an intense fluorescent emission band around 482 nm.展开更多
A lariat crown ether ligand 7,16-bis (2-hydroxy-5-methylbenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (L1) has been prepared via one-pot Mannich reaction. Its copper(II) complex Cu-L1 was synthesized and charac...A lariat crown ether ligand 7,16-bis (2-hydroxy-5-methylbenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (L1) has been prepared via one-pot Mannich reaction. Its copper(II) complex Cu-L1 was synthesized and charac-terized by elemental analysis, IR and UV-visible spectroscopy. The crystal structure of the complex has been deter-mined by X-ray diffraction analysis. The result shows that the copper(II) ion is six-coordinated by two nitrogen and four oxygen atoms, two from the crown ether and the other two from the deprotonated phenolate anions, forming an elongated octahedral complex. Electrochemical study indicates that the complex undergoes reversible reduction in DMF solution.展开更多
The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about e...The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2(apo)4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550(7), b = 8.5378(7), c = 12.082(1) ?, α = 72.807(1), β = 77.641(1), γ = 70.800(1)(, V =724.85(11) ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F(000) =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ(I). The distances between Cu(II) and O atoms are in the range from 1.934(2) to 2.042(2)?. The distance between two copper atoms Cu-Cu(A) is 3.2978(8) ?. The distances of Cu-Cl(1) and Cu-Cl(2) are 2.2322(9), 2.5095(10) ?, respectively. There is no evident hydrogen bond between N and Cl.展开更多
A p-tert-butylthiacalix[4]arene-based polydentated ligand with four Schiff base units on 1,3-alternate position at lower rim has been prepared in three steps,which coordinated to copper ion to form a novel dicopper co...A p-tert-butylthiacalix[4]arene-based polydentated ligand with four Schiff base units on 1,3-alternate position at lower rim has been prepared in three steps,which coordinated to copper ion to form a novel dicopper complex.The structures of the polydentated thiacalixarene ligand and copper complex were fully characterized by spectroscopy and X-ray single crystal diffraction method.展开更多
A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra s...A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measure- ment, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallo- graphic data: a -- 12.4537(4)/~, b = 9.3897(5) A, c = 30.1264(10) A, and Z = 8. In the crystal structure, the octahedral coordi- nated copper(II) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu'"Cu separation of 6.1719/~, along with phen ligands attached to both sides of the chain altematively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evalua- tion of the cytotoxic activity of the copper(II) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.展开更多
The title complex [Cu(BBA)(NO3)](NO3)2(BBA = [2-(benzotriazol-1-yl)ethyl][2(benzotriazol-2-yl)ethyl] amine) has been synthesized and structurally characterized.Its crystallizes in triclinic,space group P1 ...The title complex [Cu(BBA)(NO3)](NO3)2(BBA = [2-(benzotriazol-1-yl)ethyl][2(benzotriazol-2-yl)ethyl] amine) has been synthesized and structurally characterized.Its crystallizes in triclinic,space group P1 with a = 10.003(3),b = 11.399(3),c = 18.186(5),α = 77.184(4),β = 88.573(5),γ = 72.306(5)o,V = 1924.4(9)3,Z = 2,F(000) = 894,Dc = 1.493 Mg/m3,Mr = 865.31,μ = 0.644 mm-1,the final R = 0.0733 and wR = 0.1722 for 4349 observed reflections with I 2σ(I).Its polyphenol oxidase(PPO) mimic activity was studied spectroscopically by using pyrogallol as the substrate.The results showed that the kinetics of pyrogallol catalyzed by the complex obeyed the Michaelis-Mentent equation,showing that the PPO catalytic activity of the complex increased with increasing the reaction temperature and pH values.展开更多
基金supported by the Project for Innovation Team of Liaoning Province (No. 2007T052)Liaoning Provincial Key Laboratory (No. 2008S104)Startup Project of Doctor of Liaoning University
文摘The title compound [Cu(HSSA)(py)3H2O]n (H3SSA = 5-sulfosalicylic acid, py = pyridine) I has been synthesized and structurally determined by single-crystal X-ray diffraction. I was further characterized by elemental analyses, thermogravimetric analyses, IR and UV-visible spectroscopy. The crystal belongs to the monoclinic system, space group P21/c with a = 9.4564(10), b = 18.2679(19), c = 15.7284(12) A,β= 126.045(4)°, V= 2196.9(4)A^3, Z= 4, Dc = 1.618 g/cm^3, Mr = 535.02,μ = 1.141 mm^-1, F(000) = 1100, 2(MoKα) = 0.71073 A, the final R = 0.0429 and wR = 0.1044 for all observed reflections. In the structure, every two Cu(II) atoms are bridged by a bivalent 5-sulfosalicylic anion to form a 1D chain-like coordination polymer. Lattice waters between chains link them to form 2D layers which are further linked by C-H…O hydrogen bonds to form a three-dimensional supramolecular network.
文摘Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclinic, space group C2/c, with a = 24.144(5), b = 7.1622(14), c = 17.283(4) ?, C16H24Cu2N4O12, Mr = 591.47, β = 131.73(3)o, V = 2230.3(8) ?3, Z = 4, Dc = 1.761 g/cm3, F(000) = 1208, μ = 1.978 mm?1, R = 0.0400 and wR = 0.1099. The copper (II) ion is five- coordinated with a distorted square pyramidal geometry. The complex can be viewed as a one- dimensional chain structure by carboxylic bridges among copper atoms. In the complex there exist hydrogen bonding interactions to stabilize the structure.
基金the National Natural Science Foundation of China (No. 29871018) and the foundation of Open Laboratory for Chiral Technology of H
文摘A mononuclear copper(II) complex CuL with a Schiff-base L (H2L = N,N(- cyclohexanebis(3-formyl-5-tert-butyl-salicylaldimine)) has been synthesized and characterized. X-ray diffraction analysis at room temperature indicates that the complex (Cu C30H36N2O4, Mr = 552.15) crystallizes in tetrahedral system, space group P41 with a = 13.4685(6), c = 31.326(2) ?, V = 5682.5(5) ?3, Z = 8, Dc = 1.291 g/cm3, F(000) = 4656, μ(MoK() = 0.805 mm-1. The final R and Rw factors are 0.0421 and 0.0815, respectively with 4435 observed reflections. The title complex is a neutral molecule in which the ligand is doubly deprotonated, forming a four-coordinated Cu(II) complex by nitrogen and oxygen donors of the ligand and the coordination geometry of Cu(II) could be considered as an approximately planar configuration. There are two independent molecules, having a transoid arrangement in this structure.
基金ThisworkwasfinanciallysupportedbytheNationalNaturalScienceFoundationofChina (No .2 97710 2 2and 2 99710 19)andtheTrans Century
文摘The title complex [CuL3](ClO4)2·2H2O·2CH3CN (L = 1,10-phenanthroline-5,6-dione) has been synthesized and characterized by elemental analysis, conductivity, infrared and UV-Vis spectra. X-ray diffraction analysis at room temperature indicates that the complex (C40H28Cl2CuN8O16, Mr = 1011.14) crystallizes in orthorhombic system, space group P212121 with a=13.983(1), b=14.310(1), c= 20\^890(2) , V = 4179.7(6) 3, Z = 4, Dc = 1.607 g/cm3, F(000) = 2026,μ(MoKα) = 0.736 mm-1. The final R and wR factors are 0.0446 and 0.1212 respectively with 8545 independent reflections. The title complex is composed of a discrete [CuL3]2+ cation, uncoordinated ClO4- anions, H2O and CH3CN molecules. The central Cu(II) atom is six-coordinated by six nitrogen donors of three ligands. The coordination geometry of Cu(II) could be considered as an approximately ideal octahedral configuration with little static Jahn-Teller distortion (the longest and shortest Cu-N bonds are 2.102 vs 2.139 with the mean length of 2.122 ), which is very rare for a six-coordinated Cu(II) complex.
基金This work was supported by the foundation of Natural Science Research of Jiangsu Education Department (02KJB150007)
文摘The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?
基金Supported by the Natural Science Foundation of Hunan Province(No.11JJ9006)Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)the Construct Program of the Key Discipline in Hunan Province
文摘A new copper complex 2{Cu(C10H8N2)[C8H11O2(COO)](H2O)3}·(H2O)5 with bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid(H2L) [C7H8(COOH)2], basic copper carbonate and 2,2'-bipyridine has been synthesized in the mixed solvents of methanol and water. It crystallizes in the triclinic system, space group P1, with a = 7.4626(5), b = 11.9779(8), c = 12.9841(8)A, α = 109.7040(10), β = 98.7550(10), γ = 90.6240(10)°, V = 1077.50(12)A3, Dc = 1.538 g/cm^3, Z = 1, F(000) = 520, GOOF = 1.065, R = 0.0360 and wR = 0.0950. The copper ion is coordinated with four oxygen atoms from one H2 L molecule and three water molecules together with two nitrogen atoms from the 2,2'-bipyridine molecule, forming a distorted octahedral coordination geometry. The thermal stability and electrochemical properties were also studied.
基金supported by the Science and Technology Research Project of Key Laboratory of Higher Institutions of Jiangxi Province(No.GJJ10732)the Science and Technology Research Projects of the Education Department of Jiangxi Province(No.GJJ10608)+1 种基金the Research Fund of Shangrao Normal University(No.0807)Fourth point of Specialty Construction College of Education Ministry(No.TS11524)
文摘A new complex [Cu2(sala)2(H20)2(4,4'-bipy)]'H20 (sala = N-(2-hydroxybenzyl)- D,L-alaninate, 4,4'-bipy = 4,4'-bipyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. The complex crystallizes in monoclinic system, space group C2/c with a = 42.44(3), b = 10.416(8), c = 15.487(13) ./k, fl = 97.455(14)°, C30H36Cu2N4O9, Mr = 723.71, V = 6789(9) A3, Dc = 1.416 g/cm3, Z = 8, F(000) = 2992, μ(MoKa) = 1.308 mm-1, R = 0.0493 and wR = 0.1004 for 4878 observed reflections (I 〉 2σ(I)). Structural analysis shows that each copper(II) atom displays a distorted square-based pyramidal coordination geometry with two oxygen atoms and one nitrogen atom from one N-(2-hydroxybenzyl)-D,L-alaninate, one nitrogen atom from 4,4'-bipyridine ligand and one water molecule. 4,4'-Bipyridine ligand bridges two Cu(II) ions to form a dinuclear compound. The molecular structure is extended into a one-dimensional wavy chain through hydrogen bonds. These 1D chains are further expanded into 2D networks through hydrogen bonds.
文摘The complex [Cu(phen)2py](ClO4)2 was obtained by the reaction of 1,10-phenanthroline with Cu(ClO4)2·6H2O in water and by recrystallization from pyridine. A single-crystal X-ray study shows that the complex is a square pyramidal arrangement of five nitrogen atoms from the two 1,10-phenanthroline ligands and one pyridine ligand, respectively. The compound is orthorhombic, C29H21N5Cl2O8Cu, Mr = 701.958, with space group Pbcn, a = 29.9593(3), b = 16.1240(3), c = 11.9183(6) ?, V = 5757.3(3) ?3, Z = 8, Dc = 1.409g/cm3, μ =1.121 mm-1, F(000) = 2465, R = 0.0539, Rw = 0.1380 for 4293 reflections with I >2σ(I). The bond lengths of Cu(1)-N(1), Cu(1)-N(2), Cu(1)-N(3) and Cu(1)-N(4) are 2.223(3), 2.017(3), 2.013(3) and 2.038(3) ?, respectively. The distance from copper to pyridine N(5) is 2.012(3) ?. The angles N(2)-Cu(1)-N(3) and N(4)-Cu(1)-N(5) are 176.1(1) ° and 160.9(1)°, respectively. The angles between axial position nitrogen atom N (1) and four square position nitrogen atoms N(2), N(3), N(4), N(5) are 79.3(1), 98.3(1), 90.7(1), 108.4(1)°, respectively.
文摘The complex [Cu2L2(Py)2] (H2L=2-aminobenzoic alcohol condensation salicylaldehyde) was obtained. A single-crystal X-ray study shows that the complex is a binuclear compound (Cu2C38H32N4O4). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2L2(Py)2] belongs to monoclinic system with space group P21, lattice constants: a = 10.3881(1), b = 17.9724(1), c = 17.5800(2) ? b =90.4880(1), V= 3282.05(5) 3, Z= 4, Mr =735.75, Dc=1.489 g/cm3, m= 1.344mm-1, F(000) = 1512, R=0.0519, wR=0.1092 for 6725 reflections with I >2s(I). The distances between Cu(II) and O atoms are range from 1.898(6) to1.976(5)? between Cu(II) and N atoms are range from 1.990(6) to 2.369(7)? The Cu(1)Cu(2) bond length is 3.024(4) ?
文摘The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.
基金Supported by Guangxi Provincial Department of Education(No.YB2014333)the Scientific research and technological development project of Guilin(No.20110330)+2 种基金the Project of Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University)Ministry of Education of China(CMEMR2011-13)Key Subjects of Universities in Guangxi Province Applied Chemistry(2007<20>)
文摘A new chain-like coordination polymer, namely, [CuL]n (1, Na2L = 2-[(2-hydroxy- benzylidene)-amino]-benzenesulfonic acid sodium salt), has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 9.2296(16), b = 10.4754(18), c = 12.200(2) A, β = 102.392(2)°, V = 1152.0(3)A3, CI3H9CuNOaN, Mr = 338.83, Dc = 1.953 g/cm3, Z = 4, F(000) = 684, p = 2.089 mm-1, the final R = 0.0376 and wR = 0.0956. X-ray diffraction analyses indicate that 1 displays a square-pyramidal metal center with NO4 donor sets. The sulfonate-derived Schiff base serves as a common N,O,O'-tridentate and a unique O-bridged ligand connecting the metals. Dinuclear copper complexes serve as secondary building blocks (SBUs) to construct an unusual 2D coordination network. In the crystal, the components form a stable 3D supramolecular architecture by C-H...O interactions and to-stacking
基金Supported by the Natural Science Foundation of Hunan Province (No. 11JJ9006)Key Project of Science and Technology Plan of Hunan Province (2012FJ2002)+1 种基金Science and Technology Plan of Hunan Province (2012GK3031, 2012WK3029)the Construct Program of Key Discipline in Hunan Province
文摘A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.
基金This work was supported by the National Natural Science Foundation of China (20001007 20131020)+1 种基金and Natural Science Foundation of Fujian Province (2003I031 A0420002)
文摘The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2?-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was determined by single-crystal X-ray diffraction method. It crys- tallizes in triclinic, space group P1, C44H31ClCu2N4O12, Mr = 970.26, a = 8.175(2), b = 16.254(4), c = 16.946(4) ?, α = 62.966(6), β = 84.833(8), γ = 84.348(8)°, V = 1993.4(8) ?3, Z = 2, Dc = 1.616 g/cm3, F(000) = 988 and μ = 1.207 mm-1. The final R = 0.0429 and wR = 0.0843 for 5682 observed reflections with I > 2σ(I). Each copper(II) atom displays a distorted square-pyramidal geometry with two nitrogen atoms of one chelate 2,2?-bipy molecule, two oxygen atoms from two different bridging carboxylate groups of Hpht- and one bridging chloride atom occupying the apical position. The two copper(II) atoms are connected by a μ2-Cl atom and two bridging Hpht- ligands in a syn-syn coordination mode to form an isolated dinuclear unit. The molecular structure is extended to a one-dimensional wavy chain through hydrogen bonds. The title complex exhibits blue fluorescent emission at 443 nm (λex = 372 nm) in the solid state at room temperature.
基金supported by the Education Office of Henan and Anhui Provinces (2009A150020 and KJ2008B178)
文摘A planar transition metal complex Cu(L)2 (L = (E)-benzyl-2-(4-nitrobenzylidene)-hydrazinecarbodithioate) has been prepared and determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system,space group P21/c with a = 6.7101(11),b = 16.952(3),c = 13.962(3) ,β = 92.458(4)°,V = 1586.7(5) 3,Z = 4,Mr = 724.33,Dc = 1.516 g·m-3,μ = 0.998 mm-1,F(000) = 742,S = 1.021,R = 0.0634 and wR = 0.1077 for 813 observed reflections with Ⅰ〉 2σ(Ⅰ) and 205 parameters. In the molecular structure of the title complex,the copper atom exhibits a slightly distorted square-planar geometry in which the basal plane is defined by two N and two S atoms from two bidentate ligands. The complex was evaluated for its antitumor activity against two kinds of cell lines (MKN45 and HepG2) by MTT method. The preliminary bioassay indicates that the complex exhibits weak antitumor activity.
基金Supported by the Fund of Science and Technology Committee of Hunan Province(No.2012GK3030)Scientific Research Fund of Hunan Provincial Education Department(No.11C0186)Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)
文摘A new copper(II) complex Cu2(L)a(2,2'-bipy)2(H2O)2 (1) has been synthesized with 2-benzoylbenzoic acid (HL) and 2,2'-bipyridin as ligands. The crystal belongs to a monoclinic system with space group Cc, a = 13.9979(II), b = 15.9888(13), c = 30.306(3) A, β = 100.8700(10)°, V= 6661.1(10) A3, Dc= 1.372 g/cm3, Z = 8, F(000) = 2840, the final GOOF = 1.018, R= 0.0685, and wR= 0.1731. There are two mononuclear Cu(L)2(2,2'-bipy)(H20) units in the crystal of 1. Each Cu(II) cation is coordinated by five atoms. The magnetic and fluorescent properties of 1 were studied. The results show that 1 exhibits weak paramagnetism, and when the excitation wavelength is at 616 nm, it has an intense fluorescent emission band around 482 nm.
基金the Municipal Natural Science Foundation of Beijing (No. 2022011).
文摘A lariat crown ether ligand 7,16-bis (2-hydroxy-5-methylbenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (L1) has been prepared via one-pot Mannich reaction. Its copper(II) complex Cu-L1 was synthesized and charac-terized by elemental analysis, IR and UV-visible spectroscopy. The crystal structure of the complex has been deter-mined by X-ray diffraction analysis. The result shows that the copper(II) ion is six-coordinated by two nitrogen and four oxygen atoms, two from the crown ether and the other two from the deprotonated phenolate anions, forming an elongated octahedral complex. Electrochemical study indicates that the complex undergoes reversible reduction in DMF solution.
文摘The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2(apo)4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550(7), b = 8.5378(7), c = 12.082(1) ?, α = 72.807(1), β = 77.641(1), γ = 70.800(1)(, V =724.85(11) ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F(000) =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ(I). The distances between Cu(II) and O atoms are in the range from 1.934(2) to 2.042(2)?. The distance between two copper atoms Cu-Cu(A) is 3.2978(8) ?. The distances of Cu-Cl(1) and Cu-Cl(2) are 2.2322(9), 2.5095(10) ?, respectively. There is no evident hydrogen bond between N and Cl.
基金Supported by the National Natural Science Foundation of China(No.20972132) and the Priority Academic Program Development of Jiangsu Higher Education Institutions of China.
文摘A p-tert-butylthiacalix[4]arene-based polydentated ligand with four Schiff base units on 1,3-alternate position at lower rim has been prepared in three steps,which coordinated to copper ion to form a novel dicopper complex.The structures of the polydentated thiacalixarene ligand and copper complex were fully characterized by spectroscopy and X-ray single crystal diffraction method.
基金supported by the Doctoral Fund of Ministry of Education of China (20110001110054)
文摘A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measure- ment, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallo- graphic data: a -- 12.4537(4)/~, b = 9.3897(5) A, c = 30.1264(10) A, and Z = 8. In the crystal structure, the octahedral coordi- nated copper(II) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu'"Cu separation of 6.1719/~, along with phen ligands attached to both sides of the chain altematively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evalua- tion of the cytotoxic activity of the copper(II) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.
基金financially supported by the National Natural Science Foundation of China(51173060)
文摘The title complex [Cu(BBA)(NO3)](NO3)2(BBA = [2-(benzotriazol-1-yl)ethyl][2(benzotriazol-2-yl)ethyl] amine) has been synthesized and structurally characterized.Its crystallizes in triclinic,space group P1 with a = 10.003(3),b = 11.399(3),c = 18.186(5),α = 77.184(4),β = 88.573(5),γ = 72.306(5)o,V = 1924.4(9)3,Z = 2,F(000) = 894,Dc = 1.493 Mg/m3,Mr = 865.31,μ = 0.644 mm-1,the final R = 0.0733 and wR = 0.1722 for 4349 observed reflections with I 2σ(I).Its polyphenol oxidase(PPO) mimic activity was studied spectroscopically by using pyrogallol as the substrate.The results showed that the kinetics of pyrogallol catalyzed by the complex obeyed the Michaelis-Mentent equation,showing that the PPO catalytic activity of the complex increased with increasing the reaction temperature and pH values.