Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron...Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.展开更多
Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terp...Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terpyridine, 1,4-H2 BDC = 1,4-benzenedicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared analysis and X-ray single-crystal diffraction. The scrutiny of single-crystal structure reveals that complex 1 forms to a 3D supramolecular network linked by π-π stacking interactions and hydrogen bonds. X-ray diffraction analysis reveals that complex 2 exhibits a 3D supramolecular network linked through complicated hydrogen bonds. The thermogravimetric analysis and photoluminescent properties of 1 and 2 are discussed in detail.展开更多
Two new copper(I) halide complexes bearing 2-(2-benzimidazolyl)-6-methylpyridine (Hbmp) and PPh3 ligands, Cu(Hbmp)(PPh3)X (X = Br (1); I (2)), have been synthesized and characterized. Single-crystal X-...Two new copper(I) halide complexes bearing 2-(2-benzimidazolyl)-6-methylpyridine (Hbmp) and PPh3 ligands, Cu(Hbmp)(PPh3)X (X = Br (1); I (2)), have been synthesized and characterized. Single-crystal X-ray structure analysis reveals that the halide ligand has a significant impact on the Cu-Npyridyl bond lengths. Complexes 1 and 2 show the solid-state emissions at ambient temperature, varying with the halide bound to the { Cu(Hbmp)(PPh3) } motif, which are perhaps best attributed to the metal-to-ligand charge-transfer (Cu(I) → Hbmp) transition mixed with some ligand-to-ligand charge-transfer (X and PPh3 → Hbmp) character.展开更多
Introduction Nucleases which catalyze the hydrolytic cleavage of the phosphodiester backbone of DNA and RN A play animportant role in the molecular genetics and genetic engineering.The development of reagents which hy...Introduction Nucleases which catalyze the hydrolytic cleavage of the phosphodiester backbone of DNA and RN A play animportant role in the molecular genetics and genetic engineering.The development of reagents which hydrolytically cleave nucleic acids under mild conditions has currently been attracting great interest in the field of artificial nucleases"",for example,the small metal complexes that promote the hydrolysis of DNA and RNA are useful not only in molecular biology and drug design but also in elucidating the role of metal ions in enzyme catalysis.展开更多
Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. ...Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. The X ray crystallography established the structure of the Gd complex, which contains a pair of quadruply acetato bridged CuGd dinuclear subunits, and each of them is linked to the central Cu atom by a single acetato bridge. The coordination sphere of each Gd atom is completed by three aqua ligands [Gd-O=0.242 8(5)-0.244 4(4) nm] to form an 8 coordinated distorted square antiprism. The central Cu atom is coordinated by two oxygen atoms from the two bridging acetato groups and two oxygen atoms from the two monodentate acetato groups in a slightly distorted square planar fashion, while each terminal Cu atom is coordinated by the four acetato oxygen atoms at the basal plane and an aqua ligand at the apical position to form a square pyramid. The variable temperature (4 320 K) magnetic susceptibility data of the Gd complex were measured, and fitted to the Curie Weiss law with C =16.38 K cm 3·mol -1 and θ =-1.55 K, indicating very weak antiferromagnetic interaction.展开更多
Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same stru...Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same structure with different geometric parameters. The α form crystallizes in the P2(1)/c space group and the β form in the P1 space group. Both the crystal structures consist of centrosymmetric monomeric molecules of Cu(OC_6H_4CNOH)_2. The IR spectra are in agreement with the structural data.展开更多
A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 ...A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 and [Cu(H2O)3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1: triclinic, space group PT, a = 5.253(2), b = 7.406(3), c = 14.792(5) A, α = 84.195(5), β = 80.014(5), γ = 78.053(5)°, V= 553.2(3)A^3, Z = 1, F(000) = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections (I 〉 2σ(I)); and those for 2: monoclinic, space group P21/c, a = 10.222(3), b = 25.287(7), c = 9.277(3)A, β = 93.572(5)°, V = 2393.2(12)A^3, Z = 4, F(000) = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections (I 〉2o(/)).展开更多
The mononuclear copper(Ⅱ) complex [Cu(L)(2-AP)] 1 and binuclear copper(Ⅱ) complex [Cu(L)(py)]2 2 (L = C10H11O5NS, taurine o-vanillin, py = prydine, 2-AP = 2-aminopyridine) with mixed ligand have been s...The mononuclear copper(Ⅱ) complex [Cu(L)(2-AP)] 1 and binuclear copper(Ⅱ) complex [Cu(L)(py)]2 2 (L = C10H11O5NS, taurine o-vanillin, py = prydine, 2-AP = 2-aminopyridine) with mixed ligand have been synthesized and characterized by X-ray diffraction method. Crystal data for 1: orthorhombic, space group Pbca with a = 11.921(4), b = 15.816(6), c = 17.076(6) A, V= 3219.7(19) A^3, C15H17CuN3O5S, Z = 8, Mr = 414.92, De = 1.712 g/cm^3,μ(MoKα) = 1.520 mm^-1, F(000) = 1704, the final R = 0.0300 and wR = 0.0705 for 2840 observed reflections with I 〉 2σ(I); and crystal data for 2: monoclinic, space group P21/c with a = 7.929(3), b = 17.038(5), c = 11.734(4) A, β = 98.162(6)°, V = 1569.1(9) A^3, C15H16CuN2O5S, Z = 4, Mr = 399.90, Dc = 1.693 g/cm^3, F(000) = 820,μ(MoKα) = 1.554 mm^-1, the final R = 0.0351 and wR = 0.0848 for 2767 observed reflections (I 〉 2σ(I)). The molecular structure of complex 1 consists of one tetra-coordinated Cu(Ⅱ) atom generating a slightly distorted square plane, and a one-dimensional chain structure is formed by intermolecular hydrogen bonds. Complex 2 consists of a diphenolic hydroxyl O-bridged binuclear copper(Ⅱ) structure. The crystal structures of complexes 1 and 2 reveal that the coordinate copper centers are bound to both nitrogen and oxygen atom donors. The usual N,O-trans arrangement of ligands is observed in both cases.展开更多
A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]py...A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713.展开更多
Two new Cu(Ⅰ) complexes [CuCl(3-PyOH)(PPh_3)_2](1) and [Cu_2(μ-Cl)_2(4-Stpy)(Ph_3P)_3](2)(PyOH = hydroxypyridine; stpy = styrylpyridine) with triphenylphosphine and pyridine derivatives have been s...Two new Cu(Ⅰ) complexes [CuCl(3-PyOH)(PPh_3)_2](1) and [Cu_2(μ-Cl)_2(4-Stpy)(Ph_3P)_3](2)(PyOH = hydroxypyridine; stpy = styrylpyridine) with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945(7), b = 37.266(2), c = 10.9461(7) A, β = 116.0750(10)°, V = 3625.3(4) A^3, Z = 4, D_c = 1.350 Mg/cm^(-3), μ = 0.801 mm^(-1), F(000) = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections(I 〉 2σ(I)), R(all data) = 0.0413, wR(all data) = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290(3), b = 20.388(5), c = 24.092(6) A, β = 102.028(4)°, V = 5424(2) A^3, Z = 4, D_c = 1.428 Mg/cm^(-3), μ = 1.016 mm^(-1), F(000) = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections(I 〉 2σ(I)), R(all data) = 0.0716, wR(all data) = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu(I) complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.展开更多
Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal s...Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal sources and N,N-dimethylformamide was employed as a solvent as well as a reductant to produce Cu(Ⅰ) complexes.(ⅱ) An iodide-containing compound was utilized as a ligand and iodide source to prepare complexes.An in situ metalligand reaction occurred and an iodide-bridged copper complex was generated.(ⅲ) A series of aldehydes were added to the reaction systems to induce in situ metal-ligand reactions between the aldehydes and the imidazo[1,5-a]pyridine derivatives,producing polydentate ligand scaffolds.Eight complexes were prepared and characterized.The catalytic activities of these complexes toward the ketalization of ketones by ethylene glycol were investigated.With the exception of complex4,the remaining seven complexes all showed high catalytic activity.The lower activity of 4 may be due to the larger radius of bridging iodide ions and the shorter Cu(Ⅰ)…Cu(Ⅰ) distance.CCDC:2357696,1·2CH_(2)Cl_(2);2357697,2;2018292,3;2092192,4;2092190,5;2155557,6;2406155,7;2406156,8·EtOH.展开更多
Computational calculation was performed to investigate the mechanism of trifluoromethylation reactions of iodobenzene with well-defined N-heterocyclic carbene (NHC)-supported Cu~ trifiuor- omethyl complexes. Four pr...Computational calculation was performed to investigate the mechanism of trifluoromethylation reactions of iodobenzene with well-defined N-heterocyclic carbene (NHC)-supported Cu~ trifiuor- omethyl complexes. Four proposed reaction pathways, namely cr-bond metathesis (BM), concerted oxidative addition-reductive elimination (OARE), iodine atom transfer (IAT) and single-electron transfer (SET), have been computed by density functional theory (DFT). The result indicated that the concerted OARE mechanism is favored among the four reaction pathways, suggesting the trifluoromethylation may occur via concerted OARE mechanism involving Ar-X oxidative addition to the Cu(1) center as the rate determining step.展开更多
Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for ...Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for organic synthesis due to the challenges of designing novel catalytic paradigm and expanding the substrate and reaction scope. Here, we disclose a catalytic EDA/Cu cooperative strategy by employing Na I as a catalytic donor for copper-catalyzed radical asymmetric carbocyanation. A diverse range of synthetically useful chiral benzyl nitriles are produced with high enantioselectivities. This synergetic EDA/copper catalysis enables the decarboxylative cyanation without request of any photoredox catalysts, further expanding the synthetic potential of catalytic EDA chemistry in organic synthesis.展开更多
A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space...A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space group C2/c with a = 14.167(3), b = 21.209(4), c =20.680(4)A°, β = 103.93(3)°, C32H28CuN3O3P2, Mr = 628.05, Z = 8, μ = 0.868 mm^-1, V = 6031 (2) ,A°^3,F(000) = 2592, De= 1.383 g/cm^3, R = 0.0593 and wR = 0.1736. A total of 5297 independent reflections were collected, of which 3503 were observed with 1 〉 2σ(/). The central copper atom is tri-coordinated by phosphorus atoms from bridging dppm and nitrogen atom from benzimidazole. In the coordination sphere, the bond lengths of Cu-P(1) and Cu-P(2) are 2.2607(17) and 2.2503(16) A°,respectively and the P-Cu-P bond angle is 127.26(6)°.展开更多
The luminescent mechanism and properties of a triangular Cu(I) complex, (CuPz)3. have been studied by CIS method. The ground and lowest triplet excitation state geometries were optimized at MP2/SBKJC and CIS/SBKJC...The luminescent mechanism and properties of a triangular Cu(I) complex, (CuPz)3. have been studied by CIS method. The ground and lowest triplet excitation state geometries were optimized at MP2/SBKJC and CIS/SBKJC levels, respectively. A remarkable geometry distortion of the lowest triplet state was found and believed to cause the emission spectra to red shift.展开更多
Five polynuclear monovalent and mixed-valence complexes of copper with 2-thiouracil were synthesized. They were characterized by the molar conductivity, electromc spectra, infrared spectroscopy, thermogravimetric and ...Five polynuclear monovalent and mixed-valence complexes of copper with 2-thiouracil were synthesized. They were characterized by the molar conductivity, electromc spectra, infrared spectroscopy, thermogravimetric and magnetic susceptibility measurements. Their coordination properties and tentative structures were discussed.展开更多
Two complexes, Cu(HnicO)2 1 and Ni(HnicO)2(H2O)2 2 (H2nicO = 2-hydroxynicolinic acid), were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in monoclinic, space gro...Two complexes, Cu(HnicO)2 1 and Ni(HnicO)2(H2O)2 2 (H2nicO = 2-hydroxynicolinic acid), were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in monoclinic, space group P21/n, with a = 8.314(7), b = 6.275(4), c = 11.283(7)A, β = 98.32(3)°, V = 582.5(7)A^3, Z = 2, Mr = 339.74, Dc = 1.937 g/cm3, F(000) = 342, μ = 1.908 mm^-1, S = 1.097, the final R = 0.0284 mad wR = 0.0781 for 1177 observed reflections with Ⅰ 〉 2σ(Ⅰ). Complex 2 crystallizes in monoclinic, space group P21/c, with a = 7.438(5), b = 12.22(1), c = 7.537(5)A,β = 100.07(3)°, V= 674.3(8)A3, Z = 2, Mr = 370.95, Dc = 1.827 g/cm^3, F(000) = 380, = 1.487 mm^-1, S = 1.041, the final R = 0.0335 and wR = 0.0779 for 1202 observed reflections with I 〉 2σ(Ⅰ). There are extended 3D framework structures in complexes 1 and 2 due to the N-H…O and C-H…O hydrogen bonds. The copper atom in 1 has square planar coordination, while the nickel atom in 2 adopts octahedral coordination geometry. The TG curve shows that complex 2 is stable in solid state to 150 ℃.展开更多
A new binuclear complex [Cu2L(OH)](ClO4)3·2H2O has been synthesized and characterized, where L=2,6-bis{[bis-(2-aminoethyl)amino]methyl}-benzene. In the presence of 0.5 mmol/L complex at pH 8.10 and 37°C, t...A new binuclear complex [Cu2L(OH)](ClO4)3·2H2O has been synthesized and characterized, where L=2,6-bis{[bis-(2-aminoethyl)amino]methyl}-benzene. In the presence of 0.5 mmol/L complex at pH 8.10 and 37°C, the complex can efficiently cleavage pBR322 DNA with a rate constant kobs of 1.35×10-4 s-1. The cleavage occurred by a non-oxidative mechanism showing activity to be dependent on pH.展开更多
Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characteri...Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082(2), b = 15.447(3), c = 18.784(4)A^°, V= 3505.7(12)A^°3, Mr = 731.50, Dc = 1.386 g/cm^3, μ = 0.606 mm^-1, F(000) = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I 〉 2σ(I). For 2, a = 12.181(2), b = 15.501(3), c = 18.877(4) A^°, V = 3564.3(12)A^°3, Mr = 736.33, Dc = 1.372 g/cm^3, μ = 0.665 mm^-1, F(000) = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I 〉 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.展开更多
文摘Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.
基金Supported by the Program for New Century Excellent Talents in University(NCET-10-0176)the Natural Science Foundation of Jilin Province(No.20130521019JH)the fund of Jilin Provincial Education Department of China(No.2014154)
文摘Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terpyridine, 1,4-H2 BDC = 1,4-benzenedicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared analysis and X-ray single-crystal diffraction. The scrutiny of single-crystal structure reveals that complex 1 forms to a 3D supramolecular network linked by π-π stacking interactions and hydrogen bonds. X-ray diffraction analysis reveals that complex 2 exhibits a 3D supramolecular network linked through complicated hydrogen bonds. The thermogravimetric analysis and photoluminescent properties of 1 and 2 are discussed in detail.
基金support from the NNSFC(Nos21163009 and 21001057)the Key Project of Chinese Ministry of Education(No211088)+2 种基金the Advanced Program for the Retuned Overseas Chinese Scholars of the MOHRSS(No 474[2011])the Training Program for Jiangxi Provincial Young Scientiststhe Foundation of State Key Laboratory of Structural Chemistry(No20110015)
文摘Two new copper(I) halide complexes bearing 2-(2-benzimidazolyl)-6-methylpyridine (Hbmp) and PPh3 ligands, Cu(Hbmp)(PPh3)X (X = Br (1); I (2)), have been synthesized and characterized. Single-crystal X-ray structure analysis reveals that the halide ligand has a significant impact on the Cu-Npyridyl bond lengths. Complexes 1 and 2 show the solid-state emissions at ambient temperature, varying with the halide bound to the { Cu(Hbmp)(PPh3) } motif, which are perhaps best attributed to the metal-to-ligand charge-transfer (Cu(I) → Hbmp) transition mixed with some ligand-to-ligand charge-transfer (X and PPh3 → Hbmp) character.
文摘Introduction Nucleases which catalyze the hydrolytic cleavage of the phosphodiester backbone of DNA and RN A play animportant role in the molecular genetics and genetic engineering.The development of reagents which hydrolytically cleave nucleic acids under mild conditions has currently been attracting great interest in the field of artificial nucleases"",for example,the small metal complexes that promote the hydrolysis of DNA and RNA are useful not only in molecular biology and drug design but also in elucidating the role of metal ions in enzyme catalysis.
文摘Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. The X ray crystallography established the structure of the Gd complex, which contains a pair of quadruply acetato bridged CuGd dinuclear subunits, and each of them is linked to the central Cu atom by a single acetato bridge. The coordination sphere of each Gd atom is completed by three aqua ligands [Gd-O=0.242 8(5)-0.244 4(4) nm] to form an 8 coordinated distorted square antiprism. The central Cu atom is coordinated by two oxygen atoms from the two bridging acetato groups and two oxygen atoms from the two monodentate acetato groups in a slightly distorted square planar fashion, while each terminal Cu atom is coordinated by the four acetato oxygen atoms at the basal plane and an aqua ligand at the apical position to form a square pyramid. The variable temperature (4 320 K) magnetic susceptibility data of the Gd complex were measured, and fitted to the Curie Weiss law with C =16.38 K cm 3·mol -1 and θ =-1.55 K, indicating very weak antiferromagnetic interaction.
文摘Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same structure with different geometric parameters. The α form crystallizes in the P2(1)/c space group and the β form in the P1 space group. Both the crystal structures consist of centrosymmetric monomeric molecules of Cu(OC_6H_4CNOH)_2. The IR spectra are in agreement with the structural data.
基金This work was financially supported by Liuhui Center for Applied Mathematics, Nankai and Tianjin Universities (No. H10114)
文摘A flexible double betaine 1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene L has been used to generate two Cu(Ⅱ)-containing metal complexes that exhibit different polymeric structures: [Cu(H2O)2 L].2NO3 1 and [Cu(H2O)3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1: triclinic, space group PT, a = 5.253(2), b = 7.406(3), c = 14.792(5) A, α = 84.195(5), β = 80.014(5), γ = 78.053(5)°, V= 553.2(3)A^3, Z = 1, F(000) = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections (I 〉 2σ(I)); and those for 2: monoclinic, space group P21/c, a = 10.222(3), b = 25.287(7), c = 9.277(3)A, β = 93.572(5)°, V = 2393.2(12)A^3, Z = 4, F(000) = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections (I 〉2o(/)).
基金This work was supported by the Scientific Research Common Program of Beijing Municipal Commission of Education (KM20051028005)
文摘The mononuclear copper(Ⅱ) complex [Cu(L)(2-AP)] 1 and binuclear copper(Ⅱ) complex [Cu(L)(py)]2 2 (L = C10H11O5NS, taurine o-vanillin, py = prydine, 2-AP = 2-aminopyridine) with mixed ligand have been synthesized and characterized by X-ray diffraction method. Crystal data for 1: orthorhombic, space group Pbca with a = 11.921(4), b = 15.816(6), c = 17.076(6) A, V= 3219.7(19) A^3, C15H17CuN3O5S, Z = 8, Mr = 414.92, De = 1.712 g/cm^3,μ(MoKα) = 1.520 mm^-1, F(000) = 1704, the final R = 0.0300 and wR = 0.0705 for 2840 observed reflections with I 〉 2σ(I); and crystal data for 2: monoclinic, space group P21/c with a = 7.929(3), b = 17.038(5), c = 11.734(4) A, β = 98.162(6)°, V = 1569.1(9) A^3, C15H16CuN2O5S, Z = 4, Mr = 399.90, Dc = 1.693 g/cm^3, F(000) = 820,μ(MoKα) = 1.554 mm^-1, the final R = 0.0351 and wR = 0.0848 for 2767 observed reflections (I 〉 2σ(I)). The molecular structure of complex 1 consists of one tetra-coordinated Cu(Ⅱ) atom generating a slightly distorted square plane, and a one-dimensional chain structure is formed by intermolecular hydrogen bonds. Complex 2 consists of a diphenolic hydroxyl O-bridged binuclear copper(Ⅱ) structure. The crystal structures of complexes 1 and 2 reveal that the coordinate copper centers are bound to both nitrogen and oxygen atom donors. The usual N,O-trans arrangement of ligands is observed in both cases.
文摘A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713.
基金Supported by the National Natural Science Foundation of China(NSFC 21102102)
文摘Two new Cu(Ⅰ) complexes [CuCl(3-PyOH)(PPh_3)_2](1) and [Cu_2(μ-Cl)_2(4-Stpy)(Ph_3P)_3](2)(PyOH = hydroxypyridine; stpy = styrylpyridine) with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945(7), b = 37.266(2), c = 10.9461(7) A, β = 116.0750(10)°, V = 3625.3(4) A^3, Z = 4, D_c = 1.350 Mg/cm^(-3), μ = 0.801 mm^(-1), F(000) = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections(I 〉 2σ(I)), R(all data) = 0.0413, wR(all data) = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290(3), b = 20.388(5), c = 24.092(6) A, β = 102.028(4)°, V = 5424(2) A^3, Z = 4, D_c = 1.428 Mg/cm^(-3), μ = 1.016 mm^(-1), F(000) = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections(I 〉 2σ(I)), R(all data) = 0.0716, wR(all data) = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu(I) complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.
文摘Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal sources and N,N-dimethylformamide was employed as a solvent as well as a reductant to produce Cu(Ⅰ) complexes.(ⅱ) An iodide-containing compound was utilized as a ligand and iodide source to prepare complexes.An in situ metalligand reaction occurred and an iodide-bridged copper complex was generated.(ⅲ) A series of aldehydes were added to the reaction systems to induce in situ metal-ligand reactions between the aldehydes and the imidazo[1,5-a]pyridine derivatives,producing polydentate ligand scaffolds.Eight complexes were prepared and characterized.The catalytic activities of these complexes toward the ketalization of ketones by ethylene glycol were investigated.With the exception of complex4,the remaining seven complexes all showed high catalytic activity.The lower activity of 4 may be due to the larger radius of bridging iodide ions and the shorter Cu(Ⅰ)…Cu(Ⅰ) distance.CCDC:2357696,1·2CH_(2)Cl_(2);2357697,2;2018292,3;2092192,4;2092190,5;2155557,6;2406155,7;2406156,8·EtOH.
基金supported by National Natural Science Foundation of China(Nos.21073144,21173169)Fundamental Research Funds for the Central Universities(No.XDJK2013A008)
文摘Computational calculation was performed to investigate the mechanism of trifluoromethylation reactions of iodobenzene with well-defined N-heterocyclic carbene (NHC)-supported Cu~ trifiuor- omethyl complexes. Four proposed reaction pathways, namely cr-bond metathesis (BM), concerted oxidative addition-reductive elimination (OARE), iodine atom transfer (IAT) and single-electron transfer (SET), have been computed by density functional theory (DFT). The result indicated that the concerted OARE mechanism is favored among the four reaction pathways, suggesting the trifluoromethylation may occur via concerted OARE mechanism involving Ar-X oxidative addition to the Cu(1) center as the rate determining step.
基金the National Natural Science Foundation of China (No. 22201087) for the financial support。
文摘Catalytic electron donor-acceptor(EDA) complex photochemistry has recently emerged as a popular and sustainable alternative to photoredox synthetic methods. Yet, the catalytic EDA strategy is still in its infancy for organic synthesis due to the challenges of designing novel catalytic paradigm and expanding the substrate and reaction scope. Here, we disclose a catalytic EDA/Cu cooperative strategy by employing Na I as a catalytic donor for copper-catalyzed radical asymmetric carbocyanation. A diverse range of synthetically useful chiral benzyl nitriles are produced with high enantioselectivities. This synergetic EDA/copper catalysis enables the decarboxylative cyanation without request of any photoredox catalysts, further expanding the synthetic potential of catalytic EDA chemistry in organic synthesis.
基金This work was supported by the National Natural Science Foundation of China (No. 20271017) and Henan Provincial Innovation Foundation (No. 0421001300)
文摘A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space group C2/c with a = 14.167(3), b = 21.209(4), c =20.680(4)A°, β = 103.93(3)°, C32H28CuN3O3P2, Mr = 628.05, Z = 8, μ = 0.868 mm^-1, V = 6031 (2) ,A°^3,F(000) = 2592, De= 1.383 g/cm^3, R = 0.0593 and wR = 0.1736. A total of 5297 independent reflections were collected, of which 3503 were observed with 1 〉 2σ(/). The central copper atom is tri-coordinated by phosphorus atoms from bridging dppm and nitrogen atom from benzimidazole. In the coordination sphere, the bond lengths of Cu-P(1) and Cu-P(2) are 2.2607(17) and 2.2503(16) A°,respectively and the P-Cu-P bond angle is 127.26(6)°.
基金This work was supported by the Youth Innovation Fund of Fujian Province of China (No. 2003J043), National Science Foundation of China (No. 90203017, 20573114) and 973-Plan (No. 2004CB720605)
文摘The luminescent mechanism and properties of a triangular Cu(I) complex, (CuPz)3. have been studied by CIS method. The ground and lowest triplet excitation state geometries were optimized at MP2/SBKJC and CIS/SBKJC levels, respectively. A remarkable geometry distortion of the lowest triplet state was found and believed to cause the emission spectra to red shift.
文摘Five polynuclear monovalent and mixed-valence complexes of copper with 2-thiouracil were synthesized. They were characterized by the molar conductivity, electromc spectra, infrared spectroscopy, thermogravimetric and magnetic susceptibility measurements. Their coordination properties and tentative structures were discussed.
基金the National Natural Science Foundation of China (No. 20431010)
文摘Two complexes, Cu(HnicO)2 1 and Ni(HnicO)2(H2O)2 2 (H2nicO = 2-hydroxynicolinic acid), were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in monoclinic, space group P21/n, with a = 8.314(7), b = 6.275(4), c = 11.283(7)A, β = 98.32(3)°, V = 582.5(7)A^3, Z = 2, Mr = 339.74, Dc = 1.937 g/cm3, F(000) = 342, μ = 1.908 mm^-1, S = 1.097, the final R = 0.0284 mad wR = 0.0781 for 1177 observed reflections with Ⅰ 〉 2σ(Ⅰ). Complex 2 crystallizes in monoclinic, space group P21/c, with a = 7.438(5), b = 12.22(1), c = 7.537(5)A,β = 100.07(3)°, V= 674.3(8)A3, Z = 2, Mr = 370.95, Dc = 1.827 g/cm^3, F(000) = 380, = 1.487 mm^-1, S = 1.041, the final R = 0.0335 and wR = 0.0779 for 1202 observed reflections with I 〉 2σ(Ⅰ). There are extended 3D framework structures in complexes 1 and 2 due to the N-H…O and C-H…O hydrogen bonds. The copper atom in 1 has square planar coordination, while the nickel atom in 2 adopts octahedral coordination geometry. The TG curve shows that complex 2 is stable in solid state to 150 ℃.
文摘A new binuclear complex [Cu2L(OH)](ClO4)3·2H2O has been synthesized and characterized, where L=2,6-bis{[bis-(2-aminoethyl)amino]methyl}-benzene. In the presence of 0.5 mmol/L complex at pH 8.10 and 37°C, the complex can efficiently cleavage pBR322 DNA with a rate constant kobs of 1.35×10-4 s-1. The cleavage occurred by a non-oxidative mechanism showing activity to be dependent on pH.
基金supported by the Natural Science Foundation of Anhui Province (No. KJ2008B166)
文摘Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082(2), b = 15.447(3), c = 18.784(4)A^°, V= 3505.7(12)A^°3, Mr = 731.50, Dc = 1.386 g/cm^3, μ = 0.606 mm^-1, F(000) = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I 〉 2σ(I). For 2, a = 12.181(2), b = 15.501(3), c = 18.877(4) A^°, V = 3564.3(12)A^°3, Mr = 736.33, Dc = 1.372 g/cm^3, μ = 0.665 mm^-1, F(000) = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I 〉 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.