The phosphorus-containing PODIPY 1 as a chemosensor can detect Hg^2＋ by a color change from pink to violet red without the use of any instrumentation. PODIPY 1 was selective to Hg^2＋ with a remarkable absorption cha...The phosphorus-containing PODIPY 1 as a chemosensor can detect Hg^2＋ by a color change from pink to violet red without the use of any instrumentation. PODIPY 1 was selective to Hg^2＋ with a remarkable absorption change, and addition of other relevant metal ions caused almost no absorption change. The new PODIPY dye 1 was sensitive to various concentrations of Hg^2＋. The energy gap between the HOMO and LUMO of the metal complex 1–Hg^2＋ is smaller than that of chemosensor 1, which is in good agreement with the red shift in the absorption observed upon treatment of 1 with Hg^2＋. The 1-based test strips were easily fabricated and low-cost, useful in practical and efficient Hg^2＋test kits.展开更多
Density functional theory and MP2 calculations have been used to determine the geometries, stabilities, binding energies, and dissociative properties of cation-diazine complexes M^n＋-C4H4N2 （M^n＋= Li^＋, B^＋, Al^...Density functional theory and MP2 calculations have been used to determine the geometries, stabilities, binding energies, and dissociative properties of cation-diazine complexes M^n＋-C4H4N2 （M^n＋= Li^＋, B^＋, Al^＋, Be^2＋, Mg^2＋, Ca^2＋）. The calculated results indicate that most complexes are stable except the π complexes of Ca^2＋-pyridazine, Ca^2＋-pyrazine, Al^＋-pyrimidine and Al^＋-pyrimidine. The a complexes are generally much more stable than their π counterparts. Among the π complexes, the cation-pyrazine π complexes have slightly higher stability. The nature of the ion-molecule interactions has been discussed by the natural bond orbital analysis and frontier molecular orbital interactions. In these a complexes, there is stronger covalent interaction between B^＋ and diazine. In the selected π complexes, B^＋ and Be^2＋ have stronger covalent interaction with diazine, while the other cations mainly have electrostatic interaction with diazine.展开更多
In order to develop a sensor for the detection of toxic H_2S molecule,the interactions of C–NT and CSi–NT with H_2S molecule were investigated by density functional theory calculations. The effects of F functionaliz...In order to develop a sensor for the detection of toxic H_2S molecule,the interactions of C–NT and CSi–NT with H_2S molecule were investigated by density functional theory calculations. The effects of F functionalization and water on the adsorption of H_2S gas on C–NT and CSi–NT surfaces were investigated. The studied nanotubes can interact with the H_2S molecule effectively and so adsorptions of H_2S on studied nanotubes are exothermic and possible from the energetic viewpoint. Replacing the C atoms of C–NT with Si atoms may be a good strategy for improving the sensitivity of C–NT towards H_2S. F functionalization and water cause an increase and decrease in the absolute adsorption energy（Ead） values of H_2S on the studied nanotubes,respectively. There are good linearity dependencies between Ead and orbital energy values of studied nanotubes. The Ead and orbital energy values of studied nanotubes can be considered as important parameters to propose suitable nanotubes with increased potential of H_2S adsorption.展开更多
A novel copper（Ⅱ） complex with tert-butyl 2-[N-（tert-butyloxycarbonylmethyl）-2-picolyamino]acetate（ampy） was synthesized and structurally characterized by elemental analysis, FT-IR spectrum, electrospray ioniza...A novel copper（Ⅱ） complex with tert-butyl 2-[N-（tert-butyloxycarbonylmethyl）-2-picolyamino]acetate（ampy） was synthesized and structurally characterized by elemental analysis, FT-IR spectrum, electrospray ionization-mass spectrometry, UV-vis spectrum and single-crystal X-ray diffraction, respectively. A mononuclear copper（II） complex with ampy, [Cu（ampy）Cl2]（1）, was formed irrespective of the metal-to-ligand molar ratios（[Cu2＋]：[ampy] = 0.5：1, 1：1, and 2：1） as a single product. Complex 1 crystallizes in the orthorhombic system, space group Pbca with a = 12.343（2）, b = 18.928（3）, c = 20.058（4） A, V = 4686.1（14） A3, Z = 8, Dc = 1.3349（4） g/cm3, F（000） = 1920, S = 1.016, R = 0.0693 and w R = 0.1721 for 3151 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the central copper（II） ion is bound by pyridyl N, tertiary amine N and carbonyl O atoms of the quadridentate ampy as well as two Cl anions, constructing a slightly distorted octahedral geometry. Complex 1 further constructs a stable 3D supramolecular architecture by intermolecular C–H…Cl hydrogen bonds. In addition, the molecular geometry was calculated by density functional theory（DFT/B3LYP） method with the basis sets（6-31＋G（d,p） for H, C, N, O and Cl atoms, and LANL2 DZ for Cu atom, respectively）. The calculated results show that the optimized geometrical parameters are in good agreement with the experimental data. Natural bond orbital（NBO） analysis and frontier molecular orbitals（FMOs） analysis were investigated at the same level.展开更多
A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and diele...A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system（space group C2/c）. Its unit cell dimensions are a = 32.394（9） ？, b = 12.217（4） ？, c = 10.175（3） ？, β = 97.852（13）° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_（norm）surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.展开更多
The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theor...The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theory(DFT) computations, we theoretically identified that two-dimensional(2D) iron-porphyrin(Fe-Pp) sheet, in which the active Fe sites are distributed regularly and separately, is an appealing candidate. The pristine Fe-Pp sheet exhibits considerably high catalytic activity and four-electron selectivity for ORR. Especially, the adsorption of ORR intermediates on Fe-Pp sheet can be significantly weakened by the addition of axial cyanogen(CN) ligand, resulting in pronouncedly enhanced ORR activity. More interestingly, the d band center of CN attached Fe-Pp(Fe-Pp-CN) sheet can be further tuned by applying the external tensile or compressive strain, leading to an enhancement or suppression of ORR catalytic performance. In particular, under a small biaxial tensile strain of 2%, the ORR activity of Fe-Pp-CN sheet is even higher than that of Pt and reaches to the top of activity volcano. Our studies open new ways to design effective non-Pt ORR catalysts for fuel cell technology.展开更多
基金supported by the Public Research Foundation of Liaoning Province for the Cause of Science (No. 2014003009)Science and Technology Key Project of Liaoning Province (No. 2013304007)+2 种基金the Foundation of the Education Department of Henan Province for Science and Technology Research Projects (No. 13A150046)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministrythe startup funds from Shenyang University of Chemical Technology
文摘The phosphorus-containing PODIPY 1 as a chemosensor can detect Hg^2＋ by a color change from pink to violet red without the use of any instrumentation. PODIPY 1 was selective to Hg^2＋ with a remarkable absorption change, and addition of other relevant metal ions caused almost no absorption change. The new PODIPY dye 1 was sensitive to various concentrations of Hg^2＋. The energy gap between the HOMO and LUMO of the metal complex 1–Hg^2＋ is smaller than that of chemosensor 1, which is in good agreement with the red shift in the absorption observed upon treatment of 1 with Hg^2＋. The 1-based test strips were easily fabricated and low-cost, useful in practical and efficient Hg^2＋test kits.
基金Project supported by the Open Fund of State Key Laboratory for Physical Chemistry of Solid Surfaces (No. 200306) and Natural Science Fundation of Henan Province (Nos. 0311011200, 200510475012)
文摘Density functional theory and MP2 calculations have been used to determine the geometries, stabilities, binding energies, and dissociative properties of cation-diazine complexes M^n＋-C4H4N2 （M^n＋= Li^＋, B^＋, Al^＋, Be^2＋, Mg^2＋, Ca^2＋）. The calculated results indicate that most complexes are stable except the π complexes of Ca^2＋-pyridazine, Ca^2＋-pyrazine, Al^＋-pyrimidine and Al^＋-pyrimidine. The a complexes are generally much more stable than their π counterparts. Among the π complexes, the cation-pyrazine π complexes have slightly higher stability. The nature of the ion-molecule interactions has been discussed by the natural bond orbital analysis and frontier molecular orbital interactions. In these a complexes, there is stronger covalent interaction between B^＋ and diazine. In the selected π complexes, B^＋ and Be^2＋ have stronger covalent interaction with diazine, while the other cations mainly have electrostatic interaction with diazine.
文摘In order to develop a sensor for the detection of toxic H_2S molecule,the interactions of C–NT and CSi–NT with H_2S molecule were investigated by density functional theory calculations. The effects of F functionalization and water on the adsorption of H_2S gas on C–NT and CSi–NT surfaces were investigated. The studied nanotubes can interact with the H_2S molecule effectively and so adsorptions of H_2S on studied nanotubes are exothermic and possible from the energetic viewpoint. Replacing the C atoms of C–NT with Si atoms may be a good strategy for improving the sensitivity of C–NT towards H_2S. F functionalization and water cause an increase and decrease in the absolute adsorption energy（Ead） values of H_2S on the studied nanotubes,respectively. There are good linearity dependencies between Ead and orbital energy values of studied nanotubes. The Ead and orbital energy values of studied nanotubes can be considered as important parameters to propose suitable nanotubes with increased potential of H_2S adsorption.
基金supported by the National Basic Research Program of China(No.2014CB643401)the National Natural Science Foundation of China(Nos.51134007 and 51474256)
文摘A novel copper（Ⅱ） complex with tert-butyl 2-[N-（tert-butyloxycarbonylmethyl）-2-picolyamino]acetate（ampy） was synthesized and structurally characterized by elemental analysis, FT-IR spectrum, electrospray ionization-mass spectrometry, UV-vis spectrum and single-crystal X-ray diffraction, respectively. A mononuclear copper（II） complex with ampy, [Cu（ampy）Cl2]（1）, was formed irrespective of the metal-to-ligand molar ratios（[Cu2＋]：[ampy] = 0.5：1, 1：1, and 2：1） as a single product. Complex 1 crystallizes in the orthorhombic system, space group Pbca with a = 12.343（2）, b = 18.928（3）, c = 20.058（4） A, V = 4686.1（14） A3, Z = 8, Dc = 1.3349（4） g/cm3, F（000） = 1920, S = 1.016, R = 0.0693 and w R = 0.1721 for 3151 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the central copper（II） ion is bound by pyridyl N, tertiary amine N and carbonyl O atoms of the quadridentate ampy as well as two Cl anions, constructing a slightly distorted octahedral geometry. Complex 1 further constructs a stable 3D supramolecular architecture by intermolecular C–H…Cl hydrogen bonds. In addition, the molecular geometry was calculated by density functional theory（DFT/B3LYP） method with the basis sets（6-31＋G（d,p） for H, C, N, O and Cl atoms, and LANL2 DZ for Cu atom, respectively）. The calculated results show that the optimized geometrical parameters are in good agreement with the experimental data. Natural bond orbital（NBO） analysis and frontier molecular orbitals（FMOs） analysis were investigated at the same level.
文摘A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system（space group C2/c）. Its unit cell dimensions are a = 32.394（9） ？, b = 12.217（4） ？, c = 10.175（3） ？, β = 97.852（13）° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_（norm）surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.
基金supported by the National Natural Science Foundation of China (21403115 and 21522305)the Natural Science Foundation of Jiangsu Province (BK20150045)+1 种基金Innovation Project in Jiangsu Province (KYZZ16-0454)The priority academic program development of Jiangsu higher education institutions
文摘The development of non-platinum(Pt) oxygen reduction reaction(ORR) catalysts with high activity and low cost is of great importance for large-scale commercialization of fuel cells. By means of density functional theory(DFT) computations, we theoretically identified that two-dimensional(2D) iron-porphyrin(Fe-Pp) sheet, in which the active Fe sites are distributed regularly and separately, is an appealing candidate. The pristine Fe-Pp sheet exhibits considerably high catalytic activity and four-electron selectivity for ORR. Especially, the adsorption of ORR intermediates on Fe-Pp sheet can be significantly weakened by the addition of axial cyanogen(CN) ligand, resulting in pronouncedly enhanced ORR activity. More interestingly, the d band center of CN attached Fe-Pp(Fe-Pp-CN) sheet can be further tuned by applying the external tensile or compressive strain, leading to an enhancement or suppression of ORR catalytic performance. In particular, under a small biaxial tensile strain of 2%, the ORR activity of Fe-Pp-CN sheet is even higher than that of Pt and reaches to the top of activity volcano. Our studies open new ways to design effective non-Pt ORR catalysts for fuel cell technology.
