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2016 Volume 35 Issue 2
2016, 35(2): 175-184
doi: 10.14102/j.cnki.0254-5861.2011-0894
Abstract:
Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calculations were employed to investigate the structural and electronic properties of NbS6- and NbS6 clusters. Generalized Koopmans’ theorem was applied to predict the vertical detachment energies and simulate the photoelectron spectra (PES). The current study indicated that various types of sulfur ligands (i.e., S2-, S2-, S22- and S32-) were presented in the lowest-energy structures of NbS6-/0. The ground-state structure of NbS6- is shown to be Cs (1A') symmetry with a terminal S2-, a side-on bound S22- and a S32- ligands. Molecular orbital analyses were performed to analyze the chemical bonding in NbS6-/0 clusters and elucidate their structural and electronic properties.
Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calculations were employed to investigate the structural and electronic properties of NbS6- and NbS6 clusters. Generalized Koopmans’ theorem was applied to predict the vertical detachment energies and simulate the photoelectron spectra (PES). The current study indicated that various types of sulfur ligands (i.e., S2-, S2-, S22- and S32-) were presented in the lowest-energy structures of NbS6-/0. The ground-state structure of NbS6- is shown to be Cs (1A') symmetry with a terminal S2-, a side-on bound S22- and a S32- ligands. Molecular orbital analyses were performed to analyze the chemical bonding in NbS6-/0 clusters and elucidate their structural and electronic properties.
2016, 35(2): 185-192
doi: 10.14102/j.cnki.0254-5861.2011-0861
Abstract:
Several bare zigzag phosphorene nanoribbons with odd number of atoms in the direction perpendicular to the extended line are investigated by using HSE06 density functional theory. These nanoribbons are as stable as those with even number of atoms. Primitive cells of the nanoribbons are metals, while edge self-passivation and distortion in the supercell structures cause metal-semiconductor transition. The band gaps of semiconducting nanoribbons are around 0.4 eV, which is enough for high on/off ratio in device operation. Compared to the conduction bands, the valence bands have smaller deformation potential constants and larger band width. Thus, the hole mobilities of the nanoribbons (103 cm2·V-1·s-1) are one order higher than the electron mobilities. Bare zigzag phosphorene nanoribbons with odd number of atoms can also be candidates for small-size high-speed electronic devices.
Several bare zigzag phosphorene nanoribbons with odd number of atoms in the direction perpendicular to the extended line are investigated by using HSE06 density functional theory. These nanoribbons are as stable as those with even number of atoms. Primitive cells of the nanoribbons are metals, while edge self-passivation and distortion in the supercell structures cause metal-semiconductor transition. The band gaps of semiconducting nanoribbons are around 0.4 eV, which is enough for high on/off ratio in device operation. Compared to the conduction bands, the valence bands have smaller deformation potential constants and larger band width. Thus, the hole mobilities of the nanoribbons (103 cm2·V-1·s-1) are one order higher than the electron mobilities. Bare zigzag phosphorene nanoribbons with odd number of atoms can also be candidates for small-size high-speed electronic devices.
2016, 35(2): 193-198
doi: 10.14102/j.cnki.0254-5861.2011-0862
Abstract:
The reaction mechanisms of Ti (3F) + CH2Cl2 → CH2=TiCl2 and Ti (3F) + CHCl3 → HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311++G(d,p) level. The computational results revealed that: 1) Both reaction systems are initiated by Ti (3F) atom attacking the C atom of CH2Cl2 and CHCl3 to activate a C-Cl bond; 2) Both reaction systems were carried out via triplet reaction channels; 3) CH2=TiCl2 has singlet and triplet isomers, and the singlet one is more stable; 4) The HOMO of CH2=TiCl2(S) illustrates a π-bonding interaction between C and Ti; 5) Only singlet HC÷TiCl3 was located, and the Mülliken atomic spin densities show that the two single electrons are mostly on the C atom.
The reaction mechanisms of Ti (3F) + CH2Cl2 → CH2=TiCl2 and Ti (3F) + CHCl3 → HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311++G(d,p) level. The computational results revealed that: 1) Both reaction systems are initiated by Ti (3F) atom attacking the C atom of CH2Cl2 and CHCl3 to activate a C-Cl bond; 2) Both reaction systems were carried out via triplet reaction channels; 3) CH2=TiCl2 has singlet and triplet isomers, and the singlet one is more stable; 4) The HOMO of CH2=TiCl2(S) illustrates a π-bonding interaction between C and Ti; 5) Only singlet HC÷TiCl3 was located, and the Mülliken atomic spin densities show that the two single electrons are mostly on the C atom.
2016, 35(2): 199-204
doi: 10.14102/j.cnki.0254-5861.2011-0931
Abstract:
Ethyl 3,9-dihydroxy-9-methyl-7-phenyl-7,8,10-trihydro-6H-dibenzo[b,d]pyran-6-one-8-carboxylate (C23H22O6, Mr = 394.42) has been synthesized and its structure was determined by 1H and 13C NMR, ESI-MS, elemental analysis, and X-ray single-crystal diffraction. The crystal belongs to the triclinic system, space group P1, with a = 8.8220(17), b = 9.881(2), c = 12.157(2) Å, α = 90.488(3), β = 102.664(4), γ = 98.799(3)°, V = 1020.8(3) Å3, Z = 2, Dc = 1.342 g/cm3, μ = 0.099 mm-1, F(000) = 436, R = 0.0615 and wR = 0.2501 for 2592 observed reflections with (I > 2σ(I)). In the crystal structure, the coumarin ring system is planar and the 3:4 fused cyclohexane ring adopts distorted half-chair conformation. Rich hydrogen bonding interactions are formed between compound 2 and lattice water molecules. These interactions assemble molecules of 2 into 2D layered networks in an AB stacking sequence. Its in vitro antiproliferative activities against three human cancer cell lines were evaluated by MTT assay.
Ethyl 3,9-dihydroxy-9-methyl-7-phenyl-7,8,10-trihydro-6H-dibenzo[b,d]pyran-6-one-8-carboxylate (C23H22O6, Mr = 394.42) has been synthesized and its structure was determined by 1H and 13C NMR, ESI-MS, elemental analysis, and X-ray single-crystal diffraction. The crystal belongs to the triclinic system, space group P1, with a = 8.8220(17), b = 9.881(2), c = 12.157(2) Å, α = 90.488(3), β = 102.664(4), γ = 98.799(3)°, V = 1020.8(3) Å3, Z = 2, Dc = 1.342 g/cm3, μ = 0.099 mm-1, F(000) = 436, R = 0.0615 and wR = 0.2501 for 2592 observed reflections with (I > 2σ(I)). In the crystal structure, the coumarin ring system is planar and the 3:4 fused cyclohexane ring adopts distorted half-chair conformation. Rich hydrogen bonding interactions are formed between compound 2 and lattice water molecules. These interactions assemble molecules of 2 into 2D layered networks in an AB stacking sequence. Its in vitro antiproliferative activities against three human cancer cell lines were evaluated by MTT assay.
2016, 35(2): 205-211
doi: 10.14102/j.cnki.0254-5861.2011-0967
Abstract:
A series of new antitumor compounds having indolecarbazole structures were designed and synthesized. The methoxy substituted indolecarbazole parent nucleus, which was firstly synthesized, is condensed with bromine substituted amino acid methyl ester to produce the target compounds. The target compounds were performed with methylthiazolyldiphenyl-tetrazolium bromide (MTT) in vitro cytotoxin activity test and the results showed that compounds CZ-1, CZ-3 and CZ-6 have higher activity against human colon cancer (HT-29) and (HCT-8), hepatocellular carcinoma (Bel-7402), NSCLC (A549) and breast cancer (MCF-7) cells as compared to the positive control JDC-108.
A series of new antitumor compounds having indolecarbazole structures were designed and synthesized. The methoxy substituted indolecarbazole parent nucleus, which was firstly synthesized, is condensed with bromine substituted amino acid methyl ester to produce the target compounds. The target compounds were performed with methylthiazolyldiphenyl-tetrazolium bromide (MTT) in vitro cytotoxin activity test and the results showed that compounds CZ-1, CZ-3 and CZ-6 have higher activity against human colon cancer (HT-29) and (HCT-8), hepatocellular carcinoma (Bel-7402), NSCLC (A549) and breast cancer (MCF-7) cells as compared to the positive control JDC-108.
2016, 35(2): 212-218
doi: 10.14102/j.cnki.0254-5861.2011-0892
Abstract:
The target compound 1,2,4-triazole Schiff base containing pyrazole ring was synthesized by 4-amino-2,4-dihydro-5-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-3H-1,2,4-triazole-3- thione and 3,4,5-trimethoxy benzaldehyde. The structure was confirmed by IR, 1H NMR, H RMS, elemental analysis and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.8772(17), b = 8.2986(18), c = 15.392(3) Å, α = 93.360(4), β = 94.609(4), γ = 93.584(4)°, C18H22N6O3S, Mr = 402.47, V = 998.9(4) Å3, Z = 2, F(000) = 422, Dc = 1.335 g/cm3, μ = 0.194 mm-1, the final R = 0.0533 and wR = 0.1329 for 3517 observed reflections with I > 2σ(I). The preliminary bioassay results indicate that the target compound has good fungicidal activity against Gibberlla nicotiancola in EC50 value and F. O. f. sp. niveum in EC95 value.
The target compound 1,2,4-triazole Schiff base containing pyrazole ring was synthesized by 4-amino-2,4-dihydro-5-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-3H-1,2,4-triazole-3- thione and 3,4,5-trimethoxy benzaldehyde. The structure was confirmed by IR, 1H NMR, H RMS, elemental analysis and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.8772(17), b = 8.2986(18), c = 15.392(3) Å, α = 93.360(4), β = 94.609(4), γ = 93.584(4)°, C18H22N6O3S, Mr = 402.47, V = 998.9(4) Å3, Z = 2, F(000) = 422, Dc = 1.335 g/cm3, μ = 0.194 mm-1, the final R = 0.0533 and wR = 0.1329 for 3517 observed reflections with I > 2σ(I). The preliminary bioassay results indicate that the target compound has good fungicidal activity against Gibberlla nicotiancola in EC50 value and F. O. f. sp. niveum in EC95 value.
2016, 35(2): 219-226
doi: 10.14102/j.cnki.0254-5861.2011-0841
Abstract:
Two silver(I)-sulfonate complexes, [Ag(NO3)(4,4'-bipy)][Ag(HL)(4,4'-bipy)]·2H2O (1) and [Ag(H2O)(4,4'-bipy)][AgL(4,4'-bipy)]·2H2O (2), have been synthesized by in situ reaction (H2L = 2-formylbenzenesulfonic acid, 4,4'-bipy = 4,4'-bipyridine). 1 displays two parallel 1D chains expending to a 3D supramolecule by π…π interactions and O-H…O hydrogen bonds, in which the [Ag(NO3)] or [Ag(HL)] units are joined by bridging 4,4'-bipy molecules, respectively. The interactions between the complexes and DNA were studied by means of fluorescence spectra and surface-enhanced Raman scattering (SERS) spectra. The special configuration and intercalation effects between 1 and DNA are stronger than that between 2 and DNA.
Two silver(I)-sulfonate complexes, [Ag(NO3)(4,4'-bipy)][Ag(HL)(4,4'-bipy)]·2H2O (1) and [Ag(H2O)(4,4'-bipy)][AgL(4,4'-bipy)]·2H2O (2), have been synthesized by in situ reaction (H2L = 2-formylbenzenesulfonic acid, 4,4'-bipy = 4,4'-bipyridine). 1 displays two parallel 1D chains expending to a 3D supramolecule by π…π interactions and O-H…O hydrogen bonds, in which the [Ag(NO3)] or [Ag(HL)] units are joined by bridging 4,4'-bipy molecules, respectively. The interactions between the complexes and DNA were studied by means of fluorescence spectra and surface-enhanced Raman scattering (SERS) spectra. The special configuration and intercalation effects between 1 and DNA are stronger than that between 2 and DNA.
2016, 35(2): 227-236
doi: 10.14102/j.cnki.0254-5861.2011-0997
Abstract:
Two new sliver selenidoantimonates, namely, Ag3SbSe3 and Ag5SbSe4, were prepared under mid solvothermal conditions and structurally characterized by single-crystal X-ray diffraction studies. Ag3SbSe3 crystallizes in the orthorhombic space group Pnma (No. 62) with a = 8.2414(12), b = 11.4925(17), c = 21.220(3) Å, V = 2009.8(5) Å3 and Z = 12. Its structure belongs to the β-Ag3AsSe3 type and features a 3D complex network composed of distorted trigonal planar AgSe3 and tetrahedral AgSe4 units as well as SbSe3 trigonal pyramids. Ag5SbSe4 crystallizes in the orthorhombic system, nocentrosymmetric space group Cmc21 (No. 36) with a = 8.1148(6), b = 12.9829(10), c = 8.7017(7) Å, V = 916.76(12) Å3 and Z = 4. Its structure adopts the Ag5SbS4 type and features a 3D framework based on trigonal planar AgSe3 units and SbSe3 trigonal pyramids. The results of optical absorption spectra and band structure calculations indicate that the title compounds are narrow band-gap semiconductors.
Two new sliver selenidoantimonates, namely, Ag3SbSe3 and Ag5SbSe4, were prepared under mid solvothermal conditions and structurally characterized by single-crystal X-ray diffraction studies. Ag3SbSe3 crystallizes in the orthorhombic space group Pnma (No. 62) with a = 8.2414(12), b = 11.4925(17), c = 21.220(3) Å, V = 2009.8(5) Å3 and Z = 12. Its structure belongs to the β-Ag3AsSe3 type and features a 3D complex network composed of distorted trigonal planar AgSe3 and tetrahedral AgSe4 units as well as SbSe3 trigonal pyramids. Ag5SbSe4 crystallizes in the orthorhombic system, nocentrosymmetric space group Cmc21 (No. 36) with a = 8.1148(6), b = 12.9829(10), c = 8.7017(7) Å, V = 916.76(12) Å3 and Z = 4. Its structure adopts the Ag5SbS4 type and features a 3D framework based on trigonal planar AgSe3 units and SbSe3 trigonal pyramids. The results of optical absorption spectra and band structure calculations indicate that the title compounds are narrow band-gap semiconductors.
2016, 35(2): 237-245
doi: 10.14102/j.cnki.0254-5861.2011-0995
Abstract:
A new 2Fe2S complex [(2-C5H4N)N(μ-CH2S)2Fe2(CO)6] (1) related to the active site of [FeFe]-hydrogenase was obtained by treating (HS)2Fe2(CO)6 with (pyridin-2-ylazanediyl) dimethanol. Protonation occurred at the pyridine nitrogen atom when two equivalents of HBF4·OEt2 acid were added to the toluene solution of 1, leading to the formation of [(2-C5H4NH)N(μ- CH2S)2Fe2(CO)6]·BF4·OEt2 (1H+), whose molecular structure was further established by single- crystal X-ray analysis. Complex 1 crystallizes in the monoclinic system, space group P21/n with a = 7.728(3), b = 11.825(4), c = 17.888(6) Å, β = 92.968(5)°, while complex 1H+ crystallizes in the triclinic system, space group P1 with a = 7.672(4), b = 10.382(5), c = 16.480(10) Å, α = 106.575(13), β = 93.18(3), γ = 104.262(17)°.
A new 2Fe2S complex [(2-C5H4N)N(μ-CH2S)2Fe2(CO)6] (1) related to the active site of [FeFe]-hydrogenase was obtained by treating (HS)2Fe2(CO)6 with (pyridin-2-ylazanediyl) dimethanol. Protonation occurred at the pyridine nitrogen atom when two equivalents of HBF4·OEt2 acid were added to the toluene solution of 1, leading to the formation of [(2-C5H4NH)N(μ- CH2S)2Fe2(CO)6]·BF4·OEt2 (1H+), whose molecular structure was further established by single- crystal X-ray analysis. Complex 1 crystallizes in the monoclinic system, space group P21/n with a = 7.728(3), b = 11.825(4), c = 17.888(6) Å, β = 92.968(5)°, while complex 1H+ crystallizes in the triclinic system, space group P1 with a = 7.672(4), b = 10.382(5), c = 16.480(10) Å, α = 106.575(13), β = 93.18(3), γ = 104.262(17)°.
2016, 35(2): 246-256
doi: 10.14102/j.cnki.0254-5861.2011-0887
Abstract:
Intermolecular interactions and properties of TNT (2,4,6-trinitrotoluene)/CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane) cocrystal were studied by density functional theory (DFT) methods. Binding energy, natural bond orbital (NBO), and atom in molecules (AIM) analysis were performed to investigate the intermolecular interactions in the cocrystal. Results show that the unconventional CH…O type hydrogen bond plays a key role in forming the cocrystal. The variation tendency of entropy and enthalpy shows that the formation of the cocrystal is an exothermic process and low temperature will be benefit for the assembling of complexes. The calculated detonation velocity of the cocrystal agrees well with the experimental value which is higher than that of the physical mixture of TNT and CL-20. In addition, bond dissociation energies (BDEs) of the weakest trigger bond in TNT/CL-20 complex were calculated and the results show that the TNT/CL-20 complex is thermally stable. Finally, first-principles calculations were performed and analysis of the nitro group Mulliken charge indicates that the cocrystal is less sensitive than pure CL-20.
Intermolecular interactions and properties of TNT (2,4,6-trinitrotoluene)/CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane) cocrystal were studied by density functional theory (DFT) methods. Binding energy, natural bond orbital (NBO), and atom in molecules (AIM) analysis were performed to investigate the intermolecular interactions in the cocrystal. Results show that the unconventional CH…O type hydrogen bond plays a key role in forming the cocrystal. The variation tendency of entropy and enthalpy shows that the formation of the cocrystal is an exothermic process and low temperature will be benefit for the assembling of complexes. The calculated detonation velocity of the cocrystal agrees well with the experimental value which is higher than that of the physical mixture of TNT and CL-20. In addition, bond dissociation energies (BDEs) of the weakest trigger bond in TNT/CL-20 complex were calculated and the results show that the TNT/CL-20 complex is thermally stable. Finally, first-principles calculations were performed and analysis of the nitro group Mulliken charge indicates that the cocrystal is less sensitive than pure CL-20.
2016, 35(2): 257-263
doi: 10.14102/j.cnki.0254-5861.2011-0929
Abstract:
One new mixed-ligand coordination polymer, namely [Co2(btc)(bpdc)0.5(py)3]n (1), was hydrothermally synthesized using biphenyl-2,4,4'-tricarboxylic acid (H3btc) as a main building block, along with two auxiliary ligands (H2bpdc = 2,2'-bipyridine-5,5'-dicarboxylic acid and py = pyridine). The product 1 was characterized by IR spectroscopy, elemental, thermogravimetric, and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction studies show that compound 1 possesses an intricate 3D metal-organic framework based on tetracobalt(II) units. Magnetic susceptibility measurement indicates that compound 1 shows an antiferromagnetic coupling between the Co(II) ions.
One new mixed-ligand coordination polymer, namely [Co2(btc)(bpdc)0.5(py)3]n (1), was hydrothermally synthesized using biphenyl-2,4,4'-tricarboxylic acid (H3btc) as a main building block, along with two auxiliary ligands (H2bpdc = 2,2'-bipyridine-5,5'-dicarboxylic acid and py = pyridine). The product 1 was characterized by IR spectroscopy, elemental, thermogravimetric, and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction studies show that compound 1 possesses an intricate 3D metal-organic framework based on tetracobalt(II) units. Magnetic susceptibility measurement indicates that compound 1 shows an antiferromagnetic coupling between the Co(II) ions.
2016, 35(2): 264-270
doi: 10.14102/j.cnki.0254-5861.2011-0838
Abstract:
A three-dimensional coordination polymer, namely {[Zn2(tzba)(dmtrz)(OH)]·3H2O}n (1, H2tzba = 4-(5H-tetrazol)benzoic acid, Hdmtrz = 3,5-dimethyl-1H,1,2,4-triazole), was hydro- thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic system, P21/c space group with a = 8.018(11), b = 21.04(3), c = 11.069(14) Å, β = 91.26(3)°, V = 1867(4) Å3, Z = 4, Dc = 1.729 g/cm3, F(000) = 984, μ = 2.614 mm-1, R(F2 > 2σ(F2)) = 0.0612 and wR(F2) = 0.1533. Topological analysis reveals that compound 1 is a (3,5)-connected structure with a Schläfli symbol of (42.6)(42.65.83), which is a rarely observed lhh topology. In addition, the CO2 adsorption performance and luminescent property of 1 have also been studied.
A three-dimensional coordination polymer, namely {[Zn2(tzba)(dmtrz)(OH)]·3H2O}n (1, H2tzba = 4-(5H-tetrazol)benzoic acid, Hdmtrz = 3,5-dimethyl-1H,1,2,4-triazole), was hydro- thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic system, P21/c space group with a = 8.018(11), b = 21.04(3), c = 11.069(14) Å, β = 91.26(3)°, V = 1867(4) Å3, Z = 4, Dc = 1.729 g/cm3, F(000) = 984, μ = 2.614 mm-1, R(F2 > 2σ(F2)) = 0.0612 and wR(F2) = 0.1533. Topological analysis reveals that compound 1 is a (3,5)-connected structure with a Schläfli symbol of (42.6)(42.65.83), which is a rarely observed lhh topology. In addition, the CO2 adsorption performance and luminescent property of 1 have also been studied.
2016, 35(2): 271-278
doi: 10.14102/j.cnki.0254-5861.2011-0833
Abstract:
Two metal-dithiolene compounds with a formula of [4-ClBz-1-APy][Ni(dmit)2] (1) and [4-NO2Bz-1-APy][Ni(dmit)2] (2, 4-ClBz-1-APy = 1-N-(4'-chlorobenzyl)pyridinium, 4-NO2Bz- 1-APy = 1-N-(4'-nitrobenzyl)pyridinium, dmit2- = l,3-dithiole-2-thione-4,5-dithiolate) were synthesized and characterized. Two compounds crystallize in triclinic space group P1 and P1, respectively, but with different cell parameters and packing structures. The [Ni(dmit)2]- anions and cations of 1 form mixed column stacks along the a axis and alternately layered alignments in the crystal of 2, which are parallel to the crystallographic (110) plane. Two compounds show a similar magnetic behavior, the magnetic exchange natures are mainly antiferromagnetic, and the magnetic susceptibility data can be fitted to the simple Curie-Weiss law. For 1 and 2, the fitted Curie constants are much less than the spin-only value expected for an S = 1/2 system, and the fitted Weiss constants marking magnetic interaction are also very smaller. This fact implies that the weak Currie- Weiss-type paramagnetism is not the intrinsic characteristics of two compounds.
Two metal-dithiolene compounds with a formula of [4-ClBz-1-APy][Ni(dmit)2] (1) and [4-NO2Bz-1-APy][Ni(dmit)2] (2, 4-ClBz-1-APy = 1-N-(4'-chlorobenzyl)pyridinium, 4-NO2Bz- 1-APy = 1-N-(4'-nitrobenzyl)pyridinium, dmit2- = l,3-dithiole-2-thione-4,5-dithiolate) were synthesized and characterized. Two compounds crystallize in triclinic space group P1 and P1, respectively, but with different cell parameters and packing structures. The [Ni(dmit)2]- anions and cations of 1 form mixed column stacks along the a axis and alternately layered alignments in the crystal of 2, which are parallel to the crystallographic (110) plane. Two compounds show a similar magnetic behavior, the magnetic exchange natures are mainly antiferromagnetic, and the magnetic susceptibility data can be fitted to the simple Curie-Weiss law. For 1 and 2, the fitted Curie constants are much less than the spin-only value expected for an S = 1/2 system, and the fitted Weiss constants marking magnetic interaction are also very smaller. This fact implies that the weak Currie- Weiss-type paramagnetism is not the intrinsic characteristics of two compounds.
2016, 35(2): 279-285
doi: 10.14102/j.cnki.0254-5861.2011-0836
Abstract:
A new cadmium(II) complex [Cd(Hminic)(IP)]n (1, Hminic = 2-hydroxy-6-methyli- sonicotinic acid, IP = imidazo[4,5-f]-1,10-phenanthroline), has been synthesized by the reaction of a Hminic and auxiliary N-containing ligands with Cd(II) ion under hydrothermal conditions. The complex was studied by elemental analysis, IR spectroscopy and X-ray crystallography. It is formulated as C20H13CdN5O3, crystallizes in monoclinic system, space group C2/c with α = 9.6764(8), b = 26.767(2), c = 14.1332(11) Å and b = 97.4510(10)°. V = 3629.7(5) Å3, Z = 8, Mr = 483.75, Dc = 1.770 g/cm3, F(000) = 1484 and µ = 1.237 mm-1. The final refinement gave R = 0.0309 and wR = 0.0703 for 4151 reflections with I > 2s(I). In the structure of 1, two Cd(II) atoms are joined by a pair of μ2-hydroxyl oxygen atoms giving rise to a dinuclear Cd(II) unit which is bridged by Hminic linkers to form a 1D ladder-like polymer chain. The chelating ligand IP coordinated to the Cd(II) atom, and alternately attached to both sides of the ladder-like polymer chain. Adjacent chains are further bound together by strong intermolecular hydrogen bonds and face-to-face π…π interactions, resulting in the formation of a 3D supramolecular architecture. Furthermore, the thermal stability and luminescent properties of this complex and the free ligands have been investigated.
A new cadmium(II) complex [Cd(Hminic)(IP)]n (1, Hminic = 2-hydroxy-6-methyli- sonicotinic acid, IP = imidazo[4,5-f]-1,10-phenanthroline), has been synthesized by the reaction of a Hminic and auxiliary N-containing ligands with Cd(II) ion under hydrothermal conditions. The complex was studied by elemental analysis, IR spectroscopy and X-ray crystallography. It is formulated as C20H13CdN5O3, crystallizes in monoclinic system, space group C2/c with α = 9.6764(8), b = 26.767(2), c = 14.1332(11) Å and b = 97.4510(10)°. V = 3629.7(5) Å3, Z = 8, Mr = 483.75, Dc = 1.770 g/cm3, F(000) = 1484 and µ = 1.237 mm-1. The final refinement gave R = 0.0309 and wR = 0.0703 for 4151 reflections with I > 2s(I). In the structure of 1, two Cd(II) atoms are joined by a pair of μ2-hydroxyl oxygen atoms giving rise to a dinuclear Cd(II) unit which is bridged by Hminic linkers to form a 1D ladder-like polymer chain. The chelating ligand IP coordinated to the Cd(II) atom, and alternately attached to both sides of the ladder-like polymer chain. Adjacent chains are further bound together by strong intermolecular hydrogen bonds and face-to-face π…π interactions, resulting in the formation of a 3D supramolecular architecture. Furthermore, the thermal stability and luminescent properties of this complex and the free ligands have been investigated.
2016, 35(2): 286-292
doi: 10.14102/j.cnki.0254-5861.2011-0840
Abstract:
Two new coordination polymers, named {[Co3(pfca)6(phen)2]·2H2O}n (1) and [Cu(pfca)2(4,4'-bpy)(H2O)]n (2) (Hpfca = 4-fluorocinnamic acid and 4,4'-bpy = 4,4'-bipyridine), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Complex 1 crystallizes in the triclinic crystal system, space group P with a = 10.939(3), b = 12.430(4), c = 13.815(4) Å, α = 78.436(3), β = 70.261(3), γ = 80.268(3)°, V = 1721.8(9) Å3, Dc = 1.508 g/cm3, Mr = 1564.06, Z = 1, F(000) = 799, μ = 0.802 mm-1, the final R = 0.0432 and wR = 0.1015 for 13250 observed reflections with I > 2σ(I). Complex 2 is of monoclinic system, space group P21/c with a = 15.4985(14), b = 15.8424(14), c = 10.9528(10) Å, β = 107.1600(10)°, V = 2569.6(4) Å3, Dc = 1.468 g/cm3, Mr = 568.02, Z = 4, F(000) = 1164, μ = 0.906 mm-1, the final R = 0.0371 and wR = 0.0842 for 18183 observed reflections with I > 2σ(I). Complex 1 features linear Co(II)-trinuclear units, which are assembled into a final 3D supramolecular structure through π…π stacking interactions and F…H weak interactions. Complex 2 consists of 1D polymeric Cu(II)-chains that are further cohered together by extensive H-bonds.
Two new coordination polymers, named {[Co3(pfca)6(phen)2]·2H2O}n (1) and [Cu(pfca)2(4,4'-bpy)(H2O)]n (2) (Hpfca = 4-fluorocinnamic acid and 4,4'-bpy = 4,4'-bipyridine), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Complex 1 crystallizes in the triclinic crystal system, space group P with a = 10.939(3), b = 12.430(4), c = 13.815(4) Å, α = 78.436(3), β = 70.261(3), γ = 80.268(3)°, V = 1721.8(9) Å3, Dc = 1.508 g/cm3, Mr = 1564.06, Z = 1, F(000) = 799, μ = 0.802 mm-1, the final R = 0.0432 and wR = 0.1015 for 13250 observed reflections with I > 2σ(I). Complex 2 is of monoclinic system, space group P21/c with a = 15.4985(14), b = 15.8424(14), c = 10.9528(10) Å, β = 107.1600(10)°, V = 2569.6(4) Å3, Dc = 1.468 g/cm3, Mr = 568.02, Z = 4, F(000) = 1164, μ = 0.906 mm-1, the final R = 0.0371 and wR = 0.0842 for 18183 observed reflections with I > 2σ(I). Complex 1 features linear Co(II)-trinuclear units, which are assembled into a final 3D supramolecular structure through π…π stacking interactions and F…H weak interactions. Complex 2 consists of 1D polymeric Cu(II)-chains that are further cohered together by extensive H-bonds.
2016, 35(2): 293-297
doi: 10.14102/j.cnki.0254-5861.2011-0845
Abstract:
A new cadmium(II) coordination polymer, [Cd(Hcna)2]n (1), was hydrothermally synthesized based on 5-(4-carboxyphenoxy)nicotinic acid (H2cna) organic linker. X-ray single- crystal diffraction determination reveals that 1 crystallizes in the monoclinic P21/c space group, with a = 10.101(2), b = 7.9139(17), c = 15.627(3) Å, β = 103.364(3)°, V = 1215.4(4) Å3, Z = 2, Mr = 628.81, Dc = 1.718 Mg/m3, μ = 0.963 mm-1, F(000) = 628, the final R = 0.0177 and wR = 0.0432 for 2263 observed reflections with I > 2σ(I). In 1, the Cd(II) cations are connected by nicotiniate units to form a two-dimensional (2D) layer, and it is further linked through benzoate units to form a three-dimensional (3D) structure. Topologically, the structure of 1 represents a 3,6-connected 3D rtl topology. Furthermore, thermal stability and photoluminescent property of 1 have also been investigated.
A new cadmium(II) coordination polymer, [Cd(Hcna)2]n (1), was hydrothermally synthesized based on 5-(4-carboxyphenoxy)nicotinic acid (H2cna) organic linker. X-ray single- crystal diffraction determination reveals that 1 crystallizes in the monoclinic P21/c space group, with a = 10.101(2), b = 7.9139(17), c = 15.627(3) Å, β = 103.364(3)°, V = 1215.4(4) Å3, Z = 2, Mr = 628.81, Dc = 1.718 Mg/m3, μ = 0.963 mm-1, F(000) = 628, the final R = 0.0177 and wR = 0.0432 for 2263 observed reflections with I > 2σ(I). In 1, the Cd(II) cations are connected by nicotiniate units to form a two-dimensional (2D) layer, and it is further linked through benzoate units to form a three-dimensional (3D) structure. Topologically, the structure of 1 represents a 3,6-connected 3D rtl topology. Furthermore, thermal stability and photoluminescent property of 1 have also been investigated.
2016, 35(2): 298-306
doi: 10.14102/j.cnki.0254-5861.2011-0854
Abstract:
A new complex [Co(NIPH)(mbix)]n (1, H2NIPH = 5-nitroisophthalic acid, mbix = 1,3-bis(imidazol-1-ylmethyl)benzene) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, UV spectrum, TG and single-crystal X-ray diffraction. Pink crystals crystallize in the triclinic system, space group P1 with a = 8.3797(8), b = 10.2522(10), c = 13.4244(13) Å, α = 94.820(2), β = 108.105(2), γ = 104.816(2)°, V = 1042.84(17) Å3, C22H17CoN5O6, Mr = 506.34, Dc = 1.613 g/cm3, F(000) = 518, Z = 2, μ(MoKα) = 0.876 mm-1, the final R = 0.0505 and wR = 0.1254 for 3267 observed reflections (I > 2s(I)). The structure of 1 exhibits a two-dimensional network structure and is extended into a three-dimensional supramolecule through hydrogen bonds and π-π interactions. In addition, Natural Bond Orbital (NBO) analysis was performed by using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interactions between the coordinated atoms and Co(II) ion.
A new complex [Co(NIPH)(mbix)]n (1, H2NIPH = 5-nitroisophthalic acid, mbix = 1,3-bis(imidazol-1-ylmethyl)benzene) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, UV spectrum, TG and single-crystal X-ray diffraction. Pink crystals crystallize in the triclinic system, space group P1 with a = 8.3797(8), b = 10.2522(10), c = 13.4244(13) Å, α = 94.820(2), β = 108.105(2), γ = 104.816(2)°, V = 1042.84(17) Å3, C22H17CoN5O6, Mr = 506.34, Dc = 1.613 g/cm3, F(000) = 518, Z = 2, μ(MoKα) = 0.876 mm-1, the final R = 0.0505 and wR = 0.1254 for 3267 observed reflections (I > 2s(I)). The structure of 1 exhibits a two-dimensional network structure and is extended into a three-dimensional supramolecule through hydrogen bonds and π-π interactions. In addition, Natural Bond Orbital (NBO) analysis was performed by using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interactions between the coordinated atoms and Co(II) ion.
2016, 35(2): 307-312
doi: 10.14102/j.cnki.0254-5861.2011-0823
Abstract:
Treatment of indolyl-3-aldimines (3-tBuN=CH)C8H5NH with AlMe3 afforded the deprotonated indolyl aluminum complex cis-[(μ-η1:η1-3-tBuN=CH)C8H5NAlMe2]2, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the orthorhombic system, space group P21212 with a = 14.590(9), b = 15.860(2), c = 13.266(8) Å, μ = 0.118 mm-1, Mr = 512.64, V = 3069.5(3) Å3, Z = 4, Dc = 1.109 g/cm3, F(000) = 1104, R = 0.0451 and wR = 0.0937 for 4978 observed reflections with I > 2σ(I). In addition, the title compound exhibited a high catalytic activity toward the addition of amines to carbodiimide to form guanidines.
Treatment of indolyl-3-aldimines (3-tBuN=CH)C8H5NH with AlMe3 afforded the deprotonated indolyl aluminum complex cis-[(μ-η1:η1-3-tBuN=CH)C8H5NAlMe2]2, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the orthorhombic system, space group P21212 with a = 14.590(9), b = 15.860(2), c = 13.266(8) Å, μ = 0.118 mm-1, Mr = 512.64, V = 3069.5(3) Å3, Z = 4, Dc = 1.109 g/cm3, F(000) = 1104, R = 0.0451 and wR = 0.0937 for 4978 observed reflections with I > 2σ(I). In addition, the title compound exhibited a high catalytic activity toward the addition of amines to carbodiimide to form guanidines.
2016, 35(2): 313-318
doi: 10.14102/j.cnki.0254-5861.2011-0818
Abstract:
The bis-benzimidazolium salt bis[2-(N-ethylbenzimidazoliumyl)ethyl]amine hexa- fluorophosphate (LH2·(PF6)2) and its N-heterocyclic carbene silver(I) complex [L2Ag3](PF6)3 (1) have been prepared and characterized. In complex 1, a trinuclear silver(I) architecture is formed by two tridentate ligands and three silver(I) atoms, in which one 12- and two 7-membered rings are contained. In the crystal packing of 1, 1D chain and 2D supramolecular layer are formed via intermolecular weak interactions, including π…π interactions and C-H…π contacts. Additionally, the fluorescence emission spectra of LH2·(PF6)2 and 1 are described.
The bis-benzimidazolium salt bis[2-(N-ethylbenzimidazoliumyl)ethyl]amine hexa- fluorophosphate (LH2·(PF6)2) and its N-heterocyclic carbene silver(I) complex [L2Ag3](PF6)3 (1) have been prepared and characterized. In complex 1, a trinuclear silver(I) architecture is formed by two tridentate ligands and three silver(I) atoms, in which one 12- and two 7-membered rings are contained. In the crystal packing of 1, 1D chain and 2D supramolecular layer are formed via intermolecular weak interactions, including π…π interactions and C-H…π contacts. Additionally, the fluorescence emission spectra of LH2·(PF6)2 and 1 are described.
2016, 35(2): 319-325
doi: 10.14102/j.cnki.0254-5861.2011-0814
Abstract:
A new coordination polymer, {[Ag2(bpp)2(H2O)2]·bpdc·3H2O}n, derived from the ligand biphenyl-4,4'-dicarboxylic acid (H2bpdc), has been obtained through a hydrothermal technique (bpp = 1,3-bis(4-pyridyl)propane). Its single-crystal structure has been characterized by single-crystal X-ray diffraction, powder XRD, FT-IR, TGA and elemental analysis techniques. The single-crystal X-ray diffraction reveals that complex 1 consists of 1D infinite [Ag(bpp)(H2O)]nn+ cationic chains, 2D anionic layer constructed by bpdc anions and free water which provide charge compensation in the crystal structure. The 1D infinite [Ag(bpp)(H2O)]nn+ cationic chains and 2D anionic layer are further stacked in -ABAB- fashion through intermolecular H-bonding to form a 3D sandwich-like framework. In addition, the luminescent property of complex 1 in the solid state at room temperature was investigated.
A new coordination polymer, {[Ag2(bpp)2(H2O)2]·bpdc·3H2O}n, derived from the ligand biphenyl-4,4'-dicarboxylic acid (H2bpdc), has been obtained through a hydrothermal technique (bpp = 1,3-bis(4-pyridyl)propane). Its single-crystal structure has been characterized by single-crystal X-ray diffraction, powder XRD, FT-IR, TGA and elemental analysis techniques. The single-crystal X-ray diffraction reveals that complex 1 consists of 1D infinite [Ag(bpp)(H2O)]nn+ cationic chains, 2D anionic layer constructed by bpdc anions and free water which provide charge compensation in the crystal structure. The 1D infinite [Ag(bpp)(H2O)]nn+ cationic chains and 2D anionic layer are further stacked in -ABAB- fashion through intermolecular H-bonding to form a 3D sandwich-like framework. In addition, the luminescent property of complex 1 in the solid state at room temperature was investigated.
2016, 35(2): 326-334
doi: 10.14102/j.cnki.0254-5861.2011-0871
Abstract:
A series of YAG:Ce, Tb phosphors were synthesized by vacuum sintering method. Moreover, their spectral properties, thermal quenching behaviors and color rendering properties were investigated systematically. The photoluminescence emission spectra of YAG:Ce, Tb show a great red shift compared with that of YAG:Ce. Direct energy transfer from Tb3+ to Ce3+ ions is verified based on the analysis of different photoluminescence spectra. The quenching temperature for Tb3+-doped YAG:Ce phosphors is about 490 K. The thermal activation energy is estimated to be 0.18 and 0.291 eV for Tb3+-doped YAG:Ce and YAG:Ce phosphors, respectively. The smaller activation energy for Tb3+-doped YAG:Ce means a more rapid nonradiative transition from 5d to 4f state, thus resulting in the lower quenching temperature. In addition, white LEDs with improved color rendering properties are achieved by using modified YAG:Ce, Tb phosphors.
A series of YAG:Ce, Tb phosphors were synthesized by vacuum sintering method. Moreover, their spectral properties, thermal quenching behaviors and color rendering properties were investigated systematically. The photoluminescence emission spectra of YAG:Ce, Tb show a great red shift compared with that of YAG:Ce. Direct energy transfer from Tb3+ to Ce3+ ions is verified based on the analysis of different photoluminescence spectra. The quenching temperature for Tb3+-doped YAG:Ce phosphors is about 490 K. The thermal activation energy is estimated to be 0.18 and 0.291 eV for Tb3+-doped YAG:Ce and YAG:Ce phosphors, respectively. The smaller activation energy for Tb3+-doped YAG:Ce means a more rapid nonradiative transition from 5d to 4f state, thus resulting in the lower quenching temperature. In addition, white LEDs with improved color rendering properties are achieved by using modified YAG:Ce, Tb phosphors.
