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2020 Volume 39 Issue 7
2020, 39(7): 1185-1193
doi: 10.14102/j.cnki.0254–5861.2011–2922
Abstract:
Atomic clusters of subnanometer scale and variable chemical composition offer great opportunities for rational design of functional nanomaterials. Among them, cage clusters doped with endohedral atom are particularly interesting owing to their enhanced stability and highly tunable physical and chemical properties. In this perspective, first we give a brief overview of the history of doped cage clusters and introduce the home-developed comprehensive genetic algorithm (CGA) for structure prediction of clusters. Then, we show a few examples of magnetic clusters and subnanometer catalysts based on doped cage clusters, which are computationally revealed or designed by the CGA code. Finally, we give an outlook for some future directions of cluster science.
Atomic clusters of subnanometer scale and variable chemical composition offer great opportunities for rational design of functional nanomaterials. Among them, cage clusters doped with endohedral atom are particularly interesting owing to their enhanced stability and highly tunable physical and chemical properties. In this perspective, first we give a brief overview of the history of doped cage clusters and introduce the home-developed comprehensive genetic algorithm (CGA) for structure prediction of clusters. Then, we show a few examples of magnetic clusters and subnanometer catalysts based on doped cage clusters, which are computationally revealed or designed by the CGA code. Finally, we give an outlook for some future directions of cluster science.
2020, 39(7): 1194-1200
doi: 10.14102/j.cnki.0254–5861.2011–2928
Abstract:
Ligand-protected metal nanoclusters have drawn increasing research interest because of their unique physicochemical properties and practical applications. Great efforts have been made in pursuing rational synthesis of metal nanoclusters and establishing the structure-property relationships. As an indispensable part of ligand-protected metal nanoclusters, ligands play multiple roles in determining their structures and properties. In this perspective, we demonstrate the importance of ligand engineering in terms of the control of structures, optical and catalytic properties of metal nanoclusters. Furthermore, we will show that ligand engineering is prospective in structural design and preorganization of surface metal sites.
Ligand-protected metal nanoclusters have drawn increasing research interest because of their unique physicochemical properties and practical applications. Great efforts have been made in pursuing rational synthesis of metal nanoclusters and establishing the structure-property relationships. As an indispensable part of ligand-protected metal nanoclusters, ligands play multiple roles in determining their structures and properties. In this perspective, we demonstrate the importance of ligand engineering in terms of the control of structures, optical and catalytic properties of metal nanoclusters. Furthermore, we will show that ligand engineering is prospective in structural design and preorganization of surface metal sites.
2020, 39(7): 1201-1212
doi: 10.14102/j.cnki.0254–5861.2011–2929
Abstract:
Actinide-containing cluster compounds are highly important in radio- and nuclear chemistry. Until three decades ago, little attention had been paid to these heavy-element clusters because of difficulties in their syntheses and characterization as well as handling of these radioactive and chemotoxic elements. In this overview article we have selectively summarized the recent progresses in experimental and theoretical studies on actinide clusters, including actinide (An = Th, Pa, U, Np and Pu) oxide clusters as well as uranyl (UO22+) peroxide clusters and so on. It shows that An(Ⅳ) (An = Th, U, Np and Pu) is able to form highly symmetric An6ⅣO8 core clusters and further merge into larger clusters up to An38O56 clusters (An = U, Np and Pu) with the same topology. Meanwhile, An with higher oxidation states such as U(Ⅵ) in uranyl is capable to form fullerene-like peroxide cage clusters of U20, U60 with the same topology as C20 and C60. Relativistic quantum chemistry investigations on the geometric structures, electronic structures and chemical bonding patterns have also been briefly summarized herein to provide an understanding on the structural chemistry of these peculiar clusters. The advances in electronic structure studies of actinide clusters help to develop robust theoretical and computational techniques for the future development of actinide cluster chemistry. Further experimental and computational studies of actinide clusters are needed and helpful to accelerate the development of radio- and nuclear chemistry.
Actinide-containing cluster compounds are highly important in radio- and nuclear chemistry. Until three decades ago, little attention had been paid to these heavy-element clusters because of difficulties in their syntheses and characterization as well as handling of these radioactive and chemotoxic elements. In this overview article we have selectively summarized the recent progresses in experimental and theoretical studies on actinide clusters, including actinide (An = Th, Pa, U, Np and Pu) oxide clusters as well as uranyl (UO22+) peroxide clusters and so on. It shows that An(Ⅳ) (An = Th, U, Np and Pu) is able to form highly symmetric An6ⅣO8 core clusters and further merge into larger clusters up to An38O56 clusters (An = U, Np and Pu) with the same topology. Meanwhile, An with higher oxidation states such as U(Ⅵ) in uranyl is capable to form fullerene-like peroxide cage clusters of U20, U60 with the same topology as C20 and C60. Relativistic quantum chemistry investigations on the geometric structures, electronic structures and chemical bonding patterns have also been briefly summarized herein to provide an understanding on the structural chemistry of these peculiar clusters. The advances in electronic structure studies of actinide clusters help to develop robust theoretical and computational techniques for the future development of actinide cluster chemistry. Further experimental and computational studies of actinide clusters are needed and helpful to accelerate the development of radio- and nuclear chemistry.
2020, 39(7): 1213-1225
doi: 10.14102/j.cnki.0254–5861.2011–2563
Abstract:
In this paper, DFT method was used to study the relative stability of hydrogen bonding networks of numerous 512, 51262 and 435663 water cluster isomers. Herein we introduced an optimized six-digit definition to characterize diverse sub-grouped hydrogen bonds to consider the cooperative effect of the nearest and next-nearest neighbor water molecules. There are totally 74 kinds of sub-grouped hydrogen bonds in cage hydrate clusters, and these energies can be obtained by iterative calculations. This improvement effectively explains some regularity contained in hydrogen bonding cooperative effect. In general, donor or acceptor fragment sharing identical value of three independent digits usually performs poor cooperative effect, indicating that the existence of those same-digital-array fragments is the necessary condition to judge poor cooperative effect. Vice versa, the existence of different-digital-array is also the necessary condition to judge strong cooperative effect.
In this paper, DFT method was used to study the relative stability of hydrogen bonding networks of numerous 512, 51262 and 435663 water cluster isomers. Herein we introduced an optimized six-digit definition to characterize diverse sub-grouped hydrogen bonds to consider the cooperative effect of the nearest and next-nearest neighbor water molecules. There are totally 74 kinds of sub-grouped hydrogen bonds in cage hydrate clusters, and these energies can be obtained by iterative calculations. This improvement effectively explains some regularity contained in hydrogen bonding cooperative effect. In general, donor or acceptor fragment sharing identical value of three independent digits usually performs poor cooperative effect, indicating that the existence of those same-digital-array fragments is the necessary condition to judge poor cooperative effect. Vice versa, the existence of different-digital-array is also the necessary condition to judge strong cooperative effect.
2020, 39(7): 1226-1234
doi: 10.14102/j.cnki.0254–5861.2011–2568
Abstract:
28 kinds of carotenoids are studied to reveal the key parameters and regulation on the singlet oxygen quenching rate. First, the quantum chemistry parameters of carotenoids calculated by Gaussian software combined with substitution parameters were used to construct the quantitative structure-activity relationship model (QSAR) of the singlet oxygen quenching rate of carotenoids. The key parameters affecting the antioxidant activity of carotenoids are revealed, and the data predicted via the QSAR model were provided for subsequent research. Then, a three-dimensional (3D) pharmacophore model was used to regulate and modify the antioxidant activity of carotenoids. The correlation coefficients of the modeling group (R2) and verification group (Rpre2) of the established QSAR model were 0.945 and 0.916, respectively, which can be used for the analysis of antioxidant activity of carotenoids; the antioxidant activity of carotenoids can be significantly regulated by the number of conjugated C=C bonds, the energy difference between frontier molecular orbitals and the partial Mulliken charge in C1 and the π…π* excitation energy E(s); the antioxidant activity of carotenoids can be effectively regulated by the hydrogen bond acceptor pharmacophores on both sides of the conjugated C=C bonds and the hydrophobic groups on the conjugated C=C bond; the hydrophobic substituents attached to conjugated C=C bonds can effectively improve the singlet oxygen quenching rate of carotenoids.
28 kinds of carotenoids are studied to reveal the key parameters and regulation on the singlet oxygen quenching rate. First, the quantum chemistry parameters of carotenoids calculated by Gaussian software combined with substitution parameters were used to construct the quantitative structure-activity relationship model (QSAR) of the singlet oxygen quenching rate of carotenoids. The key parameters affecting the antioxidant activity of carotenoids are revealed, and the data predicted via the QSAR model were provided for subsequent research. Then, a three-dimensional (3D) pharmacophore model was used to regulate and modify the antioxidant activity of carotenoids. The correlation coefficients of the modeling group (R2) and verification group (Rpre2) of the established QSAR model were 0.945 and 0.916, respectively, which can be used for the analysis of antioxidant activity of carotenoids; the antioxidant activity of carotenoids can be significantly regulated by the number of conjugated C=C bonds, the energy difference between frontier molecular orbitals and the partial Mulliken charge in C1 and the π…π* excitation energy E(s); the antioxidant activity of carotenoids can be effectively regulated by the hydrogen bond acceptor pharmacophores on both sides of the conjugated C=C bonds and the hydrophobic groups on the conjugated C=C bond; the hydrophobic substituents attached to conjugated C=C bonds can effectively improve the singlet oxygen quenching rate of carotenoids.
2020, 39(7): 1235-1242
doi: 10.14102/j.cnki.0254–5861.2011–2570
Abstract:
Chromenones have attracted much attention since they are excellent acetylcholinesterase inhibitor (AChEi). The 1, 2, 3-triazoles are multifunctional anti-acetylcholinesterase (AChE) agents. In this paper, we report the three-dimensional quantitative structure-activity relationship (3D-QSAR) study of 25 1, 2, 3-triazole-chromenone derivatives based comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). To construct CoMFA and CoMSIA models, the 25 active molecules were randomly divided into the training and test sets. The obtained cross-validation Q2 of the CoMFA model, the coefficient of non-cross-validation R2, and the test value F are 0.597, 0.994, and 396.726, respectively. The cross-validation Q2 of the CoMSIA model, the coefficient of the non-cross-validation R2, and the test value F are 0.721, 0.979, and 131.107, respectively. The predictive correlation coefficient (rpred2) is 0.728 for CoMFA and 0.805 for CoMSIA, which verifies that the model is predictable. Based on the potential maps of CoMFA and CoMSIA, a library containing a set of potent AChEi was designed. The inhibitory potential of the compounds in this library was found to be greater than the inhibitory potential of the most active compounds in the data set. The results obtained from this study laid the foundation for the development of effective drugs for AChEi.
Chromenones have attracted much attention since they are excellent acetylcholinesterase inhibitor (AChEi). The 1, 2, 3-triazoles are multifunctional anti-acetylcholinesterase (AChE) agents. In this paper, we report the three-dimensional quantitative structure-activity relationship (3D-QSAR) study of 25 1, 2, 3-triazole-chromenone derivatives based comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). To construct CoMFA and CoMSIA models, the 25 active molecules were randomly divided into the training and test sets. The obtained cross-validation Q2 of the CoMFA model, the coefficient of non-cross-validation R2, and the test value F are 0.597, 0.994, and 396.726, respectively. The cross-validation Q2 of the CoMSIA model, the coefficient of the non-cross-validation R2, and the test value F are 0.721, 0.979, and 131.107, respectively. The predictive correlation coefficient (rpred2) is 0.728 for CoMFA and 0.805 for CoMSIA, which verifies that the model is predictable. Based on the potential maps of CoMFA and CoMSIA, a library containing a set of potent AChEi was designed. The inhibitory potential of the compounds in this library was found to be greater than the inhibitory potential of the most active compounds in the data set. The results obtained from this study laid the foundation for the development of effective drugs for AChEi.
2020, 39(7): 1243-1251
doi: 10.14102/j.cnki.0254–5861.2011–2571
Abstract:
Development of the nano-electronics requires materials with both high carrier mobility and a sufficiently large electronic band gap. In this work, by means of ab initio calculations, we have predicted a new 2D Ca2Si monolayer with a quasi-planar hexa-coordinate structure. The geometrical structure, stability and electronic properties of Ca2Si monolayer have been systemically investigated. The Ca2Si monolayer is an indirect semiconductor with band gap of about 0.77 eV, which exhibits stable chemical bonding interactions as well as thermal and dynamic stability. Moreover, the carrier mobility in Ca2Si monolayer is electron dominated with a high electron mobility about 4590.47 cm2⋅V-1⋅s-1. It is excited that the 2D Ca2Si monolayer exhibits strong directionally anisotropic carrier mobility, which could effectively facilitate the migration and separation of the generated electron-hole pairs. Our calculations demonstrate that the 2D Ca2Si monolayer is potential for high efficiency solar cells and other nano-electronic applications.
Development of the nano-electronics requires materials with both high carrier mobility and a sufficiently large electronic band gap. In this work, by means of ab initio calculations, we have predicted a new 2D Ca2Si monolayer with a quasi-planar hexa-coordinate structure. The geometrical structure, stability and electronic properties of Ca2Si monolayer have been systemically investigated. The Ca2Si monolayer is an indirect semiconductor with band gap of about 0.77 eV, which exhibits stable chemical bonding interactions as well as thermal and dynamic stability. Moreover, the carrier mobility in Ca2Si monolayer is electron dominated with a high electron mobility about 4590.47 cm2⋅V-1⋅s-1. It is excited that the 2D Ca2Si monolayer exhibits strong directionally anisotropic carrier mobility, which could effectively facilitate the migration and separation of the generated electron-hole pairs. Our calculations demonstrate that the 2D Ca2Si monolayer is potential for high efficiency solar cells and other nano-electronic applications.
2020, 39(7): 1252-1260
doi: 10.14102/j.cnki.0254–5861.2011–2589
Abstract:
Triclosan, a kind of multi-purpose biocide, was widely used household cleaning and personal care products. The widespread use of triclosan has potential risk to the ecotype and human health due to its release into sediment, surface and ground water resources. A molecularly imprinted electrochemical sensor for triclosan detection in cosmetic emulsion was synthesized and characterized. In order to determine the suitable monomer and evaluate the template-monomer geometry as well as the interaction energy in the template-monomer prepolymerization mixture, a computational study was applied. We found that the complex formed by hybrid monomers (triclosan(o-phenylenediamine-co-resorcinol)) had more hydrogen bonds and larger binding energy than that by single kind of monomers (triclosan(o-phenylenediamine)2 and triclosan(resorcinol)2). Therefore, hybrid monomers were used to synthesize the imprinted electrochemical sensor, which exhibits a high sensitivity and selectivity for triclosan sensing with the detection range 0~15 ng·mL-1 and detection limit 0.41 ng·mL-1.
Triclosan, a kind of multi-purpose biocide, was widely used household cleaning and personal care products. The widespread use of triclosan has potential risk to the ecotype and human health due to its release into sediment, surface and ground water resources. A molecularly imprinted electrochemical sensor for triclosan detection in cosmetic emulsion was synthesized and characterized. In order to determine the suitable monomer and evaluate the template-monomer geometry as well as the interaction energy in the template-monomer prepolymerization mixture, a computational study was applied. We found that the complex formed by hybrid monomers (triclosan(o-phenylenediamine-co-resorcinol)) had more hydrogen bonds and larger binding energy than that by single kind of monomers (triclosan(o-phenylenediamine)2 and triclosan(resorcinol)2). Therefore, hybrid monomers were used to synthesize the imprinted electrochemical sensor, which exhibits a high sensitivity and selectivity for triclosan sensing with the detection range 0~15 ng·mL-1 and detection limit 0.41 ng·mL-1.
2020, 39(7): 1261-1265
doi: 10.14102/j.cnki.0254–5861.2011–2587
Abstract:
The azide oxiranes were studied at the CCSD(T)/cc-PVDZ//MP2/cc-PVDZ level in this paper. The sublimation enthalpies and heats of formation both in gas phase and solid state were calculated. The thermodynamics stability was predicted by using the bond dissociation energy and characteristic height, through which all title compounds are confirmed to be more stable than hexanitrohexaazaisowurtzitane (CL-20) and A, B1 and D are less sensitive than hexahydro-1, 3, 5, -trinitro-1, 3, 5-triazine (RDX). Furthermore, the detonation property was measured by the specific impulse. The detonation performance of the title compounds is comparable to that of RDX. Our results can provide basic information for the molecular design of novel high-energy-density compounds.
The azide oxiranes were studied at the CCSD(T)/cc-PVDZ//MP2/cc-PVDZ level in this paper. The sublimation enthalpies and heats of formation both in gas phase and solid state were calculated. The thermodynamics stability was predicted by using the bond dissociation energy and characteristic height, through which all title compounds are confirmed to be more stable than hexanitrohexaazaisowurtzitane (CL-20) and A, B1 and D are less sensitive than hexahydro-1, 3, 5, -trinitro-1, 3, 5-triazine (RDX). Furthermore, the detonation property was measured by the specific impulse. The detonation performance of the title compounds is comparable to that of RDX. Our results can provide basic information for the molecular design of novel high-energy-density compounds.
2020, 39(7): 1266-1270
doi: 10.14102/j.cnki.0254–5861.2011–2619
Abstract:
Nitro and amino groups were introduced into piperidine skeleton to design derivatives of piperidine (labeled as α, β1, β2, β3, γ and δ). Heats of formation (HOFs) are calculated in detail at the B3PW91/6-311+G(d, p) level for these aminonitropiperidines. The results show that all derivatives have negative heats of formation, which were affected by the positions of substituted groups. The molecular stability is estimated and analyzed based on bond dissociation energies (BDE) and characteristic heights (H50). All derivatives designed in this paper are confirmed with lower impact sensitivity than 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX) and 1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocane (HMX). Furthermore, the detonation velocities (D) and the detonation pressures (P) are predicted via the Kamlet-Jacobs equation. In all these molecules, δ has comparable detonation character with that of RDX and HMX and can be the candidate of high-energy-density compounds (HEDCs).
Nitro and amino groups were introduced into piperidine skeleton to design derivatives of piperidine (labeled as α, β1, β2, β3, γ and δ). Heats of formation (HOFs) are calculated in detail at the B3PW91/6-311+G(d, p) level for these aminonitropiperidines. The results show that all derivatives have negative heats of formation, which were affected by the positions of substituted groups. The molecular stability is estimated and analyzed based on bond dissociation energies (BDE) and characteristic heights (H50). All derivatives designed in this paper are confirmed with lower impact sensitivity than 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX) and 1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocane (HMX). Furthermore, the detonation velocities (D) and the detonation pressures (P) are predicted via the Kamlet-Jacobs equation. In all these molecules, δ has comparable detonation character with that of RDX and HMX and can be the candidate of high-energy-density compounds (HEDCs).
2020, 39(7): 1271-1276
doi: 10.14102/j.cnki.0254–5861.2011–2615
Abstract:
The target compounds 3 (C14H15NO4) and 4 (C20H17NO8) were synthesized and structurally determined by single-crystal X-ray diffraction. The crystal of 3 is in the monoclinic system, space group P21/c with a = 7.3017(3), b = 7.8737(5), c = 22.4227(11) Å, β = 94.837(5)°, C14H15NO4, Mr = 261.27, Dc = 1.351 g/cm3, V = 1284.51(11) Å3, Z = 4, F(000) = 552, µ(MoKa) = 0.828 mm–1, T = 289.12(10) K, 2236 independent reflections with 1827 observed ones (I > 2σ(I)), R = 0.0515 and wR = 0.1394 with GOF = 1.044 (R = 0.0605 and wR = 0.1548 for all data). The crystal of compound 4 is in the monoclinic system, space group P21/c with a = 7.1269(3), b = 12.6518(6), c = 20.7540(8) Å, β = 96.941(4)°, C20H17NO8, Mr = 399.35, Dc = 1.428 g/cm3, V = 1857.61(14) Å3, Z = 4, F(000) = 832.0, µ(MoKa) = 0.950 mm–1, T = 288.81(10) K, 3216 independent reflections with 2253 observed ones (I > 2σ(I)), R = 0.0612 and wR = 0.1548 with GOF = 1.055 (R = 0.0824 and wR = 0.1790 for all data). The skeleton of 1,4-dihydroquinoline 3 is noncoplanar, while pyrrolo[1,2-a]-quinoline 4 owns a coplanar frame structure. One-dimensional interaction model of compound 4 was formed by the one kind of π-π interaction between the two adjacent molecules at upper and lower levels. And the inhibition to the strand transfer process of HIV-1 integrase of the title compounds was also evaluated.
The target compounds 3 (C14H15NO4) and 4 (C20H17NO8) were synthesized and structurally determined by single-crystal X-ray diffraction. The crystal of 3 is in the monoclinic system, space group P21/c with a = 7.3017(3), b = 7.8737(5), c = 22.4227(11) Å, β = 94.837(5)°, C14H15NO4, Mr = 261.27, Dc = 1.351 g/cm3, V = 1284.51(11) Å3, Z = 4, F(000) = 552, µ(MoKa) = 0.828 mm–1, T = 289.12(10) K, 2236 independent reflections with 1827 observed ones (I > 2σ(I)), R = 0.0515 and wR = 0.1394 with GOF = 1.044 (R = 0.0605 and wR = 0.1548 for all data). The crystal of compound 4 is in the monoclinic system, space group P21/c with a = 7.1269(3), b = 12.6518(6), c = 20.7540(8) Å, β = 96.941(4)°, C20H17NO8, Mr = 399.35, Dc = 1.428 g/cm3, V = 1857.61(14) Å3, Z = 4, F(000) = 832.0, µ(MoKa) = 0.950 mm–1, T = 288.81(10) K, 3216 independent reflections with 2253 observed ones (I > 2σ(I)), R = 0.0612 and wR = 0.1548 with GOF = 1.055 (R = 0.0824 and wR = 0.1790 for all data). The skeleton of 1,4-dihydroquinoline 3 is noncoplanar, while pyrrolo[1,2-a]-quinoline 4 owns a coplanar frame structure. One-dimensional interaction model of compound 4 was formed by the one kind of π-π interaction between the two adjacent molecules at upper and lower levels. And the inhibition to the strand transfer process of HIV-1 integrase of the title compounds was also evaluated.
2020, 39(7): 1277-1282
doi: 10.14102/j.cnki.0254–5861.2011–2698
Abstract:
The title compound maistemonine (1) was isolated from the total alkaloid fraction of the 95% ethanol extract of the roots of Stemona japonica, followed by preparative HPLC and recrystallization from a mixture of n-hexane and ethyl acetate. The crystal structure of 1, C23H29NO6, was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group P212121 with a = 8.5698(6), b = 14.0460(11), c = 17.8815(17) Å, V = 2152.4(3) Å3, Z = 4, Mr = 415.47, Dc = 1.282 g/cm3, λ = 0.71079 Å, μ = 0.092 cm–1, F(000) = 888, S = 0.995, R = 0.0535 and wR = 0.1067. A total of 5136 unique reflections were collected, of which 3523 were observed (I > 2σ(I)). The absolute configuration of 1 could be assigned by referring to the conserved configuration of the methyl groups at C(2). Compound 1 shows mild cytotoxic activity against the prostate cancer cells LNCaP and PC3 with the IC50 values of 29.4 ± 2.3 and 46.6 ± 3.1 μM, respectively. It is noteworthy that the natural maistemonine (1) is different from the synthetic compound which was a racemic with the triclinic space group P1. The lactone rings E from the natural and synthetic 1 are almost perpendicular to each other when overlapping the remaining parts of the molecules.
The title compound maistemonine (1) was isolated from the total alkaloid fraction of the 95% ethanol extract of the roots of Stemona japonica, followed by preparative HPLC and recrystallization from a mixture of n-hexane and ethyl acetate. The crystal structure of 1, C23H29NO6, was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group P212121 with a = 8.5698(6), b = 14.0460(11), c = 17.8815(17) Å, V = 2152.4(3) Å3, Z = 4, Mr = 415.47, Dc = 1.282 g/cm3, λ = 0.71079 Å, μ = 0.092 cm–1, F(000) = 888, S = 0.995, R = 0.0535 and wR = 0.1067. A total of 5136 unique reflections were collected, of which 3523 were observed (I > 2σ(I)). The absolute configuration of 1 could be assigned by referring to the conserved configuration of the methyl groups at C(2). Compound 1 shows mild cytotoxic activity against the prostate cancer cells LNCaP and PC3 with the IC50 values of 29.4 ± 2.3 and 46.6 ± 3.1 μM, respectively. It is noteworthy that the natural maistemonine (1) is different from the synthetic compound which was a racemic with the triclinic space group P1. The lactone rings E from the natural and synthetic 1 are almost perpendicular to each other when overlapping the remaining parts of the molecules.
2020, 39(7): 1283-1287
doi: 10.14102/j.cnki.0254–5861.2011–2608
Abstract:
We isolated cucurbitacin IIa from the rhizomes of Hemsleya pengxianensis, and tested the cytotoxicity of cucurbitacin IIa against various cancer cell lines by the sulforhodamine B assay (SRB). At the same time, we preliminarily found that cucurbitacin IIa has a certain inhibitory activity on kinase CDK1/cyclin B, and shows potent inhibitory activities against many cancer cell lines. The cucurbitacin IIa was structurally characterized by specific optical rotation measurement, high-resolution mass spectroscopy and NMR spectroscopic analysis. In addition, the molecular structure of cucurbitacin IIa was further determined by X-ray single-crystal crystallography.
We isolated cucurbitacin IIa from the rhizomes of Hemsleya pengxianensis, and tested the cytotoxicity of cucurbitacin IIa against various cancer cell lines by the sulforhodamine B assay (SRB). At the same time, we preliminarily found that cucurbitacin IIa has a certain inhibitory activity on kinase CDK1/cyclin B, and shows potent inhibitory activities against many cancer cell lines. The cucurbitacin IIa was structurally characterized by specific optical rotation measurement, high-resolution mass spectroscopy and NMR spectroscopic analysis. In addition, the molecular structure of cucurbitacin IIa was further determined by X-ray single-crystal crystallography.
2020, 39(7): 1288-1294
doi: 10.14102/j.cnki.0254–5861.2011–2552
Abstract:
A dinuclear cuprous complex [(mapypz)Cu(μ-I)2Cu(mapypz)] (1, mapypz = 9,9-dimethyl-10-(6-(3-phenyl-1H-pyrazol-1-yl)-pyridin-3-yl)-9,10-dihydroacridine) was synthesized from the reaction of equivalent CuI and mapypz at room temperature. The compound crystallizes in monoclinic space group P21/c with a = 13.8300(4), b = 9.5365(2), c = 19.0833(5) Å, β = 103.017(3)º, V = 2452.23(11) Å3, Z = 2, Mr = 1237.92, Dc = 1.677 g/cm3, F(000) = 1232, μ = 11.334 mm–1, GOOF = 1.001, the final R = 0.0330, and wR = 0.0741 for 4627 observed reflections with I > 2σ(I). The Cu(Ⅰ) atoms in the complex are four-coordinated with a distorted tetrahedral coordination geometry. The copper centers in the molecular structure are bridged by two iodide anions and each Cu(Ⅰ) is chelated further terminally by a diimine ligand. The [Cu(μ-I)2Cu] core is planar. In the solid state, the complex exhibits orange photoluminescence with emission peak λmax = 568 nm, lifetime τ = 16 μs and quantum yield ф = 0.22 at room temperature. The studies of varied temperature emission spectra and decay behaviours of the complex indicate that it displays thermally activated delayed fluorescence at room temperature. The results of experimental and DFT calculations suggest that the emission in the solid state originates from the 1,3MLCT excited states.
A dinuclear cuprous complex [(mapypz)Cu(μ-I)2Cu(mapypz)] (1, mapypz = 9,9-dimethyl-10-(6-(3-phenyl-1H-pyrazol-1-yl)-pyridin-3-yl)-9,10-dihydroacridine) was synthesized from the reaction of equivalent CuI and mapypz at room temperature. The compound crystallizes in monoclinic space group P21/c with a = 13.8300(4), b = 9.5365(2), c = 19.0833(5) Å, β = 103.017(3)º, V = 2452.23(11) Å3, Z = 2, Mr = 1237.92, Dc = 1.677 g/cm3, F(000) = 1232, μ = 11.334 mm–1, GOOF = 1.001, the final R = 0.0330, and wR = 0.0741 for 4627 observed reflections with I > 2σ(I). The Cu(Ⅰ) atoms in the complex are four-coordinated with a distorted tetrahedral coordination geometry. The copper centers in the molecular structure are bridged by two iodide anions and each Cu(Ⅰ) is chelated further terminally by a diimine ligand. The [Cu(μ-I)2Cu] core is planar. In the solid state, the complex exhibits orange photoluminescence with emission peak λmax = 568 nm, lifetime τ = 16 μs and quantum yield ф = 0.22 at room temperature. The studies of varied temperature emission spectra and decay behaviours of the complex indicate that it displays thermally activated delayed fluorescence at room temperature. The results of experimental and DFT calculations suggest that the emission in the solid state originates from the 1,3MLCT excited states.
Synthesis, Structure and Luminescence Property of a New Two-dimensional Znic(Ⅱ) Coordination Polymer
2020, 39(7): 1295-1300
doi: 10.14102/j.cnki.0254–5861.2011–2561
Abstract:
Based on 5-dimethylamino-isophthalic acid (H2dia) and 1,2-bis(4-pyridyl)ethylene (bpe) mixed linkers, a new d10-configuration Zn(Ⅱ) coordination polymer material, [Zn(dia)(bpe)(H2O)]n (1), was synthesized. In the asymmetric unit, there are one Zn2+ ion, two dia2− anions, one neutral bpe linker and one free H2O molecule. In the complex, adjacent Zn2+ ions are alternately bridged by the dia2− dianions to generate chains which are further connected by flexible bpe ligands to form a two-dimensional (2D) layer structure. In topology, the structure of 1 represents a non-interpenetrating 4-connected sql topology. Moreover, infrared spectroscopy, elemental analyses, thermogravimetric analysis, powder X-ray diffraction, solid UV-Vis absorption spectra and photoluminescent property of 1 are also investigated.
Based on 5-dimethylamino-isophthalic acid (H2dia) and 1,2-bis(4-pyridyl)ethylene (bpe) mixed linkers, a new d10-configuration Zn(Ⅱ) coordination polymer material, [Zn(dia)(bpe)(H2O)]n (1), was synthesized. In the asymmetric unit, there are one Zn2+ ion, two dia2− anions, one neutral bpe linker and one free H2O molecule. In the complex, adjacent Zn2+ ions are alternately bridged by the dia2− dianions to generate chains which are further connected by flexible bpe ligands to form a two-dimensional (2D) layer structure. In topology, the structure of 1 represents a non-interpenetrating 4-connected sql topology. Moreover, infrared spectroscopy, elemental analyses, thermogravimetric analysis, powder X-ray diffraction, solid UV-Vis absorption spectra and photoluminescent property of 1 are also investigated.
2020, 39(7): 1301-1306
doi: 10.14102/j.cnki.0254–5861.2011–2566
Abstract:
A new silver(Ⅰ) complex {Ag2(dppm)2[N(CN)2]}2[μ-N(CN)2]2 (1) with chelate ligand bis(diphenyl-phosphino)methane (dppm) and bridging ligand dicyanamide (N(CN)2) was carefully synthesized and fully characterized by single-crystal X-ray crystallography, IR spectrometry, high-resolution mass spectrometry, thermal analysis and 1H NMR. According to the crystal structure analysis, this complex could be considered as two binucleate moieties {Ag2(dppm)2[N(CN)2]}+ linked by two bridging anionic ligands N(CN)2−. It exhibits thermochromic property in solid state. The dependence of color or emission of substance on temperature is known as thermochromism. Various temperature luminescences of complex 1 are tested. Along with the reduction of temperature from 298 K to 77 K, a noticeable emission enhancement as well as lifetime extension is observed.
A new silver(Ⅰ) complex {Ag2(dppm)2[N(CN)2]}2[μ-N(CN)2]2 (1) with chelate ligand bis(diphenyl-phosphino)methane (dppm) and bridging ligand dicyanamide (N(CN)2) was carefully synthesized and fully characterized by single-crystal X-ray crystallography, IR spectrometry, high-resolution mass spectrometry, thermal analysis and 1H NMR. According to the crystal structure analysis, this complex could be considered as two binucleate moieties {Ag2(dppm)2[N(CN)2]}+ linked by two bridging anionic ligands N(CN)2−. It exhibits thermochromic property in solid state. The dependence of color or emission of substance on temperature is known as thermochromism. Various temperature luminescences of complex 1 are tested. Along with the reduction of temperature from 298 K to 77 K, a noticeable emission enhancement as well as lifetime extension is observed.
2020, 39(7): 1307-1313
doi: 10.14102/j.cnki.0254–5861.2011–2580
Abstract:
A new layered yttrium iodate [Y(IO3)3(H2O)2]n (1) has been prepared from the hydrothermal reaction of Y(NO3)3·6H2O with I2O5 at 170 ℃, and its structure was determined by X-ray single-crystal diffraction method. It belongs to the triclinic system, space group P\begin{document}$ \overline 1 $\end{document}
A new layered yttrium iodate [Y(IO3)3(H2O)2]n (1) has been prepared from the hydrothermal reaction of Y(NO3)3·6H2O with I2O5 at 170 ℃, and its structure was determined by X-ray single-crystal diffraction method. It belongs to the triclinic system, space group P
2020, 39(7): 1314-1322
doi: 10.14102/j.cnki.0254–5861.2011–2582
Abstract:
A new ligand, 2-(2-methoxynaphthyl)-1H-imidazo[4,5-f][1,10]phenanthroline (mnipH), was synthesized by the condensation of 2-methoxy-1-naphthaldehyde and 5,6-diamino-1,10-phenanthroline. Then three ionic copper(Ⅰ) complexes were obtained through the reactions of [Cu(MeCN)4]ClO4, mnipH and the chelating diphosphine ligands with a molar ratio of 1:1:1. The photoluminescence and the corresponding luminescent mechanism of all copper(Ⅰ) complexes in the solid state were investigated at room temperature.
A new ligand, 2-(2-methoxynaphthyl)-1H-imidazo[4,5-f][1,10]phenanthroline (mnipH), was synthesized by the condensation of 2-methoxy-1-naphthaldehyde and 5,6-diamino-1,10-phenanthroline. Then three ionic copper(Ⅰ) complexes were obtained through the reactions of [Cu(MeCN)4]ClO4, mnipH and the chelating diphosphine ligands with a molar ratio of 1:1:1. The photoluminescence and the corresponding luminescent mechanism of all copper(Ⅰ) complexes in the solid state were investigated at room temperature.
2020, 39(7): 1323-1330
doi: 10.14102/j.cnki.0254–5861.2011–2581
Abstract:
A new gadolinium iodate has been synthesized via hydrothermal method, and its structure was determined as [Gd(H2O)(IO3)2(IO3H2O)]n (1) by X-ray single-crystal diffraction. The 2-D layer is built from the linkage of Gd2O16I4 dimer via μ2/μ3-bridged iodates, and the quasi-3-D network is generated via weak I···O bonds and hydrogen bonds. FTIR, powder X-ray diffraction (PXRD) and UV-Vis spectra were conducted to characterize the as-synthesized sample. Interestingly, 1 exhibits green emission, which might be assigned to electronic transfer within iodate groups. The UV adsorption of 1 hints its UV light-driven photocatalytic property, and as expected, it exhibits photocatalytic activity for the degradation of rhodamine B. Theoretical calculation was conducted to give structure/property correlation.
A new gadolinium iodate has been synthesized via hydrothermal method, and its structure was determined as [Gd(H2O)(IO3)2(IO3H2O)]n (1) by X-ray single-crystal diffraction. The 2-D layer is built from the linkage of Gd2O16I4 dimer via μ2/μ3-bridged iodates, and the quasi-3-D network is generated via weak I···O bonds and hydrogen bonds. FTIR, powder X-ray diffraction (PXRD) and UV-Vis spectra were conducted to characterize the as-synthesized sample. Interestingly, 1 exhibits green emission, which might be assigned to electronic transfer within iodate groups. The UV adsorption of 1 hints its UV light-driven photocatalytic property, and as expected, it exhibits photocatalytic activity for the degradation of rhodamine B. Theoretical calculation was conducted to give structure/property correlation.
2020, 39(7): 1331-1336
doi: 10.14102/j.cnki.0254–5861.2011–2789
Abstract:
A new terbium(Ⅲ) complex Tb2(C15H11O3)6(2,2'-bipy)2 has been synthesized with 2-(4-methylbenzoyl)benzoic acid and 2,2'-bipy ligands. Crystal data for the complex: monoclinic, space group P21/n, a = 14.9738(5), b = 13.5469(4), c = 23.0683(7) Å, β = 103.950(3)°, V = 4541.4(3) Å3, Dc = 1.511 g/cm3, Z = 2, μ(MoKα) = 1.620 mm-1, F(000) = 2088, the final R = 0.0318 and wR = 0.0727. The Tb(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows three fluorescence emission bands arising from the transitions of Tb3+: 5D4 → 7F6 (490 nm), 5D4 → 7F5 (545 nm) and 5D4 → 7F4 (584 nm). The complex exhibits antiferromagnetism in the temperature range of 300~2 K. Also reported are the thermal stability properties of the complex.
A new terbium(Ⅲ) complex Tb2(C15H11O3)6(2,2'-bipy)2 has been synthesized with 2-(4-methylbenzoyl)benzoic acid and 2,2'-bipy ligands. Crystal data for the complex: monoclinic, space group P21/n, a = 14.9738(5), b = 13.5469(4), c = 23.0683(7) Å, β = 103.950(3)°, V = 4541.4(3) Å3, Dc = 1.511 g/cm3, Z = 2, μ(MoKα) = 1.620 mm-1, F(000) = 2088, the final R = 0.0318 and wR = 0.0727. The Tb(Ⅲ) ion is coordinated by eight atoms to give a distorted square antiprism coordination geometry. The complex shows three fluorescence emission bands arising from the transitions of Tb3+: 5D4 → 7F6 (490 nm), 5D4 → 7F5 (545 nm) and 5D4 → 7F4 (584 nm). The complex exhibits antiferromagnetism in the temperature range of 300~2 K. Also reported are the thermal stability properties of the complex.
2020, 39(7): 1337-1342
doi: 10.14102/j.cnki.0254–5861.2011–2609
Abstract:
By using Co(NH3)63+ as the template, a new complex HNU-38 was synthesized under hydrothermal reaction through the adoption of H3BTC and Cl- as the ligands (H3BTC = 1,3,5-benzenetricarboxylic acid). HNU-38 crystallized in the monoclinic system, P21/c space group with a = 9.9696(3), b = 17.0580(6), c = 16.5263(6) Å, β = 100.400(2)º, Z = 4, V = 2764.31(16) Å3, Mr = 883.63, Dc = 2.123 g/cm3, F(000) = 1736, S = 0.920, R = 0.0358 and wR = 0.0838 (I > 2σ(I)). In HNU-38, the Cd2+ and BTC3- were linked together to form layers with Cl- serving as the pillar. It should be noted that (H2O)n chains were found in the channels and play a co-templating role along with the Co(NH3)63+ cations in HNU-38, and the proton conduction properties were investigated.
By using Co(NH3)63+ as the template, a new complex HNU-38 was synthesized under hydrothermal reaction through the adoption of H3BTC and Cl- as the ligands (H3BTC = 1,3,5-benzenetricarboxylic acid). HNU-38 crystallized in the monoclinic system, P21/c space group with a = 9.9696(3), b = 17.0580(6), c = 16.5263(6) Å, β = 100.400(2)º, Z = 4, V = 2764.31(16) Å3, Mr = 883.63, Dc = 2.123 g/cm3, F(000) = 1736, S = 0.920, R = 0.0358 and wR = 0.0838 (I > 2σ(I)). In HNU-38, the Cd2+ and BTC3- were linked together to form layers with Cl- serving as the pillar. It should be noted that (H2O)n chains were found in the channels and play a co-templating role along with the Co(NH3)63+ cations in HNU-38, and the proton conduction properties were investigated.
2020, 39(7): 1343-1349
doi: 10.14102/j.cnki.0254–5861.2011–2772
Abstract:
The sequential reaction of the N, N, O-tridentate ligand HOC(CH2)5CH2N(Me)CH2 CH2NMe2 (LH) in diethyl ether with AlEtCl2 and MeLi afforded a lithium-aluminum complex containing a polymeric structure of one-dimensional chain [{-LiOC(CH2)5CH2N(Me)CH2CH2NMe2}AlMe2CH3-}n] (1), which was characterized by 1H, 13C NMR spectra, elemental analyses and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in triclinic, space group P\begin{document}$ \overline 1 $\end{document}
The sequential reaction of the N, N, O-tridentate ligand HOC(CH2)5CH2N(Me)CH2 CH2NMe2 (LH) in diethyl ether with AlEtCl2 and MeLi afforded a lithium-aluminum complex containing a polymeric structure of one-dimensional chain [{-LiOC(CH2)5CH2N(Me)CH2CH2NMe2}AlMe2CH3-}n] (1), which was characterized by 1H, 13C NMR spectra, elemental analyses and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in triclinic, space group P
2020, 39(7): 1350-1356
doi: 10.14102/j.cnki.0254–5861.2011–2599
Abstract:
One new polyoxometalate-based coordination polymer with 2,6-bis(1-imidazoly) pyridine (L) as the ligand, [Ni(L)(HL)(H2O)(H2W12O40)0.5·H2O]n, has been synthesized under hydrothermal method and characterized by IR spectra, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analyses and thermogravimetric analyses (TGA). It crystallizes in orthorhombic, space group Pnma with a = 20.169(7), b = 23.924(8), c = 15.333(5) Å, V = 7398(4) Å3, Z = 8, F(000) = 6992, Dc = 3.488 Mg/m3, Mr = 1942.32, µ = 19.177 mm−1 and the final R = 0.0299, wR = 0.0551. In the title compound, each Ni(Ⅱ) atom is bridged by two ligands L to form Ni2L2, which are further connected into a one-dimensional chain structure by coordination with [H2W12O40]6– polyoxoanions, and thus the ultimate 3D framework is constructed via different hydrogen bonding interactions. In addition, the cyclic voltammograms, magnetism, luminescence and photocatalytic activity towards RhB are investigated. The title compound exhibits antiferromagnetic behaviors, luminescent behaviors at solid state and photocatalytic activity to RhB.
One new polyoxometalate-based coordination polymer with 2,6-bis(1-imidazoly) pyridine (L) as the ligand, [Ni(L)(HL)(H2O)(H2W12O40)0.5·H2O]n, has been synthesized under hydrothermal method and characterized by IR spectra, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analyses and thermogravimetric analyses (TGA). It crystallizes in orthorhombic, space group Pnma with a = 20.169(7), b = 23.924(8), c = 15.333(5) Å, V = 7398(4) Å3, Z = 8, F(000) = 6992, Dc = 3.488 Mg/m3, Mr = 1942.32, µ = 19.177 mm−1 and the final R = 0.0299, wR = 0.0551. In the title compound, each Ni(Ⅱ) atom is bridged by two ligands L to form Ni2L2, which are further connected into a one-dimensional chain structure by coordination with [H2W12O40]6– polyoxoanions, and thus the ultimate 3D framework is constructed via different hydrogen bonding interactions. In addition, the cyclic voltammograms, magnetism, luminescence and photocatalytic activity towards RhB are investigated. The title compound exhibits antiferromagnetic behaviors, luminescent behaviors at solid state and photocatalytic activity to RhB.
