The title compounds Mo3S4(dtp)3(o-CH3OC6H4COO)(Py) 1 and Mo3S(dtp)3(p-HOC6H4COO)(DMF)稥tOH 2 (dtp = diethyldithiophosphate) were synthesized by thereactions of Mo3S4(dtp)4(CH3CN) and Mo3S4(dtp)3(CH2ClCOO)(Py) with o-m...The title compounds Mo3S4(dtp)3(o-CH3OC6H4COO)(Py) 1 and Mo3S(dtp)3(p-HOC6H4COO)(DMF)稥tOH 2 (dtp = diethyldithiophosphate) were synthesized by thereactions of Mo3S4(dtp)4(CH3CN) and Mo3S4(dtp)3(CH2ClCOO)(Py) with o-methoxylbenzoic acid and p-hydroxybenzoic acid, respectively. Their crystal structures were determined by X-ray diffraction analysis. The crystal data for compound 1: Mo3S10P3C25H42O9N, monoclinic P21/n, Mr = 1201.93, Z = 4, a = 14.164(1), b = 23.065(2), c = 14.732(1) ? = 109.677(1) ? V = 4532(1) ?, D= 1.762 gcm-3, = 1.428 mm-1, F (000) = 2408, R = 0.0739, wR = 0.1528 for 3552 observed reflections (I > 2); and for compound 2: Mo3S10P3C24H48O11N, triclinic P ? Mr = 1227.96, Z = 2, = 10.2098(3), b = 14.3333(4), c = 18.1711(5) ? = 94.694(1), = 102.166(1), = 110.665(1) , V = 2396.5(1)3, Dc = 1.638 gcm-3, = 1.350mm-1, F (000) = 1184, R = 0.0445, wR = 0.1281 for 6597 observed reflections (I > 2). Intermolecular S…S interactions are observed between the molecules of compound 1 while intramolecular O…HC and intermolecular S…HC hydrogen bondings are found in the crystal packing diagram of compound 2.展开更多
DNA primase catalyzes de novo synthesis of a short RNA primer that is further extended by replicative DNA polymerases during initiation of DNA replication. The eukaryotic primase is a heterodimeric enzyme comprising a...DNA primase catalyzes de novo synthesis of a short RNA primer that is further extended by replicative DNA polymerases during initiation of DNA replication. The eukaryotic primase is a heterodimeric enzyme comprising a catalytic subunit Pril and a regulatory subunit Pri2. Pri2 is responsible for facilitating optimal RNA primer synthesis by Pril and mediating interaction between Pril and DNA polymerase o for transition from RNA synthesis to DNA elongation. All eukaryotic Pri2 proteins contain a conserved C-terminal iron-sulfur （Fe-S） cluster-binding domain that is critical for primase catalytic activity in vitro. Here we show that mutations at conserved cysteine ligands for the Pri2 Fe-S cluster markedly decrease the protein stability, thereby causing S phase arrest at the restrictive temperature. Furthermore, Pri2 cysteine mutants are defective in loading of the entire DNA pol α-primase complex onto early replication origins resulting in defective initiation. Importantly, assembly of the Fe-S cluster in Pri2 is impaired not only by mutations at the conserved cysteine ligands but also by increased oxidative stress in the sodlA mutant lacking the Cu/Zn superoxide dismutase. Together these findings highlight the critical role of Pri2＇s Fe-S cluster domain in replication initiation in vivo and suggest a molecular basis for how DNA replication can be influenced by changes in cellular redox state.展开更多
The intermolecular clusters of sulfur dioxide with water, SO2（H2O）n （n = 2～5）, are studied by using B3LYP density functional theory and MP2 ab initio methods along with the large basis sets （6-311＋＋G（d,p） an...The intermolecular clusters of sulfur dioxide with water, SO2（H2O）n （n = 2～5）, are studied by using B3LYP density functional theory and MP2 ab initio methods along with the large basis sets （6-311＋＋G（d,p） and aug-cc-pVDZ）. The equilibrium geometries, intermolecular binding energies, and anharmonic frequencies of the clusters are calculated and compared with those of pure water clusters and available experiments. SO2 tends to form cyclic hydrogen-bonded complexes with two or three water molecules. In the larger clusters, however, water molecules begin to retain the structure of pure water clusters and segregate from SO2. Infrared absorption assignments for the small clusters are discussed to resolve a possible incorrect assignment in a recent spectroscopic experiment on the clusters.展开更多
A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)?(H2O)2?(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPRO...A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)?(H2O)2?(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P1, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3) ?, α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) ?3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.展开更多
We investigate the structures and the melting temperature of the Si6 cluster by using the first-principles pseudopotential method in real space and Langevin molecular dynamics. It is shown that the ground structure of...We investigate the structures and the melting temperature of the Si6 cluster by using the first-principles pseudopotential method in real space and Langevin molecular dynamics. It is shown that the ground structure of the Si6 cluster is a square bipyramid, and the corresponding melting temperature is about 1923 K. In the heating procedure, the structures of the Si6 cluster change from high symmetry structures containing 5-8 bonds, via prolate structures containing 3-4 bonds, to oblate structures containing 1-2 bonds.展开更多
This paper investigates the geometrical structures and relative stabilities of neutral A1Sn （n=2-9） using the density functional theory. Structural optimisation and frequency analysis are performed at the B3LYP/6-3...This paper investigates the geometrical structures and relative stabilities of neutral A1Sn （n=2-9） using the density functional theory. Structural optimisation and frequency analysis are performed at the B3LYP/6-311C（d） level. The ground state structures of the A1Sn show that the sulfur atoms prefer not only to evenly distribute on both sides of the aluminum atom but also to form stable structures in AlSn clusters. The structures of pure Sn are fundamentally changed due to the doping of the Al atom. The fragmentation energies and the second-order energy differences are calculated and discussed. Among neutral AlSn （n = 2-9） clusters, AlS4 and AlS6 are the most stable.展开更多
The reaction of [Et4N]2WOS3 with three equiv.of CuI and dmpzm in MeCN afforded [WOS3Cu3I（dmpzm）2]·2（MeCN）0.5（1·2（MeCN）0.5） while that of [PPh4]2WS4 with four equiv.of CuI in DMF/MeCN followed by the ...The reaction of [Et4N]2WOS3 with three equiv.of CuI and dmpzm in MeCN afforded [WOS3Cu3I（dmpzm）2]·2（MeCN）0.5（1·2（MeCN）0.5） while that of [PPh4]2WS4 with four equiv.of CuI in DMF/MeCN followed by the addition of two equiv.of dmpzm in MeOH gave rise to [WS4Cu4I2（dmpzm）2]·DMF（2·DMF）.Both compounds were characterized by elemental analysis,IR,and single-crystal X-ray diffraction analysis.1·2（MeCN）0.5 crystallizes in triclinic,space group P1-with a = 11.4552（5）,b = 11.6735（3）,c = 16.2278（9） ,α = 99.537（9）,β = 101.986（2）,γ = 118.464（13）o,V = 1775.5（3）3,Z = 2,μ = 6.080 mm-1,Dc = 1.983 Mg/m3,T = 193（2） K,C24H35Cu3IN9OS3W,Mr = 1063.22,F（000） = 1018,S = 1.060,R = 0.0376 and wR = 0.0870.2·DMF belongs to the orthorhombic system,space group Pmn21 with a = 22.145（4）,b = 11.464（2）,c = 7.7370（15） ,V = 1964.2（6）3,Z = 2,μ = 6.865 mm-1,Dc = 2.189 Mg/m3,T = 193（2） K,C25H39Cu4I2N9OS4W,Mr = 1301.72,F（000） = 1226,R = 0.0632,wR = 0.1706 and S = 1.130.1·2（MeCN）0.5 consists of one CuI and two [Cu（dmpzm）]＋ fragments that are linked by [WOS3]2-species via six Cu-S bonds,forming a nido-like [WS3Cu3] core.2·DMF contains a saddle-shaped [WS4Cu4] core with two iodides coordinated at two Cu centers in a cis position and two dmpzm ligands being chelated at another two Cu centers in a cis position.展开更多
Reactions of the preformed cluster precursor [Et4N]2[Mo2S2（μ-S）2（edt）2] （edt = ethanedithiolate） （1） with [Au（PPh3）Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4（AuPPh3）...Reactions of the preformed cluster precursor [Et4N]2[Mo2S2（μ-S）2（edt）2] （edt = ethanedithiolate） （1） with [Au（PPh3）Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4（AuPPh3）（edt）2]·0.25Et2O·0.25MeOH （2·0.25Et2O·0.25MeOH）. It was characterized by elemental analysis, IR spectrum and X-ray analysis. 2·0.25Et2O·0.25MeOH crystallizes in the monoclinic system, space group C2/c with a = 20.117（4）, b = 9.2705（19）, c = 44.418（9） A^°, β= 93.19（3）°, V = 8271（3） A^°^3, Z = 8, Dc = 1.794 g/cm^3, T = 193 K, C31.25H43AuMo2NO0.50PS8, Mr = 1116.96, F（000） = 4380, μ（MoKa） = 4.603 mm^-1, S = 1.019, R = 0.0672 and wR = 0.1708 for 7243 observed reflections with I 〉 2σ（I）. The anion of 2 consists of a butterfly-shaped Mo2S4Au core in which one [AuPPh3]^＋ cation is coordinated by one bridging S and two terminal S atoms of the [（edt）2Mo2（S）2（μ-S）2] moiety. The Au（I） center adopts a pseudo-tetrahedral coordination geometry, and the Au-S bond lengths vary from 2.425（2） to 2.898（3）A^°.展开更多
基金① This work was financially supported by the NNSF of China (No. 29733090 and No. 20173063)Key Project in KIP of CAS (KJCX2-H3) the NNSF of Fujian Province (E0020001)
文摘The title compounds Mo3S4(dtp)3(o-CH3OC6H4COO)(Py) 1 and Mo3S(dtp)3(p-HOC6H4COO)(DMF)稥tOH 2 (dtp = diethyldithiophosphate) were synthesized by thereactions of Mo3S4(dtp)4(CH3CN) and Mo3S4(dtp)3(CH2ClCOO)(Py) with o-methoxylbenzoic acid and p-hydroxybenzoic acid, respectively. Their crystal structures were determined by X-ray diffraction analysis. The crystal data for compound 1: Mo3S10P3C25H42O9N, monoclinic P21/n, Mr = 1201.93, Z = 4, a = 14.164(1), b = 23.065(2), c = 14.732(1) ? = 109.677(1) ? V = 4532(1) ?, D= 1.762 gcm-3, = 1.428 mm-1, F (000) = 2408, R = 0.0739, wR = 0.1528 for 3552 observed reflections (I > 2); and for compound 2: Mo3S10P3C24H48O11N, triclinic P ? Mr = 1227.96, Z = 2, = 10.2098(3), b = 14.3333(4), c = 18.1711(5) ? = 94.694(1), = 102.166(1), = 110.665(1) , V = 2396.5(1)3, Dc = 1.638 gcm-3, = 1.350mm-1, F (000) = 1184, R = 0.0445, wR = 0.1281 for 6597 observed reflections (I > 2). Intermolecular S…S interactions are observed between the molecules of compound 1 while intramolecular O…HC and intermolecular S…HC hydrogen bondings are found in the crystal packing diagram of compound 2.
文摘DNA primase catalyzes de novo synthesis of a short RNA primer that is further extended by replicative DNA polymerases during initiation of DNA replication. The eukaryotic primase is a heterodimeric enzyme comprising a catalytic subunit Pril and a regulatory subunit Pri2. Pri2 is responsible for facilitating optimal RNA primer synthesis by Pril and mediating interaction between Pril and DNA polymerase o for transition from RNA synthesis to DNA elongation. All eukaryotic Pri2 proteins contain a conserved C-terminal iron-sulfur （Fe-S） cluster-binding domain that is critical for primase catalytic activity in vitro. Here we show that mutations at conserved cysteine ligands for the Pri2 Fe-S cluster markedly decrease the protein stability, thereby causing S phase arrest at the restrictive temperature. Furthermore, Pri2 cysteine mutants are defective in loading of the entire DNA pol α-primase complex onto early replication origins resulting in defective initiation. Importantly, assembly of the Fe-S cluster in Pri2 is impaired not only by mutations at the conserved cysteine ligands but also by increased oxidative stress in the sodlA mutant lacking the Cu/Zn superoxide dismutase. Together these findings highlight the critical role of Pri2＇s Fe-S cluster domain in replication initiation in vivo and suggest a molecular basis for how DNA replication can be influenced by changes in cellular redox state.
基金supported by the National Natural Science Foundation of China (20528706)the China Postdoctoral Science Foundation (20090450385)
文摘The intermolecular clusters of sulfur dioxide with water, SO2（H2O）n （n = 2～5）, are studied by using B3LYP density functional theory and MP2 ab initio methods along with the large basis sets （6-311＋＋G（d,p） and aug-cc-pVDZ）. The equilibrium geometries, intermolecular binding energies, and anharmonic frequencies of the clusters are calculated and compared with those of pure water clusters and available experiments. SO2 tends to form cyclic hydrogen-bonded complexes with two or three water molecules. In the larger clusters, however, water molecules begin to retain the structure of pure water clusters and segregate from SO2. Infrared absorption assignments for the small clusters are discussed to resolve a possible incorrect assignment in a recent spectroscopic experiment on the clusters.
基金This work was supported by the State Key Basic Research and Development Plan of China (001CB108906)the NNSF of China (20173063) NSF of Fujian Province (E0020001)
文摘A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)?(H2O)2?(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P1, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3) ?, α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) ?3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.
基金Supported by the National Natural Science Foundation of China under Grant No 10274055, the Natural Science Foundation of Sichuan Education Bureau under Grant No 2004A181, and the Research Fund for the Doctoral Program of Yibin University under Grant No 2005B01.
文摘We investigate the structures and the melting temperature of the Si6 cluster by using the first-principles pseudopotential method in real space and Langevin molecular dynamics. It is shown that the ground structure of the Si6 cluster is a square bipyramid, and the corresponding melting temperature is about 1923 K. In the heating procedure, the structures of the Si6 cluster change from high symmetry structures containing 5-8 bonds, via prolate structures containing 3-4 bonds, to oblate structures containing 1-2 bonds.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10647008 and 50971099)the Research Fund for the Higher Education Doctoral Program (Grant No. 20096101110017)+1 种基金Key Project of Natural Science Foundation of Shaanxi Province of China (Grant No. 2010JZ002)the Graduate Innovation Fund of the Northwest University of China(Grant No. 09YZZ44)
文摘This paper investigates the geometrical structures and relative stabilities of neutral A1Sn （n=2-9） using the density functional theory. Structural optimisation and frequency analysis are performed at the B3LYP/6-311C（d） level. The ground state structures of the A1Sn show that the sulfur atoms prefer not only to evenly distribute on both sides of the aluminum atom but also to form stable structures in AlSn clusters. The structures of pure Sn are fundamentally changed due to the doping of the Al atom. The fragmentation energies and the second-order energy differences are calculated and discussed. Among neutral AlSn （n = 2-9） clusters, AlS4 and AlS6 are the most stable.
基金Supported by the National Natural Science Foundation of China (No. 20525101,20801038) "Soochow Scholar" Program of Suzhou University
文摘The reaction of [Et4N]2WOS3 with three equiv.of CuI and dmpzm in MeCN afforded [WOS3Cu3I（dmpzm）2]·2（MeCN）0.5（1·2（MeCN）0.5） while that of [PPh4]2WS4 with four equiv.of CuI in DMF/MeCN followed by the addition of two equiv.of dmpzm in MeOH gave rise to [WS4Cu4I2（dmpzm）2]·DMF（2·DMF）.Both compounds were characterized by elemental analysis,IR,and single-crystal X-ray diffraction analysis.1·2（MeCN）0.5 crystallizes in triclinic,space group P1-with a = 11.4552（5）,b = 11.6735（3）,c = 16.2278（9） ,α = 99.537（9）,β = 101.986（2）,γ = 118.464（13）o,V = 1775.5（3）3,Z = 2,μ = 6.080 mm-1,Dc = 1.983 Mg/m3,T = 193（2） K,C24H35Cu3IN9OS3W,Mr = 1063.22,F（000） = 1018,S = 1.060,R = 0.0376 and wR = 0.0870.2·DMF belongs to the orthorhombic system,space group Pmn21 with a = 22.145（4）,b = 11.464（2）,c = 7.7370（15） ,V = 1964.2（6）3,Z = 2,μ = 6.865 mm-1,Dc = 2.189 Mg/m3,T = 193（2） K,C25H39Cu4I2N9OS4W,Mr = 1301.72,F（000） = 1226,R = 0.0632,wR = 0.1706 and S = 1.130.1·2（MeCN）0.5 consists of one CuI and two [Cu（dmpzm）]＋ fragments that are linked by [WOS3]2-species via six Cu-S bonds,forming a nido-like [WS3Cu3] core.2·DMF contains a saddle-shaped [WS4Cu4] core with two iodides coordinated at two Cu centers in a cis position and two dmpzm ligands being chelated at another two Cu centers in a cis position.
基金supported by the National Natural Science Foundation of China (No. 20525101 and 20871088)the "SooChow Scholar" Program and Program for Innovative Research Team of Suzhou University
文摘Reactions of the preformed cluster precursor [Et4N]2[Mo2S2（μ-S）2（edt）2] （edt = ethanedithiolate） （1） with [Au（PPh3）Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4（AuPPh3）（edt）2]·0.25Et2O·0.25MeOH （2·0.25Et2O·0.25MeOH）. It was characterized by elemental analysis, IR spectrum and X-ray analysis. 2·0.25Et2O·0.25MeOH crystallizes in the monoclinic system, space group C2/c with a = 20.117（4）, b = 9.2705（19）, c = 44.418（9） A^°, β= 93.19（3）°, V = 8271（3） A^°^3, Z = 8, Dc = 1.794 g/cm^3, T = 193 K, C31.25H43AuMo2NO0.50PS8, Mr = 1116.96, F（000） = 4380, μ（MoKa） = 4.603 mm^-1, S = 1.019, R = 0.0672 and wR = 0.1708 for 7243 observed reflections with I 〉 2σ（I）. The anion of 2 consists of a butterfly-shaped Mo2S4Au core in which one [AuPPh3]^＋ cation is coordinated by one bridging S and two terminal S atoms of the [（edt）2Mo2（S）2（μ-S）2] moiety. The Au（I） center adopts a pseudo-tetrahedral coordination geometry, and the Au-S bond lengths vary from 2.425（2） to 2.898（3）A^°.
