钪配合物催化丙烯与月桂烯的共聚合

研究了两种钪配合物(C5Me4SiMe3)Sc(CH2C6H4NMe2-o)2(记作钪配合物1,Me为甲基)和(C5Me4SiMe3)Sc(CH2SiMe3)2(THF)(记作钪配合物2,THF为四氢呋喃)催化丙烯与月桂烯共聚合的性能.结果表明:在室温及丙烯压力为0.6?MPa时,通过调控月桂烯的用量,采用钪配合物1和...     

Facile synthesis and optical properties of magic-number Au13 clusters

Synthesis of molecular gold clusters through a post-synthetic scheme involving HCl-promoted nuclearity convergence was examined with various phosphine ligands. Systematic studies with a series of bis(diphenylphosphino) ligands (Ph(2)P-(CH(2))(m)-PPh(2)) using electrospray ionization mass spectrometry (ESI-MS) and electronic absorption spectroscopy demonstrated that the use of dppp (m = 3), dppb (m = 4) and dpppe (m = 5) as the ligands resulted in the formation of [Au(13)P(8)Cl(4)](+) type clusters, whereas the [Au(13)P(10)Cl(2)](3+) type cluster was formed with dppe (m = 2). The cluster species did not survive the HCl treatment step when monophosphines PPh(3), PMe(2)Ph, and POct(3) were employed, but [Au(13)(POct(3))(8)Cl(4)](+) was isolated as a minor product in the NaBH(4) reduction of Au(POct(3))Cl in aqueous THF. Electronic absorption and photoluminescence studies of a series of Au(13) clusters revealed that their optical properties are highly dependent on the phosphine/chloride composition ratio, but are far less so on the phosphine structure.     

醇对络合物TpRu(PPh3)(CH3CN)H催化氢化二氧化碳生成甲酸的影响

研究了络合物TpRu(PPh3)(CH3CN)H 在甲醇溶液中催化氢化CO2生成甲酸的最佳条件,进一步研究了甲醇、乙醇、正丙醇、异丙醇、特丁醇为溶剂时对该络合物催化氢化CO2生成甲酸的影响,提出可能的催化反应机理.     

Antibacterial and Antifungal Activity of Zinc(II) Carboxylates With/Without N-Donor Organic Ligands

The antibacterial and antifungal activity of zinc(II) carboxylates with composition Zn(RCOO)(2)*nH(2)O(R =H-, CH(3) (-), CH(3)CH(2)CH(2) (-), (CH(3))(2)CH-, XCH(2) (-), X=Cl, Br, I, n=0 or 2), [ZnX(2)(Nia(+)CH(2)COO(-))(2)](Nia=nicotinamide, X=Cl, Br, I) and [Zn(XCH(2)COO)(2)(Caf)(2)]*2H(2)O (Car=caffeine, X=Cl, Br) is studied against bacterial strains Staphylococcus aureus, Escherichia coli and yeast Candida albicans. The structural types are assigned to the prepared compounds and the influence of (i) carboxylate chain length, (ii) substitution of hydrogen atom of carboxylate by halogen and (iii) presence of N-donor organic ligands on the biological activity is discussed.     

Ag(I)(Et(2)PCH(2)CH(2)PPh(2))(2)]NO(3): An Antimitochondrial Silver Complex

The silver(I) complex [Ag(eppe)(2)]NO(3) (eppe = Et(2)PCH(2)CH(2)PPh(2)) is shown by X-ray crystallography to be tetrahedral with Ag - PEt(2) and Ag - P Ph(2) bond lengths of 2.482 and 2.518 A, respectively. The complex is selectively antimitochondrial and inhibits the growth of a number of yeast strains in non-fermentable media at concentrations as low as 2.5 muMu and induces the mitochondrial mutation petite The effect is largely reversed by the presence of aspirin. The complex is shown to be stable in the cell culture media and in the presence of glutathione, but readily reacts with disulfides of oxidized glutathione and serum albumin. Surprisingly, neither [Au(eppe)(2)]Cl nor [Au(eppe)(2)]Cl (dppe = Ph(2)PCH(2)CH(2)PPh(2)) showed any mitochondrial selectivity in the same screening protocol.     

Reactions of organic disulfides and gold(i) complexes

Gold-thiolate/disulfide exchange reactions of (p-SC(6)H(4)Cl)(2) with Ph(3)PAu(SC(6)H(4)CH(3)), dppm(AuSC(6)H(4)CH(3))(2), and dppe(AuSC(6)H(4)CH(3)) (2) were investigated. The rate of reactivity of the gold-thiolate complexes with (p-SC(6)H(4)Cl)(2) is: dppm(AuSC(6)H(4)CH(3))(2)> dppe(AuSC(6)H(4)CH(3))(2)>Ph(2)PAu (SC(6)H(4)CH(3)). This order correlates with conductivity measurements and two ionic mechanisms have been evaluated. (1)H NMR experiments demonstrate that in the reaction of dppm(AuSC(6)H(4)CH(3))(2) with (p-SC(6)H(4)Cl)(2), the mixed disulfide, ClC(6)H(4)SSC(6)H(4)CH(3), forms first, followed by the formation of (p-SC(6)H(4)CH(3))(2). The rate law is first order in (pp-SC(6)H (4)Cl)(2) and partial order in dppm(AuSC(6)H(4)CH(3))(2). Results from electrochemical and chemical reactivity studies suggest that free thiolate is not involved in the gold-thiolate/disulfide exchange reaction. A more likely source of ions is the dissociation of a proton from the methylene backbone of the dppm ligand which has been shown to exchange with D(2)O. The implications of this are discussed in terms of a possible mechanism for the gold-thiolate/disulfide exchange reaction.     

Darstellung und Charakterisierung oligomeree und polymerer Ethinylsilane mit Si2?Si4-Einheiten

Preparation and Characterization of Oligomeric as well as Polymeric Ethynylsilanes Containing Si₂ Si₄ Units The treatment of methylchlorodisilanes with ethynyldigrignard (BrMgCCMgBr) resulted in oligomeric as well as polymeric ethynyldisilanes. The kind of this products is related to the chloro functionality of the starting disilane. The reaction of SiClMe(SiCl₂Me)₂ as well as SiMe(SiCl₂Me)₃ yielded polymers beside small amounts of the monomeric products (HCC)MeSi[SiMe(CCH)₂]₂ and MeSi[SiMe(CCH)₂]₃.     

Syntheses and characterization of new nickel coordination polymers with 4,4'-dipyridylsulfide. Dynamic rearrangements of one-dimensional chains responding to external stimuli: temperature variation and guest releases/re-inclusions

Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4'-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO(3))(2)·6H(2)O with dps in EtOH yielded [Ni(dps)(2)(NO(3))(2)] ·EtOH (1), which had channels filled with guest EtOH molecules among the four Ni(dps)(2) chains. This coordination polymer reversibly transformed the channel structure responding to temperature variations. Immersion of 1 in m-xylene released guest EtOH molecules to yield a guest-free coordination polymer [Ni(dps)(2)(NO(3))(2)] (2a), which was also obtained by treatment of Ni(NO(3))(2)·6H(2)O with dps in MeOH. On the other hand, removal of the guest molecules from 1 upon heating at 130 °C under reduced pressure produced a guest-free coordination polymer [Ni(dps)(2)(NO(3))(2)] (2b). Although the 2a and 2b guest-free coordination polymers have the same formula, they showed differences in the assembled structures of the one-dimensional chains. Exposure of 2b to EtOH vapor reproduced 1, while 2a did not convert to 1 in a similar reaction. Reaction of Ni(NO(3))(2)·6H(2)O with dps in acetone provided [Ni(dps)(NO(3))(2)(H(2)O)] ·Me(2)CO (4) with no channel structure. When MeOH or acetone was used as a reaction solvent, the [Ni(dps)(2)(NO(3))(2)] · (guest molecule) type coordination polymer, which was observed in 1, was not formed. Nevertheless, the reaction of Ni(NO(3))(2)·6H(2)O with dps in MeOH/acetone mixed solution produced [Ni(dps)(2)(NO(3))(2)]·0.5(MeOH·acetone) (5), which has an isostructural Ni-dps framework to 1.     

Interaction of Some Non-Platinum Metal Anticancer Complexes With Nucleotides and DNA and The Two-Pole Complementary Principle (TPCP) Arising Therefrom

The binding modes of some non-platinum metal anticancer complexes, Cp(2)TiCl(2), Cp(2)ZrCl(2), (CH(3))(2)SnCl(2), (C(2)H(5))(2)SnCl(2), (C(2)H(5))(2)SnCl(2)(phen) (phen=Phenanthroline) and cis-Ru(II)Cl(2)(DMSO)(3) (DMSO) (cis-RDT) with nucleotides and DNA in aqueous solution at physiological pH values were investigated by various modern techniques. 5'-dGMP with Cp(2)TiCl(2) or cis-RDT forms chelate complexes in which both N(7) and phosphate of dGMP bind to the metal center. Whereas Cp(2)ZrCl(2) and all the diorganotin compounds can bind dGMP only via the phosphate group. The investigations of the interactions between Cp(2)TiCl(2) or (C(2)H(5))(2)SnCl(2) and DNA indicate that there are two types of binding sites on DNA for Cp(2)TiCl(2), i.e., the base nitrogen rings and the phosphate group, while (C(2)H(5))(2)SnCl(2) can bind to DNA only via the phosphate group. At last, by carefully comparing and analysing the binding modes-activity relationships of the above anticancer complexes and other non-platinum and platinum anticancer complexes, a hypothesis named "Two-Pole Complementary Principle" was put forward.     

Aqueous solution properties of disulfide linked gemini and cleaved monomeric thiol surfactants

Monomeric thiol surfactants, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SH]Br, were produced by the cleavage of gemini surfactant containing a disulfide bond in the spacer chain, [C(n)H(2n+1)N(CH(3))(2)CH(2)CH(2)SSCH(2)CH(2)N(CH(3))(2)C(n)H(2n+1)]2Br. The disulfide bond was completely reduced by the addition of four times moles of dithiothreitol in water at room temperature. The critical micelle concentrations of monomeric surfactants were significantly increased in comparison with original gemini surfactants. The monomeric thiol surfactants were stable in the presence of dithiothreitol, whereas they returned gradually to their original gemini surfactants within several days due to air oxidation in water without dithiothreitol. The micelle formation induced by the disulfide linkage formation was suggested by the fluorescence intensity ratio of pyrene. The time course of decrease in thiol concentration associated with the recovery of gemini surfactants was confirmed by the absorption spectra utilizing the reactions with 4,4'-dithiopyridine.     

Cytotoxic Phosphinoarsino and Diphosphino Pd(II) Complexes of Thiolate Amino Acids and Glutathione

The novel complexes [Pd(L-L')(SR)Cl] where L-L' is Ph(2)PCH(2)CH(2)PPh(2) (dppe) or Ph(2)AsCH(2)CH(2)PPh(2) (dadpe) and RSH is glutathione, L-cysteine, or N-acetyl-L-cysteine, have been prepared and characterised. Their structures in the solid-state and in solution are discussed. The introduction of cysteine or glutathione as a ligand in these complexes greatly improved their aqueous solubility compared with the hydrophobic parent dichloro complexes. The cytotoxicities of the glutathione complexes towards the cell-lines L1210, ADJ/PC6 and CH1 were investigated. Their cytotoxicities towards L1210 cells were comparable to those of the parent dichloro complexes.     

Aqueous biphasic hydrogenations

In addition to the useful physical properties of biphasic systems (easy separation of products and catalyst, facile catalyst reuse) aqueous media may largely influence the chemistry of catalytic reactions. By appropriate pH manipulations, the selectivity of hydrogenation of unsaturated aldehydes with ruthenium(II) phosphine catalysts was controlled from the exclusive formation of saturated aldehydes to that of unsaturated alcohols. Phase separation of the constituents of catalytic systems eliminated substrate inhibition (hydrogenation of aldehydes) and helped formation of catalytically active species ([RhH(PPh(3))(3)] from [RhCl(PPh(3))(3)] in hydrogenation of acetophenone). The reactive nature of H(2)O was revealed by fast catalysis of H/D exchange and deuteration processes.     

Ligand-exchange synthesis of selenophenolate-capped Au25 nanoclusters

We report the synthesis and characterization of selenophenolate-capped 25-gold-atom nanoclusters via a ligand-exchange approach. In this method, phenylethanethiolate (PhCH(2)CH(2)S) capped Au(25) nanoclusters are utilized as the starting material, which is subject to ligand-exchange with selenophenol (PhSeH). The as-obtained cluster product is confirmed to be selenophenolate-protected Au(25) nanoclusters through characterization by electrospray ionization (ESI) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), thermogravimetric analysis (TGA), elemental analysis (EA), UV-Vis and (1)H/(13)C NMR spectroscopies. The ligand-exchange synthesis of [Au(25)(SePh)(18)](-)[(C(8)H(17))(4)N](+) nanoclusters demonstrates that the core size of gold nanoclusters is retained in the thiolate-to-selenolate exchange process and that the 18 surface thiolate ligands can be completely exchanged by selenophenolate, rather than giving rise to a mixed ligand shell on the cluster. The two types of Au(25)L(18) (L = thiolate or selenolate) nanoclusters also show some differences in stability and optical properties.     

Pentamethylcyclopentadienyl ruthenium(III) vs hexamethylbenzene ruthenium(II) in sulfur-centered reactivity of their thioether-thiolate and allied complexes

The reactivity features of [Cp*Ru(III){eta(3)-tpdt)}] (7) and [(HMB)Ru(II)(eta(3)-tpdt)] (10) {Cp* = eta(5)-C(5)Me(5); HMB = eta(6)-C(6)Me(6); tpdt = 3-thiapentane-1,5-dithiolate, S(CH(2)CH(2)S(-))(2)} are presented, together with selected aspects of their (eta(3)-apdt) analogues 8 and 11 {apdt = 3-azapentane-1,5-dithiolate, HN(CH(2)CH(2)S(-))(2)}. This account will highlight the differences observed in their reactions with metal fragments of compounds of Ru and groups 10 and 11 in various coordination environments and with alkylating agents, including alpha,omega-dibromoalkanes. The mechanistic pathway of the alkylation of 7 will be discussed in some detail.     

混合C_8烯烃氢甲酰化反应的实验研究

对几种铑膦络合物催化混合 C8烯烃氢甲酰化反应作了实验研究 ,结果表明 ,在一定反应条件下 ,[Rh( CH3COO) 2 ]2 、Rh( CO) PPh3( acac)和 Rh6 ( CO) 16 均是有效的催化剂前体。配体、铑的浓度及溶剂对催化体系性能影响的实验证明 ,外加 OPPh3、选用适量 Rh浓度及加入二乙二醇二甲醚或四乙二醇二甲醚等溶剂对 C8烯烃氢甲酰化反应生成 C9醛是有利的。实验表明 ,对于 [Rh( CH3COO) 2 ]2 - OPPh3催化体系在 1 40℃及 1 0 .5MPa反应条件下 ,混合 C8烯烃氢甲酰化反应生成 C9醛的收率可达 90 %以上。     

Interaction of [Rh(2)(O(2)CCH(3))(4)(H(2)O)(2)] and [Rh(2)(O(2)CCH(OH)Ph)(2)(phen)(2)(H(2)O)(2)](O(2)C-CH(OH)Ph)(2) With Sulfhydryl Compounds and Ceruloplasmin

The interaction of binuclear rhodium(II) complexes [Rh(2)(OOCCH(3))(4)(H(2)O)(2)], [Rh(2){OOCCH(OH)Ph}(2)(phen)(2)(H(2)O)(2)] {OOCCH(OH)Ph}(2), [Rh(2)(OOCCH(3))(2)(bpy)(2)(H(2)O)(2)](OOCCH(3))(2) and [Rh(2)Cl(2)(OOCMe)(2)(bpy)(2)](3H(2)O) with ceruloplasmin, cysteine, glutathione and coenzyme A have been investigated using. UV-Vis and CD spectroscopies. The complexes containing phen or bpy at pH = 7.4 and 4.0 are readily reduced with sulfhydryl compounds, while rhodium(II) acetate is relatively stable in these conditions. Complex [Rh(2){OOCCH(OH)Ph}(2)(phen)(2)(H(2)O)(2)] strongly changes structure of ceruloplasmin leading to the decrease of of alpha-helix content and loss of oxidase activity.     

Facile Routes to Manganese(II) Triflate Complexes

Manganese(II) chloride reacts with trimethylsilyl triflate (TMS(OTf) where OTf = (-)OSO(2)CF(3)) in a 1:1 mixture of acetonitrile and tetrahydrofuran, and after recrystallization affords the linear coordination polymer [Mn(II)(CH(3)CN)(2)(OTf)(2)](n). Each distorted octahedral manganese(II) center in the polymeric chain has trans-acetonitriles and the remaining equatorial coordination positions are occupied by the bridging triflate anions. Dissolving [Mn(II)(CH(3)CN)(2)(OTf)(2)](n) in equal volumes of acetonitrile and pyridine followed by recrystallization with diethyl ether yields trans-[Mn(II)(C(5)H(5)N)(4)(OTf)(2)]. The distorted octahedral geometry of the manganese center features monodentate trans-triflate anions and four equatorial pyridines. Exposure of either [Mn(II)(CH(3)CN)(2)(OTf)(2)](n) or [Mn(II)(C(5)H(5)N)(4)(OTf)(2)] to water readily gives [Mn(II)(H(2)O)(6)](OTf)(2). XRD reveals hydrogen-bonding interactions between the [Mn(II)(H(2)O)(6)](2+) cation and the triflate anion. All three of these species are easily crystallized and provide convenient sources of manganese(II) for further synthetic elaboration.     

Synthesis, Characterization and Photophysical Properties of Metallopolyynes and Metallodiynes of Platinum(II) with Dibenzothiophene Derivatives

Soluble, thermally stable, and easily processable platinum(II) polyyne polymers of the form trans-[–Pt(PBu₃)₂C≡CRC≡C–]_n (R = 2,8-disubstituted dibenzothiophene, 2,8-disubstituted and 3,7-disubstituted dibenzothiophene-S,S-dioxide units) have been prepared in good yields by CuI-catalyzed polymerization involving the dehydrohalogenating coupling of trans-[PtCl₂(PBu₃)₂] and HC≡CRC≡CH. We report their optical absorption and photoluminescence spectra and compare the results with the monomeric model complexes trans-[Pt(Ph)(PEt₃)₂C≡CRC≡CPt(Ph)(PEt₃)₂]. The different electronic properties and linkage geometry of the central R group lead to new organometallic materials with distinct photophysical traits. The polymer with more conjugated 3,7-disubstituted dibenzothiophene-S,S-dioxide mainly displays fluorescence band, while its isomer with less conjugated 2,8-disubstituted spacer effectively enhances the intersystem crossing rate and strong phosphorescence emission can be detected even at room temperature.     

Magnetostructural effects in ligand stabilized Pd13 clusters: a density functional theory study

We show computationally that ligation allows tuning of the magnetostructural properties of the Pd(13) cluster. The bare, phosphine and thiol capped clusters were investigated at the density functional level. The most stable conformers of the bare cluster are of high spin, septet and nonet and of distorted C(3v), C(s) and I(h) geometries. Ligation stabilizes the I(h) geometry and quenches the high spin states, down to a triplet for Pd(13)(PH(3))(12) and to a quintet for Pd(13)(SCH(3))(12).The influence of the two capping systems on the magnetostructural properties of the ligated clusters is analyzed in connection with their different bonding properties. The mixed ligand species Pd(13)(SCH(3))(6)(PH(3))(6) is also characterized. Due to the multiple energetically accessible spin states, unusual thermal behaviour of the average magnetic moment is predicted for these clusters.     

Synthesis, Characterisation and Antifungal Activities of Some New Copper(II) Complexes of Isomeric 3,5,7,7,10,12,14,14-Octamethyl-1,4,8,11-Tetraazacyclotetradecanes

Three isomeric Me(8)[14]anes, L(A), L(B) and L(C), undergo complexation with copper(II) salts to form a series of [CuLX(n)(H(2)O)(x)]X(y).(H(2)O)(z) complexes where L = L(A), L(B) and L(C); X = Cl, Br, NO(3); n, x, y and z may have values of 0, 1 or 2. The complexes have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. Further, the X-ray crystal structure of one complex, [CuL(B)(OH(2))(2)](NO(3))(2), has been determined. The antifungal activity of all three isomeric ligands and their complexes has been investigated against a range of phytopathogenic fungi.