Studies on the Interaction of Ru(Ⅱ) Polypyridyl Mixed-ligand Complexes and DNA by Viscosity Measurement

The interaction of transition metal polypyridyl coordination compounds with DNA has been extensively studied in the past few years^[1]. Li the case of double stranded DNA, some coordination compounds may bind in the major groove with one ligand inserting between two base pairs DNA. The viscosity studies provide a strong argument for intercalation^[2].     

Studies on Lead(Ⅱ) Complexes of Ferrocenylaldehyde Aroylhydrazones

ＩｎｔｒｏｄｕｃｔｉｏｎＯｗｉｎｇｔｏｔｈｅｆｏｒｍａｔｉｏｎｏｆｓｔａｂｌｅａｎｄｄｅｅｐｌｙｃｏｌｏｒｅｄｃｏｍｐｌｅｘｅｓｗｉｔｈｈｅａｖｙｍｅｔａｌｉｏｎｓ（ｓｕｃｈａｓｌｅａｄ（Ⅱ）ｅｔｃ）,ｔｈｅｆｅｒｒｏｃｅｎｙｌａｒｏｙｌｈｙｄｒａｚｏｎｅｓａｒｅｎｏｔｏｎｌｙｐｏｔｅｎｔｉａｌｌｙｕｓｅｆｕｌａｓｓｐｅ－ｃｉｆｉｃｒｅａｇｅｎｔｓｉｎａｎａｌｙｔｉｃａｌａｎｄｅｘｔｒａｃｔｉｖｅｃｈｅｍｉｓｔｒｙ［１］ｂｕｔａｌｓｏｓｔｒｏｎｇｌｙａｃｔｉｖｅｂｉｏｌｏｇｉｃａｌｌｙ,ａｎｄｃ…     

Studies on Transition Metal Complexes of Schiff Base( Ⅰ )——Oxygen-carrying Properties of Cobalt( Ⅱ )Schiff Base Complexes

Introduction The compounds that can take up and release molecular oxygen reversibly is of significance because they can be used as model compounds for the study of the reversible oxygenation mechanisms involved in the very complex natural oxygen carriers, e.g., the hemoglobins and hemocyanins, and as the means of separating molecular oxygen from the air. The dioxygen carriers extensively studied are the Cobalt     

Investigation on Magnetic Properties of Exchange Coupled Transition Metal Complexes Ⅱ．Theoretical Model for Trinuclear Complexes

ＩｎｖｅｓｔｉｇａｔｉｏｎｏｎＭａｇｎｅｔｉｃＰｒｏｐｅｒｔｉｅｓｏｆＥｘｃｈａｎｇｅＣｏｕｐｌｅｄＴｒａｎｓｉｔｉｏｎＭｅｔａｌＣｏｍｐｌｅｘｅｓⅡ．ＴｈｅｏｒｅｔｉｃａｌＭｏｄｅｌｆｏｒＴｒｉｎｕｃｌｅａｒＣｏｍｐｌｅｘｅｓＸｉｅＸｉｕ－Ｌａｎ；...     

Theoretical Studies on the Coordin

Theoretical　Studies　on　the　Coordin...     

Theoretical Studies on the Third-order Nonlinear Optical Properties and Two-photon Absorption of Stilbene Derivatives

Different types of stilbene derivatives (D-π-D, A-π-A, D-π-A) were investigated with AM1, and specially, equilibrium geometries of symmetrical stilbene derivatives (D-π-D) were studied using of PM3. With the same method INDO/CI, the UV-vis spectra were explored and the position and strength of the two-photon absorption were predicated by Sum-Over-States expression. The relationships of the structures, spectra and nonlinear optical properties have been examined. The influence of various substituents on two photon absorption cross-sections was discussed micromechanically.     

Studies of the Intramolecular Aromatic-ring Stacking Interactions in the Ternary Platinum(Ⅱ) Complexes

The stability constants of some ternary mixed-ligand complexes, Pt(Phen)(CA) , where Phen=1,10-phenanthroline and CA- =carboxylate, were determined by means of potentiometric pH titration in aqueous solutions(I=0.1 mol/L, KNO3; 25 ℃), and the stability of them was compared with that of the corresponding binary complexes. It was revealed that the ternary complexes containing phenylalkane carboxylates ligands(PCA-) are much more stable than those formed with formate and acetate. The results indicate that there exist the intramolecular aromatic-ring interactions between the phenanthroline ring of Phen and the phenyl moiety of ligand PCA- in the ternary mixed-ligand Pt(Phen)(PCA)- complexes. The extent of the stacking interactions, which depends on the number of methylene groups between the phenyl moieties and the coordinated phenylalkane carboxylate groups, was calculated. The best-fitted stack was obtained for the complexes with 2-phenylacetate and 3-phenylpropionate as the ligands.     

Theoretical Studies on the Spin Exchange Interaction in Copper(II) Complexes Coordinated with Nitronyl Nitroxide

In the recent years, a wide variety of transition metal complexes with the nitronyl radical ligands have been reported1,2. These systems display the various magnetic behaviors (ferro- or antiferro-magnetism) between the unpaired electrons on the radical ligands and on the paramagnetic metal ion center. However, few theoretical studies on the metal-radical complexes were reported and quite few are known about the nature of the exchange coupling interactions. In this work, we are interested i…     

Theoretical study on second-order nonlinear optical properties of 1,10-phenanthroline Ru(Ⅱ) complexes

The dynamic first hyperpolarizabilities of a series of 1,10-phenanthroline Ru(Ⅱ) complexes were carried out using density functional theory(DFT).The results indicate that these complexes have large second-order nonlinear optical(NLO) responses.Specially,complex 6b has a maximal first hyperpolarizability βtot value.The first hyperpolarizabilities can be tuned by changing the ancillary ligand,introducing electron-acceptor group NO2 and/or increasing π-conjugation on phenanthroline.Calculations on absorption spectra demonstrate that the second-order NLO responses of complexes in series a are ascribed to the intraligand charge transfer(ILCT),while the complexes in series b exhibit metal-to-ligand charge transfer(MLCT) and ligand-to-ligand charge transfer(LLCT) transition at relatively low-energy absorptions.     

Theoretical Study on the Structures and Properties of Hydrogen Bonding Complexes between Diazines and Water

Density functional theory B3LYP method and second-order Moller-Plesset perturbation theory MP2 method were employed to obtain the optimized geometries of the ground state and interaction energy for diazines and water complexes. The results show that the ground state complexes have strong hydrogen bonding interaction with -20.99, -16.73 and -15.31 kJ/mol after basis set superposition error and zero-point vibration energy correction for pyridazine-water, pyrimidine-water and pyrazine-water, respectively, and large red-shift for the symmetric H-O stretching vibration frequencies due to the formation of N…H-O hydrogen bond in the diazine-water complexes. The NBO analysis indicates that intermolecular charge transfer are 0.0316, 0.0255 and 0.0265 e respectively. In addition, the first singlet （n,n＊） vertical excitation energy of the monomer and the hydrogen bonding complexes between diazines and water was investigated by time-dependent density functional theory.     

Tuning the Excited-state Properties of Cyclometalated Platinum(II) Complexes of 6-Phenyl-2,2′-bipyridine by Ancillary Acetylide Ligand

Luminescentcoordinativelyunsaturatedmetalcomplexesareappealingfromphotochemicalandphotophysicalperspec tive.1,2 Square planarplatinum(II)complexescontainingachelatingdiimineligandrepresentapromisingclassofthesemolecules.2 However,theyareusuallyweakemittersorevennonemissiveinfluidsolutionatroomtemperatureduetoaD2ddistortion .3Therefore ,manyresearchershavedivertedtheirattentiontothetridentateligand ,whichfavorsplanargeometryandwoulddiscourageaD2ddistortion .Inparticu lar,platinum(II)complexe…     

DNA Binding Properties and Cytotoxic Activities of Two Trinuclear Ruthenium（Ⅱ） Polypyridyl Complexes

The interactions between two trinuclear Ru（II） complexes and calf thymus DNA（CT DNA） were studied via absorption spectroscopy, reverse salt titrations, binding stoichiometry, DNA melting experiments, as well as viscosity measurement. The results indicate that complexes 1 and 2 bind to DNA via the interaction of the planar π-delocalized system of the complexes with intrinsic binding constants of 4.18 × 10^5 and 3.85 × 10^6 L/tool, respectively, and non-electrostatic binding free energy makes a predominant contribution to the binding free energy. The in vitro cytotoxic activity of complexes 1 and 2 was evaluated by the MTT[3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl- 2H-tetrazolium bromide] method. Complex I shows higher anticancer potency than complex 2 against four tumor cell lines. Further mechanism study indicates that complexes 1 and 2 can cause cell cycle arrest in the G2/M phase.     

Synthesis and Properties of u-Oxamido Heterobinuclear Cu(Ⅱ)-Co(Ⅱ) Complexes

Three heterobinuclear complexes were synthesized, namely [Cu (oxpn) Co (L)2] (ClO4)2·xH2O(L= 2,2'-bipyridyl(bpy), 1,10-phenanthroline(phen) , and 5-nitro-1, 10-phenanthroline (NO2-phen)), where oxpn represents N, N'-bis(3-aminopropyl) oxam-ido. Based on 1R, elemental analysis, conductivity measurement and electronic spectra, these complexes were characterized by an extended oxamido-bridged structure with Cu(Ⅱ) in a planar environment and Co(Ⅱ) in a octahedral environment. The symmetry of the cation is very close to C2v.The complexes were also characterized with variable temperature (4~300K) magnetic susceptibility, and the data were fit for the susceptibility equation derived from spin Hamilton, H= -2JS1.S2-DSx12 by least square strategy. The exchange integral, J, was found to be -22.36 cm-1 (for bpy);-15.45 cm-1 (for phen); -19. 10cm-1(for NO2-phen), indicating that there is a weak antiferromagnetic spin-exchange interaction between the metal ions.     

Studies on α-Methacrylate Copper(Ⅱ) Complexes with Imidazole

Two complexes of α-methacrylate copper(Ⅱ) with imidazole, Cu[CH₂=C(CH₃)COO]₂· (imH)₂(1) and Cu ₂[CH₂C(CH₃)COO]₄(imH)₂(2) were prepared and characterized. The single crystal X-ray diffraction study of complex 1 showed that the copper(Ⅱ) atom in the symmetric centre of the square planar environment was coordinated by two monodentate α methacrylate groups and two imidazole ligands that were in trans position with each other. Each molecular unit is linked with four neighbouring units by means of hydrogen bond interactions, forming a two-dimensional supermolecular compound( d_N…O =0.278 1 nm). Complex 1 crystallizes in monoclinic, space group P2₁/n with a =1.023 94(12) nm, b =0.842 94(8) nm, c =1.079 35(10) nm, β=117.231(7)°, Z =2. The forming mechanism of the complexes was discussed.     

Theoretical Studies on the Spin Exchange Interaction in Copper（Ⅱ） Complexes Coordinated with Nitronyl Nitroxide

Nitronyl nitroxide radical 1, NIT (4, 4, 5, 5-tetramethyl-4, 5-dihydro-1H-imidazolyl-1-oxyl-3-oxide) and copper(Ⅱ) chloride complexes with nitronyl nitroxide 2, [Cu(NITPh)2Cl2](NITPh = 2-phenyl-4, 4, 5, 5-tetramethyl-imidazoline-1-oxyl-3-oxide) were studied with density functional theory (DFT). The magnetic orbital analysis reveals that the antiferromagnetic coupling for complex 2 is due to the antibonding σ^*-orbital overlap between dx^2-y^2 (Cu)and π^* (NO) orbitals. Also, spin population and atomic charge distribution analysis suggest that for AFS of complex 2 the antiferromagnetic coupling between the radical ligands and the copper(Ⅱ) ion originates from the spin delocalization induced by the a electron transfer from π^*(NO) to d^x2-y^2 (Cu) orbital.     

Theoretical Studies on the Thermodynamic Properties and Detonation Performances of Bicyclic Nitramines： TNAD Isomers

1 INTRODUCTION Nowadays, HEDMs have been receiving heated attention because of their superior explosive per- formances to the currently used materials. Searching for novel HEDMs to meet the future demands has become one of the most activated regions and seems to be never ending. As is well known, nitramines have important applications in both civilian and military fields for a long time. This group of com- pounds is still a source of explosives or propellants that possess predominantl…     

Synthesis of New Ruthenium(II) Bipyridyl Complexes and Studies on Their Photophysical and Photoelectrochemical Properties

IntroductionDye sensitizedsolarcells (DSSC)havebecomethefocusofmanyinvestigationssinceMichaelGr tzelandco workersmadethedyemoleculesadsorbedonaporousnet workoftheinterconnectednanometer sizedcrystallinesofawidebandgapsemiconductor.1 3Animpressivesolar to electricalenergyconversionefficiencyof 10 %hasbeenre portedanditmakespracticalapplicationfeasible .4 Thissystemconsistsofadye coatedsemiconductorelectrodeandacounterelectrodearrangedinasandwichconfigura tionandtheinter electrodespaceisfilled…     

Synthesis and Magnetic Studies of Oxamido-Bridged Cu(Ⅱ)-Fe(Ⅱ) Heterobinuclear Complexes

~The~andmagneti~Of~~areatoPicthahasndchinndinndnd.bondinthewiin-wtofbinudearCU(n)-Fe(u)-,chewedwiththe~alleq-nettrioftwnew~-,[CU(oxa)Fe(L)21sa(Lbo1,1o-~(Phen)nd5-nithe1'1o-~(NQ-Phen)),whereOxaisN,N'-bis(2-amhathy).edfor.-Synboor(1)ToCh(oxae)2(94.2mp'o.4ed)theindri(5nd)wasbo-lyadtalaedboofso.Wio(111.2mp,o.4nuno)inmeto(1ond)ndaboofPhen(144-2mp,o.8mrnO)inrne~(1OrnL)underN2atrmpe.theedfor2hthegreddebm~thuSfo~wereforoff,washededtimeswithrne~anddiethyletheranddriedoverP2QUnderededpe.ha:C,…     

Syntheses,Spectral Characterization of the Nickel(Ⅱ) Complexes of Macrocyclic Dioxotetraamine and the Effect of the Functional Pendant Arms on their Properties

１ＩＮＴＲＯＤＵＣＴＩＯＮＭａｃｒｏｃｙｃｌｉｃｄｉｏｘｏｔｅｔｒａｍｉｎｅｓｗｉｔｈｖａｒｉｏｕｓｆｕｎｃｔｉｏｎａｌｐｅｎｄａｎｔｓｈａｖｅｒｅｃｅｉｖｅｄｍｕｃｈａｔ ｔｅｎｔｉｏｎ，ｔｈｅｉｎｔｒｏｄｕｃｔｉｏｎｏｆｖａｒｉｏｕｓａｄｄｉｔｉ...