Ruthenium Coordination Compounds with Polypyridines Ⅶ． Non－intercalative Binding of Ru（Ⅱ） Complexes with Calf Thymus DNA

Two new ruthenium polypyridine complexes. L2RuL2+ where L=2,2'-bipyridine (bpy) and 2, 9-dimethyl-1. 10-phenanthroline (dmp); L' is Schiff base prepared from condensation of 4. 5 diazafluoren-9-one (AFO) and aniline. have been prepared and characterized by elemental analyses, electronic absorption, IR spectra. The binding of the complexes to calf thymus DNA has beeninvestics by absorption. emission spectra and circular dichroism spectroscopy. Experimental results show these two complexes bind to DNA by electrostatic mode and non-interactive binding mode.

Ruthenium Coordination Compounds with Polypyridines(Ⅵ)--Interaction of Ruthenium Polypyridine Complexes with Calf Thymus DNA-An Example of Non-intercalative Binding

Two new ruthenium polypyridine complexes, L 2RuL 2+ (L represents 2,2 bipyridine(bpy) or 1,10 phenanthroline(phen); L represents Schiff base derived from 4,5 diazafluoren 9 one(AFO) and n propylamine) have been prepared and characterized by means of elementary analyses, electronic absorption and IR spectra. The binding of the complexes to calf thymus DNA has been investigated via absorption, emission spectrometry, emission quenching, equilibrium dialysis and circular dichroism spectrometry. The experimental results show that these two complexes bind to calf thymus DNA by electrostatic mode and by non intercalative binding mode respectively.

Polypyride intercalation boosting the kinetics and stability of V_(3)O_(7)·H_(2)O cathodes for aqueous zinc-ion batteries

V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.

Efficient photoelectrocatalytic CO_2 reduction by cobalt complexes at silicon electrode

Two homogeneous photoelectrocatalytic systems composed of simple polypyridyl Co complexes[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2as electrocatalysts and a Si wafer as the photoelectrode were used for combined photoelectrochemical reduction of CO2to CO.A high photocurrent density of1.4mA/cm2was observed for the system with the[Co(tpy)2](PF6)2catalyst and a photovoltage of400mV was generated.Faradaic efficiencies of CO were optimized to83%and94%for the[Co(tpy)2](PF6)2and[Co(bpy)3](PF6)2complexes,respectively,in acetonitrile solution with10%methanol(volume fraction,same below)as a protic additive.Addition of2%water volume fraction induced a large amount of non‐specific H2evolution by the Si photoelectrode.

Synthesis of Novel Polypyridine Ligands

Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(II) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO2 film electrode.

Synthesis of a new 2,2':6',2''-terpyridine derivative and its coordination property

A novel compound, （E）-4′-（4-（but-1-en-3-ynyl）phenyl）-2,2′：6′,2″-terpyridine 1 was synthesized from 4′-（4-bromomethylphenyl）-2,2P：6P,2PP-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and ^1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu（I） or Zn（ID, are investigated.

Theoretical studies of structures and spectroscopic properties of [(tpy)(bpy)RuC≡CC_6H_4R]^+(tpy = 2,2′:6′,2″-terpyridine, bpy = 2,2′-bipyridine; R = F, Cl, H, Me and OMe)

A series of polypyridine ruthenium （II） acetylide complexes, [（tpy）（bpy）RuC≡CC6H4R]^＋ （tpy = 2,2＇：6＇,2＂-terpyridine, bpy = 2,2＇-bipyridine; R = F （1）, C1 （2）, H （3）, Me （4） and OMe （5）） are investigated theoretically to explore their electronic structures and spectroscopic properties. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of the complexes in acetonitrile solution are also obtained by using TDDFT （B3LYP） method associated with the CPCM model. The calculations show that the energy levels of HOMOs for 1-5 are sensitive to the substituent on phenylacetylide ligand and increase with the same order of the electron-donating ability of the substituents; however, those of polypyridine-based LUMOs vary slightly. The lowest-energy absorptions and emissions for 1-5 are progressively red-shifted in the order of 1 ~ 2 〈 3 〈 4 〈 5 when the electron-donating groups are introduced into the phenylacetylide [igand. The phosphorescence of 1 are attributed to {[dxz（Ru） ＋π（C≡C）]→[π^＊（tpy）]} （3MLCT/3LLCT） transition, whereas those of 2-5 are originated from { [dxz/dxy（Ru）＋ π（C ≡C）＋g（C6H4R）] → [＊（tpy/bpy）] } （3MLCT/3LLCT） transitions.