MM CALCULATIONS OF THE METAL-PROTEIN MODEL COMPLEXES Ⅰ.MOLECULAR FORCE FIELD FOR COBALT COMPEXES

Cobalt-protein complexes play an important role in biochemical processes.The structure of the model molecule,Co(H_2O)_3SO_4(phen) has been studied by molecular mechanics.The molecular force field (MM2) parameters have been developed for the particular class of the complexes.

Synthesis,Crystal Structure and Photoluminescence of a TADF Cuprous Complex

A cuprous mononuclear copper complex [Cu（adpypz）CH3CNPPh3]BF4·CH2Cl2（1, adpypz = 9,9-dimethyl-10-（6-（3-phenyl-1H-pyrazol-1-yl）pyridin-2-yl）-9,10-dihydroacridine） was synthesized and characterized by Elemental Analysis, NMR, UV-Vis and X-ray single-crystal structure analysis. It crystallizes in triclinic, space group P1 with a = 11.3388（4）, b = 13.4569（4）, c = 16.2561（6） ？, α = 97.154（3）, β = 92.187（3）, γ = 114.119（4）°, V = 2235.38（13） ？3, Z = 2, Mr = 967.12, Dc = 1.437 g/cm^3, F（000） = 996, μ = 2.62 mm^–1, GOOF = 1.031, the final R = 0.0417, and w R = 0.1024 for 8043 observed reflections with I 〉 2σ（I）. The Cu（I） atoms in the complex are four-coordinated and adopt a tetrahedral coordination geometry. In the solid state, the complex exhibits bluish-green photoluminescence with emission peaks λmax = 492 nm（1）, lifetimes 235 μs and quantum yields（ф = 0.279） at room temperature. The studies of varied temperature emission spectra and decay behaviours of the complex indicate that the complex displays thermally activated delayed fluorescence（TADF） at room temperature. The results of the experimental and DFT calculations suggest that the emission in the solid state originates from the ILCT excited states.

Synthesis,Crystal Structure and Photoluminescence of a Dinuclear Cuprous Complex with Thiocyanate Bridges

A cuprous dinuclear copper complex [PPh_2PAr_2Cu（μ-SCN）_2CuPPh_2PAr_2]（1,PPh_2PAr_2 =（1-bis（2-methylphenyl）-phosphine-2-diphenylphosphino）benzene） was synthesized from the reaction of Cu SCN and PPh_2PAr_2 in CH_3CN at room temperature. The compound was characterized by Elemental Analysis,NMR,UV-Vis and X-ray single-crystal structure analysis. It crystallizes in triclinic,space group P1 with a = 10.225（2）,b = 11.360（2）,c = 13.420（3） ？,α = 95.81（3）,β = 93.45（3）,γ = 113.78（3）°,V = 1410.4（5） ？~3,Z = 1,Mr = 1192.21,Dc = 1.404 g/cm^3,F（000） = 616,μ = 3.029 mm^（–1）,GOOF = 1.052,the final R = 0.0359,and w R = 0.0964 for 4878 observed reflections with I 〉 2σ（I）. The Cu（I） atoms in the complex are four-coordinated and adopt a tetrahedral coordination geometry. The copper centers in the molecular structure are bridged by two thiocyanate anions and each Cu（I） is chelated further terminally by a PPh_2PAr_2 ligand. The [Cu（μ-SCN）_2Cu] cores have essential planar configurations. In the solid state,the complex exhibits blue photoluminescence with emission peaks λ_（max）= 478 nm（1）,lifetimes 4.7 μs and quantum yields（ф = 0.43） 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 the experimental and DFT calculations suggest that the emission in the solid state originates from the ^（1,3）MLCT excited states.

Synthesis,Crystal Structure,and Photo-and Electro-luminescence of a TADF Cu(Ⅰ)Complex

A four-coordinate mononuclear cuprous complex [Cu（ac1m）POP]BF4·0.5（C6H14）· 0.5（C2H5OH）（1, ac1 m = 2-（2-ethoxyphenyl）-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline, POP = bis[2-（dipenylphosphino）phenyl]ether） was synthesized and characterized by elemental analysis, NMR, UV-vis, cyclic voltammetry and X-ray single-crystal structure analysis. It crystallizes in monoclinic space group P21/c with a = 17.0546（19）, b = 15.4650（17）, c = 23.685（2） A, β = 104.007（11）°, V = 6061.1（12）A^3, Z = 4, Mr = 1171.46, Dc = 1.284 g/cm^3, F（000） = 2432, μ = 1.50 mm^–1, GOOF = 1.070, the final R = 0.059 and wR = 0.1640 for 8952 observed reflections with I 〉 2σ（Ⅰ）. Compound 1 is composed of a BF4-anion and a [Cu（ac1m）POP]^＋ cation. The Cu（Ⅰ） ion adopts a tetrahedral coordination geometry defined by two nitrogen and two phosphorous atoms. The complex exhibits yellow luminescence with maximum emission peaks at 546 nm, lifetimes 15.1 μs and quantum yields（ф = 0.130） at room temperature. The complex displays thermally activated delayed fluorescence（TADF） at room temperature, which is proved experimentally and theoretically. And the organic light-emitting diode（OLED） with 1 as the light emitting material has the maximum current efficiency of 5.86 cd/A and the highest brightness of 3215 cd/m^2.

New luminescent cyclometalated iridium(Ⅲ) complexes containing fluorinated phenylisoquinoline-based ligands: Synthesis, structures,photophysical properties and DFT calculations

Two new fluorinated phenylisoquinoline-based iridium（Ⅲ） complexes,[Ir（f2piq）2（bipy）][PF6]（3a） and[Ir（fmpiq）2（bipy）][PF6]（3b）（f2piq = l-（2,4-difluorophenyl）isoquinoline,fmpiq = 1-（4-fluoro-2-methylphenyl）isoquinoline,bipy = 2,2＇-bipyridine）,have been synthesized and fully characterized.Single crystal X-ray diffraction study has been undertaken on complexes 3a and 3b,which show that each adopts the distorted octahedral coordination geometry with the cis-C,C＇ and trans-N,N＇ configuration.The photoluminescence spectra of 3a and 3b exhibit yellow and orange emission maxima at 584 and 600 nm,respectively.The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 3a-3b have been calculated with density functional theory（DFT） and time-dependent DFT（TD-DFT）.The absorption and emission spectra of complex 3b is red-shifted relative to those of complex 3a,as a consequence of the nature of the methyl group.

Investigation on ab initio calculations of the electron donor-acceptor complex H_3N·SiH_3Cl and the hypervalence of Si in it

The formation and the presence of hypervalent Si in the electron donor-acceptor com- plex H_3N·SiH_3 Cl have been investigated by ab initio calculation. The results show that there is a 0.707eV decrease of energy when the complex H_3N.SiH_3 Cl is formed from NH_3 and H_3SiCl, the interaction potential between the donor NH_3 and the acceptor H_3SiCl belongs to the Morse type, and the bond angle A(H-Si-Cl) versus bond length d(N-Si) presents a linear relation. The results also show that the interaction is mainly from giving the lone pair electrons in HOMO of NH_3 to LUMO of H_3SiCl, in which the 2P_z of N and the 3d_0 of Si play important role. Bond N-Si is a weak n-σ*type dative one.