具有分子内折叠结构锌配合物的合成，与DNA键合及其对DNA切割作用研究

本文报道了一个锌配合物[Zn(bipy)(pmal)(H2O)]·2H2O（其中bipy = 2,2’-联吡啶, pmal = 苯基丙二酸）的合成,晶体结构及其光谱学研究。并通过单晶X射线衍射,元素分析,红外光谱等手段对它进行了表征。同时,利用紫外光谱和荧光光谱方法考察了该配合物与小牛胸腺DNA的键和作用。琼脂糖凝胶电泳实验的结果说明该配合物的平面结构对pBR 322DNA切割作用显著。     

Synthesis, Characterization and Weak Intramolecular Interactions of Porphyrins Bearing Nucleobases

5,10, 15-Triphenyl-20-{2- [α- (adenine-9 ) acetylamino]} phenyl porphyrin ( 1 ), 5,10, 15-triphenyl-20-{2-[α-(cytosine-1)acetylamino]} phenyl porphyrin (2), 5, 10, 15-triphenyl-20-{4-[α-(cytosine-1)ethoxy]} phenyl porphyrin (3) and their zinc complexes Zn-1, Zn-2 and Zn-3 have been prepared and characterized by ^1H NMR spectra, elemental analyses, electronic absorption spectra and mass spectra (FAB). Intramolecular π-π interactions and intramolecular metal-~ interaction for 1, 2, Zn-1,and Zn-2 have been investigated by several methods. ^1H NMR studies demonstrate that the porphyrin π-system in 1 and 2 is parallel to the adenine and the cytosine aromatic ring, respectively. The electronic absorption spectral properties of free porphyrin derivatives and their zinc complexes have been compared with those of H2TPP and ZnTPP. The results show that the UV-vis spectra of 1 and 2 are the same as that of H2TPP,whereas the spectra of their zinc complexes show 7 nm red shifts of the Soret bands compared to that of ZnTPP. The emission spectra of Zn-1 and Zn-2 are independent of excitation wavelength. From combination of the evidence of absorption and emission spectra it is suggested the existence of intramolecular metal-π interaction in Zn-1 and Zn-2. The results of conformational analysis agreed quite nicely with that of experiments, thus it was further to validate the experimental conclusions.     

蒽与苯甲酸及其衍生物之间的作用机理研究

用紫外差光谱、红外光谱法和荧光猝灭法研究了典型多环芳烃蒽与苯甲酸及其羟基取代衍生物邻羟基苯甲酸和对羟基苯甲酸之间的作用机理。实验结果表明,在此芳香羧酸与蒽之间存在定向的、特异性的作用,其作用方式受到反应物结构和环境酸度的影响。对苯甲酸和邻羟基苯甲酸而言,当pH<pKa时,二者之间以蒽离域大π电子与羧基质子之间的π-H氢键作用为主,pH>pKa时,π-π电子给体受体作用逐渐成为主要结合方式。邻位羟基的存在使得苯甲酸与蒽的作用强度明显降低。对羟基苯甲酸特殊的D-π-A型分子结构使得它在溶液中形成平面多分子聚集体,这种多分子聚集体的生成使得对羟基苯甲酸与蒽的结合方式不随酸度变化,在pH2.0~10.0的范围内均以π-π电子给体受体作用相结合,且结合强度大于苯甲酸和邻羟基苯甲酸。     

Performance assessment of density-functional methods for study of charge-transfer complexes

Various density functionals are applied to a number of weakly bound intermolecular pi-pi charge-transfer (CT) complexes. Most functionals, including the recently developed mPWPW91 and mPW1PW91, grossly underestimate experimental excitation energies; good agreement is obtained only with the half-and-half hybrid BH&HLYP functional. PW91PW91 provides the best agreement with intermolecular distances measured in crystal, while the BH&HLYP values are about 0.1 A too long. Various hybrid functionals with nonlocal exchange correction provide binding energies that compare favorably with the experimental heats of formation measured in solution.     

Effect of octabromination of a tetrakis(4-carboxyphenyl)porphine derivative bound to silica gels on HPLC retention behaviors of polyaromatic hydrocarbons

The effect of bromination of Cu-porphyrin-derivative-immobilized silica gels (Cu-TCPP_D) was examined by comparing the retention behaviors of polyaromatic hydrocarbons (PAHs) on Cu-TCPP_D and Cu-octabromotetrakis(4-carboxyphenyl)porphine-derivative-immobilized silica gels (Cu-OBTCPP_D) columns. It was revealed that bromination affects strongly the π–π electron interactions caused from hydration energy in a polar eluent (80% methanol) possibly as a result of a destruction of planar structure of porphine-ring by bromination. It was also revealed that bromination enhances π–d interactions as well as the π–π electron interactions in a broad sense (e.g., dispersion forces) in a non-polar eluent (n-hexane). However, the bromination did not exert much influence on electrostatic interactions caused from polarization of mono-halogenated benzenes.     

Violet-to-blue tunable emission of aryl-substituted dispirofluorene-indenofluorene isomers by conformationally-controllable intramolecular excimer formation

Two series of DiSpiroFluorene-IndenoFluorene (DSF-IF) positional isomers, namely dispiro[2,7-diarylfluorene-9',6,9',12-indeno[1,2-b]fluorenes], (1,2-b)-DSF-IFs 1 and dispiro[2,7-diarylfluorene-9',6,9',12-indeno[2,1-a]fluorenes], (2,1-a)-DSF-IFs 2 have been synthesized. These violet-to-blue fluorescent emitters possess a 3π-2spiro architecture, which combines via two spiro links two different indenofluorene cores, that is, (1,2-b)-IF or (2,1-a)-IF and 2,7-substituted-diaryl-fluorene units. Due to their different geometric profiles, the two families of positional isomers present drastically different properties. The marked difference observed between the properties of (1,2-b)-DSF-IF (1) and (2,1-a)-DSF-IF (2) is discussed in terms of intramolecular π-π interactions occurring in (2,1-a)-DSF-IF (2) leading to conformationally-controllable intramolecular excimer formation. Indeed, the original geometry of the (2,1-a)-DSF-IF (2) family, with face-to-face "aryl-fluorene-aryl" moieties, leads to remarkable excimer emission through intramolecular π-π interactions in the excited state. Furthermore, the emission wavelengths can be gradually modulated by the control of the steric hindrance between the adjacent substituted phenyl rings. Thus, through a comparative and detailed study of the (1)H NMR, electrochemical and photophysical properties of DSF-IFs 1 and 2, we have evidenced the intramolecular π-π interactions occurring between the two "aryl-fluorene-aryl" moieties in the ground state and in the excited state. These properties have been finally correlated to the spectacular conformational change modeled by density functional theory (DFT) calculations. Indeed, the two "aryl-fluorene-aryl" moieties switch from a staggered conformation in the ground state to an eclipsed conformation in the first excited state.     

Competition between π–π stacking and hydrogen bonding in (1:2) picrates of 1,5-diamino-3-oxapentane, 1,8-diamino-3,6-dioxaoctane and 1,5-diamino-3-azapentane—solid state studies

Crystallographic studies of (2:1) salts of picric acid with 1,5-diamino-3-oxapentane (1OPICR), 1,8-diamino-3,6-dioxaoctane (2OPICR) and 1,5-diamino-3-azapentane (1NPICR) showed significant conformational change of the picrate ion due to numerous electrostatic, H-bonding and π–π stacking interactions present in the crystal lattice. In particular, intermolecular N–HO H-bonds were found to cause significant twisting of the o-NO₂ groups from the plane of the benzene ring, whereas overlapping of the picrate ions due to electrostatic interactions and π–π stacking caused flattening of the molecule. Analysis of the geometry of 74 picrate ions found in the Cambridge Crystallographic Database, in their various crystallochemical environments, showed that competition between essentially weak but numerous intermolecular interactions of different types led to systematic changes in geometric parameters within the picrate ion. In particular, relations found between the C1–C2–N–O (C1–C6–N–O) torsion angle and the endocyclic C1–C2–C3 (C1–C6–C5) valence angle can be explained on the basis of competition between resonance effects of the o-NO₂ group and π–π stacking.     

Asymmetric Epoxidation of Terminal Olefins with Binaphthyl Strapped Porphyrin Catalysts: (‐( Stacking Interaction and Steric Effects on the Enantioselectivities

将两种具有相似手性联萘空腔的手性卟啉1b和2b作为催化剂,对苯乙烯衍生物及非芳香烯烃底物进行了催化不对称环氧化反应。应用理论计算方法研究了底物同两种催化剂之间的作用机理;应用1H NMR探讨了催化剂的手性空腔结构;结果表明芳香烯烃同催化剂的手性联萘基团之间的p-p相互作用是决定该类催化剂对映选择性的重要因素,同时催化剂手性结构的立体位阻效应使该类催化剂具有良好的ee值。     

Unique Interaction between Directly Linked Laminated π Planes in the Benzonorrole Dimer

Direct link: Two directly linked benzonorrole dimers were prepared and characterized, and both have short interplane distances less than 3.5??. While a strong π-π interaction was recognized in the oxidized form (left), only a negligible π-π interaction was observed in the reduced form (right) in spite of its shorter π-π distance.     

Synthesis and structural characterization of lanthanide picrate complexes with a new binaphthylamide

Solid complexes of lanthanide picrates with N-Ethyl-2-{2′-[(ethyl-phenyl-carbamoyl)-methoxy]-[1,1′]binaphthalenyl-2-yloxy}-N-phenyl-acetamide (L), [Ln(pic)₃L] (Ln=La, Tb, Y), have been prepared and characterized by elemental analysis, IR and ¹H NMR spectra. The molecular structure of [Tb(pic)₃L] shows that the Tb(III) ion is nine-coordinated by four oxygen atoms from the L and five from two bidentate and one unidentate picrates. The complex forms a 1D supramolecular structure along z-axis.     

Reactivity of oxo-rhenium precursor trans-ReOCl3(OPPh3)(SMe2) with diaza heterocyclic congeners: Synthesis and spectroscopic characterization of mono and dinuclear compounds

The treatment of ReOCl₃(OPPh₃)(SMe₂) with an appropriate amount of [1,3]- and [1,4]-diaza heterocyclic ligands N  N (were N  N = pyrimidine (pym) and pyrazine (pyz)) in boiling acetonitrile under different reaction conditions yielded either the mononuclear ReOCl₃(OPPh₃)(pym) (1), ReOCl₃(OPPh₃)(pyz) (2) or dinuclear compounds [ReOCl₃(OPPh₃)]₂(μ-pym) (3), [ReOCl₃(OPPh₃)]₂(μ-pyz) (4). The new complexes were characterized in solution by means of NMR, IR, FIR, and UV–Vis spectroscopic methods. The molecular and crystal structures of 1, 3 and 4 were also determined by X-ray crystallography. All complexes adopt distorted octahedral geometries, with similar donor atoms arrangement, were axial positions are taken by terminal oxygen and triphenylphosphine oxide molecules. The equatorial planes are occupied by three chloride ligands and one nitrogen atom of the diaza ligand. The dinuclear complexes 3 and 4 comprise two equivalent six-coordinated monomeric units. Two halves of the dimer molecule are rotated about the Re–N  N–Re fragment: thus, an N-heterocyclic ring is stacked with two adjacent phenyl rings belonging to two triphenylphosphine oxide ligands. The preliminary results concerning the reactivity of the dimeric complexes point to their relative inertness in attempted further substitution towards synthesis of polynuclear complexes.     

Synthesis and crystal structure of 9,10-dihydro-9,10-etheno-1,8-dichloro-11-diphenylphosphinyl-12-(diphenylphosphinylethynyl)anthracene

The title compound, 9,10-dihydro-9,10-etheno-1,8-dichloro-11-diphenylphosphinyl-12-(diphenylphosphinylethynyl)anthracene (1), has been synthesized and its crystal structure has been determined. The compound 1 crystallized into the triclinic space group P-1 with =74.837(4)°, β=88.156(4)°, γ=65.398(4)°, Z=2, D_c=1.352 gcm⁻³. In the crystal structure of 1a, one chloroform molecule was included by the compound 1 with a 1:1 ratio and the existence of non-classical intermolecular C–HO hydrogen bonds, intramolecular C–HCl and C–HO hydrogen bonds and π–π stacking were observed.     

A novel octadecylsilane functionalized graphene oxide/silica composite stationary phase for high performance liquid chromatography

An octadecylsilane functionalized graphene oxide/silica stationary phase was fabricated by assembling graphene oxide onto the silica particles through an amide bond and subsequent immobilization of octadecylsilane. The chromatographic properties of the stationary phase were investigated by reversed-phase chromatography with alkylbenzenes, polycyclic aromatic hydrocarbons, amines, and phenolic compounds as the analytes. All the compounds achieved good separation on the column. The comparison between a C18 commercial column and the new stationary phase indicated that the existence of π-electron system of graphene oxide allows π-π interaction between analyte and octadecylsilane functionalized graphene oxide/silica stationary phase except for hydrophobic interaction, while only hydrophobic interaction presented between analyte and C18 commercial column. This suggests that some analytes can be better separated on the octadecylsilane functionalized graphene oxide/silica column.     

Synthesis,Characterization and Crystal Structure of （2,2′—Bipyridine）（μ—maleato）copper（Ⅱ）Dihydrate

The title polymeric complex [Cu(C₄H₂O₄)(C₁₀H₈N₂)]_n·2nH₂O was prepared and its crystal structure was determined by X‐ray diffraction methods. The crystal belongs to space group P2₁/c with cell dimensions of a = 1.0104(1), b = 1.9952(2), c = 0.7357(2) nm, β= 98.38(2)° and Z = 4. The complex forms zig‐zag chains along crystallographic axis c via Cu—O (carboxyl) bond in the apical direction. Each repeated unit consists of a square pyramidal Cu(II) centre with one maleate dianion and one 2,2′‐bipyridine forming a basal plane. Adjacent chains link to each other by H‐bonding between carboxyl groups and crystalline water. The distance of 0.3482 nm between parallel bipyridine rings shows a π‐π stacking interaction. The title complex was also characterized by IR, UV and ESR spectra.     

Hydrogenmaleato bridged supramolecular double chains via π–π stacking interactions: syntheses, crystal structures and magnetic properties of ∞[Cu(phen)X(HL)2/2] with X=Cl (1), NO3 (2) and H2L=maleic acid

Two novel hydrogen maleato (HL) bridged Cu(II) complexes _∞¹[Cu(phen)Cl(HL)_2/2] 1 and _∞¹[Cu(phen)(NO₃)(HL)_2/2] 2 were obtained from reactions of 1,10-phenanthroline, maleic acid with CuCl₂·2H₂O and Cu(NO₃)₂·3H₂O, respectively, in CH₃OH/H₂O (1:1 v/v) at pH=2.0 and the crystal structures were determined by single crystal X-ray diffraction methods. Both complexes crystallize isostructurally in the monoclinic space group P2₁/n with cell dimensions: 1 a=8.639(2) Å, b=15.614(3) Å, c=11.326(2) Å, β=94.67(3)°, Z=4, D_calc=1.720 g/cm³ and 2 a=8.544(1) Å, b=15.517(2) Å, c=12.160(1) Å, β=90.84(8)°, Z=4, D_calc=1.734 g/cm³. In both complexes, the square pyramidally coordinated Cu atoms are bridged by hydrogen maleato ligands into 1D chains with the coordinating phen ligands parallel on one side. Interdigitation of the chelating phen ligands of two neighbouring chains via π–π stacking interactions forms supramolecular double chains, which are then arranged in the crystal structures according to pseudo 1D close packing patterns. Both complexes exhibit similar paramagnetic behavior obeying Curie–Weiss laws χ_m(T−θ)=0.414 cm³ mol⁻¹ K with the Weiss constants θ=−1.45, −1.0 K for 1 and 2, respectively.     

两种吩噻嗪衍生物的合成，光学性质及其电化学性质

The synthesis, luminescence and electrochemical properties of two novel phenothiazine derivatives were presented, which exhibit good one-photon fluorescence emission. The quantum yields and solvent effects of them were studied in detail. Compound 3,7-bis（2-4＇-imidazolylbenzylidenehydrazonoethyl）-（0-ethylphenothiazine） （5） was used as an effective initiator, of which two-photon fluorescence spectra were investigated under 800 nm fs laser pulse and the measured two-photon absorption cross-section was 18 × 10^-50 cm^4·s per photon. Two-photon initiated polymerization microfabrication experiments were carried out. X-ray diffraction analyses revealed that the shape of the compound 3,7-bis（2-pyrid-4＇-ylmethylidenehydrazonoethyl）-（0-ethylphenothiazine） （4） looks like a butterfly with nearly planar wings. The dihedral angle of the two benzene rings is 37.6° and there is an obvious π-π stacking interaction between the molecules in the crystal.     

Synthesis and Crystal Structure of 1D Coordination Polymer of N,N＇-Bis（3-pyridylmethyl）-1,4-benzenedicarboxamide and Cobalt（Ⅱ） Nitrate

A noval cobalt(II) coordination polymer, {[Co(bpmb)(H₂O)₂(C₂H₅OH)₂]·(NO₃)₂}‐ (1). where bpmb=N,N′‐bis(3‐pyridylmethyl)‐1,4‐benzenedicarboxamide, was synthesized by self‐assembly of the two topic ligands with cobalt nitrate in ethanol solution, and characterized structurally by X‐ray crystallography analysis. The crystal data belong to triclinic, space group P1 with cell parameters a=0.8911(3) nm, b=0.9042(3) nm, c= 1.0068(3) nm, α= 73.083(5)°, β=81.069(5)°, γ=76.210(5)°, R₁=0.0518, wR₂=0.0947. The results of structure analysis indicate that each bpmb ligand coordinates two Co(II) atoms and each metal atom is in octahedral coordination geometry with four oxygen atoms of two ethanol and two water molecules, two nitrogen atoms from two different bpmb ligands in trans position forming an infinite 1D chain‐like structure. There BTC hydrogen bonding and π‐π stacking interaction among these chains, leading to supramolecular formation with 3D net structure.     

Strongly fluorescent, switchable perylene bis(diimide) host-guest complexes with cucurbit[8]uril in water

Supramolecular complexation of perylene bis(diimide) (PDI) dyes with the macrocyclic host cucurbit[8]uril (CB[8]) prevents self-aggregation of the dye molecules and enables their use as highly (photo)chemically stable, strongly-emitting fluorophores in water. The complexes are stimuli-responsive to binders and can be electrochemically cycled, leading to reversible on-off fluorescence switching and access to noncovalent formation of higher-order architectures in water.