Synthesis, crystal structure and optoelectronic properties of a new unsymmetrical photochromic diarylethene

A new unsymmetrical photochromic diarylethene, 1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(3-trifluoromethylphenyl)-3-thienyl]perfluorocyclopentene (1a), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. Its optical and electrochemical properties, including photochromic reactivity both in solution and in the solid state (PMMA film and the single-crystalline phase), fluorescence and electrochemical properties were investigated in detail. The compound showed excellent photochromism even in the single-crystalline phase by photo-irradiation. In acetonitrile, the open-ring isomer of diarylethene 1 exhibited relatively strong fluorescence at 470nm when excited at 300nm, and its emission intensity decreased along with the photochromism upon irradiation with 313nm light. Its closed-ring isomer showed almost no fluorescence. The electrochemical properties of diarylethene were investigated by performing cyclic voltammetry experiment and its HOMO and LUMO energy level were calculated.     

Synthesis,crystal structure,and fluorescence of a 2-D coordination polymer

A 2-D coordination polymer with mixed ligands, [Zn₂(BDC)(4,4′-bipy) (HCOO)₂] (1) (BDC, 1,4-benzenedicarboxylate; 4,4′-bipy, 4,4′-bipyridine), has been synthesized by solvothermal reaction. Compound 1 provides the first coordination polymer structure constructed by bridging BDC, 4,4′-bipy, and formate. Both BDC and 4,4′-bipy link zincs alternatively, resulting in a zigzag coordination chain; adjacent chains are further linked by formates to form an infinite extended 2-D folding screen layer. The synthesis mechanism and fluorescence property are discussed.     

Modulation of the absorption, fluorescence, and liquid-crystal properties of functionalised diarylethene derivatives

Systematic variation of the molecular symmetry in a photochromic system based on a 1,2-bis(2-methylbenzo[b]thiophen-3-yl)hexafluorocyclopentene group, connected by decyl spacers to two cyanobiphenyl groups as mesogens, allows for a systematic investigation of the correlations between molecular shape and symmetry, electronic effects, photochromic conversion and liquid-crystalline properties.     

Synthesis, structure and photoluminescent property of a novel potassic compound

A novel 3D coordination compound of K(H2TDA)(H20)(1)(H_3TDA=1H-1,2,3-triazole-4,5-dicarboxylic acid) has been prepared and characterized by IR spectroscopy,elemental analysis,ICP and single-crystal X-ray diffraction.Compound 1 displays strong fluorescent emission at room temperature.     

Synthesis, growth, structure, and characterization of a novel semiorganic crystal

Single crystals of (chloro)tris(thiourea-κS)cadmium(II) picrate have been grown by slow evaporation of a mixed solvent system water–acetone containing thiourea, cadmium chloride, and picric acid. The yellow crystals belong to triclinic system with centrosymmetric space group P-1 and the corresponding lattice parameters are a = 7.4632(3) ?, b = 7.9567(3) ?, c = 17.4885(7) ?, α = 98.990(2)°, β = 100.137(2)°, γ = 95.275(2)°, and Z = 2. The vibrational patterns of the as-grown crystals are analyzed by FT-IR and FT-Raman spectral analyses. The optical absorption study was performed to analyze the optical transparency of CTTCP and the crystals were transparent in the visible region and have a lower optical cutoff at ~507 nm with band gap energy of 2.47 eV. TG–DTA thermal analysis shows that the crystal is stable up to ~208 °C and has a good chemical stability.     

Synthesis, structure, and cation complexation of a novel crown ether porphyrin

A new porphyrin appended with four crown ether units at meso-positions via an acetylene bridge was synthesized and structurally characterized, and its complexation with a variety of metal and diammonium cations was investigated.     

具有双荧光发射的螺吡喃的合成与性质研究

设计合成了未见文献报道的含有双官能团的螺吡喃类化合物1,通过红外光谱、核磁共振氢谱、碳谱和高分辨质谱对其结构进行了确证。紫外可见吸收光谱表明化合物在有机溶剂中的光致变色性良好;化合物的乙醇溶液在365 nm光激发时产生双荧光发射,分别为闭环体和开环体所对应的的荧光峰。本文首次从场效应角度推测了螺吡喃吲哚林N原子上含有极性基团时开环体稳定的原因。     

Modulation of diarylethene fluorescence by photochromic switching and solvent polarity

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一种3-吲哚甲酸吡唑酯的合成、结构及荧光性能

以3-吲哚甲酸与1-苯基-3-甲基-5-吡唑啉酮为原料合成3-甲基-1-苯基吡唑-5-基-1H-吲哚-3-甲酸酯（3）,用IR、1 H NMR、热重分析、X-射线单晶衍射对化合物结构进行了表征,并对其荧光光谱进行了研究.X-射线单晶衍射结果表明：该晶体为斜方晶系,Pbca空间群,a=1.090 90（10）nm,b=1.618 93（14）nm,c=1.819 11（16）nm,α=β=γ=90.00°,V=3.212 7（5）nm3,Z=8,dC=1.312g/cm3,μ=0.088mm-1,F（000）=1 328.     

Synthesis,crystal structure,and fluorescence properties of several schiff-base compounds

Two new Schiff-base compounds, 1,6-bis(4-dimethylaminobenzyl)-2,5-diaza-1,5-hexadiene (bdh), 1,4-bis(4-dimethylaminobenzyl)-2,3-diaza-1,3-butadiene (bdb), and a silver complex of the latter ([Ag₂(bdb)₃(NO₃)₂]·H₂O, 1) have been synthesized and characterized. The crystal structure of complex 1 was determined. 1 is a dinuclear complex, with the silver ions lying in coordination tetrahedra formed by two nitrogen atoms from the bdb ligands and two oxygen atoms from the nitrate anions. The fluorescence properties of bdh and bdb were studied; the fluorescence of bdb was quenched by the addition of silver ions, indicating that it is a potential fluorescent reagent for the analysis of silver.     

Synthesis, structure, and fluorescence of the novel cadmium(II)-trimesate coordination polymers with different coordination architectures

Three novel complexes, Cd3tma2*13H2O (1), Cd3tma2*dabco*2H2O (2), and Cd3Htma3*8H2O (3) (tma = trimesate), of cadmium(II)-trimesate coordination polymers are obtained from hydrothermal reaction. 1 (C18H32O25Cd3) crystallizes in the monoclinic C2/c space group [a = 18.985(2) A, b = 7.3872(6) A, c = 20.432(2) A, = 97.1660(10), and Z = 4]. 2 (C24H22N2O14Cd3) crystallizes in the monoclinic P2(1)/c space group [a = 10.1323(2) A, b = 19.5669(5) A, c = 13.15880(10) A, = 108.9810(10), and Z = 4]. 3 (C27H28O26Cd3) belongs to the trigonal P31c space group [a = 15.7547(3) A, b = 15.7547(3) A, c = 7.93160(10) A, and Z = 2]. The Cd(II) centers in the three complexes are bridged by tma ligands in the coordination fashion of unidentate, bridging unidentate, bidentate, chelating bis-bidentate, chelating/bridging bis-bidentate, or chelating/bridging bidentate to form the T-shaped molecular bilayer motif for 1, chicken-wire-like motif for 2, and honeycomb-like porous structure for 3, respectively, in which the T-shaped molecular bilayer motif and chicken-wire-like motif are further interlinked in interdigitating or alternating fashion to construct the different coordination architectures. These three complexes exhibit strong fluorescent emission bands at 355 nm (lambda(ex) = 220 nm) for 1, 437 nm (lambda(ex) = 365 nm) for 2, and 353 nm (lambda(ex) = 218 nm) for 3 in the solid state at room temperature.     

Synthesis, crystal structure, electrochemical and fluorescence studies of a novel Zn(II)-fluorophore, 1,10-phenanthroline-5,6-dione (phen-dione)

The crystal structure of 1,10-phenanthroline-5,6-dione ligand with Zn(II), tris(1,10-phenanthroline-5,6-dione)zinc(II) hexafluorophosphate, [Zn(phen-dione)₃](PF₆)₂, is reported. The complex was characterized by elemental analysis, IR, ¹H NMR, electronic absorption spectroscopies, cyclic voltammetry and X-ray crystallography. Yellow crystals of [Zn(phen-dione)₃](PF₆)₂ were formed by ether diffusion into an acetonitrile solution of the complex. The title complex crystallized in monoclinic crystal system (Z = 2) with space groups of P2 ₁, a = 12.0299(15) Å, b = 14.5306(19) Å, c = 13.1879(17) Å, β = 94.058(2)º and V = 2299.5(5) ų. The structure was refined by using 10048 independent reflections, with I > 2σ(I) to an R factor of 0.0490. Single-crystal structure showed that the coordination geometry around the Zn(II) was a distorted octahedron. The complex showed an intense fluorescence band at visible region (690 nm) in CH₃CN with an excitation wavelength of 310 nm at 25.0 ± 0.1 ºC. Cyclic voltammogram of the title complex showed two quasi-reversible reduction couples at negative potential, which were assigned to the consecutive reduction of phen-dione ligand to phen-semiquinonate and phen-diolate respectively by analogy to other phen-dione complexes at scan rate 200 mV s^-1.     

Rapid amplitude-modulation of a diarylethene photoswitch: en route to contrast-enhanced fluorescence imaging

A water soluble diarylethene (DAE) derivative that displays exceptionally intense fluorescence from the colorless open form has been synthesized and characterized using UV/vis spectroscopy and fluorescence microscopy. We show that the bright emission from the open form can be rapidly switched using amplitude modulated red light, that is, by light at wavelengths longer than those absorbed by the fluorescent species. This is highly appealing in any context where undesired background fluorescence disturbs the measurement, e.g., the autofluorescence commonly observed in fluorescence microscopy. We show that this scheme is conveniently applicable using lock-in detection, and that robust amplitude modulation of the probe fluorescence is indeed possible also in cell studies using fluorescence microscopy.

A water soluble diarylethene derivative displaying exceptionally bright fluorescence in the open isomeric form has been used for emission amplitude-modulation. We apply this scheme in fluorescence microscopy, aiming to suppress undesired background.     

含有二芳基乙烯的新型分子荧光性质的理论研究

采用DFT/TDDFT下的PBE0/6-31G(d)方法研究了由二芳基乙烯DE与荧光基团二萘嵌苯双酰亚胺PBI合成的新型荧光分子的一系列吸收以及发光性质.利用内稟反应坐标(IRC)以及频率分析对三重态副反应过程进行验证,得到相对应的反应路径.计算结果表明,实验中PBI的芳香环修饰有效地降低了跃迁能级差,引起吸收光谱的红移,从而避免副反应发生.使用Rehm-Weller公式对光激发电子转移过程进行热力学评估,以解释在二芳基乙烯为闭环的情况下发生荧光猝灭的原因.     

Synthesis,structure, and NMR characterization of a novel [3.3] metacyclophane

The synthesis and crystal structure of metacyclophane 2 are reported. The nmr data relevant to conformational properties are also presented.     

Synthesis and X-ray structure of a novel 1,2,4-trithiolane

Photolysis of 1,2-dithiole-3-thione derivative 1 results in the formation of the 1,2,4-trithiolane derivative 2 , the structure of which was established by single crystal X -ray analysis. Interesting bond delocalisation is observed in the molecular structure. A mechanism involving dimerisation of 1 followed by loss of sulfur is proposed.     

Synthesis, properties, and crystal structure of a novel anthracene-bridged molybdenum-zinc porphyrin dimer

The synthesis and properties of novel anthracene-bridged porphyrin dimers having an oxomolybdenum(V) porphyrin unit, H(2)(DPA)[Mo(V)O(OMe)] (1) and (DPA)[Mo(V)O(OMe)][Zn(II)(MeOH)] (2), and the relevant monomer porphyrin complexes Mo(V)O(MPP)OMe (3) and Zn(II)(MPP) (4) are presented. An oxomolybdenum(V) unit was introduced into one of the two porphyrins in DPA to give 1, which has a free-base porphyrin unit. By introducing a zinc(II) ion to the free-base part, a mixed-metal complex of 2 was prepared and isolated. The structure of 2 was analyzed by X-ray crystallography (2.(7)/(6)CH(2)Cl(2), triclinic, P(-)1 (no. 2), a = 15.2854(12) A, b = 19.9640(15) A, c = 13.6915(12) A, alpha = 90.968(3), beta = 113.108(4), gamma = 96.501(4), Z = 2, R1 = 9.9, wR2 = 19.2). The structure of 2 demonstrated that a methanol is stably coordinated to the Zn(II) ion with the aid of a hydrogen bond to the methoxo ligand on the Mo(V) ion in the binding pocket of DPA. The electrochemical measurements of 2 suggested that the methanol was kept in the pocket of DPA in solution even at the reduced state of the molybdenum ion.     

Synthesis, crystal structure and thermal decomposition of a novel praseodymium supermolecular complex

A novel complex, [Pr(5-nip)(phen)(NO3)(DMF)] (5-nip: 5-nitroisophthalic acid; phen: 1,10-phenanthroline, DMF: N,N-dimethylformamide), was prepared and characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum and DTG-DSC techniques. The results show that the crystal is monoclinic, space group P2(1)/n with a=11.0876(6) Å, b=12.8739(7) Å, c=16.9994(8) Å; β=91.193(4)°, Z=4, D _c=1.822 Mg m^–3, F(000)=1320. Each Pr(III) ion is nine-coordinated by one chelating bidentate and two monodentate bridging carboxylate groups, one chelating bidentate nitryl group, one DMF molecule and one 1,10-phenanthroline molecule. The complex is constructed with one-dimensional ribbons featuring dinuclear units and the one-dimensional ribbons are further assembled into two-dimensional networks by strong π–π stacking interactions. The complex has high stability up to 500°C. The enthalpy change of formation of the compound in DMF was measured using an RD496-III type microcalorimeter with the value of –9.214±0.173 kJ mol^–1.     

Synthesis of novel calixarenes having a tweezer-type structure

Monobromide was used as the starting material. The [2+2]photocycloaddition of diolefins directly gave all the calix[4]arene regioisomers having chiral and achiral structures in 20-47% yields. They formed a complex with alkali metal ions and extracted large metal picrates rather than small ones.