Low‐Band‐Gap BODIPY Conjugated Copolymers for Sensing Volatile Organic Compounds

Conjugated polymers with strong photophysical properties are used in many applications. A homopolymer ( P1 ) and five new low band gap copolymers based on 4,4′‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) and acceptors 3,6‐dithienyldiketopyrrolopyrrole ( P2 ), phthalimide ( P3 ), benzotriazole ( P4 ), 4,7‐dithienyl[1,2,3]triazolo[4,5g]quinoxaline ( P5 ), and 2,5‐dithienylthieno[3,4‐b]pyrazine ( P6 ) were prepared by means of Sonogashira polymerization. The characterization of polymers by using ¹H NMR, absorption, and emission spectroscopy is discussed. All polymers with high molecular weights (M_n) of 16 000 to 89 000 g mol^?1 showed absorption maxima in the deep‐red region (λ=630–760 nm) in solution and exhibited significant redshifts (up to 70 nm) in thin films. Polymers P2 , P5 , and P6 showed narrow optical band gaps of 1.38, 1.35, and 1.38 eV, respectively, which are significantly lower than that of P1 (1.63 eV). The HOMO and LUMO energy levels of the polymers were calculated by using cyclic voltammetry measurements. The LUMO energy levels of BODIPY‐based alternating copolymers were independent of the acceptors; this suggests that the major factor that tunes the LUMO energy levels of the polymers could be the BODIPY core. All polymers showed selective and reproducible detection of volatile organic solvents, such as toluene and benzene, which could be used for developing sensors.     

叠氮二(2,2''-联吡啶)钌(Ⅱ)配合物的光物理和光化学性质

本文研究了叠氮二(2,2'—联吡啶)钌(Ⅱ)配合物在有机溶剂及乙腈—水中的一些光物理和光化学性质。在77K的甲醇—乙醇玻璃态时,用245nm等波长激发表现较强的荧光,其最大发射峰在540nm,另一弱带在580nm。在室温甲醇中测得的磷光发射是弱的,且寿命<15us。 在254nm、300nm及514nm照射下,光反应机制及量子产率与溶剂、照射波长有关。在乙腈—水及乙腈中,分别用254nm和514nm照射均发生取代反应,最后的光产物为Ru(bpy)₂(N₃)(CH₃CN)⁺,配合物消失的量子产率分别为0.129±0.008mol einstein^-1及(6.77±0.22)×10^-5mol einstein^-1;在乙腈—水中用514nm照射,生成的光产物先是Ru(bpy)₂(N₃)(CH₃CN)⁺,再生成Ru(bpy)₂(CH₃CN)₂²⁺,配合物消失的量子产率为(5.32±0.13)×10^-4mol einstein^-1。     

取代基对4-N,N-二苯胺基均二苯乙烯类电致发光材料光电特性的影响

用紫外吸收光谱、荧光发射光谱、循环伏安法(CV)、微分脉冲伏安法(DPV)等手段研究了4个4-N,N-二苯胺基均二苯乙烯类化合物的光电性能, 计算出它们的电离势(P_I)在5.70～5.90 eV, 带隙值(E_g)在2.78～2.88 eV, 分析了电化学行为, 讨论了取代基对吸收光谱、发射光谱和电子结构的影响. 结果表明, 引入供电子基团OCH₃后, 分子氧化电位降低, HOMO能量升高, 电离势降低; 引入吸电子基团—Cl后, 氧化电位升高, LUMO能量降低, 电子亲和势增加. 取代基—Cl和—OCH₃都使化合物的带隙(E_g)减小, 紫外-可见光谱的吸收峰和荧光光谱的发射峰均发生红移.     

Strong electric-field effects on the doubly-excited intrashell states of He below the He+(N = 2) threshold

The method of complex-coordinate rotation is used to investigate electric-field effects on the doubly-excited 2s2p ¹P⁰, 2p^{2 1}D^e, 2p^{2 3}P^e and 2s2p ³P⁰ states of He. Strong electric-field strengths up to F=0.02 Ry are used in our present study. Products of Slater orbitals are used to represent the two-electron wave functions, with l_max=8 being employed for the individual electron. Block matrices with up to L_max=5 (H-states) are used to investigate the convergence behavior for the resonance parameters (resonance energy and width). When the external electric field is turned on, "classic" Stark effect is observed for the M=0 and M=ǃ components of the two singlet-spin states and for the M=ǃ components of the triplet-spin states. Comparisons are made with other calculations when available.     

两个手性氧钒配合物[VO(Naph-Leu)(OMe)(CH3OH)]和[VO(Naph-Phe)(OMe)(CH3OH)]的合成、晶体结构和光谱表征

合成了2个新的手性L-亮氨酸萘酚醛和L-苯丙氨酸萘酚醛希夫碱氧钒配合物,[VO(Naph-Leu)(OMe)(CH3OH)](1)和[VO(Naph-Phe)(OMe)(CH3OH)](2)。X-射线单晶衍射分析表明,1晶体属于正交晶系,P21212空间群,晶胞参数为:a=0.946 80(8)nm,b=3.246 3(3)nm,c=0.662 37(5)nm,V=2.035 9(3)nm3,Z=4,F(000)=864,R1=0.046 3,wR2=0.112 7,S=1.076。2晶体属于单斜晶系,P21空间群,晶胞参数为:a=1.113 41(11)nm,b=0.724 09(6)nm,c=1.342 99(12)nm,V=1.047 95(16)nm3,Z=2,F(000)=464,R1=0.035 8,wR2=0.088 8,S=1.024。测定了它们的红外光谱、紫外光谱和圆二色光谱,讨论了紫外吸收光谱和圆二色光谱性质。     

Synthesis and characterization of novel poly(p‐phenylenevinylene) derivatives containing phenothiazine‐5‐oxide and phenothiazine‐5, 5‐dioxide moieties

PPV‐based copolymers containing phenothiazine‐5‐oxide and phenothiazine‐5, 5‐dioxide moieties have been successfully synthesized by Wittig‐Horner reaction and characterized by means of UV‐vis, photoluminescence, electroluminescence spectra, and cyclic voltammetry. All of these copolymers can be dissolved in common organic solvents such as chloroform, tetrahydrofuran, and toluene. The PL maxima in the film state are located at 582, 556, and 552 nm for P1, P2, and P3, respectively. The HOMO and LUMO levels of P2 are found to be ?5.21 and ?2.68 eV, respectively; whereas those of P3 are found to be ?5.26 and ?2.71 eV, respectively. The cyclic voltammetry result indicates that the conversion of electron‐donating sulfide to electron‐withdrawing sulfoxide or sulfone group in polymers plays a dominating role in increasing its oxidation potential. Yellowish‐green light ranging from 568 to 540 nm was observed for the single layer device with the configuration of ITO/Polymer/Ca/Al. Double layer devices with Zn (BTZ)₂ as a hole blocking layer exhibited enhanced EL performance compared to the single layer devices. The maximum brightness of the double layer devices of P1, P2, and P3 is 278, 400, and 796 cd/m², respectively. The results of EL and electrochemical analyses revealed that they are promising candidate materials for organic, light‐emitting diodes with hole‐transporting ability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4291–4299, 2007     

Copolymers of 4-thieno[3,2-b]thiophen-3-ylbenzonitrile with anthracene and biphenyl; synthesis,characterization, electronic,optical, and thermal properties

Two novel copolymers of 4-thieno[3,2-b]thiophen-3-ylbenzonitrile (TT-CN), possessing electron withdrawing cyano moiety, with anthracene (P1) and biphenyl (P2) were prepared via Suzuki coupling. Optic, electronic, and thermal properties of the copolymers were investigated through UV–Vis spectroscopy, cyclic voltammetry, gel permeation chromatography, and thermal gravimetric analysis. The polymers with anthracene and biphenyl had electronic band gaps of 2.01 and 1.90 eV, respectively. Both polymers demonstrated excellent large Stokes shifts of 101 (anthracene) and 105 nm (biphenyl) as well as very good thermal properties. As they had good optical, electronic, and thermal properties, they are promising candidates for electronic applications.     

含硝基二代光致变色液晶树枝状大分子的光化学研究

研究了树外围含36个硝基偶氮苯端基新型二代碳硅烷光致变色液晶树枝状大分子(G₂)在溶液中的最大吸收波长, 摩尔消光系数, 反-顺光异构化反应速率常数, 热回复异构化反应速率常数, 光化学回复异构化反应平衡常数及速率常数. G₂的光致变色反应速率常数的数量级为10^－1 s^－1, 而含偶氮端基侧链聚硅氧烷的光致变色反应速率常数的数量级为10^－8 s^－1, 因此, 液晶树枝状大分子的光响应速率比后者快10⁷倍. G₂的光化学回复异构化反应平衡常数k_t/k_c为1.77～1.97, 有作为光控开关材料的应用前景.     

SYNTHESIS AND CHARACTERIZATION OF POLY(L-GLUTAMIC ACID-co-L-ASPARTIC ACID)

Poly(amino acid)has been widely utilized in drug delivery,tissue engineering and biomedical materials.The biomaterials based on poly(glutamic acid)are usually modified via copolymerization with other monomers such as L-aspartic acid to improve the uncontrolled degradation rate.The ring-opening homo- and co-polymerization ofγ-benzyl-L-glutamate N-carboxyanhydride(BLG-NCA)andβ-benzyl-L-aspartate N-carboxyanhydride(BLA-NCA)were carried out in solution by using triethylamine(TEA)as initiator.The BLG-NCA homo...     

Photophysical and electrochemical characterization of new poly(arylene vinylene) copolymers containing quinoline or bisquinoline segments

Four new fluorescent conjugated vinylene‐copolymers incorporating quinoline or bisquinoline segments along the backbone were synthesized by Heck coupling. Three of them were fluorenevinylene‐copolymers and contained quinoline ( PQFV , PQFVT ) or bisquinoline segments ( PBQFV ). One of them ( PBQPV ) was phenylenevinylene‐copolymer and contained bisquinoline segments. All the copolymers were soluble in common organic solvents and had relatively low glass transition temperature (T_g = 50–56 °C for fluorenevinylenes and T_g < 25 °C for phenylenevinylene). In THF solutions, the quinoline‐containing copolymers showed absorption maxima at 411–420 nm while the bisquinoline‐containing ones exhibited maxima at 357–361 nm. The emission maxima of solutions were 465–490 nm. The copolymers showed high quantum yields up to 64%. The films exhibited absorption and emission maxima in the range of 371–437 nm and 480–521 nm, respectively. All copolymers revealed reversible reduction with electron affinity of 2.66–3.53 eV and irreversible oxidation scans with ionization potential of 5.39–5.53 eV. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3370–3379, 2009     

异质型BiOI/NaBiO_3光催化剂的合成及其光催化性能

根据表面化学蚀刻原理采用加热冷凝回流的方法制备了一系列组成的异质结构BiOI/NaBiO3光催化剂。利用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见漫反射光谱(UV-Vis-DRS)等技术对其晶相结构、微观形貌和光吸收性能进行了表征。光催化实验表明,BiOI/NaBiO3在可见光下可以有效降解罗丹明B(RhB),当BiOI与NaBiO3的物质的量分数为一定值时,异质结构的光催化剂明显优于单一组分的光催化活性。通过加入不同的牺牲剂及荧光实验结果推测了该异质结构材料的光催化机理,并且分析了其光生载流子的传输方向及光催化过程的活性物种。研究表明,BiOI/NaBiO3的催化活性增强主要归结为两者之间形成了有效的异质结构,其内建电场能够促进光生载流子的分离,同时光生空穴h+在光催化降解过程中是主要的活性物种。     

Synthesis and properties of polyfluorene copolymers bearing thiophene and porphyrin

To search for more wider absorption and higher charge carriers mobilities materials of polymer solar cell, a series of soluble alternating polyfluorene copolymers were synthesized by palladium-catalyzed Suzuki coupling reaction. Their structures were determined by 1H NMR, IR and UV-vis. And their UV-vis absorption spectra indicated that they had strong absorption over 600 nm spectral range and nearly cover 400-700 nm visible region. The band gaps of copolymers calculated according to cyclic voltammetry （CV） were between 1.96 and 2.03 eV. Polymer：TiO2 bulk-heterojunction films were made from mixtures of polymer and titanium isopropoxide, a precursor for TiO2, via hydrolysis in air overnight. The photoluminescence at 380-800 nm of the blend film of PT-TPP20 （5 mg/mL）：Ti（OC3H7）4 （80 μL/mL） （20% volume fraction） was significantly quenched in the 50% Ti（OC3H7）4 blend film, indicating that rapid and efficient separation of photoinduced electron-hole pairs.     

含有p-n单元的苝聚酰亚胺的合成及其敏化光电池的性能研究

设计、合成并表征了含有p-n(供电子-吸电子)单元的苝聚酰亚胺PPI, 并研究了其作为敏化电极材料的光电池的性能. 产物为非晶态. 从电子谱中计算出其能带带宽为2.16 eV, 用电化学循安伏安法计算得到其电子亲和势(E_a, 最低空轨道能级)为－3.97 eV, 离子势(IP, 最高占据轨道能级的绝对值)为6.13 eV, 其能级与二氧化钛的能级相匹配, 对二氧化钛有较好的敏化作用. 光电池的光电流作用谱(IPCE)与紫外电子谱十分相似, 光电压与光强之间有指数的关系. 用苝聚酰亚胺为敏化剂的光电池的光电转换效率为0.0135%.     

Synthesis and photovoltaic properties of alternating conjugated polymers derived from indolo[3,2-<Emphasis Type="Italic">b</Emphasis>]carbazole and thiophene/thieno[3,2-<Emphasis Type="Italic">b</Emphasis>]thiophene-cored benzoselenadiazole

Two alternating narrow band gap (NBG) copolymers derived from 5,11-di(N-9-heptadecanyl)-indolo[3,2-b]carbazole (ICZ) and 4,7-di(thien-2-yl)-2′,1′,3′-benzoselenadiazole (DSeBT) or 4,7-di(thieno[3,2-b]thien-2-yl)-2′,1′,3′-benzoselenadiazole (DTSeBT), were synthesized and named PICZ-DSeBT and PICZ-DTSeBT, respectively. The PICZ-DSeBT shows good solubility in common organic solvent, and the PICZ-DTSeBT is soluble in hot o-dichlorobenzene (ODCB) and not good soluble in chloroform, toluene etc. The chemical structure, molecular weight and fundamental physical properties of the copolymers were characterized by ¹H NMR, gel permeation chromatography (GPC), cyclic voltammetry (CV), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) etc. Potential application of the copolymers to be employed as electron donor material and PC61BM ([6,6]-phenyl-C₆₁ butyric acid methyl ester) for photovoltaic solar cells (PSCs), were investigated. PSCs based on the blends of PICZ-DSeBT/PC₆₁BM (w: w; 1: 2) or PICZ-DTSeBT/PC₆₁BM (w: w; 1: 2) with devices configuration as ITO/PEDOT: PSS/blend/Al, show the power conversion efficiencies (PCEs) of 1.06% and 1.52%, with the open circuit voltage (V _oc) of 0.75 V and 0.70 V, short circuit current densities (J _sc) of 3.45 mA/cm² and 5.30 mA/cm² under an AM1.5 simulator (100 mW/cm²) and the photocurrent response on-set wavelength extending up to 760 nm and 800 nm, respectively. It indicates that the NBG copolymers are viable electron donor materials for PSCs.     

Synthesis,characterization, and electroluminescence of novel copolyfluorenes and their applications in white light emission

New copolyfluorenes (PC8OF0–PC8OF50) comprised of 9,9‐dioctylfluorene and jacketed units 2,5‐bis[(5‐octyloxy‐phenyl)‐1,3,4‐ oxadiazole]‐1‐(3,5‐dibromophenyl)‐benzene (35C8) were synthesized by palladium‐catalyzed Suzuki coupling reaction. They were characterized by molecular weight determination, ¹H NMR, elemental analysis, DSC, TGA, absorption and emission spectroscopy, and cyclic voltammetry (CV). These copolymers were readily soluble in common organic solvents and exhibited high glass transition temperature and thermal stability.The copolymer films showed absorption peaks from 381 nm to 351 nm, and PL peaks from 432 nm to 421 nm with a blue shift originated from 35C8 units. Both the HOMO energy levels and LUMO levels changed little as the content of 35C8 units increased (?5.59 eV to ?5.48 eV and ?2.60 eV to ?2.49 eV). Electroluminescent devices: ITO/PEDOT:PSS[poly(ethylenedioxythiophene):polystyrenesulfonate]/polymer/Ca (25 nm)/Ag(80 nm) (a), ITO/PEDOT:PSS/polymer/TPBI [1,3,5‐ tris(N‐phenylbenzimidazol‐2‐yl)benzene](15 nm)/Mg:Ag(10:1, wt)/Ag (b), and ITO/ PEDOT:PSS/PVK[Poly(N‐vinylcarbazole)]/polymer/TPBI(15 nm)/Ca(25 nm)/Ag(80 nm) (c) were fabricated to investigate the influence of jacketed contents and device architectures on emission characteristics. The maximum brightness and current efficiency of the PC8OF25 device (5097.8 cd/m² and 0.484 cd/A) surpassed those of the PC8OF0 device (3122.8 cd/m² and 0.416 cd/A). The EL emissions of PC8OF0 – PC8OF50 were pure blue and low‐energy excimer emission bands were successfully suppressed, indicating that these copolymers could be good candidates for blue light‐emitting materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4555–4565, 2009     

Fourier transform IR spectroscopic study on phase transitions of copolymers of <Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide and alkyl acrylates in water

Copolymers of N-isopropylacrylamide (IPA) and alkyl acrylates [methyl acrylate (MA), ethyl acrylate, and butyl acrylate] or vinyl acetate have been prepared and their phase transitions in water have been observed by means of IR spectroscopy. The incorporation of these alkyl acrylates into a poly(IPA) (PIPA) chain induces a decrease in the phase-transition temperatures, T_p, and the magnitude increases with increasing size of the alkyl chains. The profiles of the C=O stretching absorption bands of the ester groups [9(C=O)_ester] and the IR bands due to IPA units exhibit critical changes at the T_p of these copolymers. The 9(C=O)_ester bands shift slightly toward higher wavenumbers (blueshift) upon phase transition, while the amide I and amide II bands of the IPA units undergo a blueshift and a redshift, respectively. Analysis of the 9(C=O)_ester band of PIPA-MA by using a curve-fitting method shows that it consists of three components, at 1,703, 1,720, and 1,738 cm^-1. The relative peak area of the largest component (1,720 cm^-1) is almost constant, and those of the 1,703-cm^-1 and 1,738-cm^-1 components increase and decrease with increasing temperature during the phase transition, respectively. However, the changes are rather small, suggesting that changes in hydrogen bonding of the C=O groups of MA units upon phase transition are not significant. The 9(C=O)_ester bands of other comonomers examined here also exhibit similar changes. The situation is consistent with the change in the hydration states of the amide groups of IPA units, most of which associate with water molecules through hydrogen bonds even after the phase separation.     

2,6-二乙酰吡啶类双希夫碱配合物的合成和研究 Ⅱ.Cu(Ⅱ)配合物的合成和研究

合成了五个2,6-二乙酰吡啶缩肼基硫代甲酸酯双希夫碱合铜(Ⅱ)配合物,用元素分析、磁化率、红外光谱及紫外-可见光谱等对它们进行了表征,研究了配合物的电化学性质和Cu₃L₂²X₂(X=Cl^-、SCN^-)的光电子能谱。结果表明:五个Cu(Ⅱ)配合物均为三核配合物,在Cu₃L₂²(SCN)₂中存在Cu(Ⅱ)间的自旋-交换作用。     

Hyperbranched copolyfluorene from a 2,4,7‐trifunctional fluorene monomer

A new hyperbranched ( P1 ) and linear copolyfluorene ( P2 ) were prepared from 2,4,7‐trifunctional (branching) and 2,7‐bifunctional fluorene monomer, respectively, by the Wittig reaction, followed with end‐capping by aromatic oxadiazole groups, to study the effect of hyperbranch structure. The weight‐average molecular weights (M_w) of P1 and P2 , determined by gel permeation chromatography using polystyrene as standard, were 33,000 and 25,700, respectively. The polymers were readily soluble in common organic solvents and exhibited good thermal stability (T_d > 400 °C). Optical properties, both in solution and film state, were investigated using absorption and photoluminescence (PL) spectra. In film state, the absorption and PL spectra peaked at 401–425 nm and 480–495 nm, respectively. The P1 showed energy funnel effect and enhanced fluorescence efficiency owing to hyperbranched structure and terminal oxadiazole groups. The HOMO and LUMO levels of P1 ( P2) , estimated from cyclic voltammograms, are ?5.34 (?5.25) eV and ?2.94 (?2.94) eV, respectively. Two‐layer polymer light‐emitting diodes devices (ITO/PEDOT/ P1 /Ca/Al) exhibited maximal luminance and luminous efficiency of 3630 cd/m² and 0.78 cd/A, respectively, which are superior to its linear counterpart P2 (598 cd/m², 0.11 cd/A). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5541–5551, 2007     

Synthesis and characterization of novel conjugated polymers based on 3-cyclobutene-1,2-dione moiety

Three novel conjugated polymers bearing 3,4-bis（4-hexylthiophen-2-yl）-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,¹H NMR and ¹³C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers have good thermostability and solubility in common organic solvents.Moreover,all these objective macromolecules possess high electron affinity of～3.8 eV determined from cyclic voltammetry measurement,implying that they are potential n-type polymeric photovoltaic materials.