若干香豆素衍生物在滤纸基质上的RTP和RTF特性

详细考察了各种基质、重原子微扰剂和实验条件的影响之后,成功地实现了多种香豆素衍生物的室温磷光(RTP)发射。在滤纸基质上,以1mol/L的Pb(Ac)_2作重原子微扰剂时,近20种香豆素衍生物大都能产生较强的RTP发射。而且某些衍生物的RTP强度和λ_(ex)/λ_(em)等特性间呈现出明显的取代基效应。本文还对这些衍生物在滤纸基质上的室温荧光(RTF)和其混和光谱(在重原子微扰剂存在下以荧光方式测得的光谱)等特性作了对比测定,发现其间亦呈现类似的取代基效应。有关香豆素衍生物的RTP特性,迄今尚未报道。这类衍生物RTP发射的实现,预示着它们用作RTP标记物的可能性。     

AMl-MO理论对方酸燃料结构和电子性质的研究

通过对一系列具有C－5取代基的吲哚方酸菁染料的AM1分子轨道计算，研究了染料结构和基态与单线激发态电子特性，并用（＋）（-）sparkles模拟溶剂化作用，通过AM1－CI计算的染料吸收波长接近实际测量值，并通过基态与单线激发态原子电荷密度的变化，讨论取代基效应对吸收波长的影响；循环伏安法测量的染料有两个可逆的氧化电位，电位数值随取代基给电子性的增加而减小．第一氧化电位与AM1计算的染料离子电离势，用测量的跃迁能校正的电子亲和能与AM1计算值均有很好的线性关系．     

苯并噻唑类核酸分子荧光探针的合成及光谱性质

设计合成了3种两端杂环氮原子上具有不同取代基的苯并噻唑类不对称三甲川菁染料,并对染料的结构进行了表征。 测试了染料在乙醇中的吸收和荧光发射光谱,染料的最大吸收值和荧光发射值分别在629~635 nm和656~672 nm之间。 染料8、9和10的斯托克斯位移分别为23、37和27 nm。 染料在溶剂中基本无荧光,荧光量子产率小于0.021,可以极大的降低染料自身的荧光背景干扰。 染料的光降解实验表明,两端杂环氮原子苄基取代后可以明显增强染料的光稳定性。 测试循环伏安曲线得到染料的氧化电位分别为0.535、0.456和0.399 V,氧化电位越大,光降解速率常数越小,与光降解实验得到的降解速率常数结果一致。     

新型不对称苯并噻唑三次甲基菁染料的合成及光稳定性研究

合成了系列杂环氮原子具有不同取代基的不对称苯并噻唑三次甲基菁染料,染料结构经过质谱、1H NMR表征.测试了染料在乙醇中的吸收和荧光发射光谱,染料的最大吸收值和荧光发射值分别在628～631和662～666 nm之间.染料在溶剂中几乎无荧光,可以极大的降低染料自身的荧光背景干扰.染料的光降解实验表明:喹啉环上辛烷基取代和噻唑环上苄基取代时,染料的光稳定性最强.染料8a～8d的光降解速率常数分别为6.38×10-4,12.5×10-4,2.68×10-4和6.30×10-4mol min-1.循环伏安实验法测试了染料的氧化电位.     

新型中位取代七甲川菁染料的合成及光稳定性研究

本文合成了两种新型中位取代近红外七甲川菁染料,采用核磁1 HN-MR和HRMS质谱对其结构进行了表征.并测试了染料在不同溶剂中的吸收光谱和荧光发射光谱性质.染料3b、3c在甲醇中的最大吸收波长和最大荧光发射波长分别为677/790nm和647/786nm,斯托克斯位移分别为113 nm、139nm.经过光降解实验测试得到3种染料3a—3c在乙醇中的光降解速率常数分别为1.21×10-3 mol/min、1.81×10-3 mol/min和2.14×10-3 mol/min.循环伏安法测得染料3a—3c的氧化电位分别在0.729V、0.624V和0.598V.光降解实验表明:七甲川菁染料中位亚甲基链上吸电基取代增强染料光稳定性,供电基取代减弱染料的光稳定性;供-吸电子能力强弱决定了染料的光稳定性强弱;同时中位氯原子取代与共轭链上的氢键作用有利于染料的稳定性增强,中位氮原子取代无法形成很好的氢键作用,不利于染料稳定性的提高.     

6-磺酰氯香豆素的室温燐光特性

通过多种重原子微扰剂和实验条件的选择,成功地实现了C6SCl在数种基质上的RTP发射。发现Pb(Ⅱ)盐是这种RTP发射的最有效的外部重原子微扰剂。在滤纸基质上,以1mol/L Pb(Ac)_2作重原子微扰剂获得了强度高且信/背比亦高的RTP信号,λ_(ex)/λ_(em)=320/496nm。0.2μl点样体积中,C6SCl含量在4～200pmol范围内与RTP信号强度呈良好的线性关系。     

不同取代基的噻碳菁和吲哚碳菁染料对其在溴化银微晶上吸附能力及形成J-聚集体尺寸分布的影响

本文研究了5-位不同取代基的噻碳菁和吲哚碳菁染料对其在立方型颗粒和T-颗粒溴化银微晶上吸附能力的影响,并采用ACFEM(Analytical Color Fluore scence Electron Microscopy)研究了上述结构染料对其吸附在溴化银微晶所形成的J-聚集体尺寸分布的影响。实验结果表明,对吲哚碳菁染料来说,立方体溴化银微晶表面的吸附能力较T-颗粒溴化银微晶表面的吸附能力强;但对噻碳菁染料来说则相反,它们在T-颗粒溴化银微晶表面的吸附能力较立方体溴化银微晶表面的吸附能力强。另外,对5-位不同取代基的噻碳菁染料而言,无论是在立方型颗粒或T-颗粒溴化银微晶上的吸附能力来说,含取代基(无论4-取代基是吸电子型还是推电子型)的噻碳菁染料较未取代的噻碳菁染料强;而5-位取代基是吸电子型的噻碳菁染料更有利于其吸附在T-颗粒溴化银微晶表面。此外,本文还进一步证明了溴化银微晶表面上染料J-聚集体的生长过程是符合奥斯瓦尔特成熟过程的。吲哚碳菁染料在T-颗粒溴化银微晶上形成的J-聚集体的平均尺寸明显大于在立方体溴化银微晶上形成的J-聚集体的平均尺寸。吸附在立方体溴化银微晶上的5-不同取代基的噻碳菁染料对其形成J-聚集体尺寸分布的影响的研究结果表明,含取代基(-CH₃,-Ph,-Cl)的噻碳菁染料形成的J-聚集体的尺寸分布几乎相同,但与未取代的噻碳菁染料形成的J-聚集体的尺寸分布明显不同;5-位含取代基的噻碳菁染料形成的J-聚集体平均尺寸大于未取代的噻碳菁染料的。     

噻菁染料的合成及吸收光谱的研究

合成了阳离子型、两性离子型和阴离子型的噻菁染料，对它们的结构进行了表征，并研究了染料的结构(阴离子和取代基的改变) 对吸收光谱的影响。     

噻菁染料的合成

本实验合成了6个二磺酸盐的水溶性噻菁染料，并通过UV-vis、^1H NMR、IR谱图和元素分析给予确定。从紫外可见光谱可看出，苯环上的取代基影响染料的最大吸收(λ~m~a~x)和摩尔消光系数ε~m~a~x。     

滤纸基质室温燐光法测定痕量硫鸟嘌呤的研究

本文对硫鸟嘌呤在不同的固体基质和重原子微扰剂存在下的RTP发射强度进行了比较。结果表明,适宜的固体基质是国产慢速定量滤纸,有效重原子盐为NaI或In_2(SO_4)_3。在此基础上对响影硫鸟嘌呤RTP发射强度的各种因素进行了研究,建立了测定痕量硫鸟嘌呤的SS-RTP法。以NaI为重原子时,方法的线性范围为3.3～200.4ng,检出限为0.4ng/斑点。以In_2(SO_4)_3为重原子时,线性范围为3.3～334.3ng,检出限为1.6ng/斑点。     

Spatial effect and resonance energy transfer for the construction of carbon dots composites with long-lived multicolor afterglow for advanced anticounterfeiting

Carbon dots (CDs) with room-temperature phosphorescence (RTP) have attracted dramatically growing interest in optical functional materials. However, the photoluminescence mechanism of CDs is still a vital and challenging topic. In this work, we prepared CD-based RTP materials via melting boric acid with various lengths of alkyl amine compounds as precursors. The spatial effect on the structure and the RTP properties of CDs were systematically investigated. With the increase in carbon chain length, the interplanar spacing of the carbon core expands and crosslink-enhanced emission weakens, resulting in a decrease in the phosphorescence intensity and lifetimes. Meanwhile, based on triplet-to-singlet resonance energy transfer, we employed intense and long-lived phosphorescence CDs as the donor and short-lived fluorescent dyes as the acceptor to achieve long-lived multicolor afterglow. By the triplet-to-singlet resonance energy transfer, the afterglow color can change from green to orange. The afterglow lifetimes are more than 0.9 s. Thanks to the outstanding afterglow properties, the composites were used for time-resolved and multiple-color advanced anticounterfeiting. This work will promote the design of multicolor and long-lived afterglow materials and expand their applications.     

Visible-light-excited long-lived organic room-temperature phosphorescence of phenanthroline derivatives in PVA matrix by H-bonding interaction for security applications

Organic room-temperature phosphorescence (RTP) materials are very attractive, but there is still a challenge to achieve RTP for their practical applications under visible light excitation (λ > 400 nm) because of the implement for the most organic RTP is under ultraviolet light. Herein, a simple tactics for inhibiting the vibrational dissipation of three amorphous phenanthroline derivatives by doping them into polyvinyl alcohol (PVA) matrix was utilized to afford visible-light excitation RTP. By using this method, on account of the mutual H-bonding and confinement effect with PVA matrix, a series of organic RTP materials with blue-green phosphorescence emission were obtained under visible-light excitation. The afterglow colors of RTP materials can be adjusted by co-doping the available fluorescence dyes (RhB or Rh6G) into the PVA films through a triplet-to-singlet Förster resonance energy transfer. However, the H-bonding is easily broken by water molecules resulting in the RTP phenomenon disappears. Hence, Aphen-epoxy resin composite system was constructed to overcome this drawback. It is shown that the composite still has good phosphorescence properties after soaking in water for 7 days. The superior RTP of the amorphous phenanthroline derivatives in processable polymer matrices endows these materials with a highly potential for the night warning clothing coating and information encryption.     

香豆素衍生物在数种薄层基质上的室温磷光发射特性

考查了二十多种香豆素衍生物在国产ＭＮ－Ｐ型和ＭＮ－Ｃ型微晶纤维素膜，ＤＥＡＥ离子交换膜上的室温磷光发射特性，并与用滤纸作基质时的结果作了比较。在这些基质上，多数衍生物都能发射不同强度的ＲＴＰ信号，且在其ＲＴＰ特性间呈现，某些取代基效应。从发光稳定性和信背比考虑，ＭＮ－Ｃ型比ＭＮ－Ｐ型膜更适合于这些衍生物的ＲＴＰ发射。     

Thiazole Boron Difluoride Dyes with Large Stokes Shift,Solid State Emission and Room-Temperature Phosphorescence

The small Stokes shift and weak emission in the solid state are two main shortcomings associated with the boron-dipyrromethene (BODIPY) family of dyes. This study presents the design, synthesis and luminescent properties of boron difluoro complexes of 2-aryl-5-alkylamino-4-alkylaminocarbonylthiazoles. These dyes display Stokes shifts (Δλ, 77–101 nm) with quantum yields (ϕ_FL) up to 64.9 and 34.7 % in toluene solution and in solid state, respectively. Some of these compounds exhibit dual fluorescence and room-temperature phosphorescence (RTP) emission properties with modulable phosphorescence quantum yields (ϕ_PL) and lifetime (τ_p up to 251 μs). The presence of intramolecular H-bonds and negligible π-π stacking revealed by X-ray crystal structure might account for the observed large Stokes shift and significant solid-state emission of these fluorophores, while the enhanced spin-orbit coupling (SOC) of iodine and the self-assembly driven by halogen bonding, π-π and C−H^…π interactions could be responsible for the observed RTP of iodine containing phosphors.     

醇对环糊精/溴代萘超分子组合体系室温燐光的影响

研究了ＣＤ／溴化萘／醇体系的室温燐光发射条件、发光特性和不同醇、不同ＣＤ的影响。认为就本质而言，这类发光体系属一种超分子组合体系。其中，ＣＤ与内含重原子的发光体借助于分子间作用力形成二元包结物；而醇则与ＣＤ端口的羟基形成氢键，其烷基链借助于疏水作用力覆盖在ＣＤ的端口，如同一种疏密不同的盖子，不仅提高了ＣＤ腔内的疏水性，增大了发光体与ＣＤ的结合常数，同时，对外部氧向ＣＤ腔内的扩散起着隔离作用，其效应如同通Ｎ２除氧过程，从而可在不除氧条件下，观察到强的室温磷光发射。由于这类流体室温■光现象，在属性上已超出原有环糊精诱导室温■光范畴，醇的作用属超分子化学中典型的分子调控作用，其主体理应不局限于环糊精，因此建议将其命名为超分子组合室温■光（Ｓｕｐｒａｍｏｌｅｃｕｌａｒ Ａｓｓｅｍｂｌｙ ＲｏｏｍＴｅｍｐｅｒａｔｕｒｅＰｈｏｓｐｈｏｒｅｓｃｅｎｃｅ，简写为 ＳＭ－ＲＴＰ）。     

Room-Temperature Phosphorescence Emitters Exhibiting Red to Near-Infrared Emission Derived from Intermolecular Charge-Transfer Triplet States of Naphthalenediimide−Halobenzoate Triad Molecules

Room-temperature phosphorescence (RTP) emitters have attracted significant attention. However, purely organic RTP emitters in red to near-infrared region have not been properly investigated. In this study, a series of naphthalenediimide−halobenzoate-linked molecules are synthesized, one of which exhibits efficient RTP properties, showing red to near-infrared emission in solid and aqueous dispersion. Spectroscopic studies and single-crystal X-ray diffraction analysis have shown that the difference in the stacking modes of compounds affects the optical properties, and the formation of intermolecular charge-transfer complexes of naphthalenediimide−halobenzoate moiety results in a bathochromic shift of absorption and RTP properties. The time-dependent density functional theory calculations showed that the formation of charge-transfer triplet states and the external heavy atom effect of the halogen atom enhance the intersystem crossing between excited singlet and triplet states.     

Spectroscopy behavior of 6-Mercaptopurine, Azathiopurine, and 8-Azaguanine

A comparative study, luminescence behavior of 6-Mercaptopurine (6-MP), Azathiopurine (BAN), and 8-Azaguanine (8-Azan) have been investigated including the low temperature phosphorescence, the low temperature fluorescence, the room temperature phosphorescence (RTP) and the room temperature fluorescence (RTF). The effect of pH on the luminescence intensity is discussed. Analytical characteristics of RTF and RTP of 6-MP, BAN, and 8-Azan have been studied. The lifetime of phosphorescence and the polarity of RTF and RTP have been examined.     

Influence of the alkyl side chain length on the room-temperature phosphorescence of organic copolymers

Pure organic room-temperature phosphorescence(RTP) materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications. In this work, iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide. It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission, and polymers with the larger conjugated structure of the ...     

9,9-Dimethylxanthene Derivatives with Room-Temperature Phosphorescence: Substituent Effects and Emissive Properties

Room-temperature phosphorescence (RTP) emitters with ultralong lifetimes are emerging as attractive targets because of their potential applications in bioimaging, security, and other areas. But their development is limited by ambiguous mechanisms and poor understanding of the correlation of the molecular structure and RTP properties. Herein, different substituents on the 9,9-dimethylxanthene core (XCO) result in compounds with RTP lifetimes ranging from 52 to 601 ms, which are tunable by intermolecular interactions and molecular configurations. XCO-PiCl shows the most persistent RTP because of its reduced steric bulk and multiple sites of the 1-chloro-2-methylpropan-2-yl (PiCl) moiety for forming intermolecular interactions in the aggregated state. The substituent effects reported provide an efficient molecular design of organic RTP materials and establishes relationships among molecular structures, intermolecular interactions, and RTP properties.     

A Simple Organic Molecule Realizing Simultaneous TADF,RTP, AIE,and Mechanoluminescence: Understanding the Mechanism Behind the Multifunctional Emitter

Aggregation‐induced emission (AIE), thermally activated delayed fluorescence (TADF), room‐temperature phosphorescence (RTP), and mechanoluminescence (ML) have attracted widespread interest. However, a multifunctional organic emitter exhibiting simultaneous AIE, TADF, RTP, and ML has not been reported. Now, two multifunctional blue emitters with very simple structures, mono‐DMACDPS and Me‐DMACDPS, exhibit typical AIE, TADF, and RTP properties but different behavior in mechanoluminescence. Crystal structure analysis reveals that large dipole moment and multiple intermolecular interactions with tight packing mode endow mono‐DMACDPS with strong ML. Combined with the data of crystal analysis and theoretical calculation, the separated monomer and dimer in the crystal lead to the typical TADF and RTP properties, respectively. Simple‐structure mono‐DMACDPS is the first example realizing TADF, RTP, AIE, and ML simultaneously.