- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Divergent Terpyridine-Based Coordination for the Construction of Photoactive Supramolecular Structures
摘要： Exploring new materials to manipulate luminescent radiation and investigate the interaction of light and matter is one of the most compelling prospects of our century. Supramolecular chemistry has unraveled the opportunity to synergistically combine the chemical and optoelectronic properties of the most diverse classes of compounds. Among these, terpyridines have acted as pivotal ligand units that enable self-assembly of multicomponent chromophoric systems. In this review we therefore elucidate the metal-coordinating ability of these materials, that promote a plethora of aggregation-induced phenomena. In particular, fluorescence tuning, reversible stimuli-responsive phosphorescence enhancement and low-dimensional complexation have been demonstrated for carbon and sulfur based terpyridine oligomeric structures. Common thread of such processes is the versatile application of light as a trigger for spectroscopic investigation and output for superior optical, medical and sensing devices.
关键词： Luminescence,Terpyridine,Supramolecular chemistry,Polymers
更新于2025-09-23 15:23:52
-
Cellulose nanopaper with controllable optical haze and high efficiency ultraviolet blocking for flexible optoelectronics
摘要： For Zn-nanopapers obtained from grafting of Zn(II)-terpyridine complex (Zn-tpy) into tCNFs (2,2,6,6-tetramethylpiperidine-1-oxyl radical, TEMPO, oxidized cellulose nano?brils), their optical hazes were ?rst found to be highly dependent on alcohol-characteristic solvent stimulation. By addressing the controllable issue of benzyl alcohol (BA) disposal, the optical haze of Zn-nanopaper was adjusted to regulate from BA-induced instability wrinkling and swelling patterns, which was dictated by Zn-nanopaper thickness. Moreover, upon long-term UV radiation, these Zn-nanopapers exhibited stable UV-blocking, which, together with the optical haze adjustment, offered an opportunity for utilization in ?uorescent lamps, ?at panel displays or glass walls.
关键词： Oxidized cellulose nano?brils,Post-processing,Controllable optical haze,Zn(II)-terpyridine,UV-blocking
更新于2025-09-23 15:22:29
-
Resonance Raman Spectro-Electrochemistry to Illuminate Photo-Induced Molecular Reaction Pathways
摘要： Electron transfer reactions play a key role for artificial solar energy conversion, however, the underlying reaction mechanisms and the interplay with the molecular structure are still poorly understood due to the complexity of the reaction pathways and ultrafast timescales. In order to investigate such light-induced reaction pathways, a new spectroscopic tool has been applied, which combines UV-vis and resonance Raman spectroscopy at multiple excitation wavelengths with electrochemistry in a thin-layer electrochemical cell to study [RuII(tbtpy)2]2+ (tbtpy = tri-tert-butyl-2,2′:6′,2′′-terpyridine) as a model compound for the photo-activated electron donor in structurally related molecular and supramolecular assemblies. The new spectroscopic method substantiates previous suggestions regarding the reduction mechanism of this complex by localizing photo-electrons and identifying structural changes of metastable intermediates along the reaction cascade. This has been realized by monitoring selective enhancement of Raman-active vibrations associated with structural changes upon electronic absorption when tuning the excitation wavelength into new UV-vis absorption bands of intermediate structures. Additional interpretation of shifts in Raman band positions upon reduction with the help of quantum chemical calculations provides a consistent picture of the sequential reduction of the individual terpyridine ligands, i.e., the first reduction results in the monocation [(tbtpy)Ru(tbtpy?)]+, while the second reduction generates [(tbtpy?)Ru(tbtpy?)]0 of triplet multiplicity. Therefore, the combination of this versatile spectro-electrochemical tool allows us to deepen the fundamental understanding of light-induced charge transfer processes in more relevant and complex systems.
关键词： ruthenium bis-terpyridine complex,resonance Raman,in situ spectro-electrochemistry,TDDFT,UV-vis
更新于2025-09-23 15:22:29
-
Rapid, sensitive and highly specific label-free fluorescence biosensor for microRNA by branched rolling circle amplification
摘要： A simple fluorescence biosensor for rapid and sensitive target microRNA (miRNA) quantification by branched rolling circle amplification (BRCA) is developed in this work. Target miRNA functions as primer to recognize and hybridize with a circle DNA template, initiating rolling circle amplification (RCA) by Phi29 DNA polymerase. The introduction of reverse primers complementary to the RCA products enables isothermal BRCA, in which a large amount of deoxynucleotide (dNTP) were consumed and same number of pyrophosphates (PPi) were produced. In this study, a simple and non-expensively synthesized terpyridine-based Zn(II) complex is utilized as fluorescent probe for selective detection of pyrophosphate (PPi) over dNTP. The PPi generated in this isothermal amplification process efficiently chelates to this terpyridine-Zn(II) complex, forming a highly fluorescent complex, terpyridine-Zn(II)-PPi, whose fluorescence intensity is closely related with the initial target miRNA concentration. The utilization of the isothermal BRCA amplification and direct monitoring of the DNA polymerization by-product, i.e. PPi, for non-label fluorescence detection of miRNA greatly simplify this sensor procedure. This sensor shows a linear response between the fluorescence intensity and the target miRNA concentration from 50 to 500 fM with a detection limit of 25 fM. This much-simplified sensor offers a sensitive and easy-to-use platform for miRNA quantification, and hence may significantly enhance the utilisation of miRNAs as biomarkers in drug discovery, clinical diagnosis and life science research.
关键词： Pyrophosphate,Fluorescent sensor,MicroRNA,Branched rolling circle amplification,Terpyridine zinc
更新于2025-09-23 15:21:01
-
A genetically encoded photosensitizer protein facilitates the rational design of a miniature photocatalytic CO2-reducing enzyme
摘要： Photosensitizers, which harness light energy to upgrade weak reductants to strong reductants, are pivotal components of the natural and artificial photosynthesis machineries. However, it has proved difficult to enhance and expand their functions through genetic engineering. Here we report a genetically encoded, 27 kDa photosensitizer protein (PSP), which facilitates the rational design of miniature photocatalytic CO2-reducing enzymes. Visible light drives PSP efficiently into a long-lived triplet excited state (PSP*), which reacts rapidly with reduced nicotinamide adenine dinucleotide to generate a super-reducing radical (PSP?), which is strong enough to reduce many CO2-reducing catalysts. We determined the three-dimensional structure of PSP? at 1.8 ? resolution by X-ray crystallography. Genetic engineering enabled the site-specific attachment of a nickel–terpyridine complex and the modular optimization of the photochemical properties of PSP, the chromophore/catalytic centre distance and the catalytic centre microenvironment, which culminated in a miniature photocatalytic CO2-reducing enzyme that has a CO2/CO conversion quantum efficiency of 2.6%.
关键词： quantum efficiency,photosensitizer protein,visible light,photocatalytic CO2-reducing enzymes,X-ray crystallography,nickel–terpyridine complex,genetic engineering
更新于2025-09-23 15:21:01
-
Synthesis, Photophysics, and Switchable Luminescence Properties of a New Class of Ruthenium(II)–Terpyridine Complexes Containing Photoisomerizable Styrylbenzene Units
摘要： We report here the synthesis and structural characterization of a new class of homoleptic terpyridine complexes of Ru(II) containing styrylbenzene moieties to improve room-temperature luminescence properties. Solid-state structure determination of 2 was done through single-crystal X-ray diffraction. Tuning of photophysical properties was done by incorporating both electron-donating and electron-withdrawing substituents in the ligand. The complexes exhibit strong emission having lifetimes in the range of 10.0?158.5 ns, dependent on the substituent and the solvent. Good correlations were also observed between Hammett σ p parameters with the lifetimes of the complexes. Styrylbenzene moieties in the complexes induce trans?trans to trans?cis isomerization accompanied by huge alteration of their spectral profiles upon treating with UV light. Reversal of trans?cis to trans?trans forms was also achieved on interacting with visible light. Change from trans?trans to the corresponding trans?cis form leads to emission quenching, whereas trans?cis to the corresponding trans?trans form leads to restoration of emission. In essence, “on?off” and “off?on” photoswitching of luminescence was observed. Calculations involving density functional theory (DFT) and time-dependent-DFT methods were performed to understand the electronic structures as well as for appropriate assignment of the absorption and emission bands.
关键词： Ruthenium(II)?Terpyridine Complexes,Photophysics,Switchable Luminescence,Styrylbenzene Units,Photoisomerization
更新于2025-09-23 15:21:01
-
Synthesis of the diketopyrrolopyrrole/terpyridine substituted carbazole derivative based polythiophenes for photovoltaic cells
摘要： A series of conjugated polythiophenes (PTs) having low band gap energies (PDPP, PDPCz21, PDPCz11), with 2-ethylhexyl-functionalized 2,5-thienyl diketopyrrolopyrrole (TDPP) as the electron acceptor and terpyridine-substituted carbazole (TPCz) as the electron donor, have been synthesized and studied for their applicability in polymer-based photovoltaic cells (PVCs). The thermal stability and solvent solubility of PTs increased upon increasing the content of the TPCz derivative. PVCs were fabricated having the following architecture: indium tin oxide/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/PT:6,6-phenyl-C71-butyric acid methyl ester (PC71BM)/Ca/Ag. The compatibility between the PT and PC71BM improved upon increasing the TPCz content. The photovoltaic properties of the PDPCz21-based PVCs were superior to those of their PDPP- and PDPCz11-based counterparts.
关键词： electron donor,photovoltaic cells,diketopyrrolopyrrole,electron acceptor,conjugated polythiophenes,terpyridine-substituted carbazole
更新于2025-09-19 17:13:59
-
Synthesis, Characterization, Photophysical and Electrochemical Studies of Ruthenium(II) Complexes with 4′-Substituted Terpyridine Ligands and Their Biological Applications
摘要： Three 4’-(4-Methylbenzoate-benzyloxy)-2,2’:6’,2’’-terpyridine (MBBtpy), 4’-(4-Ethylbenzoate-benzyloxy)-2,2’:6’,2’’-terpyridine (EBBtpy) and 4’-(5-(1,3-Dimethylbenzoate)-benzyloxy)-2,2’:6’,2’’-terpyridine (DMBBtpy) ligands and seven ruthenium(II) symmetrical [Ru(MBBtpy)2](PF6)2 (Ru1), [Ru(EBBtpy)2](PF6)2 (Ru2), [Ru(DMBBtpy)2](PF6)2 (Ru3) and unsymmetrical [Ru(MBBtpy)(EBBtpy)](PF6)2 (Ru4), [Ru(MBBtpy)(ttpy)](PF6)2 (Ru5), [Ru(MBBtpy)(Brttpy)](PF6)2 (Ru6), [Ru(MBBtpy)(HOttpy)](PF6)2 (Ru7) complexes were synthesized and characterized by UV/Vis, Fluorescence, FTIR, 1H & 13C NMR, ESI-mass spectral studies and electrochemical studies. The crystal structure of HOttpy ligand was determined by single crystal X-ray diffraction. The cyclic voltammograms of Ru(II) complexes exhibit a quasi-reversible oxidation peak corresponding to RuII/RuIII process. The peak current Ipa and Ipc increases with increase in scan rate. The Ru(II) complexes tested for in vitro antimicrobial activity against four human pathogens and fungus Candida albicans showed good antibacterial and antifungal activity. The binding of Ru(II) complexes with calf thymus DNA was determined by UV/Vis spectroscopy. The cleavage activity of ruthenium(II) complexes studied by gel electrophoresis indicates that these complexes can cleave pUC19 DNA more efficiently when compared to that of control.
关键词： Ruthenium(II) Bis(terpyridine) complexes,Antimicrobial studies,DNA studies,Photophysical studies,Cyclic voltammograms
更新于2025-09-10 09:29:36
-
Effect of substituents on photophysical and aggregation behaviour in quinoline based bis-terpyridine Zn(II) complexes
摘要： Synthesis of the terpyridine based novel Zn(II) complexes (C1-C3) have been described. Characterization of these complexes has been achieved by spectroscopic studies (IR, 1H, 13C, 19F, HRMS, UV/Vis and fluorescence) and structure of C1 determined by X-ray single crystal analyses. Cautious tuning by incorporating appropriate substituents (–H; C1, –CH3; C2 and –OCH3; C3) enabled the complexes to exhibit solvent dependent emission indicative of more polarized excited state probably due to enhanced intramolecular charge transfer (ICT). Occurrence of aggregation induced emission (AIE) in C3 has been validated by solid state emission and vital role of RIR in inducing AIE upon aggregation by fluorescence lifetime experiments. The role of solvent and substituents on photophysical behaviour and morphology of the complexes has been investigated by UV/Vis, emission and scanning electron microscopy (SEM). As well, lowering of the energy gap between HOMO and LUMO by electron donating substituents –CH3 (C2) and –OCH3 (C3) has been supported by DFT studies.
关键词： Zn(II) complexes,photophysical properties,DFT studies,aggregation induced emission,terpyridine
更新于2025-09-10 09:29:36
-
Heteroleptic complexes of silver(I) featuring 4′-hydroxy- and 4′-(2-furyl)-2, 2′:6′, 2″-terpyridine: an easy route to synthesis silver nanoparticles
摘要： New coordination complexes of silver(I) containing triphenylphosphine and 4′-hydroxy-2,2′:6′,2″-terpyridine (tpyOH) or 4?-(2-furyl)-2,2′:6′,2″-terpyridine (ftpy) have been synthesized to afford the new compounds [Ag(tpyOH)(PPh3)](NO3) (1) and [Ag(ftpy)(PPh3)](NO3) (2). In addition, the reaction of silver(I) nitrate with ftpy in the presence of excess of 4,4′-bipyridine (bpy) and NH4PF6 led to the formation of binuclear complex [Ag2(ftpy)2(μ-bpy)](PF6)2 (3). The products have been characterized by elemental analysis, IR, UV-Vis, NMR (1H, 31P) spectroscopy and single crystal X-ray diffraction in the case of 3. The 31P NMR data reveal that the interaction of PPh3 with silver(I) is maintained in solution in 1-2. The crystal structure of 3 shows that each Ag+ ion is coordinated by three N-atoms of ftpy and a nitrogen from the bridging ligand of bpy in a slightly distorted square planar geometry. There are some strong noncovalent interactions of hydrogen bonding and Ag-η2-furyl in the crystal structure, connecting molecules to form a supramolecular network. The thermal decomposition of 1-3 has also been investigated. The thermal stability of all complexes, as determined by thermogravimetric analysis (TGA), are almost the same and they are thermally stable up to 220 oC. The complex 3 was used for the preparation of Ag nanoparticles by simple calcination method at two different temperatures of 400 and 600 ?C resulting in the formation of silver nanoparticles, crystalline in nature with the size of 66 and 52 nm, respectively, using Scherrer’s equation. The nano-sized silver particles have also been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDX).
关键词： Crystal Structure,Thermal Properties,Nano Particle,Silver,Terpyridine
更新于2025-09-09 09:28:46