Photophysical Properties of 4t-（p-aminophenyl）-2,2＇：6＇,2″-terpyridine

Spectral and photophysical investigations of 4＇-（p-aminophenyl）-2,2＇：6＇,2″-terpyridine （APT） have been performed in various solvents with different polarity and hydrogen-bonding ability. The emission spectra of APT are found to exhibit dual fluorescence in polar solvents, which attributes to the local excited and intramolecular charge transfer states, respectively. The two-state model is proven out for APT in polar solvent by the time-correlated single photon counting emission decay measurement. Interestingly, the linear relationships of different emission maxima and solvent polarity parameter are found for APT in protic and aprotic solvents, because of the hydrogen bond formation between APT and alcohols at the amino nitrogen N25. Furthermore, the effects of the complexation of the metal ion with tpy group of APT and the hydrogen bond formation between APT with methanol at the terpyridine nitrogen N4-NS-N14 are also presented. The appearance of new long-wave absorption and fluorescence bands indicates that a new ground state of the complexes is formed.

Synthesis, Crystal Structure and Two-photon Absorption Properties of 4′-(N,N-di(4-hydroxymethyl phenyl) amino)phenyl-2,2′:6′,2''-terpyridine

A novel donor-acceptor （D-A） triphenylamino terpyridine derivative L was facilely synthesized and fully characterized, and its single crystals were obtained and determined by X-ray diffraction analysis. It crystallizes in triclinic, space group P/ with a = 11.760（5）, b =12.516（5）, c = 12.850（5） A, α = 67.141（5）, β= 65.284（5）, γ = 75.876（5）°, Mr = 621.54, F= 1575.6（11） A3, Z= 2, Dc = 1.310 g/cm3,μ = 0.245 mm-1, F（000） = 648, the final R = 0.0671 and wR = 0.1869 for 11328 observed reflections with 1〉 2σ（I）. Linear and nonlinear optical properties of terpyridine derivative L were systematically investigated. The maximum two-photon cross-section of L was 382.5 GM （Goeppert-Mayer）, measured by two-photon excited fluorescence （TPEF） method. This result demonstrates that the increase of intramolecular charge transfer （ICT） leads to enhanced two-photon absorption （2PA）, which could be achieved by introducing additional electron-donor groups to the molecular framework.

Terpyridine-derived Zn^(2+) Selective Fluorescence Sensor: Ratiometric Fluoroionophoric Behavior Study

A sensitive and selective zinc ion ratiometric fluorescence sensor has been synthesized and characterized. This material displays dual fluorescence. After the material was bonded to a closed-shell metal ion, such as Zn2＋, the recovery of the local excited fluorescence of the material-Zn2＋ complex, largely at the expense of the intramolecular charge transfer fluorescence, is consistent with the difference between selected orbital transitions of the free dye and the metal-chelated complex. For instance, the contribution of the πtpy→πtpy, transition becomes more prominent. This is also consistent with the results of the fluorescence decay behavior, measured via a time-correlated single photon counting setup. In contrast, the corresponding open shell Ni2＋ -bound complex quenches both kinds of photoluminescence, due to spin-orbit coupling.

Controllable synthesis of novel mono-and di-terpyridine derivatives

A series of novel mono- and di-terpyridine derivatives with purinyl and pyrimidyl group were obtained from the reaction of 4′-p- bromomethylphenyl-2,2′：6,2″-terpyridine with 6-mercaptopurine, 2,6-dimercaptopurine and thymine, respectively. The active hydrogens on these alkaloids could be abstracted stepwise using different bases, which made the addition controllable.

Synthesis of Terpyridine Derivatives Containing β-Cyclodextrin

A novel b-cyclodextrin-based terpyridine derivatives has been prepared by the coupling of 4-(4-bromomethyl phenyl)- 2, 2:6, 2-terpyridine with mono-6-hydroxy permethylated b- cyclodextrin. The cyclodextrin dimmer appending a 4-phenyl-2,2:6,2- terpyridine spacer on the primary faces was synthesized by reaction of 4-phenyl-2,2:6,2-terpyridine-6,6-dicarbonitrile with an excess of 6-deoxy-6-O-tosyl-b-cyclodextrin.

Synthesis and Crystal Structure of a Novel Terpyridine-based Cd(Ⅱ) Complex

A novel terpyridine-based complex CdL＇S2 （L＇ = oxide of L; L = 10-hexyl-3-（2,6- di（pyridine-2-yl）pyridine-4-yl）-10H-phenothiazine） has been solvothermally synthesized and characterized by FT-IR spectroscopy, elemental analysis, 1HNMR and X-ray crystallography. The sulfur of phenothiazine moiety was oxidized when the crystal is formed. The complex C36H37CdN5O2S3 crystallizes in triclinic, space group P1 with a = 9.4452（9）, b = 13.0181（14）, c = 14.6721（18） A, a = 73.872（1）, β = 81.531（1）, y = 87.547（2）°, V= 1714.2（3） A3, Mr = 780.29, Dc= 1.512 g.cm-3,μ = 0.861 mm-l, F（000） = 800, Z = 2, the final R = 0.0456 and wR = 0.1059 for I 〉 2σ-（I）. The Cd（II） is coordinated by two terminal sulfur ions and three pyridyl nitrogen atoms in a distorted trigonal bipyramidal geometry. Universal hydrogen bonds between the neighboring molecules have generated a supramolecular arrangement which contributes to the stability of the title complex. Fluorescence property and thermogravimetry of the complex have also been investigated and discussed.

Synthesis,Crystal Structure,Spectroscopic Property and Redox Behavior of Zinc(Ⅱ) Complexes Containing Oligoaniline-functionalized Terpyridine Ligands

Two novel mono-nuclear zinc（Ⅱ） complexes with oligoaniline-functionalized terpyridine ligands have been synthesized and verified by 1H-NMR,13C-NMR,Elemental Analysis （EA） and X-ray Diffraction （XRD）. The UV-vis spectra show the ligand-centered （LC） π-π＊ transitions and intra-ligand charge transfer （1ILCT） transitions,and the 1ILCT band red-shifts with the increasing number of aromatic amine groups in the ligands. Complex [Zn（L1）2]（PF6）2 with an aromatic amine group in ligand shows a strong emission peak at 523 nm in the MeCN solution at 293 K and a blue-shifted band at 517 nm in the alcoholic glass at 77 K. However,for complex [Zn（L2）2]（PF6）2 containing aniline dimer modified ligand,no apparent emission can be observed in the MeCN solution at room temperature due to a PET non-radiative decay pathway. Both of them show multiplicate redox processes based on oligoaniline and terpyridine units. The shifts of redox potentials also reflect the D-A interactions between the oligoaniline units and [Zn（TPY）2]2＋ core.

Synthesis,Crystal Structure and Photoluminescence of a One-dimensional Zinc(Ⅱ)Coordination Polymer with Substituted Terpyridine

The title compound, [Zn（4-pytpy）（NO3）2] （4-pytpy = 4′-（4-pyridyl）-2,2′：6′,2＂- terpyridine） 1, has been synthesized by the solvothermal reaction of Zn（NO3）2·6H2O with 4-pytpy in CH3OH solution. It crystallizes in the triclinic system, space group P1 with a = 8.358（6）, b = 11.121（8）, c = 11.374（8）A, α = 74.226（11）, β = 74.532（11）, γ = 83.085（12）°, Mr= 499.74, V= 979.3（12） A3, Z = 2, Dc = 1.695 g/cm3, F（000） = 508,μ = 1.309 mm^-1, the final R = 0.0547 and wR = 0.1588. X-ray crystal structure analysis revealed that the Znn is hexa-eoordinated by two oxygen atoms from two nitrate groups and four nitrogen atoms, three of which are from the tridentate domain of one 4-pytpy and the other from the monodentate domain of another 4-pytpy. 4-pytpy as a bridging ligand connects ZnⅡ into a one-dimensional coordination polymer.

Experimental Evidence of Reversible Crystalline State Transformation of 2,2':6',2"-Terpyridine: Visualization and Seed Effect

We have succeeded in causing reversible polymorphic transformation of 2,2':6',2"-terpyridine (terpy). By contacting a template terpy crystal with the target crystal, reversible orthorhombic-to-monoclinic transformation occurred directly without via melting state. The transformation process is successfully visualized and it is found that the template crystal influences the transition temperature itself.

Multi-Color Photoluminescence of Terpyridine Crystals

New type of photoluminescence properties of 2,2’:6’,2”-Terpyridine (Terpy) is described. Orthorhombic form of Terpy crystals, which is known to be inherently nonluminous in the visible region, was found to emit strong green light in the presence of traces amount of impurities. Hydroxy-terpyridine, originally included in the Terpy reagent, was found to be the main cause of the green luminescence. Tuning of the luminescent color is possible depending on the dopant species.

One dimensional terpyridine-based metal organic framework for stable supercapacitor

In summary,a novel structure of MOF based on 1,4-di([2,2':6',2''terpyridin]-4'-yl)benzene and 1,4-naphthalenedicarboxylic acid has been constructed through hydrothermal reaction.The Ni-MOF displays one dimensional zigzag chain,which connect each other by hydrogen bonding to form three dimensional supramolecule with large channels.The conjugated systems of the terpyridin and benzene ligands enhance the chain rigidity,accelerate the electron transport.The massive channels provides electrolyte rapid transfer.By the structural feature aforementioned,the Ni-MOF demonstrates stable electrochemical performance as suprocapacitor.

Four New Terpyridine Complexes Based Polyoxometalates with[W_(10)O_(32)]^(4-) Anions as High-Efficiency Dual-Site Catalysis for Thioether Oxidation Reaction

Polyoxometalates modified with complex cations have attracted increasing attention because of the fascinating properties and the controllable structures.By adjusting the synthesis conditions,four new terpyridine complexes based hybrid POMs,[(TPY-H)CuCl]_(4)[W_(10)O_(32)]·2DMF·2H_(2)O(1),[(TPY-H)Cu(DMSO)(H_(2)O)]_(2)[W_(10)O_(32)]·2H_(2)O(2),[(TPY-H)_(2)Cu]_(2)[W_(10)O_(32)]·6DMSO·8H_(2)O(3) and[(TPY-Br)CuCl(DMSO)(H_(2)O)]_(2)[(TPY-Br)CuCl]_(2)[W_(10)O_(32)]·2DMSO·4H_(2)O(4),were prepared by using‘one-pot’method.Sing-crystal X-ray diffraction analyses,infrared radiation,etc.,revealed the structural composition of compounds 1—4,which indicates that synthesis conditions have a directional regulatory effect on the compounds synthesis.Thioether oxidation catalytic reactions show 1—4 have good catalytic activities,and powder X-ray diffraction and thermogravimetry analysis show 1—4 have superduper catalytic stability.Moreover,4 has better catalytic activity because of the different structure of terpyridine complexes.Therefore,a possible mechanism of dual-site catalysis by both cations and anions is proposed.

Synthesis and fluorescent properties of a novel europium(Ⅲ) complex with terpyridine-capped poly(ethylene glycol)

Terpyridine-capped poly（ethylene glycol） （PEG） was synthesized as a novel polymeric ligand and rare earth complex was prepared from Eu（NO3）3 and the telechelic macromolecules. The structure of the complex was characterized by 1H NMR, FT-IR, UV-vis and fluores-cence spectroscopy. Strong fluorescent emission of the complex was observed at 593 and 616 nm upon the excitation of 300 nm. The fluo-rescent emission was quenched upon addition of trace amount of diethyl chlorophosphate （DCP）. And the observed Ksv values for DCP were measured to be 0.568×10^3 and 0.89×10^3 L/mol for quenching at 593 and 616 nm, which indicated the detection limit for DCP was about 0.014 mmol/L. These results showed that the terpyridine-lanthanide complex could be an effective chemosensor with a potential application in the detection of organophosphates.

Decoration of Terpyridine with Electron-Rich Unit TH DTAP: an Efficient Way to Explore Fluorescence Sensors for Recognizing Metal Ions

The electron-donating unit 2,3,4,6-tetrahydro-1,6-dithia-3a-azaphenalene (THDTAP) was introduced onto terpyridine (TPy) to give a donor-acceptor (D-A) type TPy-ligand (compound 2).Upon selective oxidation of two sulfur atoms on the THDTAP moiety of 2,the ligands 3-6 were created.The electronic structures of 2-6 were evaluated by theoretical,electrochemical,and spectroscopic investigations.The oxidation on the sulfur atoms brings significant influence on the electron-donating ability of THDTAP moiety,subsequently,leads to fine modulations on intramolecular charge-transfer (ICT) of 2-6 and the electronically excited states of the complexes of 2-6 with metal ions.Based on the optical response of 2-6 toward metal ions,the step-by-step recognition of Zn2+,Cd2+,and Ag+ ions is set up by employing 2 and 3 as combined fluorescence sensors.

Two novel terpyridine-based chromophores with donor-acceptor structural model containing modified triphenylamine moiety: Synthesis, crystal structures and two-photon absorption properties

Two novel terpyridine-based chromophores with D-A (D = donor, A = acceptor) structural model containing modified triphenylamine moiety (L1 and L2 ) have been conveniently synthesized via formylation and reduction in satisfactory yields, and fully characterized. The single crystals of them were obtained and determined by X-ray diffraction analysis. The relationships between structure and photophysical properties of the two chromophores were investigated both experimentally and theoretically. The measured maximum TPA cross-sections per molecular weight (δmax /MW) of the chromophores are 0.63 GM/(g mol) (L1) and 0.72 GM/(g mol) (L2), respectively, in DMF as a high polar solvent. The results indicate that the value of δmax/MW could be well tuned by the intramolecular charge transfer (ICT), which could be realized by introducing additional elecron-donor/acceptor groups.

Synthesis and Characterization of a Terpyridine Ligand and Its Interactions with Selected Metal Ions

In this work,a terpyridine ligand L,(4΄-phenyl-2,2΄:6΄,2΄΄-terpyridine),was synthesized and fully characterized.Interactions of the ligand with selected metal ions like Cu(Ⅱ),Fe(Ⅲ),Pb(Ⅱ),Fe(Ⅱ),Cr(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)and Mn(Ⅱ)were investigated.Compared to ligand L,only Fe(Ⅱ)and Pb(Ⅱ)ions show new band in electronic absorption spectroscopy.Fluorescent spectroscopy indicates that Zn(Ⅱ)and Cd(Ⅱ)ions enhance the emission intensity of ligand L,and other selected ions quench emission intensity.To explore how Fe(Ⅱ)ion interacts with ligand L,Fe(L)-based complex 1 was synthesized,spectroscopic studies and single-crystal X-ray diffraction analysis.This implies ligand L has an excellent selectivity for Zn(Ⅱ)and Cd(Ⅱ)ions.

Tetraphenylethylene-Based Emissive Supramolecular Metallacages Assembled by Terpyridine Ligands

We report the preparation and emission properties of tetraphenylethylene(TPE)-based metallacages with aggregation-induced emission(AIE)activities through coordination-driven self-assembly.Two supramolecular cages,[Zn6LA3]and[Zn6LB3],were assembled via TPE-decorated terpyridine(tpy)ligands,LA and LB,respectively,with Zn(II)ions.We performed a subtle change by introducing extra alkyne connectivity into LB to increase the degree of conjugation and geometric constraint,compared with LA.As a result,we obtained a highly emissive cage,[Zn6LB3],even in a dilute solution.

Synthesis,characterization and cytotoxicity of fluorescent organotin complexes of terpyridine derivatives

Five organotin complexes of terpyridine derivatives were synthesized and characterized. The mononuclear Sn（IV） complexes were six-coordinated adopting a distorted octahedral coordination geometry. A brief outline of the fluorescence spectra and the in vitro cytotoxicity of the Sn（IV） complexes have been given.

Deep eutectic ionic liquids based on DABCO-derived quaternary ammonium salts: A promising reaction medium in gaining access to terpyridines

Owing to the directional H-bonding,coordination and π-stacking abilities,terpyridines have been widely used as supramolecular tectons in molecular architectures,skeletons in molecular devices and metallopolymers,and are gaining importance in medicinal chemistry.In this paper,we have synthesized,characterized and applied deep eutectic ionic liquids (DEILs) based on 1,4-diazabicyclo[2.2.2]octane;triethylenediamine (DABCO)-derived quatemary ammonium salts for the preparation ofterpyridines.These DEILs were synthesized through N-alkylation of DABCO with haloalkanes (1-bromopentane or 1-bromoheptane) followed by mixing and heating with methanol or polyethylene glycol as a hydrogen bond donor.The synthesized DEILs were structurally characterized by IR and NMR.The formation of deep eutectic solvent was confirmed by freezing point depression,it composition was investigated through phase diagram,and its thermal stability was determined through differential scanning calorimetry,derivative thermogravimetry and thermal gravimetric analysis studies.Further,these DEILs were investigated for their effectiveness towards synthesis of 2,2':6',2"-terpyridine,3,2':6',3"-terpyridineand 4,2':6',4"-terpyridine derivatives through Kr(o)hnke reaction.The results show that these three types ofterpyridines can be obtained in reasonable yields (80%-97%) by the one-pot reaction of 2-,3-or 4-acetylpyridine with a variety of aromatic aldehydes in the presence of DEIL as a reaction medium,sodium hydroxide as a base and ammonium acetate as a cyclizing agent.This methodology is highly efficient and cost-effective for synthesis of symmetrical as well as unsymmetrical terpyridines.Importantly,these DEILs can be reused several times without an obvious loss of activity and are non-toxic,low-volatile,biodegradable and highly thermally stable.Therefore,these DEILs as a non-conventional reaction medium for the synthesis of terpyridines provides appealing opportunities to be investigated in the domain of green synthesis.

Novel Terpyridine-bridged Parallel Dication Metallo-bisviologens and Their Supramolecular Complexes

By utilizing terpyridine-bridged parallel metallo-complexes as dication metallo-bisviologens,herein we present the synthesis and characterization of two novel supramolecular complexes.1-Methylpyridin-1-ium-terpyridine ligands and their metallo-complexes were first designed and synthesized,and the association of methyl-pyridiniums with dibenzo-24-crawn-8 ether(DB24C8)afforded the desired novel complexes through host-guest interactions.The self-assembly behavior of the supramolecular complexes was comprehensively investigated and could be exploited for furtlaer construction of ID to 3D supramolecular infrastructures.