Synthesis and Properties of Crown Ether Benzotellurazole Heterocyclic Styryl Cyanines and Merocyanines

Two Crown ether benzotellurastyryl cyanines and three crown ether benzotelluramerocyanines are synthesized via the key intermediate 3 methyl 5,6(15 crown 5) 2(β acetanilide)vinyl benzotellurazolium iodide.The reactive conditions are discussed.The influence of alkali( earth)metal ions on the visible absorption spectra of these two types of crown ether cyanines are also studied.

STUDIES ON CROWN ETHER CYANINE DYES(XI)THE SYNTHESIS OF BENZOTELLURAZOLE CROWN ETHER CYANINE DYES

Three methods for synthesis of benzotellurazole crown ether(6)are described.The cyanine dye(8)can be easily obtained by treating(6) with CH_3I and CH(OEt)_3.

STUDIES ON CROWN ETHER CYANINE DYES (X). THE SYNTHESIS OF BENZOXAZOLE CROWN ETHER CYANINE DYES

A simple method for synthesis of benoxazole crown ether cyanine dyes is described.

Novel Heptamethine 3H-Indocyanines and their Spectral Properties

Novel heptamethine 3H-indocyanine dyes are synthesized and embedded into a matrix of silica gel derived from tetraethoxysilicane. The photophysical properties of these near infrared dyes in various solvents and in SiO2 sol gel were investigated. The results show that the dyes containing cyclohexenylene bridge and N-(p-carboxy)benzyl groups have better photostability and longer absorption wavelength than those containing linear heptamethine bridge and/or N-(5- carboxy)pentanyl groups. The absorption maxima of these dyes are in reverse proportion to the polarity of the solvents. The microenvironment of the dyes in SiO2 sol-gel characters medium polarity (between methanol and DMF) according to the absorption maxima.

Highly Efficient Photosensitization of Mesoporous TiO_2 Electrode with a Cyanine Dye

A low cost cyanine dye, 1,1-dimethyl-3-ethyl-2-[3-(1,3-dihydro-3,3-dimethyl-1-ethyl- 5-carboxyl-2H-indol-2-ylidene)-1-propenyl]-1H-benz[e] indolium iodide (1) was synthesized and applied to sensitize mesoporous TiO2 electrode. Photoresponse of the electrode was extended to the visible and remarkably high incident photon-to-current conversion efficiency (IPCE) over 70% was achieved from 500 nm to 600 nm.

Topography Multiplicity of Titanyl Phthalocyanine on Ultrathin Insulating Films Observed by STM

Individual titanyl phthalocyanine(TiOPc)molecules on ultrathin sodium chloride striped films grown on Cu(110)exhibit two different topographies with 8-lobes and 6-lobes when imaged by scanning tunneling microscopy(STM).Direct images of the molecular orbitals of the molecules with 8-lobes are obtained,indicating that the electronic structure of the TiOPc molecule are decoupled from the metallic substrate.For the TiOPc molecule with 6-lobes,the STM images at negative and positive bias polarities show the same structures as 2-fold symmetry except for the 90°rotation with respect to each other.This phenomenon may be attributed to the splitting of the two former degenerate lowest unoccupied molecular orbitals due to the negative charging of the molecule.The identification of the molecular orbital splitting on the ultrathin insulating layer could deepen the understanding of the intrinsic properties of semi-conducting molecules.

DFT Investigation on the Trans-cis Photoisomerization of Pentamethine Cyanine Dye Model Molecule

The trans-cis photoisomerization of pentamethine cyanine dye （Cy5） has been theoretically investigated by the analysis on an analogical molecule model. All possible isomers have been searched by rotating the different bridge C-C bonds of the model. The relative stability of the isomers for the ground and first excited states as well as the corresponding excitation mechanism has been envisaged by DFT and time-dependent DFT method. The results show different conjugation degree of the isomers resulting in different absorption energy upon the different C-C bridge bond rotation. From the analyses of electronic density distribution of the frontier orbitals, it is predicted that there is charge transfer besides the π-π^＊ excitation for the cyanine dye model, which makes the mechanism and photo-properties different form those of other conjugated molecules.

Geometric and Electronic Structures at the Interface between Iron Phthalocyanine and Si (110)

The geometric and electronic structures at the interface between iron phthalocyanine(FePc)and Si(110)surface are studied by ultraviolet photoelectron spectroscopy and density functional theory(DFT)calculation.After FePc is deposited on Si(110),the emission features are located at 2.56,4.90,7.90,10.88 eV below the Fermi level for monolayer and 2.73,4.90,7.74,10.52 eV below the Fermi level for multilayer.At the coverage of 1 ML,FePc molecules are adsorbed on the bridge site in a flat-lying geometry with a 2.17?separation between the molecule and the substrate.The molecular plane is bent due to the interaction between the adsorbate and the substrate.

Langmuir-Blodgett Films with Bilayer Alternation of Hemicyanine Dye and Cadmium Stearate

Multilayers consisting of bilayer alternation of hemicyanine dye and cadmium stearate have been prepared by the Langmuir-Blodgett technique.x-ray diffraction and optical absorption spectra are used to characterixe thleir periodic structures and optical properties.The results show that a well ordered superlattice is produced and the hemicyanine dye is in non-aggregated formation in the alternating multilayers.

Synthesis and Characterization of a Squarylium Cyanine Dye with Two [60]Fullerene Units

A new [60]fullerene dimer 2 in which two C-60 units are covalently attached to a squarylium cyanine dye has been synthesized and characterized.

Optimized liver resection range and perioperative safety in patients with high levels of indocyanine green R15

The indocyanine green(ICG)clearance test is an objective measurement of functional liver reserve(FLR)[1].The liver can preserve normal functions with a 70%−80%functional liver volume resection[2]and the remnant is capable of regeneration.However,liver regenerative properties are affected by hepatitis,fatty liver,cirrhosis and damage caused by chemotherapy[3].ICG combined with the Child-Pugh score are main criteria for evaluating FLR.A safe hepatectomy procedure requires the remnant liver to be 25%−30%of the normal volume.For patients with an indocyanine green retention rate at 15 min(ICG-R15)>20%,segment liver resection,limited hepatectomy or tumor enucleation is recommended,but there has been no clear clarification of the essential remnant liver volume[4].In China,the experts’consensus of preoperative evaluation of liver reserve function incorporates ICGR15 tests.

Enhancing sensitivity of SERRS nanoprobes by modifying heptamethine cyanine-based reporter molecules

Surface enhanced resonance Raman scattering(SERRS)is a physical phenomenon that occurs when the energy of incident light is dose to that of electronic excitation of reporter molecules(RMs)attached on substrates.SERRS has showed great promise in healthcare applications such as tumor diagnosis,image guided tumor surgery and real-time evaluation of therapeutic response due to its ultra-sensitivity,manipulating convenience and easy acessibility.As the most widely used organic near-infrared(NIR)fuorophore,heptamethine cyanines possess the electronic ex-citation energy that is close to the plasmon absorption energy of the gold nano scafolds,which results in the extraordinary enhancement of the SERRS signal.However,the effect of hepta-methine cyanine structure and the gold nanoparticle morphology to the SERRS intensity are barely investigated.This work developed a series of SERRS nanoprobes in which two hepta-methine cyanine derivatives(IR783 and IR780)were used as the RM and three gold nanoparticles(nanorod,nanosphere and nanostar)were used as the substrates.Interestingly,even though IR780 and IR783 possess very similar chemical structure,SERRS signal produced by IR780 was determined as 14 times higher than that of IR783 when the RM concentration was6.5 × 10^(-6) M.In contrast,less than 4.0 fold SERRS signal intensity increase was measured by changing the substrate morphologies.Above experimental results indicate that finely tuning the chemical structure of the heptamethine cyanine could be a feasible way to develop robust SERRS probes to visualize tumor or guide tumor resection with high sensitivity and target to background ratio.

Theoretical and Experimental Study of the Mechanism of Reaction Formation of Cyanine Dyes

To study the theoretical bases of the mechanism of reaction formation of cyanine dyes, special importance is gained by methods of quantum chemistry. The use of these methods is provided with the known molecular and dynamic HyperChem program. The purpose of studying was quantum and chemical studying of features of a geometrical and electronic structure of model molecules of penicillin acid, of derivative of glutaconic dialdehyde (DGD), and the cyanine dyes, and also an assessment of power of process of their formation. For studying was carried out the experimental mark of chemism of course of reaction with theoretical justification of the mechanism of reaction formation of cyanine dyes. The results show that all studied model molecules are thermodynamic steady systems to what values of enthalpies of their formation, rather high on an absolute value, testify negative on a sign. Reaction goes by the mechanism of nucleophilic addition.

Synthesis and Photophysical Properties of Novel Highly Stable Zero/Bis-Zero Methine Cyanine Dyes Based on N-Bridgehead Heterocycles

Cyanine dyes of zero/bis-zero methine incorporating imid-azo(1,2-a)Pyridine (quinoline) or pyrazino(1,2-a)pyridine (quinoline) with stable C-N bond were synthesized using keto-oxime methylene C-link heterocyclic quaternary salts [1-phenyl-3-methyl-pyrazolino-4-keto-oxime-α-methylene-bis-pyridin-(quinoin)-1(4)-di-ium-iodide(ethiodide) salts and 1-phenyl-3-methyl-pyrazolino- 4-ketooxime-α-methylene-N-2-methyl-bis pyridin (quinoin)-1(4)-di-ium-iodide(ethiodide) salts]. Such heterocyclic precursors and related dyes were identified by elemental and spectral analyses. The absorption spectra properties of such dyes were investigated in 95% Ethanol to attempt and throw some light on the influence of such new heterocyclic nuclei and to compare or evaluate spectral behaviors. The absorption spectra of dyes in different pure solvents were examined in the visible region showing solvatochromism and the colour changes of dyes with solvents having different polarities. This permits a selection of the optimal solvent (fractional solvent) when such dyes are applied as photosensitizers. The spectral behavior of some selected newly synthesized cyanine dyes is observed in mixed solvents of different polarities and progressively increasing quantities of one solvent over the other were studied and showed an increase in the absorbance of CT band with increasing proportion of that solvent. Evidence for hydrogen bond formation between the solute molecules and solvent molecules allows measurement of certain energies such as hydrogen bonding, orientation, and free energies.

Unusual Spectral Change Due to a Cyanine Dye Adsorbed on an Inorganic Layered Material upon Photoirradiation

Photoinduced spectral change can be utilized for various optical devices. The photoinduced spectral change due to an organic dye was demonstrated for the organic-inorganic hybrid film without the aid of photochromism with a simple preparation method for the first time. By the hybridization of a cyanine dye of 2-[5-(1,3-dihydro-3,3-dimethyl-1-octadecyl-2H-indol-2-ylidene)-1,3-pentadienyl]-3,3-dimethyl-1-octadecyl-3H-indolium perchlorate (NK3175) with an inorganic layered material of cation-exchangeable clay, smectite (SWN), a spectral change attributed to NK3175 was generated upon the irradiation of UV light. This result might serve as useful information on the methodology to produce optically controlled function for photoresponsive systems. Furthermore, the hybrid film of SWN and NK3175 was characterized by the use of XRD and FT-IR measurements. NK3175 molecules adsorbed onto external surfaces of SWN were confined by oriented SWN. It was suggested that the enhanced intermolecular interaction between NK3175 molecules caused by the hybridization with SWN resulted in the change of the aggregation state of NK3175 upon the UV light irradiation, which accounts for the spectral change of NK3175.

Study on the Direct Photooxidation of Near-Infrared Absorbing Benzothiazolone Cyanine Dye

In this paper, direct photooxidation of benzothiazolone cyanine dye: in acetonitrile was studied. The photoproducts had been identified by (HNMR)-H-1 and fast atom bombardment (FAB) mass spectrometry. The results showed that the N-ethylbenzothiazolone (I), the ionic acid (II), and ionic aldehyde (III) are the principal photoproducts.

Squarylium Cyanine Dyes for Photoelectric Conversion

Two squarylium cyanine dyes (Sqs) were synthesized to explore their applications in photoelectrochemical solar cells. Nanocrystalline TiO2 electrodes modified with Sqs have been prepared to probe the photosensitization effects. A rather high photoelectric conversion efficiency of up to 2.17% and the top incident monochromatic photon-to-photocurrent conversion efficiency (IPCE) of 6.2% at 650nm were obtained from the Sq2-modified nanocrystalline TiO2 electrode.

The 2^(nd)Asian Conference on Porphyrins,Phthalocyanines and Related Materials

In the past decades,porphyrins,phthalocyanines and related materials have attracted significant attention due to their diverse and brilliant structures[1,2],as well as their unique electronic structures and photophysical properties which could be applicable in a wide range of areas[3–5].

The unexpected“butterfly effect”of Pt-coordinated cyanine self-assembly for enhanced tumor photothermal therapy

J-aggregates of cyanine have shown great merits in tumor photothermal therapy(PTT)due to their distinct redshift absorption as well as superior photothermal conversion efficiency(PCE).However,due to the complexity of intermolecular interactions,especially the impact of steric hindrance on aggregation,exploring effective strategies to regulate the aggregation modes of organic materials remains challenging.Herein,steric hindrance-regulated J-aggregation of near-infrared(NIR)cyanine was reported based on Pt-coordinated cyanine self-assembly with unexpected“butterfly effect”.Two Pt-coordinated cyanine dimers CyR-Pt(R=Me and Et)were synthesized and spontaneously self-assembled into aggregates in aqueous solution.CyEt-Pt aggregates were loose and amorphous stacking.By replacing ethyl with methyl to reduce steric hindrance,a tiny change resulted in the generation of tightly stacked cyanine J-aggregates(thickness less than 3 nm)observed in CyMe-Pt self-assembly.Significantly,this unexpected“butterfly effect”enabled CyMe-Pt J-aggregates to effectively inhibit reactive oxygen species and greatly improve its photostability.Besides,CyMe-Pt J-aggregates with NIR-II absorption exhibited outstanding photothermal stability and higher PCE(η=37%)than CyEt-Pt disordered aggregates(η=20%).Evident tumor suppression performance of CyMe-Pt J-aggregates was validated under 980 nm laser irradiation,demonstrating its great potential in tumor PTT.

Heptamethine cyanines in bioorthogonal chemistry

Due to their excellent fluorescence properties and biological function,cyanine dyes have been widely applied in biological imaging.Heptamethine cyanine(Cy7)dyes,as a type of classic near-infrared(NIR)fluorescent dyes,are considered as one of the effective fluorescent tools in the living organisms due to their good biocompatibility and very low background interference.Bioorthogonal reactions performed in living cells and tissues have developed by leaps and bounds in recent years.The NIR fluorescent labeling technique involving cyanine has attracted widespread attention.This review summarizes their recent application in the field of bioorthogonal imaging,mainly concluding Cy7-type dyes,labeling strategy,bioimaging application,etc.We expect this work can provide some helps for the studies of NIR bioorthogonal reaction in vivo.