Indoline (In) and aniline (An) donor-based visible light active unsymmetrical squaraine (SQ) dyes were synthesized for dye-sensitized solar cells (DSSCs), where the position of An In units was changed with respect to anchoring group (carboxylic acid) have In-SQ-An-CO2H An-SQ-In-CO2H sensitizers, AS1–AS5. Linear or branched alkyl groups functionalized N atom either control aggregation on TiO2. AS1–AS5 exhibit an isomeric π-framework squaric acid unit is placed in middle, AS2 AS5 possess...

Squaraine dyes are promising chromophores to harvest visible and near-infrared (NIR) photons. A series of indoline-based unsymmetrical squaraine (SQ) that contain alkyl chains at sp3 C- N- atoms indoline moieties with a carboxylic acid anchoring group were synthesized. The optical electrochemical properties the SQ in solution nearly identical as there was no change D-A-D framework; however, remarkable changes respect power conversion efficiencies (PCE) observed depending upon position groups...

The turn-on of emission in fluorescent protein chromophores sequestered an "octaacid" capsule is controlled by stereoelectronic effects described a linear free energy relationship. stereochemical are governed both the positions and volumes aryl substituents, while electronic effects, including ortho can be treated with Hammett σ parameters. use substituent rather than A values reflects packing molecule within confines capsule.

Chromophores related to fluorescent proteins, when sequestered into the "octaacid" capsule, recover their fluorescence. The fluorescence recovery is inhibition of torsional motions within cavity, implicating single-bond torsion as an important contributor internal conversion this class chromophores.

We have been exploring the use of a deep cavity cavitand known by trivial name 'octa acid' as photochemical reaction for manipulating and photophysical properties organic molecules. In current study, we monitored micropolarity interior recording fluorescence five different probes. They all indicate that octa acid capsuleplex (2:1, H/G complex) is nonpolar does not contain water molecules in spite complex being present water. The nature acid-probe each case has characterized 1H NMR data to be...

Factors that govern inclusion of organic molecules within octa acid (OA), a synthetic deep cavity cavitand, have been delineated by examining the complexation behavior number with varying dimensions and functionalities OA. The formation two types complexes has noted: one which we call cavitandplex is partially open complex in part guest molecule remains exposed to water, other termed capsuleplex formed through assembly OA molecules. In capsuleplex, protected from water. Generally, possess...

A series of metal-free indoline-based donor-π-acceptor (D-π-A) visible-light active organic dyes, where an indoline unit wrapped with alkyl or and glycolic (TEG) groups is used as a donor, mono- bi-thiophene π-spacer, cyanoacrylic acid acts acceptor unit, have been designed synthesized for dye-sensitized solar cell (DSSC) application. These dyes showed three absorption bands in dichloromethane solution: the first second transitions are observed UV (337–385 nm) visible (477–514 regions...

Metal-free near-infrared (NIR) active unsymmetrical squaraine dyes, RSQ1 and RSQ2, with benzodithiophene (BDT) π-spacer cyanoacrylic acid acceptor were synthesized by utilizing palladium catalyzed direct (hetero)arylation reaction. Methyl 2-ethylhexyl groups strategically placed at the BDT unit for respectively, to investigate effect of alkylated on dye aggregation TiO2 surface recombination reactions TiO2/dye/electrolyte interface. These dyes have strong absorption (ε > 105 M-1 cm-1) in...

Electron transfer processes at the interfaces dictate factors that improve photovoltaic parameters, such as open-circuit voltage (Voc) and short-circuit current (Jsc), of a dye-sensitized solar cell device, besides selection set suitable anode, dye, electrolyte, cathode materials. An inefficient charge injection process dye-TiO2 interface recombination TiO2-dye/electrolyte have detrimental effects on improving both Jsc Voc. Hence, tailoring govern improvement Voc will be an ideal approach to...

A series of donor–acceptor–donor (D–A–D) based unsymmetrical squaraine dyes have been synthesized with indoline and aniline as donor units. The sp3-C, N atoms the atom donors are appended alkyl groups systematically to control self-assembly on TiO2 passivate photoanode that helps in improving open circuit voltage (Voc) dye-sensitized solar cell (DSSC) device. resulting dyes, AK1–4, possess strong absorptions between 529 541 nm extinction coefficients 1.44–1.84 × 105 M–1 cm–1. Photophysical...

Water-soluble poly(alkyl aryl ether) dendrimers have been explored for their use as hosts of organic substrates in aqueous media. Prototypical photoreactions, namely, photo-Fries reaction (a) 1-naphthyl benzoate and (b) phenyl ester alpha-cleavage dibenzyl ketones benzoin alkyl ethers, examined. We find that a dendritic microenvironment not only restricts the mobility radical intermediates but also rigidly encapsulates substrate, intermediates, products from "leaking" to bulk environment....

A 15N-labeled nitroxide was incarcerated into an octa acid nanocapsule, which confirmed by 1H NMR and EPR spectroscopy. Electron paramagnetic interaction between the a 14N-labeled free in external aqueous solution observed The observation of spin−spin interaction, through walls carcerand is reflected simultaneous line-broadening both nitroxides. computer-assisted analysis data further provides direct information on motion polarity nitroxides bulk phase. We also show how communication guest...

With the help of 1H NMR and EPR techniques, we have probed dynamics guest molecules included within a water-soluble deep cavity cavitand known by trivial name octa acid. All investigated here form 2:1 (host/guest) complexes in water, two host encapsulate molecule forming closed capsule. We this container through techniques. The timescales offered these techniques are quite different, millisecond nanosecond, respectively. For studies, paramagnetic nitroxide for wide variety structurally...

Supramolecular complexation behavior of cucurbiturils with paramagnetic nitroxide spin probes was examined by 1H NMR, X-ray diffraction studies crystals, computation, and EPR. Both cucurbit[7]uril (CB7) cucurbit[8]uril (CB8) form a 1:1 complex 4-(N,N,N-trimethylammonium)-2,2,6,6-tetramethylpiperidinyl-N-oxy bromide (CAT1). The structure the in solid state inferred gas phase computation (B3LYP/6-31G(d)). Whereas ESI-MS data provided evidence for existence solution, indirect obtained through...

This manuscript is concerned with the opening and closing of a capsuleplex made up organic guest molecules two cavitand known as octaacid (OA). The loosely held together in water through weak interactions. We have investigated opening–closing OA by monitoring quenching excited singlet (or) triplet states nine different encapsulated within capsule molecular oxygen that dissolved surrounding capsule. rate constants for were estimated intensity fluorescence/phosphorescence or lifetimes presence...

Organic dyes possessing conjugated π-framework forms closely packed monolayers on photoanode in dye-sensitized solar cell (DSSC), because of the limitation to control orientation and extend intermolecular π-π interaction, self-aggregation leads reduced performance. In this report, a series homodimeric (D1-D1 D2-D2) heterodimeric (D1-D2 D2-D4) donor/acceptor (D/A) containing spiroBiProDOT π-spacer were designed synthesized by utilizing Pd-catalyzed direct arylation reaction correlates device...

Abstract A series of alkyl‐group‐functionalized, aniline‐ and indoline‐donor‐based, unsymmetrical visible‐light‐active squaraine dyes, AM1‐3 , were designed synthesized. Dye‐sensitized solar cell (DSSC) devices fabricated with both I − /I 3 [Cu(tmby) 2 ] +/2+ electrolytes. DSSC sensitized the AM1 AM2 dyes showed relatively high‐power conversion efficiency 7.44 % 7.22 %, respectively in absence chenodeoxycholic acid (CDCA) than those AM3 dye (5.41 %). The electrolyte along...

Alkyl group wrapped visible, far-red, and NIR active unsymmetrical squaraine dyes with π-extension in the polymethine framework-based AM4-AM7 have been designed, synthesized, utilized as sensitizers for dye-sensitized solar cells. To extend π-conjugation within framework, thiophene moieties incorporated between donor acceptor moieties. Absorption spectroscopic studies revealed that each −C═C– unit resulted ∼100 nm of redshift charge transfer transition λmaximum 541, 643, 747, 833 AM4, AM5,...

The self-organization of cucurbit[n]uril (n = 7 and 8, CBs) complexes was probed by electrospray mass spectrometry. self-association CB is a general phenomenon but shows some dependence on the absence, presence, type included guest molecules.

Thiocarbonyl compounds possess unusual photophysical properties: they fluoresce from S(2), phosphoresce T(1) only at extremely low concentrations in solution room temperature, have unit quantum yield of intersystem crossing S(1) to T(1), undergo self-quenching diffusion-controlled rates, and are quenched by ground-state oxygen leading self-destruction. In this article, we concerned with finding a new method observe phosphorescence thioketones temperature aqueous high concentrations. To...

Light absorbing sensitizer is the heart of third generation photovoltaic technologies such as dye-sensitized solar cells. Despite possessing large extinction coefficients for metal-free organic dyes, light-harvesting efficiency limited with narrow absorption profile in either visible or NIR regions spectrum. Though monolayer formation sensitizers on semiconducting metal oxide surface leads to dye–dye interaction that broadening profile, contribution aggregated state power conversion process...

Alkyl group wrapped donor-acceptor-donor (D-A-D) based unsymmetrical squaraine dyes SQ1, SQ5, and SQS4 were used to evaluate the effect of sensitizing solvents on dye-sensitized solar cell (DSSC) efficiency. A drastic change in DSSC efficiency was observed when photo-anodes sensitized acetonitrile (bad solvent considering dye solubility) chloroform (good solvent) with an Iodolyte (I-/I3-) electrolyte. The device showed better photovoltaic performance enhanced photocurrent generation...

A series of azobenzene-functionalized poly(alkyl aryl ether) dendrimers have been synthesized and their photochemical photophysical properties in solution as thin films investigated. Although the behavior azodendrimers indicated that azobenzene units behave independently, very similar to constituent monomer unit, solid were distinctly different. The azodendrimers, AzoG1, AzoG2, AzoG3 observed form stable supercooled glasses, which showed long-wavelength absorption red emission...