Abstract We report the synthesis and physical study of a series 1,1‐dicyano‐4‐[4‐(diethylamino)phenyl]buta‐1,3‐dienes in which number position additional CN substituents along 1,1‐dicyanobuta‐1,3‐dienyl fragment is systematically varied. While X‐ray analysis provided unambiguous information about molecular geometries crystal, UV/Vis electrochemical measurements, by cyclic voltammetry (CV) rotating disk (RDV), revealed that introduction cyano groups C2‐ C4‐positions most affected optical...

Although complexation of hydrophilic guests inside the cavities hydrophobic hosts is considered to be unlikely, we demonstrate herein between γ- and β-cyclodextrins (γ- β-CDs) with an archetypal polyoxometalate (POM)—namely, [PMo12O40]3– trianion—which has led formation two organic–inorganic hybrid 2:1 complexes, namely [La(H2O)9]{[PMo12O40]⊂[γ-CD]2} (CD-POM-1) [La(H2O)9] {[PMo12O40]⊂[β-CD]2} (CD-POM-2), in solid state. The extent which these complexes assemble solution been investigated by...

Singlet exciton fission (SF) is a promising strategy for increasing photovoltaic efficiency, but in order SF to be useful solar cells, it should take place chromophore that air-stable, highly absorptive, solution processable, and inexpensive. Unlike many chromophores, diketopyrrolopyrrole (DPP) conforms these criteria, here we investigate DPP the first time. yields thin films of derivatives, which are widely used organic electronics photovoltaics, shown depend critically on crystal...

Singlet fission (SF) in two or more electronically coupled organic chromophores converts a high-energy singlet exciton into low-energy triplet excitons, which can be used to increase solar cell efficiency. Many known SF are unsuitable for device applications due chemical instability and low state energies. The results described here show that efficient occurs polycrystalline thin films of 9,10-bis(phenylethynyl)anthracene (BPEA), commercial dye has energies 2.40 1.11 eV, respectively, the...

Here we describe the synthesis of two Zr-based benzothiadiazole- and benzoselenadiazole-containing metal-organic frameworks (MOFs) for selective photocatalytic oxidation mustard gas simulant, 2-chloroethyl ethyl sulfide (CEES). The photophysical properties linkers MOFs are characterized by steady-state absorption emission, time-resolved ultrafast transient spectroscopy. MOF shows superior catalytic activity compared to that containing benzothiadiazole with a half-life 3.5 min CEES nontoxic...

Photodriven electron transfer from a donor excited state to an assembly of electronically coupled acceptors has been proposed enhance charge efficiency in functional organic electronic materials. However, the circumstances under which this may occur are difficult investigate controlled manner disordered donor–acceptor Here we effects anion delocalization on using zinc meso-tetraphenylporphyrin (ZnTPP) as and perylene-3,4:9,10-bis(dicarboximide) dimer acceptor (PDI2). The PDI units positioned...

Thin films of 5,11-dicyano-6,12-diphenyltetracene (TcCN) have been studied for their ability to undergo singlet exciton fission (SF). Functionalization tetracene with cyano substituents yields a more stable chromophore favorable energetics exoergic SF (2E(T1)-E(S1)=-0.17 eV), where S1 and T1 are triplet excitons, respectively. As result tuning the triplet-state energy, is faster in TcCN relative corresponding endoergic process tetracene. proceeds two time constants film samples (τ=0.8±0.2 ps...

We present the stereoselective synthesis of a chiral covalent organic cage consisting three redox-active naphthalene-1,4:5,8-bis(dicarboximide) (NDI) units by dynamic imine chemistry. Single crystal X-ray diffraction analysis shows that host-guest interactions and racemic cocrystallization allow for controlling solid state structure. Electronic between NDI probed absorption circular dichroism spectroscopies, electrochemistry theoretical calculations are shown to be weak. Photoexcitation...

Nanoparticles (NPs) of the singlet fission chromophore 3,6-bis(5-phenylthiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (PhTDPP) having average hydrodynamic diameters 63–193 nm were prepared by rapidly injecting variable concentrations PhTDPP solutions in tetrahydrofuran into water. These NPs are stable over months water and exhibit fluorescence quantum yields ≪1%. Femtosecond transient absorption spectroscopy shows that is more rapid smaller NPs, likely reflecting their greater surface...

Abstract Secondary amines, due to their reactivity, can transform protein templates into catalytically active entities, accelerating the development of artificial enzymes. However, existing methods, predominantly reliant on modified ligands or N‐terminal prolines, impose significant limitations template selection. In this study, genetic code expansion was used break boundary, enabling secondary amines be incorporated alternative proteins and positions choice. Pyrrolysine analogues carrying...

Isomeric charge-transfer chromophores using 1,2,3-triazol-diyl as linker have been studied experimentally and computationally. The instability of the polarized reactants precluded use Huisgen reaction alternative synthetic methodologies were employed. Charge-transfer absorptions between an N,N-dimethylanilino a dicyanovinyl group are modest to strong, with maxima from λmax = 400 453 nm depending on substituent positioning. TD-B3LYP/6-31G(d) calculations within 0.6 eV experiment assign these...

A new class of polymers, which have a double-stranded polybinorbornene skeleton with multilayer planar oligoaryl linkers, defined as polymeric ladderphanes, are synthesized. The structures these ladderphanes determined by spectroscopic means. Photophysical studies and time-resolved fluorescence investigations reveal that there is strong interaction between the chromophore linkers. Thus, Soret band splitting in absorption spectrum polymer porphyrin linker (12e), significant quenching linkers...

Electrochemically active corannulene derivatives with various numbers of electron-donating 4-(N,N-dimethylamino)phenylethynyl (1-4) or electron-withdrawing cyanobutadienyl peripheral substitutents (5-8) were prepared. The latter resulted from formal [2 + 2] cycloaddition cyanoolefins to 1-4 followed by retro-electrocyclization. Conformational properties examined variable-temperature NMR and X-ray diffraction opto-electronic electronic absorption/emission spectra electrochemical measurements;...

Development of purely organic materials displaying room-temperature phosphorescence (RTP) will expand the toolbox inorganic phosphors for imaging, sensing or display applications. While molecular solids were found to suppress non-radiative energy dissipation and make RTP process kinetically favourable, such an effect should be enhanced by presence multivalent directional non-covalent interactions. Here we report a series fast triplet-forming tetraethyl naphthalene-1,4,5,8-tetracarboxylates....

The efficient methodology of the cycloaddition between electron-rich alkynes and tetracyanoethylene (TCNE) or 7,7,8,8-tetracyanoquinodimethane (TCNQ), followed by retro-electrocyclisation, is extended to dicyanovinyl derivatives produce new donor–acceptor push–pull 1,1-dicyanobutadienyl chromophores in excellent quantitative yield (63–98%) that express strong charge-transfer (CT) absorptions from 300 600 nm. scope this reaction established both varying nucleophilic electrophilic components....

Double [2+2] cycloaddition/retro-electrocyclisation reactions between tetracyanoethene (TCNE) and various anilino-capped buta-1,3-diynes furnished a series of octacyano[4]dendralene derivatives featuring intense, low-energy intramolecular charge-transfer absorptions. These novel chromophores are strong electron acceptors undergo facile one-electron reductions at potentials (–0.09 to –0.17 eV vs.Fc+/Fc, in CH2Cl2–0.1 M nBu4NPF6) lower than those reported for the benchmark organic acceptors,...

We report here a potassium-induced guanine quadruplex as supramolecular platform for controlled assembly of electron donor-acceptor systems. A monodisperse, C4-symmetric octamer guanine-perylene-3,4,9,10-bis(dicarboximide) conjugate (GPDI) was prepared in tetrahydrofuran. The two layers cyclic tetramers have the same direction rotation, and PDI moiety between adopts nearly eclipsed relationship (H-aggregation), revealed by small- wide-angle X-ray scattering, NMR spectroscopy, steady-state...

[4]Chrysaorene, a fully conjugated carbocyclic coronoid, is shown to be low-bandgap π-conjugated system with distinct open-shell character. The shows good chemical stability and can oxidized well-defined radical cation dication states. cavity of [4]chrysaorene acts as an anion receptor toward halide ions particular selectivity iodides (Ka = 207 ± 6 M–1). interplay between binding redox chemistry demonstrated using 1H NMR analysis in solution. In particular, well-resolved, paramagnetically...

Abstract Diketopyrrolopyrrole (DPP) is a strongly absorbing, photostable chromophore that can undergo singlet fission (SF), photophysical process promises to significantly enhance solar‐cell performance. In the solid state, DPP packs in herringbone arrangement maximizes intermolecular donor–acceptor interactions, suggesting charge‐transfer (CT) states play role SF. order characterize CT molecular assemblies, we have synthesized covalent dimer bridged by xanthene linker, which places two...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPhotoexcited Naphthalene Diimide Radical Anion Linking the Nodes of a Metal–Organic Framework: A Heterogeneous Super-reductantSubhadip GoswamiSubhadip GoswamiDepartment Chemistry, Northwestern University, Evanston, Illinois 60208, United StatesMore by Subhadip Goswamihttp://orcid.org/0000-0002-8462-9054, Jordan N. NelsonJordan NelsonDepartment Nelson, Timur IslamogluTimur IslamogluDepartment Islamogluhttp://orcid.org/0000-0003-3688-9158,...

Small-molecule fluorophores are invaluable tools for fluorescence imaging. However, means their covalent conjugation to the target proteins limit applications in multicolor Here, we identify 2-[(alkylthio)(aryl)methylene]malononitrile (TAMM) molecules reacting with 1,2-aminothiol at a labeling rate over 104 M–1 s–1 through detailed mechanistic investigation. The fast TAMM and mild reaction conditions enable site-specific of surface not only cell lines but also primary neurons living mice....

The kinetics and mechanism of the formal [2+2] cycloaddition-cycloreversion reaction between 4-(N,N-dimethylamino)phenylacetylene (1) para-substituted benzylidenemalononitriles 2 b-2 l to form 2-donor-substituted 1,1-dicyanobuta-1,3-dienes 3 b-3 via postulated dicyanocyclobutene intermediates 4 b-4 have been studied experimentally by method initial rates computationally at unrestricted B3LYP/6-31G(d) level. transformations were found follow bimolecular, second-order kinetics, with...