Molecular solar thermal energy storage (MOST) systems based on photochromic molecules that undergo photoisomerization to high‐energy isomers are attractive for of in a closed‐energy cycle. One challenge is control the discharge time isomer. Here we show incorporation strong acceptor substituent seven‐membered ring dihydroazulene/vinylheptafulvene (DHA/VHF) couple increases half‐life energy‐releasing VHF‐to‐DHA back‐reaction from hours more than day polar solvent. For some derivatives,...

Abstract Graphyne allotropes of carbon are fascinating materials, and their electronic properties predicted to rival those the “wonder material” graphene. One allotrope graphyne, having rectangular symmetry rather than hexagonal, stands out as particularly attractive, namely 6,6,12-graphyne. It is currently an insurmountable challenge, however, design execute a synthesis this material. Herein, we present molecules that serve model compounds. These oligomers, so-called radiaannulenes,...

Abstract One challenge in the development of molecular photoswitches for solar energy storage is to increase isomer formed upon irradiation. This work focuses on how affect relative stabilities isomers dihydroazulene/ vinylheptafulvene (DHA/VHF) couple by combining light‐induced DHA VHF conversion with loss aromaticity. We present a synthetic procedure benzannulation at C7−C8 bond, key steps being stereoselective Diels–Alder cycloaddition followed an oxidation. The optical properties and...

Conjugates of norbornadiene (NBD) and dihydroazulene (DHA) photoswitches were synthesised subjected to isomerisation studies.

Molecular solar thermal (MOST) systems that undergo photoisomerizations to long-lived, high-energy forms present one approach of addressing the challenge energy storage. For this mature, photochromic molecules which can absorb at right wavelengths and store a sufficient amount in controlled time period have be developed. Here we show combined experimental theoretical study incorporation pyridyl substituent onto dihydroazulene/vinylheptafulvene photo-/thermoswitch results whose optical...

Functionalization of molecular photoswitches at specific positions offers a way tuning their switching properties. The work presented here describes the development new protocol towards synthesis and functionalization dihydroazulene/vinylheptafulvene (DHA/VHF) photo‐/thermoswitch. key step is facile condensation reaction using functionalized tropone derivative, synthetic method was employed in regioselective preparation novel dimethyl‐substituted DHA photoswitch. This compound presents first...

Indenofluorene‐extended tetrathiafulvalenes (IF‐TTFs) comprise a class of π‐conjugated sensitizers that exhibit strong absorptions in the visible region and two reversible one‐electron oxidations. Herein we present synthesis optical as well redox properties novel IF‐TTF donor‐acceptor scaffolds were integrated dye‐sensitized solar cells (DSCs) via anchoring carboxylic acid end‐group on to TiO 2 . Synthetically, constructed by Sonogashira coupling reactions between an iodo‐functionalized...

Norbornadiene monomers and dimers incorporating an electron-donating dithiafulvene unit were prepared studied for their absorption properties photoswitching abilities.

Electrochemical processes drive many chemical and biochemical reactions. Theoretical methods to accurately predict redox potentials are therefore crucial for understanding these reactions designing new species with desired properties. We have investigated a theoretical methodology using electronic structure based on density functional theory continuum solvation models. These been validated linear correlation plots comparing experimental results the properties of series azulene derivatives....

The promotion of mixed-valence interactions between redox-active, π-conjugated scaffolds is interest when developing new conducting or electrochromic materials as well in the construction redox-controlled supramolecular assemblies. In this work, dimeric structures redox-active indenofluorene-extended tetrathiafulvalene (IF-TTF) unit were synthesized a stepwise protocol. synthesis relied on development unsymmetrical IF-TTF building block by combination phosphite-mediated and...

Boron subphthalocyanines (SubPcs) are powerful chromophoric heterocycles that can be synthetically modified at both axial and peripheral positions. Acetylenic scaffolding offers the possibility of building large, unsaturated carbon-rich frameworks exhibit excellent electron-accepting properties, when combined with SubPcs it presents a convenient method for preparing interesting chromophore-acceptor architectures. Here we present synthetic methodologies post-functionalization relatively...

The boron subphthalocyanine (SubPc) fluorescence is reversibly modulated by photoisomerization of a covalently attached dihydroazulene (DHA) photoswitch into vinylheptafulvene (VHF).

A selection of 2,3‐diarylated photochromic dihydroazulenes (DHAs) was prepared by following two different protocols. The first protocol relies on the synthesis a 3‐bromo‐substituted dihydroazulene, which is subjected to Suzuki cross‐coupling reaction in final step. In second protocol, aryl substituents are introduced early synthesis. DHAs photoactive and undergo light‐induced ring‐opening reactions form vinylheptafulvene (VHF) isomers. These VHFs quickly converted back at room temperature...

Abstract Tetrathiafulvalene (TTF) is a redox‐active compound, which reversibly undergoes two one‐electron oxidations to give stable species. Several features of TTF, such as redox and optical properties well geometry self‐associating nature, can be tuned by extension the conjugated system with an aromatic linker indenofluorene (IF) moiety. In this work we present synthesis novel dimeric scaffold IF‐extended TTF (IF‐TTF) in units are linked rigid 1,4‐bis(2‐ethynylphenyl)buta‐1,3‐diyne 1 H‐NMR...

A dumbbell‐shaped molecule with a central monopyrrolo‐tetrathiafulvalene (MPTTF) unit and 1,1‐dicyano‐dihydroazulene (DHA) photoswitch as one of the two end‐groups was prepared subsequently converted into [2]rotaxane cyclobis(paraquat‐ p ‐phenylene) (CBPQT 4+ ) ring component. Investigations revealed that both DHA its vinylheptafulvene (VHF) photoisomer prevent deslipping CBPQT . It found presence on MPTTF‐DHA dumbbell changes rate thermal back‐conversion VHF DHA, i.e., this conversion to be...

Orthogonal photoswitching is a convenient but challenging way of controlling multiple functions in system by selective photoisomerization one unit before the other any arbitrarily chosen sequence. Here, we present this concept for norbornadiene/quadricyclane (NBD/QC) photo/thermo-switch presence or absence coordinated metal ion. Thus, introducing two pyridyl ligands via ethyne-1,2-diyl bridges provides that chelation ions, such as PdII , has altered optical and switching properties. Mixing...

Axial alkynylation of boron subphthalocyanine with dibromo-substituted enynes and enediynes is presented the convenient use these compounds for subsequent metal-catalyzed coupling reactions.

Bromination of 1,8a-dihydroazulene-1,1-dicarbonitriles (DHA) followed by elimination HBr was previously shown to be an important protocol for functionalizing these molecular photoswitches in the seven-membered ring (at C7). Here we show systematically how outcome bromination reaction depends on electronic character aryl substituent at C2 position DHA, and solvent polarity as can lead either addition product or corresponding 2-aryl-1-bromo-3-cyanoazulene.

Abstract The optical and switching properties of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo‐/thermoswitch can be finely tuned by substituent groups at specific positions. While kinetics thermal ring closure VHF into DHA have previously been shown to follow systematic trends in regard electron‐withdrawing/donating character substituents positions C(2), C(3), C(7) ( Hammett correlations), no such correlation has so far established for a selection compounds with different C(1)....

An extension of a new method for forming thioesters with mesomorphic properties has been described, whereby the treatment aryl tert-butylthioethers long-chain acid chlorides in presence bismuth triflate afforded simple derivatives good yields. This case 1-cyanoazulenes was, however, complicated by competitive Friedel–Crafts-type acylation side reaction at 3-position. Long-chain cyanobiphenyl attached through thioester linkage exhibited mesophases comparable their ester analogues. The use...

Abstract Here we present a synthetic procedure for regioselectively functionalizing the tetrahydronaphtho[2,1‐ ]azulene (THNA) photoswitch in its seven‐membered ring (position C10). Bromination of C10–C11 positions occurred with excellent selectivity when using carbondisulfide as solvent at room temperature. Elimination HBr provided C10 bromo‐substituted THNA that could be arylated by Suzuki cross‐coupling reactions. A series compounds was prepared and subjected to switching studies. Upon...