Multi-Photochromic Molecules Based on Dihydroazulene Units.

Multi-photochromic systems incorporating individually addressable switching units are attractive for development of advanced data storage devices. Here, we present the synthesis and properties of a selection of such molecular systems incorporating the dihydroazulene/vinylheptafulvene (DHA/VHF) photo-/thermoswitch. The influence of the linker (meta-phenylene vs.

Multistate Photoswitches: Macrocyclic Dihydroazulene/Azobenzene Conjugates.

Molecules comprised of three covalently linked bi-stable switches can exist in states described by a combination of binary numbers, one for each individual switch: ⟨000⟩, ⟨001⟩, etc. Here we have linked three photo-/thermoswitches together in a rigid macrocyclic structure, one azobenzene (bit no 1) and two dihydroazulenes (DHAs; bits no 2 and 3) and demonstrate how electronic interactions and unfavorable strain in some states can be used to control the speed by which a certain state is reached. More specifically, upon irradiation of state ⟨000⟩, the AZB isomerizes from trans to cis and the two DHAs to vinylheptafulvenes (VHFs), generating ⟨111⟩.

Photoswitchable Dihydroazulene Macrocycles for Solar Energy Storage: The Effects of Ring Strain.

Efficient energy storage and release are two major challenges of solar energy harvesting technologies. The development of molecular solar thermal systems presents one approach to address these issues by tuning the isomerization reactions of photo/thermoswitches. Here we show that the incorporation of photoswitches into macrocyclic structures is a particularly attractive solution for increasing the storage time.

An effective trigger for energy release of vinylheptafulvene-based solar heat batteries.

Stoichiometric copper(i) tetrakis(acetonitrile) is found to activate the thermal ring-closure reaction of a series of high-energy vinylheptafulvene isomers to the corresponding low-energy and photoactive dihydroazulenes, allowing the release of energy upon request.

Solar Thermal Energy Storage in a Photochromic Macrocycle.

The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple.

Multistate Switches: Ruthenium Alkynyl-Dihydroazulene/Vinylheptafulvene Conjugates.

Multimode molecular switches incorporating distinct and independently addressable functional components have potential applications as advanced switches and logic gates for molecular electronics and memory storage devices. Herein, we describe the synthesis and characterization of four switches based on the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermoswitch pair functionalized with the ruthenium-based Cp*(dppe)Ru ([Ru*]) metal complex (dppe=1,2-bis(diphenylphosphino)ethane; Cp*=pentamethylcyclopentadienyl). The [Ru*]-DHA conjugates can potentially exist in six different states accessible by alternation between DHA/VHF, Ru(II) /Ru(III) , and alkynyl/vinylidene, which can be individually stimulated by using light/heat, oxidation/reduction, and acid/base.

BN/CC isosterism in borazaronaphthalenes towards phosphodiesterase 10A (PDE10A) inhibitors.

The application of BN/CC isosterism is explored as a method of expanding the scope of core scaffolds in biologically active compounds. The viability of potential drug candidates incorporating BN-heteroaromatic moieties was investigated through the synthesis of BN-substituted analogs to known phosphodiesterase (PDE10A) inhibitors, namely MP10 and a selection of N-methylanilide analogs. These in some cases revealed unexpectedly potent and relatively stable derivatives, providing further support for the potential of BN-incorporation in medicinal chemistry.