New materials are advancing the field of soft robotics. Composite films of magnetic iron microparticles dispersed in a shape memory polymer matrix are demonstrated for reconfigurable, remotely actuated soft robots. The composite films simultaneously respond to magnetic fields and light. Temporary shapes obtained through combined magnetic actuation and photothermal heating can be locked by switching off the light and magnetic field. Subsequent illumination in the absence of the magnetic field drives recovery of the permanent shape. In cantilevers and flowers, multiple cycles of locking and unlocking are demonstrated. Scrolls show that the permanent shape of the film can be programmed, and they can be frozen in intermediate configurations. Bistable snappers can be magnetically and optically actuated, as well as biased, by controlling the permanent shape. Grabbers can pick up and release objects repeatedly. Simulations of combined photothermal heating and magnetic actuation are useful for guiding the design of new devices.

Here, we show for the first time that main-chain organometallic polymers (MCOPs) can be prepared from Janus N-heterocyclic carbene (NHC) linkers and polynuclear cluster nodes. The crosslinked framework Co4S4-MCOP is...

The design of metal-organic frameworks (MOFs) that incorporate more than one metal cluster constituent is ac hallenging task. Conventionalo ne-pot reactionp rotocols requirej udiciouss election of ligand and metal ion precursors, yet remainu npredictable. Stable, preformed nanoclusters, with ligand shells that can undergo additional coordination-driven reactions, provide ap latform for assembling multi-cluster solids with precision.H erein, ad iscrete Co 6 S 8 (PTA) 6 (PTA = 1,3,5-triaza-7-phosphaadamantane) superatomic-metalloligand is assembled into a three-dimensional (3D) coordination polymer comprising Cu 4 I 4 secondary building units (SBUs). The resulting heterobimetallic framework (1)c ontains two distinct cluster constituents and bifunctional PTAl inkers. Solid-state diffuse reflectances tudies revealt hat 1 is an optical semiconductor with ab and-gap of 1.59 eV.F ramework-modified electrodes exhibit reversible redox behaviori nt he solid state arising from the Co 6 S 8 superatoms, which remain intact during framework synthesis.

The study of excited-state energy diffusion has had an important impact in the development and optimization of organic electronics. For instance, optimizing excited-state energy migration in the photoactive layer in an organic solar cell device has been shown to yield efficient solar energy conversion. Despite the crucial role that energy migration plays in molecular electronic device physics, there is still a great deal to be explored to establish how molecular orientation impacts energy diffusion mechanisms. In this work, we have synthesized a new library of solution-processable, Zn (alkoxycarbonyl)phenylporphyrins containing butyl (ZnTCB4PP), hexyl (ZnTCH4PP), 2-ethylhexyl (ZnTCEH4PP), and octyl (ZnTCO4PP) alkoxycarbonyl groups. We establish that, by varying the length of the peripheral alkyl chains on the metalloporphyrin macrocycle, preferential orientation and molecular self-assembly is observed in solution-processed thin films. The resultant arrangement of molecules consequently affects the electronic and photophysical characteristics of the metalloporphyrin thin films. The various molecular arrangements in the porphyrin thin films and their resultant impact were determined using UV-Vis absorption spectroscopy, steady-state and time-resolved fluorescence emission lifetimes, and X-ray diffraction in thin films. The films were doped with C60 quencher molecules and the change in fluorescence was measured to derive a relative quenching efficiency. Using emission decay, relative quenching efficiency, and dopant volume fraction as input, insights on exciton diffusion coefficient and exciton diffusion lengths were obtained from a Monte Carlo simulation. The octyl derivative (ZnTCO4PP) showed the strongest relative fluorescence quenching and, therefore, the highest exciton diffusion coefficient (5.29 × 10−3 cm2 s−1) and longest exciton diffusion length (~81 nm). The octyl derivative also showed the strongest out-of-plane stacking among the metalloporphyrins studied. This work demonstrates how molecular self-assembly can be used to modulate and direct exciton diffusion in solution-processable metalloporphyrin thin films engineered for optoelectronic and photonic applications.

We found that we can prepare atomically precise coordination polymers containing two different metal-cluster units. The way in which this material was synthesized is also noteworthy.M ost heterobimetallic frameworks are made via one-pot protocols. Our team used as tepwise approach with ad iscrete Co 6 S 8 "superatom" building block serving as the monomer.T his stable cluster remains intact during the synthesis and its redox properties are preserved after framework assembly.W eenvision that metal-chalcogenide superatoms of various composition, size, and nuclearity can be coupled with bifunctional phosphine ligands to construct as eries of multi-cluster materials using this methodology.