Enhancing drug delivery with supramolecular amphiphilic macrocycle nanoparticles: selective targeting of CDK4/6 inhibitor palbociclib to melanoma.

Drug delivery systems based on amphiphilic supramolecular macrocycles have garnered increased attention over the past two decades due to their ability to successfully formulate nanoparticles. Macrocyclic (MC) materials can self-assemble at lower concentrations without the need for surfactants and polymers, but surfactants are required to form and stabilize nanoparticles at higher concentrations. Using MCs to deliver both hydrophilic and hydrophobic guest molecules is advantageous.

Enhancing Drug Delivery with Supramolecular Amphiphilic Macrocycle Nanoparticles: Selective Targeting of CDK4/6 Inhibitor Palbociclib to Melanoma.

Drug delivery systems based on amphiphilic supramolecular macrocycles have garnered increased attention over the past two decades due to their ability to successfully formulate nanoparticles. Macrocyclic (MC) materials can self-assemble at lower concentrations without the need for surfactants and polymers, but surfactants are required to form and stabilize nanoparticles at higher concentrations. Using MCs to deliver both hydrophilic and hydrophobic guest molecules is advantageous.

Electrochemical Performance of Polymer-Derived Silicon-Oxycarbide/Graphene Nanoplatelet Composites for High-Performance Li-Ion Batteries.

Amorphous polymer-derived silicon-oxycarbide (SiOC) ceramics have a high theoretical capacity and good structural stability, making them suitable anode materials for lithium-ion batteries. However, SiOC has low electronic conductivity, poor transport properties, low initial Couloumbic efficiency, and limited rate capability. Therefore, there is an urgent need to explore an efficient SiOC-based anode material that could mitigate the abovementioned limitations.

Square-Facet Nanobar MOF-Derived CoO@Co/N-doped CNT Core-Shell-based Nanocomposites as Cathode Materials for High-Performance Supercapacitor Studies.

The binary as well as ternary nanocomposites of the square-facet nanobar Co-MOF-derived CoO@Co/N-CNTs (N-CNTs: nitrogen-doped carbon nanotubes) with Ag NPs and rGO have been synthesized via an easy wet chemical route, and their supercapacitor behavior was then studied. At a controlled pH of the precursor solution, square-facet nanobars of Co-MOF were first synthesized by the solvothermal method and then pyrolyzed under a controlled nitrogen atmosphere to get a core-shell system of CoO@Co/N-CNTs. In the second step, different compositions of CoO@Co/N-CNT core-shell structures were formed by an method with Ag NPs and rGO moieties.

Effects of intervalence charge transfer interaction between π-stacked mixed valent tetrathiafulvalene ligands on the electrical conductivity of 3D metal-organic frameworks.

Achieving a molecular-level understanding of how the structures and compositions of metal-organic frameworks (MOFs) influence their charge carrier concentration and charge transport mechanism-the two key parameters of electrical conductivity-is essential for the successful development of electrically conducting MOFs, which have recently emerged as one of the most coveted functional materials due to their diverse potential applications in advanced electronics and energy technologies. Herein, we have constructed four new alkali metal (Na, K, Rb, and Cs) frameworks based on an electron-rich tetrathiafulvalene tetracarboxylate (TTFTC) ligand, which formed continuous π-stacks, albeit with different π-π-stacking and S⋯S distances ( and ). These MOFs also contained different amounts of aerobically oxidized TTFTC˙ radical cations that were quantified by electron spin resonance (ESR) spectroscopy.

Electrically Conductive 3D Metal-Organic Framework Featuring π-Acidic Hexaazatriphenylene Hexacarbonitrile Ligands with Anion-π Interaction and Efficient Charge-Transport Capabilities.

Semiconducting metal-organic frameworks (MOFs) show great potential to foster myriad advanced electronics and energy technologies, but they must possess adequate charge-carrier concentration and efficient charge-transport pathways in order to display useful electrical conductivity. A new intrinsically conducting 3D framework [Ag(HATHCN)(CFSO)] was constructed by employing a highly π-acidic 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile (HATHCN) ligand, which assumed a paramagnetic HATHCN radical anion character by acquiring electron density from the TfO anions involved in the anion-π interaction and facilitated charge movement along the staircase-like [-Ag-HATHCN-] chains having ample Ag-N orbital overlap in the valence band region. As a result, the MOF displayed a narrow band gap (1.

The Advent of Electrically Conducting Double-Helical Metal-Organic Frameworks Featuring Butterfly-Shaped Electron-Rich π-Extended Tetrathiafulvalene Ligands.

To diversify metal-organic framework (MOF) structures beyond traditional Euclidean geometries and to create new charge-delocalization pathways beneficial for electrical conductivity, we constructed a novel double-helical MOF (dhMOF) by introducing a new butterfly-shaped electron-rich π-extended tetrathiafulvalene ligand equipped with four benzoate groups (ExTTFTB). The face-to-face oriented convex ExTTFTB ligands connected by Zn(COO) paddlewheel nodes formed ovoid cavities suitable for guest encapsulation, while π-π-interaction between the ExTTFTB ligands of neighboring strands helped create new charge-delocalization pathways in iodine-mediated partially oxidized dhMOF. Iodine vapor diffusion led to oxidation of half of the ExTTFTB ligands in each double-helical strand to ExTTFTB radical cations, which putatively formed intermolecular ExTTFTB/ExTTFTB π-donor/acceptor charge-transfer chains with the neutral ExTTFTB ligands of an adjacent strand, creating supramolecular wire-like charge-delocalization pathways along the helix seams.

Thiazolothiazole-Based Luminescent Metal-Organic Frameworks with Ligand-to-Ligand Energy Transfer and Hg-Sensing Capabilities.

Photoinduced electron and energy transfer through preorganized chromophore, donor, and acceptor arrays are key to light-harvesting capabilities of photosynthetic plants and bacteria. Mimicking the design principles of natural photosystems, we constructed a new luminescent pillared paddle wheel metal-organic framework (MOF), Zn(NDC)(DPTTZ), featuring naphthalene dicarboxylate (NDC) struts that served as antenna chromophores and energy donors and ,-di(4-pyridyl)thiazolo-[5,4-]thiazole (DPTTZ) pillars as complementary energy acceptors and light emitters. Highly ordered arrangement and good overlap between the emission and absorption spectra of these two complementary energy donor and acceptor units enabled ligand-to-ligand Förster resonance energy transfer, allowing the MOF to display exclusively DPTTZ-centric blue emission (410 nm) regardless of the excitation of either chromophore at different wavelengths.

Efficient MOF-Sensitized Solar Cells Featuring Solvothermally Grown [100]-Oriented Pillared Porphyrin Framework-11 Films on ZnO/FTO Surfaces.

Owing to their abilities to assemble and organize a large number of redox and photoactive components in highly ordered periodic fashion, crystalline porous metal-organic frameworks (MOFs) have the potential to execute myriad complex functions, including charge transport and light to electrical energy conversion when the required conditions are fulfilled. Herein, we demonstrate an unprecedented spontaneous solvothermal growth of precisely [100]-oriented pillared porphyrin framework-11 (PPF-11) films featuring vertically aligned Zn-tetrakis(4-carboxyphenyl)porphyrin (ZnTCPP) walls and horizontally aligned 2,2'-dimethyl-4,4'-bipyridine beams attached to annealed ZnO-fluorine-doped tin oxide (FTO) surfaces and their remarkable photovoltaic performance in liquid-junction solar cells. The [100]-oriented PPF-11/ZnO-FTO photoanodes displayed excellent photovoltaic response (short-circuit current ( J): 4.

Structural and Optical Properties of Nanocrystalline TiO with Multiwalled Carbon Nanotubes and Its Photovoltaic Studies Using Ru(II) Sensitizers.

In this study, the sol-gel method has been deployed to prepare the titanium dioxide/multiwalled carbon nanotubes (TiO/MWCNTs) nanocomposite (NCs) powders with varying content of MWCNTs (0.01-1.0 wt %), to construct the dye-sensitized solar cells (DSSCs).

Cation-Assisted Reversible Folding and Anion Binding by a Naphthalenediimide-Based Ditopic Ion-Pair Receptor.

A novel heteroditopic ion-pair receptor was synthesized by tethering two π-acidic naphthalenediimide units with a tridentate bisimine linker. Upon chelating a Zn or Cd ion with the linker, it adopts a U-conformation allowing the parallel NDI arms to sandwich charge-diffuse anions, and two such folded receptor molecules interlock with each other forming an [R3·M·R3·X] ion-pair complex. Extraction of the guest cation with a tetraazacrown ether returns the receptor to its original unfolded form.

Lowering Band Gap of an Electroactive Metal-Organic Framework via Complementary Guest Intercalation.

A new honeycomb-shaped electroactive metal-organic framework (MOF) has been constructed from an electron deficient naphthalenediimide (NDI) ligand equipped with two terminal salicylic acid groups. π-Intercalation of electron-rich planar tetrathiafulvalene (TTF) guests between the NDI ligands stacked along the walls lowers the electronic band gap of the material by ca. 1 eV.

Fluoride-induced reduction of Ag(I) cation leading to formation of silver mirrors and luminescent Ag-nanoparticles.

In aprotic solvents, Lewis basic F(-) anion reduces Lewis acidic Ag(I) cation to Ag(0), forming metallic silver mirrors on the inner surfaces of reaction vessels and luminescent Ag-nanoparticles (AgNPs) in supernatant solutions, which emit blue light upon UV irradiation. The F(-)-induced formation of silver mirrors and AgNPs was confirmed through X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), fluorescence spectroscopy, and mass spectrometry, whereas the Ag(I)-induced oxidation of F(-) to Ḟ radical, followed by its conversion to HF2(-) via H-abstraction and H-bonding, was evident from (19)F NMR spectroscopy. This redox reaction is deactivated in water, as the reducing power of hydrated F(-) diminishes drastically.

Dye-sensitized solar cells based on multichromophoric supramolecular light-harvesting materials.

Multichromophoric dye-sensitized solar cells (DSSCs) comprised of a supramolecular zinc-phthalocyanineperyleneimide (ZnPc···PMI) dyad convert light to electrical energy with much higher power conversion efficiency (PCE = 2.3%) and incident-photon-to-current-efficiency (IPCE = ca. 40%) than the devices made of individual dyes.

Tunable electronic interactions between anions and perylenediimide.

Over the past decade anion-π interaction has emerged as a new paradigm of supramolecular chemistry of anions. Taking advantage of the electronic nature of anion-π interaction, we have expanded its boundaries to charge-transfer (CT) and formal electron transfer (ET) events by adjusting the electron-donating and accepting abilities of anions and π-acids, respectively. To establish that ET, CT, and anion-π interactions could take place between different anions and π-acids as long as their electronic and structural properties are conducive, herein, we introduce 3,4,9,10-perylenediimide (PDI-1) that selectively undergoes thermal ET from strong Lewis basic hydroxide and fluoride anions, but remains electronically and optically silent to poor Lewis basic anions, as ET and CT events are turned OFF.

Anion-directed assembly of a non-interpenetrated square-grid metal-organic framework with nanoscale porosity.

A non-interpenetrated square grid metal-organic framework (MOF) comprised of octahedral Zn(II) ions and linear N,N'-di(4-pyridyl)-1,4,5,8-naphthalenediimide (DPNDI) ligands was formed in the presence of noncoordinating perchlorate counterions that occupied the cavities of the porous network by forming CH···anion hydrogen bonds with DPNDI ligands, whereas a linear coordination polymer was obtained when Zn(II)-coordinated nitrate ions were present as counterions.

Controllable self-assembly of amphiphilic macrocycles into closed-shell and open-shell vesicles, nanotubes, and fibers.

Depending on functional groups, amphiphilic hexaamide macrocycles self-assemble into closed-shell and open-shell vesicles in polar solvents. In the presence of water, open-shell vesicles morph into closed-shell vesicles, whereas acidification of the medium transforms vesicles into nanotubes and fibers.

Multichromophoric dye-sensitized solar cells based on supramolecular zinc-porphyrin···perylene-imide dyads.

Multichromophoric dye-sensitized solar cells (DSCs) based on self-assembled zinc-porphyrin···peryleneimide dyads on TiO(2) films display more efficient light-to-electrical energy conversion than DSCs based on individual dyes. Higher efficiency of multichromophoric dyes can be attributed to co-sensitization as well as vectorial electron transfer that lead to better electron-hole separation in the device.

Microsecond dye regeneration kinetics in efficient solid state dye-sensitized solar cells using a photoelectrochemically deposited PEDOT hole conductor.

Microsecond dye-regeneration kinetics was observed in efficient solid state dye-sensitized solar cells using photoelectrochemically deposited poly(3,4-ethylenedioxythiophene (PEDOT) hole conductors using transient absorption spectroscopy. The dye-regeneration rate is orders of magnitude slower than the case using the I(-)/I(3)(-) redox couple or commonly used small molecule hole conductor and is attributed to the low dye to PEDOT ratio within the films.

Flexible and compressible Goretex-PEDOT membrane electrodes for solid-state dye-sensitized solar cells.

A porous, flexible electrode based on a PTFE (Teflon) membrane (Goretex) coated with a metallic current collector and a conducting polymer (poly(3,4-ethylenedioxythiophene), PEDOT) has been developed for applications in solid-state dye-sensitized solar cells. Its low sheet resistance and compressibility make it an ideal electrode on uneven TiO(2) surfaces with high efficiency and reproducibility. The porous nature of the electrode enables the feed-through of reactants and treatment agents, which opens up exciting opportunities to interface these photoelectrochemical devices with electrocatalytic, energy conversion, and storage systems.