Porous organic cages present many opportunities in functional materials chemistry, but the synthetic challenges for these molecular solids are somewhat different from those faced in the areas of ...metal–organic frameworks, covalent–organic frameworks, or porous polymer networks. Here, we highlight the practical methods that we have developed for the design, synthesis, and characterization of imine porous organic cages using CC1 and CC3 as examples. The key points are transferable to other cages, and this perspective should serve as a practical guide to researchers who are new to this field.
Membranes with high selectivity offer an attractive route to molecular separations, where technologies such as distillation and chromatography are energy intensive. However, it remains challenging to ...fine tune the structure and porosity in membranes, particularly to separate molecules of similar size. Here, we report a process for producing composite membranes that comprise crystalline porous organic cage films fabricated by interfacial synthesis on a polyacrylonitrile support. These membranes exhibit ultrafast solvent permeance and high rejection of organic dyes with molecular weights over 600 g mol
. The crystalline cage film is dynamic, and its pore aperture can be switched in methanol to generate larger pores that provide increased methanol permeance and higher molecular weight cut-offs (1,400 g mol
). By varying the water/methanol ratio, the film can be switched between two phases that have different selectivities, such that a single, 'smart' crystalline membrane can perform graded molecular sieving. We exemplify this by separating three organic dyes in a single-stage, single-membrane process.
The inferior temporal gyrus (ITG) is known to be involved in high-cognitive functions, including visual and language comprehensions and emotion regulation. A detailed understanding of the nature of ...association fibers could significantly improve postoperative morbidity related to declining capacity. Through diffusion spectrum imaging−based fiber tracking, we have characterized these connections on the basis of their relationships to other cortical areas.
Diffusion spectrum images from 10 healthy adults of the Human Connectome Project were randomly selected and used for tractography analysis. We evaluated the ITG as a whole based on connectivity with other regions. All ITG tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes.
We identified 5 major connections of the ITG: U-fiber, inferior longitudinal fasciculus, vertical occipital fasciculus, arcuate fasciculus, and uncinate fasciculus. There was no fiber lateralization detected.
This study highlights the principal white-matter pathways of the ITG and demonstrates key underlying connections. We present a summary of the relevant clinical anatomy for this region of the cerebrum as part of a larger effort to understand it in its entirety.
Hypercrosslinked polymers (HCPs) are an important class of porous materials that can be synthesized from aromatic precursors using a one-step “knitting” procedure. This scalable process allows wide ...synthetic diversity and ease of functionalization. However, pristine HCPs lack electrical conductivity, which limits their potential for electrochemical applications. Supercapacitors are energy storage devices with advantages over conventional batteries such as high power densities, rapid charge speeds, and superior cyclability. In this work, carbonization of functionalized HCPs yields highly conductive and porous materials that can be used as supercapacitor electrodes. Both electric double-layer capacitance (EDLC) and pseudocapacitance (PC) mechanisms are observed. The relative EDLC and PC contributions were quantified for a range of 20 HCP-derived materials, thus allowing a controlled approach to tuning the energy storage properties. The HCP-based carbons show ideal supercapacitor behavior and the best performing material, which shows 63% PC, displays exceptionally high capacitances of up to 374 F g−1, excellent capacitance retention at fast charging speeds, and stability for up to 15,000 charge/discharge cycles.
Display omitted
•Carbonized HCPs exhibit high capacitance, capacitance retention, and stability.•The EDLC and PC of 20 HCP-based carbons were quantified and correlated with structure.•A capacitance of 374 F g−1 was observed for N-Py-700 exceeding other leading carbons.
The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there ...is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation.
The medial occipital lobe, composed of the lingual gyrus and cuneus, is necessary for both basic and higher level visual processing. It is also known to facilitate cross-modal, nonvisual functions, ...such as linguistic processing and verbal memory, after the loss of the visual senses. A detailed cortical model elucidating the white matter connectivity associated with this area could improve our understanding of the interacting brain networks that underlie complex human processes and postoperative outcomes related to vision and language.
Generalized q-sampling imaging tractography, validated by gross anatomic dissection for qualitative visual agreement, was performed on 10 healthy adult controls obtained from the Human Connectome Project.
Major white matter connections were identified by tractography and validated by gross dissection, which connected the medial occipital lobe with itself and the adjacent cortices, especially the temporal lobe. The short- and long-range connections identified consisted mainly of U-shaped association fibers, intracuneal fibers, and inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, middle longitudinal fasciculus, and lingual–fusiform connections.
The medial occipital lobe is an extremely interconnected system, supporting its ability to perform coordinated basic visual processing, but also serves as a center for many long-range association fibers, supporting its importance in nonvisual functions, such as language and memory. The presented data represent clinically actionable anatomic information that can be used in multimodal navigation of white matter lesions in the medial occipital lobe to prevent neurologic deficits and improve patients' quality of life after cerebral surgery.
We describe the a priori computational prediction and realization of multi‐component cage pots, starting with molecular predictions based on candidate precursors through to crystal structure ...prediction and synthesis using robotic screening. The molecules were formed by the social self‐sorting of a tri‐topic aldehyde with both a tri‐topic amine and di‐topic amine, without using orthogonal reactivity or precursors of the same topicity. Crystal structure prediction suggested a rich polymorphic landscape, where there was an overall preference for chiral recognition to form heterochiral rather than homochiral packings, with heterochiral pairs being more likely to pack window‐to‐window to form two‐component capsules. These crystal packing preferences were then observed in experimental crystal structures.
From molecular structure to solid‐state assembly, a multi‐component self‐sorted organic cage pot is computationally predicted and then synthetically realized. The molecules were formed by the social self‐sorting of a tri‐topic aldehyde with both a tri‐topic amine and di‐topic amine, without using orthogonal reactivity or precursors of the same topicity.
Porous carbons with extremely high surface areas are produced through the carbonization of hypercrosslinked benzene, pyrrole, and thiophene. Such carbons show largely microporous and mesoporous ...domains and exhibit Brunaeur–Emmett–Teller surface areas up to 4300 m2 g−1. The best performing material also displays exceptionally high CO2 and H2 uptakes.
Conjugated microporous polymers (CMPs) are considered an important material, combining aspects of both microporosity and extended π-conjugation. However, pristine CMP electrodes suffer from poor ...electrical conductivity which limits the material in electrochemical applications. In this work, direct carbonisation of conjugated microporous polymers (CMPs) yields porosity-engineered carbons, important for the flow of ions through the electrode. These conductive carbonised CMPs show specific capacitance as high as 260 F g
−1
, excellent rate capability and no loss in performance after 10 000 charge/discharge cycles. This study provides a procedure to enhance the performance of CMP-based materials, opening up a new source of electroactive materials.
PDF
