PEIPNet: Parametric Efficient Image-Inpainting Network with Depthwise and Pointwise Convolution.

Research on image-inpainting tasks has mainly focused on enhancing performance by augmenting various stages and modules. However, this trend does not consider the increase in the number of model parameters and operational memory, which increases the burden on computational resources. To solve this problem, we propose a Parametric Efficient Image InPainting Network (PEIPNet) for efficient and effective image-inpainting. Unlike other state-of-the-art methods, the proposed model has a one-stage inpainting framework in which depthwise and pointwise convolutions are adopted to reduce the number of parameters and computational cost. To generate semantically appealing results, we selected three unique components: spatially-adaptive denormalization (SPADE), dense dilated convolution module (DDCM), and efficient self-attention (ESA). SPADE was adopted to conditionally normalize activations according to the mask in order to distinguish between damaged and undamaged regions. The DDCM was employed at every scale to overcome the gradient-vanishing obstacle and gradually fill in the pixels by capturing global information along the feature maps. The ESA was utilized to obtain clues from unmasked areas by extracting long-range information. In terms of efficiency, our model has the lowest operational memory compared with other state-of-the-art methods. Both qualitative and quantitative experiments demonstrate the generalized inpainting of our method on three public datasets: Paris StreetView, CelebA, and Places2.

Cationic Iridium(III) Complexes with Benzothiophene-Quinoline Ligands for Deep-Red Light-Emitting Electrochemical Cells.

Three new cationic cyclometalated iridium(III) complexes equipped with differently substituted benzo[b]thiophen-2-ylquinoline cyclometalating ligands and with a sterically demanding tert-butyl-substituted 2,2'-bipyridine ancillary ligand were synthesized and structurally characterized by NMR and X-ray diffraction techniques. To tune the electronic properties of such complexes, the quinoline moiety of the cyclometalating ligands was kept pristine or equipped with electron-withdrawing phenyl and -CF3 substituents, leading to complexes 1, 2, and 3, respectively. A complete electrochemical and photophysical investigation, supported by density functional theory calculations, permits a deep understanding of their electronic properties. The emission of all complexes arises from ligand-centered triplet states in the spectral range between 625 and 950 nm, with excited-state lifetimes between 2.10 and 6.32 µs at 298 K. The unsubstituted complex (1) exhibits the most blue-shifted emission in polymeric matrix at 298 K (λmax = 667 nm, photoluminescence quantum yield (PLQY) = 0.25 and τ = 5.32 µs). The phenyl-substituted complex (2) displays the highest photoluminescent quantum yields (up to 0.30 in polymeric matrix), while the CF3-substituted counterpart (3) shows the most red-shifted emission, peaking at approx. 720 nm, but with lower quantum yields (e.g., 0.10 in polymeric matrix at 298 K). Complexes 1 and 2 were tested in single-layer nondoped light-emitting electrochemical cells (LEECs), using a nozzle-printing technique; both devices display deep-red electroluminescence with an external quantum efficiency close to 20%.

Synthesis and structure of the medium-pore zeolite PST-35 with two interconnected cages of unusual orthorhombic shape.

The search for new zeolite structures and compositions remains important in synthetic materials science due to the high impact on developing new chemical technologies, as well as on improving existing ones. Herein we present the synthesis and structure of PST-35, a novel medium-pore germanosilicate (Si/Ge = 2.1-6.6) zeolite, achieved by combining the excess fluoride approach and the unique structure directing ability of Ge in the presence of 1,2,3-triethylimidazolium ions as an organic structure-directing agent. PST-35 contains a zig-zag 10-ring (4.6 × 6.7 Å) channel system constructed of strictly alternating large 28-hedral ([48·58·68·82·102]) and smaller 18-hedral ([46·54·64·82·102]) cages of anomalous orthorhombic shape. The PST-35 structure is built from the connection of pst-35 layers consisting of small 8-hedral ([43·54·6]) cages, previously unobserved zeolite building layers, through single 4-rings.

Hydrogen-Bonded Water-Aminium Assemblies for Synthesis of Zeotypes with Ordered Heteroatoms.

Water plays a central role in the crystallization of a variety of organic, inorganic, biological, and hybrid materials. This is also true for zeolites and zeolite-like materials, an important class of industrial catalysts and adsorbents. Water is always present during their hydrothermal synthesis, either with or without organic species as structure-directing agents. Apart from its role as a solvent or a catalyst, structure direction by water in zeolite synthesis has never been clearly elucidated. Here, we report the crystallization of phosphate-based molecular sieves using rationally designed, hydrogen-bonded water-aminium assemblies, resulting in molecular sieves exhibiting the crystallographic ordering of heteroatoms. We demonstrate that a 1:1 assembly of water and diprotonated N,N-dimethyl-1,2-ethanediamine acts as a structure-directing agent in the synthesis of a silicoaluminophosphate material with phillipsite (PHI) topology, using SMARTER crystallography, which combines single-crystal X-ray diffraction and nuclear magnetic resonance spectroscopy, as well as ab initio molecular dynamics simulations. The molecular arrangement of the hydrogen-bonded assembly matches well with the shape and size of subunits in the PHI structure, and their charge distributions result in the strict ordering of framework tetrahedral atoms. This concept of structure direction by water-containing supramolecular assemblies should be applicable to the synthesis of many classes of porous materials.

Graphitic Carbon with MnO/Mn7 C3 Prepared by Laser-Scribing of MOF for Versatile Supercapacitor Electrodes.

Pseudocapacitive materials encapsulated in conductive carbon matrix are of paramount importance to develop energy storage devices with high performance and long lifespan. Here, via simple laser-scribing, the Mn-based metal-organic framework [EG-MOF-74(Mn)] is transformed into pseudocapacitive hybrid MnO/Mn7 C3 encapsulated in highly conductive graphitic carbon. It is revealed that the rapid carbothermic reduction of MnO (C + MnO → C' + Mn7 C3 + CO) leads to the formation of the intermediate pseudocapacitive MnO/Mn7 C3 and the concurrent catalytic graphitization of disordered carbon. This reaction produces a new type of pseudocapacitive material in the form of MnO/Mn7 C3 fully embedded in highly conductive graphitic carbon. Thanks to the synergistic effect of the MnO/Mn7 C3 nanoparticles and the graphitic carbon, the composite exhibits a high specific capacitance of 403 F g-1 with excellent stability. Asymmetric coin-cell supercapacitors based on the composite demonstrate high energy (29.2 Wh kg-1 ) and power densities (8000 W kg-1 ) with a long lifespan. Prototypes of flexible paper-based supercapacitors made of the composite also show great potential toward applications of flexible electronics.

Bay-Substitution Effect of Perylene Diimides on Supramolecular Chirality and Optoelectronic Properties of Their Self-Assembled Nanostructures.

One-dimensional (1D) organic chiral supramolecules have received a great deal of attention for their promising applications in chiral recognition systems, chemical sensors, catalysts, and optoelectronics. Compared to modifications at the imide position of a perylene diimide (PDI), few studies have explored bay substitution of chiral PDIs and their self-assemblies into 1D nanomaterials. Herein, we describe the synthesis of three bay-substituted PDIs and explore the effects of bay substitution on supramolecular chirality by examining circular dichroism spectra and the optoelectronic performance of chiral PDI nanomaterials in phototransistors. Among the three fabricated self-assemblies, nanomaterials based on (R)-CN-CPDI-Ph exhibited the highest electron mobility of 0.17 cm2 V-1 s-1, a low threshold voltage of -1 V, and enhanced optoelectronic performance. For example, the photoresponsivity and external quantum efficiency of (R)-CN-CPDI-Ph assemblies were 4-fold higher than those of (R)-2Br-CPDI-Ph and (R)-2F-CPDI-Ph. All three nanomaterials exhibited fast switching speeds compared with previously reported N-substituted PDIs, suggesting that bay substitution can be an effective means of achieving rapid photoswitching. A comprehensive study using density functional theory calculations and crystal analyses revealed that the enhanced optoelectronic performance of (R)-CN-CPDI-Ph nanomaterials is related to the substitution of CN at the bay position of PDI. This minor change provides simultaneous improvements in electron injectability and structural order. Our findings demonstrate that bay substitution can significantly impact the self-assembly, supramolecular chirality, and optoelectronic properties of PDI nanomaterials.

Surface-Doped Quasi-2D Chiral Organic Single Crystals for Chiroptical Sensing.

Chiral organic optoelectronics using circularly polarized light (CPL) as the key element in the photonic signal has recently emerged as a next-generation photonic technology. However, it remains challenging to simultaneously achieve high polarization selectivity and superior optoelectronic performance. Supramolecular two-dimensional (2D) chiral organic single crystals may be good candidates for this purpose due to their defect-free nature, molecular diversity, and morphologies. Here, quasi-2D single crystals of chiral perylene diimides with parallelogram and triangle/hexagon morphologies have been selectively fabricated via self-assembly using different cosolvent systems. These materials exhibit amplified circular dichroism (CD) spectral signals, due to their molecular packing modes and supramolecular chirality. Through molecular surface n-doping using hydrazine, chiral single crystals exhibit electron mobility surpassing 1.0 cm2 V-1 s-1, which is one of the highest among chiral organic semiconductors, and excellent optoelectronic functions. Theoretical calculations reveal that the radical anions formed by n-doping increase the electron affinity and/or reduce the energy gap, thus facilitating electron transport. More importantly, the doped organic chiral crystals selectively discriminate CPL handedness with a high anisotropy factor of photoresponsivity (∼0.12). These results demonstrate that surface-doped quasi-2D chiral organic single crystals are highly promising for chiral optoelectronics.

Heterochiral Doped Supramolecular Coordination Networks for High-Performance Optoelectronics.

Chiral self-sorting has great potential for constructing new complex structures and determining chirality-dependent properties in multicomponent mixtures. However, it is still of great challenge to achieve high fidelity chiral self-discrimination. Besides, the researches on the coordination polymers or metal-organic frameworks for micro/nanooptoelectronics are still rare due to their low conductivity and difficulty in developing a rapid and simple scale-up synthetic method. Here, heterochiral supramolecular coordination networks (SCNs) were synthesized by the solvothermal reaction of naphthalene diimide enantiomers and cadmium iodide, using the chirality as a synthetic tuning parameter to control the morphologies. Intriguingly, heterochiral micro/nanocrystals exhibited photochromic and photodetecting properties. Furthermore, we also developed a simple and efficient doping method to enhance the conductivity and photoresponsivity of micro/nanocrystals using hydrazine. From experimental and theoretical studies, the mechanism was suggested as follows: the radicals in the singly occupied molecular orbital level of the ligands provide charge carriers that can undergo "through-space" transport between π-π stacked ligands and the electron transfer from adsorbed hydrazine to the SCNs results in reduction of energy gap, leading to increased conductivity. Our findings demonstrate a simple and powerful strategy for implementing coordination networks with redox ligands for micro/nanooptoelectronic applications.

An open-framework silicogermanate regularly constructed from natrolite zeolite chains and Ge9O18(OH)4 clusters.

Here we describe the synthesis and structure of PST-18, a novel open-framework silicogermanate with Si/Ge ∼ 0.6, which contains a three-dimensional pore system consisting of large cuboid-shaped cavities with 8-ring windows, as well as with 7-rings interrupted by one OH group. Synchrotron single-crystal X-ray diffraction reveals that the structure of PST-18, synthesized using only tetramethylammonium fluoride as a structure-directing agent, is built up of natrolite zeolite chains and Ge9O18(OH)4 clusters in a fully ordered manner. The discovery of such a hybrid structure of zeolitic building units and non-zeolitic oxide clusters provides a new direction for expanding the structural regime of inorganic microporous crystalline materials.

Chiral self-sorted multifunctional supramolecular biocoordination polymers and their applications in sensors.

Chiral supramolecules have great potential for use in chiral recognition, sensing, and catalysis. Particularly, chiral supramolecular biocoordination polymers (SBCPs) provide a versatile platform for characterizing biorelated processes such as chirality transcription. Here, we selectively synthesize homochiral and heterochiral SBCPs, composed of chiral naphthalene diimide ligands and Zn ions, from enantiomeric and mixed R-ligands and S-ligands, respectively. Notably, we find that the chiral self-sorted SBCPs exhibit multifunctional properties, including photochromic, photoluminescent, photoconductive, and chemiresistive characteristics, thus can be used for various sensors. Specifically, these materials can be used for detecting hazardous amine materials due to the electron transfer from the amine to the SBCP surface and for enantioselectively sensing a chiral species naproxen due to the different binding energies with regard to their chirality. These results provide guidelines for the synthesis of chiral SBCPs and demonstrate their versatility and feasibility for use in various sensors covering photoactive, chemiresistive, and chiral sensors.

Organic-Free Synthesis of Silicoaluminophosphate Molecular Sieves.

Silicoaluminophosphate (SAPO) molecular sieves are an important class of microporous materials and are useful for industrial catalysis and separations. They have been synthesized exclusively by the use of expensive and environmentally unfriendly organic structure-directing agents. Now the synthesis of SAPO molecular sieves is reported with MER, EDI, GIS, and ANA topologies under wholly inorganic conditions. Multinuclear MAS NMR analyses demonstrate the presence of Si, Al, and P atoms in their frameworks. These SAPO materials all have unusually high framework charge densities (0.25-0.46), owing to the small size of alkali metal cations used as an inorganic structure-directing agent. A continuous Si increase in the synthesis gel for MER-type SAPO molecular sieves led to the formation of framework Si(0Al) units, decreasing the number of extra-framework cations per unit cell and thus making the resulting solid useful for CO2 adsorption.

Safe P4 reagent in a reusable porous coordination network.

P4 generated from red phosphorus via the gas phase was trapped into an interactive pore of a porous coordination network, showing weak interactions which stabilize the reactive P4 in a pore. The network is reusable as a safe container of P4. Furthermore, we found a size dependence of the P4 trapping amount: for 100-50 µm crystal, 27% occupancy of P4; and for <20 µm crystal, ca. 93% occupancy of P4.

Single-crystal growth of coordination networks via the gas phase and dependence of iodine encapsulation on the crystal size.

Self-assembly of the tripyridyl ligand 2,4,6-tris(4-pyridyl)triazine(TPT) and ZnI2via the gas phase produced three kinds of networks: [(ZnI2)(TPT)]n; [(ZnI2)3(TPT)2]n; and [(ZnI2)(µ-I)(ZnI)(TPT)]n. [(ZnI2)3(TPT)2]n is the first example of the single crystal formation of a porous network via the gas phase and showed the dependence of iodine encapsulation on the crystal size.

Selective trapping of labile S3 in a porous coordination network and the direct X-ray observation.

S3 is one of the basic allotropes of sulfur but is still a mysterious labile species. We selectively trapped S3 in a pore of a thermally stable coordination network and determined S3 structure by ab initio X-ray powder diffraction analysis. S3 in a pore has a C2v bent structure. The network containing trapped S3 is remarkably stable under ambient conditions and is inert to photoirradiation. S3 in the network could be transformed to S6 by mechanical grinding or heating in the presence of NH4X (X = Cl or Br). S6 could be reverse-transformed to S3 by photoirradiation. We also determined the structure of the network containing S6 by ab initio X-ray powder diffraction analysis.