Spin Crossover in a Series of Non-Hofmann-Type Fe(II) Coordination Polymers Based on [Hg(SeCN)3]-; or [Hg(SeCN)4]2-; Building Blocks

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c00802.[EN] Self-assembly of [Hg(SeCN)(4)](2)-tetrahedral building blocks, iron(II) ions, and a series of bis-monodentate pyridyltype bridging ligands has afforded the new heterobimetallic Hg-II-Fe-II coordination polymers {Fe[Hg(SeCN)(3)](2)(4,4'-bipy)(2)}(n) (1), {Fe[Hg(SeCN)(4)](tvp)}(n) (2), {Fe[Hg(SeCN)(3)](2)(4,4'-azpy)(2)}(n) (3), {Fe[Hg(SeCN)(4)](4,4'-azpy)(MeOH)} n (4), {Fe[Hg(SeCN)(4)](3,3'- bipy)} n (5) and {Fe[Hg(SeCN)4](3,3'-azpy)}(n) (6) (4,4-bipy = 4,4'-bipyridine, tvp = trans-1,2-bis(4-pyridyl)ethylene, 4,4'-azpy = 4,4'-azobispyridine, 3,3-bipy = 3,3'bipyridine, 3,3'-azpy = 3,3'-azobispyridine). Single-crystal X-ray analyses show that compounds 1 and 3 display a two-dimensional robust sheet structure made up of infinite linear [(FeL)n]2n+ (L = 4,4'-bipy or 4,4'-azpy) chains linked by in situ formed {[Hg(L)(SeCN)(3)](2)}(2)-anionic dimeric bridges. Complexes 2 and 4-6 define three-dimensional networks with different topological structures, indicating, in combination with complexes 1 and 3, that the polarity, length, rigidity, and conformation of the bridging organic ligand play important roles in the structural nature of the products reported here. The magnetic properties of complexes 1 and 2 show the occurrence of temperature-and light-induced spin crossover (SCO) properties, while complexes 4-6 are in the high-spin state at all temperatures. The current results provide a new route for the design and synthesis of new SCO functional materials with non-Hofmann-type traditional structures.This work was supported by the Natural Science Foundation of China (21671121and 21773006), the Spanish Ministerio de Ciencia e Innovacion (MICINN) and FEDER funds (PID2019-106147GB-I00), and Unidad de Excelencia Maria de Maeztu (CEX2019-000919-M).Cao, T.; Valverde-Muñoz, FJ.; Duan, X.; Zhang, M.; Wang, P.; Xing, L.; Sun, F.... (2021). Spin Crossover in a Series of Non-Hofmann-Type Fe(II) Coordination Polymers Based on [Hg(SeCN)3]-; or [Hg(SeCN)4]2-; Building Blocks. Inorganic Chemistry. 60(15):11048-11057. https://doi.org/10.1021/acs.inorgchem.1c008021104811057601

Detection and Characterization of Defects in Additive Manufacturing by Polarization-Based Imaging System

Abstract Additive manufacturing (AM) technology such as selective laser melting (SLM) often produces a high reflection phenomenon that makes defect detection and information extraction challenging. Meanwhile, it is essential to establish a characterization method for defect analysis to provide sufficient information for process diagnosis and optimization. However, there is still a lack of universal standards for the characterization of defects in SLM parts. In this study, a polarization-based imaging system was proposed, and a set of characterization parameters for SLM defects was established. The contrast, defect contour information, and high reflection suppression effect of the SLM part defects were analyzed. Comparative analysis was conducted on defect characterization parameters, including geometric and texture parameters. The experimental results demonstrated the effects of the polarization imaging system and verified the feasibility of the defect feature extraction and characterization method. The research work provides an effective solution for defect detection and helps to establish a universal standard for defect characterization in additive manufacturing

Optimum Design of a Composite Optical Receiver by Taguchi and Fuzzy Logic Methods

This paper investigates a composite optical receiver for an indoor visible light communication (VLC) system. The optical gain, received power, and signal-to-noise ratio (SNR) are considered to be optimized. However, it is difficult to find a balance between them in general design and optimization. We propose the Taguchi and fuzzy logic combination method to improve multiple performance characteristics effectively in the optical receiver. The simulated results indicate that the designed receiver has the characteristics of an optical gain of 10.57, a half field of view (HFOV) of 45°, a received power of 6.4635 dBm, a signal-to-noise ratio (SNR) of 89.8874 dB, and a spot size of 2 mm. The appropriate weights of the three performance characteristics for the inputs of the fuzzy controllers increase the optical gain by 13.601 dB, and the received power and SNR by 11.097 dB and 0.373 dB, respectively. Therefore, the optical receiver optimally designed by the Taguchi and fuzzy logic methods can significantly meet the requirements of an indoor VLC system

Multi-Sensor Image Fusion Method for Defect Detection in Powder Bed Fusion

Multi-sensor defect detection technology is a research hotspot for monitoring the powder bed fusion (PBF) processes, of which the quality of the captured defect images and the detection capability is the vital issue. Thus, in this study, we utilize visible information as well as infrared imaging to detect the defects in PBF parts that conventional optical inspection technologies cannot easily detect. A multi-source image acquisition system was designed to simultaneously acquire brightness intensity and infrared intensity. Then, a multi-sensor image fusion method based on finite discrete shearlet transform (FDST), multi-scale sequential toggle operator (MSSTO), and an improved pulse-coupled neural networks (PCNN) framework were proposed to fuse information in the visible and infrared spectra to detect defects in challenging conditions. The image fusion performance of the proposed method was evaluated with different indices and compared with other fusion algorithms. The experimental results show that the proposed method achieves satisfactory performance in terms of the averaged information entropy, average gradient, spatial frequency, standard deviation, peak signal-to-noise ratio, and structural similarity, which are 7.979, 0.0405, 29.836, 76.454, 20.078 and 0.748, respectively. Furthermore, the comparison experiments indicate that the proposed method can effectively improve image contrast and richness, enhance the display of image edge contour and texture information, and also retain and fuse the main information in the source image. The research provides a potential solution for defect information fusion and characterization analysis in multi-sensor detection systems in the PBF process

A Review of Post-Processing Technologies in Additive Manufacturing

10.3390/jmmp5020038Journal of Manufacturing and Materials Processing5238-3

Metal-ligand cooperative iridium complex catalyzed C-alkylation of oxindole and 1,3-dimethylbarbituric acid using alcohols

A general and high-efficiency C-alkylation of oxindoles and barbituric acids has been developed by a Cp∗Ir complex [Cp∗Ir (2,2′-bpyO)(OH)]Na with a bipyridine-based functional ligand. In particular, H2O was selected as the solvent instead of the organic solvent in this catalytic system. Through mild reaction conditions gave a variety of corresponding alkylated heterocyclic compounds with good to excellent yields. More importantly, the gram-scale C-alkylation reaction was successfully carried out with good yield using a common route with only a single purification by column chromatography

Designing Oxide Catalysts for Oxygen Electrocatalysis: Insights from Mechanism to Application

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