Spectral Characterization Research Articles

Stereoselective Polymerization of 3,6-Disubstituted N-Vinylcarbazoles.

Poly(N-vinylcarbazole) (PNVC-H) is a valuable nonconjugated photoconductive polymer, but the free radical polymerization conditions typically used for its synthesis do not control polymer stereochemistry and are not tolerant to many substituted N-vinylcarbazoles. Here, we report the stereoselective cationic polymerization of a series of 3,6-disubtituted N-vinylcarbazole derivatives using a chiral scandium-bis(oxazoline) Lewis acid catalyst. The combination of asymmetric ion-pairing catalysis and inherent monomer stereoelectronics facilitated stereoselective polymerization at room temperature, which enabled the polymerization of less soluble 3,6-disubstituted-N-vinylcarbazole derivatives. Isotactic halogen-substituted PNVCs demonstrated self-assembly in solution through halogen-halogen bonding, which was not observed in their atactic counterparts. Initial spectral characterization displayed a wide range of excitation-emission profiles for substituted PNVCs, which demonstrate the promise of these materials as a new class of nonconjugated photoconductive polymers for optoelectronic applications. Overall, these results showcase a diverse class of isotactic poly(N-vinylcarbazoles), highlight the benefits of identifying alternative stereocontrol mechanisms for polymerization, and expand the suite of accessible nonconjugated hole-transport materials.

Spectral and mass characterization of kinetic conversion from retinoids to retinoic acid in an in vitro 3-D human skin equivalent model.

To investigate the effect of retinoids, such as retinol (ROL), retinal (RAL), and retinyl palmitate (RP), on epidermal integrity, skin deposition, and bioconversion to retinoic acid (RA). 3-D human skin equivalent model (EpiDermFT™) was used. Epidermal cellular integrity measured by TEER values was significantly higher for a topical treatment of ROL and RAL than RP (p<0.05). The skin deposition (μM) of ROL and RAL was approximately 269.54±73.94 and 211.35±20.96, respectively, greater than that of RP (63.70±37.97) over 2 hr incubation. Spectral changes were revealed that the C=O maximum absorbance occurred between 1600∼1800 cm-1 and was greater from ROL than that from RAL and RP, indicating conjugation of R-OH to R-CHO or R-COOH could strongly occur after ROL treatment. Subsequently, a metabolite from the bioconversion of ROL and RAL was identified as RA, which has a product ion of m/z 283.06, by using liquid a chromatography-mass spectrometry (LC-MS) - total ion chromatogram (TIC). The amount of bioconversion from ROL and RAL to RA in artificial skin was 0.68±0.13 and 0.70±0.10 μM at 2 hr and 0.60±0.04 and 0.57±0.06 μM at 24 hr, respectively. RA was not detected in the skin and the receiver compartment after RP treatment. ROL could be a useful dermatological ingredient to maintain epidermal integrity more effectively, more stably deposit on the skin, and more steadily metabolize to RA than other retinoids such as RAL and RP.

Fluorine-decoration induced deep reconstruction of iron cobalt oxide for high-efficiency oxygen evolution reaction

The oxygen evolution reaction (OER) is a pivotal process in water electrolysis systems, yet developing cost-effective and highly active OER electrocatalysts from earth-abundant materials through straightforward methods remains a formidable challenge. In this study, FeCo oxides and their fluorides are synthesized using a one-step room-temperature process followed by fluorination with fluorine gas. We compared the OER performance of Fe, Co, and FeCo oxides and investigated the impact of fluorine doping on their physical properties and OER efficiency. Results revealed that the FeCo–O bimetallic oxide exhibited an overpotential of 370 mV in an alkaline electrolyte at a current density of 10 mA/cm2, significantly surpassing the performance of monometallic Fe–O (1 V) and Co–O (467 mV). Fluorine modification markedly enhanced the OER activity of these materials, with Fe-OF at 570 mV, Co-OF at 330 mV, and FeCo-OF at 285 mV. Notably, FeCo-OF demonstrated a stable overpotential lower than commercial RuO2 (289 mV) during a continuous 12 h OER test. Electrochemical analyses and spectral characterizations indicated that fluorine ion electronic regulation facilitated efficient electrocatalytic active sites in the spent FeCo-OF catalyst through in situ self-reconstruction, leading to its stable and superior OER performance. Density functional theory (DFT) calculations confirmed that fluorine modification of the bimetallic oxides decreased the O* Gibbs free energy from 4.86 to 2.44 eV, thereby enhancing the kinetics of the OER reaction.

Fe-Doped Ni2P/NiSe2 Composite Catalysts for Urea Oxidation Reaction (UOR) for Energy-Saving Hydrogen Production by UOR-Assisted Water Splitting.

The development of efficient urea oxidation reaction (UOR) catalysts helps UOR replace the oxygen evolution reaction (OER) in hydrogen production from water electrolysis. Here, we prepared Fe-doped Ni2P/NiSe2 composite catalyst (Fe-Ni2P/NiSe2-12) by using phosphating-selenizating and acid etching to increase the intrinsic activity and active areas. Spectral characterization and theoretical calculations demonstrated that electrons flowed through the Ni-P-Fe-interface-Ni-Se-Fe, thus conferring high UOR activity to Fe-Ni2P/NiSe2-12, which only needed 1.39 V vs RHE to produce the current density of 100 mA cm-2. Remarkably, this potential was 164 mV lower than that required for the OER under the same conditions. Furthermore, EIS demonstrated that UOR driven by the Fe-Ni2P/NiSe2-12 exhibited faster interfacial reactions, charge transfer, and current response compared to OER. Consequently, the Fe-Ni2P/NiSe2-12 catalyst can effectively prevent competition with OER and NSOR, making it suitable for efficient hydrogen production in UOR-assisted water electrolysis. Notably, when water electrolysis is operated at a current density of 40 mA cm-2, this UOR-assisted system can achieve a decrease of 140 mV in the potential compared to traditional water electrolysis. This study presents a novel strategy for UOR-assisted water splitting for energy-saving hydrogen production.

Shielding Mn3+ Disproportionation with Graphitic Carbon-Interlayered Manganese Oxide Cathodes for Enhanced Aqueous Energy Storage System.

Manganese dioxide (MnO2) materials have recently garnered attention as prospective high-capacity cathodes, owing to their theoretical two-electron redox reaction in charge storage processes. However, their practical application in aqueous energy storage systems faces a formidable challenge: the disproportionation of Mn3+ ions, leading to a significant reduction in their capacity. To address this limitation, the study presents a novel graphitic carbon interlayer-engineered manganese oxide (CI-MnOx) characterized by an open structure and abundant defects. This innovative material serves several essential functions for efficient aqueous energy storage. First, a graphitic carbon layer coats the MnOx molecular interlayer, effectively inhibiting Mn3+ disproportionation and substantially enhancing electrode conductivity. Second, the phase variation within MnOx generates numerous crystal defects, vacancies, and active sites, optimizing electron-transfer capability. Third, the flexible carbon layer acts as a buffer, mitigating the volume expansion of MnOx during extended cycling. The synergistic effects of these features result in the CI-MnOx exhibiting an impressive high capacity of 272 mAh g-1 (1224 F g-1) at 0.25 A g-1. Notably, the CI-MnOx demonstrates zero capacity loss after 90000 cycles (≈3011h), an uncommon longevity for manganese oxide materials. Spectral characterizations reveal reversible cation intercalation and conversion reactions with multielectron transfer in a LiCl electrolyte.

Spectral characterization of human leg EMG signals from an open access dataset for the development of computational models.

Large-scale neuromusculoskeletal models have been used for predicting mechanisms underlying neuromuscular functions in humans. Simulations of such models provide several types of signals of practical interest, such as surface electromyographic signals (EMG), which are compared with experimental data for interpretations of neurophysiological phenomena under study. Specifically, realistic characterization of spectral properties of simulated EMG signals is important for achieving powerful inferences, whereas considerations should be taken for myoelectric signals of different muscles. In this study, we characterized spectral properties of surface interference pattern EMG signals and motor unit action potentials (MUAP) acquired from three plantar flexor muscles: Soleus (SO), Medial Gastrocnemius (MG), and Lateral Gastrocnemius (LG); and one dorsiflexor muscle: Tibialis Anterior (TA). Surface EMG signals were acquired from 20 participants using the same convention for electrode placement. Specifically, interference pattern EMG signals were obtained during isometric constant force contractions at 5%, 10% and 20% of maximum voluntary contraction (MVC), whereas surface MUAPs were decomposed from surface EMG signals obtained at low contraction forces. We compared the spectrum median frequency (MDF) estimated from interference pattern EMG signals across muscles and contraction intensities. Additionally, we compared MDF and durations of MUAPs between muscles. Our results showed that MDF of interference pattern EMG signals acquired from TA were higher compared to SO, MG, and LG for all contraction intensities i.e., 5%, 10%, and 20% MVC. Consistently, MUAPs acquired from TA also had higher MDF values and shorter durations compared to the other leg muscles. We provide herein a dataset with the surface MUAPs waveforms and interference pattern EMG signals obtained for this study, which should be useful for implementing and validating the simulation of myoelectrical signals of leg muscles. Importantly, these results indicate that spectral properties of myoelectrical signals should be considered for improving EMG modeling in large-scale neuromusculoskeletal models.

The identification of psychedelic compounds within Australian Acacia species

ABSTRACT N,N-dimethyltryptamine (DMT) is a psychedelic substance produced within various Acacia species; however, the range of species that contain it and the quantity of the compound found within each species is relatively unknown. This work focused on the identification of DMT in 104 plant samples, representing 79 Acacia species, utilizing a reverse phase liquid chromatographic separation prior to mass spectral characterization with a robust Q-TOF-MS method. The findings of this work determined 51 DMT-containing species, 41 of which were previously unknown to contain the psychedelic.

Integrated multispectral remote sensing approach for high-resolution spectral characterization and automated mapping of carbonate lithofacies

Field-based high-resolution carbonate facies mapping is often challenging due to the limited accessible exposure, high-degree of heterogeneity, and lack of distinct natural characteristics between different lithofacies. To mitigate this issue, we proposed a novel approach by integrating multispectral remote sensing, advanced image processing techniques, and supervised classification to perform high-resolution carbonate lithofacies mapping and utilized the extensive Mesozoic carbonate in Saudi Arabia as an example. For this study, the Tuwaiq Mountain Formation (TMF) was selected not only because of its wide aerial distribution but also its importance as conventional and unconventional hydrocarbon reservoirs in the subsurface. Our proposed method was able to map and delineate different members (T1, T2, T3) and key lithofacies in the TMF. In addition, based on the spectral characteristics, the middle member of TMF (T2) can be further subdivided into two subunits (T2-a of higher reflectance & T2-b of lower reflectance). These findings are further corroborated by detailed microfacies analysis, which validates the presence of two sub-members of T2 (T2-a: Spiculitic foraminiferal wackestone and T2-b: Coralline floatstone facies). This resulted in a revised and accurate lithofacies map that made significant modifications over older maps. The overall accuracy of TMF lithofacies is 93.4 % with a kappa coefficient of 0.88. This study demonstrates that multispectral remote sensing approach are effective at distinguishing different carbonate units and providing high-resolution carbonate facies maps. The proposed approach should be applicable to other carbonate outcrops globally and could help in improving carbonate lithofacies mapping where the outcrops are not accessible.

Mechanochemical Solid-State Immobilization of Photofunctional Dyes on Amorphous Silica Particles and Investigation of Their Interactive Mechanisms

Amorphous silica particles (ASPs) have been reported to exhibit bioactive properties and are becoming the focus of attention as bioceramics. However, their interactions with proteins in living organisms remain to be understood and need to be investigated in order to achieve wider applications. Our research group found that chlorine (Cl)-containing ASPs are useful for protein immobilization. Photofunctional dyes (fluorescein (FS−), methylene blue (MB+)) that have the carboxy and amino groups as the main functional groups were immobilized on the Cl-containing ASPs via the mechanochemical method as the model molecule and their spectral properties were used to investigate and discuss the organic/inorganic interfacial bonding states. In FS−, the oxygen atoms of the carboxy groups in the molecule were immobilized by the hydrogen bonds with the silanol groups on the ASPs surfaces, indicating that there is an optimum Cl content for the immobilization as the monomer state. In the case of MB+, as the Cl concentration in the ASPs increases, the immobilization via the electrostatic interactions between the Cl in the ASPs and the terminal dimethylamino group, and the hydrogen bonding between the N atoms of the MB+ hetero ring and the particle silanol group were enhanced. These results mainly suggest that the protein adsorption system occurs through the hydrogen bonding between the carboxy groups of the protein and the silanol groups on the particles and via electrostatic interactions between the amino groups of the protein and the dissociated silanol groups and the contained Cl at the particles. Thus, the spectral characterization using dyes as probes is expected to predict the protein interactions with the amorphous silica particles.

Spectral characterization of elemental emissions, experimental insights and theoretical evaluation

This experimental study delves into the spectral analysis of five discrete spectral lamps, namely helium, sodium, mercury, cadmium and zinc, utilizing a suite of scientific instrumentation including an optical spectrometer with converging lenses and a diffraction grating. The primary objective is to determine the wavelengths corresponding to visible spectral lines emitted by these lamps. Calibration of the spectrometer with the helium lamp facilitated the derivation of the diffraction grating constant. Subsequent measurements of diffraction angles allowed for the computation of experimental wavelengths, which were then compared with theoretical values. Analysis revealed slight discrepancies between experimental and theoretical values, likely attributed to systematic errors such as extraneous light sources and parallax errors in angle measurements. Furthermore, examination of spectral line splitting demonstrated the removal of degeneracy within specified energy levels, resulting in the observation of distinct spectral components. Overall, this study underscores the significance of meticulous experimental techniques in the elucidation of fundamental physical phenomena and highlights the interplay between theory and observation in spectral analysis.

Nickel(II) and Palladium(II) complexes with imine-based tridentate ligand: Synthesis, spectral characterization, Antimicrobial, cytotoxicity and DFT studies

The organic compound (Z)-2-bromo-2-(5-bromo-2-hydroxy-3-methoxybenzylidene)-N-metylhydrazine-1-carbothioamide (L1H2) and its nickel(II) complex [Ni(L1)(PPh3)](1) and palladium(II) complex [Pd(L1)(PPh3)](2) were synthesized and characterized using various spectroscopic methods, including NMR,FT-IR, HRMS, and UV–Vis spectroscopy. Single-crystal X-ray diffraction analysis was used to determine the crystal structures of [Ni(L1)(PPh3)](1) and [Pd(L1) (PPh3)](2). The Hirshfeld surface analysis was used to study various interactions in the crystal structure of complexes. In addition, an energy framework computational analysis was also done to gain a further understanding of the structural details of the complexes. DFT-based calculations were done for the ligand and its associated metal complexes to establish the correlations between their structural characteristics and integral properties. Ligand and its complexes were evaluated for their antimicrobial effects. The antimicrobial effects of ligands and their complexes were assessed. It was found that both Ni(II) and Pd(II) complexes showed better antimicrobial activity.The minimum inhibitory concentration for the [Ni(L1)(PPh3)] complex ranges from 1.95–250 µM; for the [Pd(L1)(PPh3)] complex, it ranges from 3.5–250 µM; and for the ligand, it ranges from 62.5–250 µM against both bacterial and fungal strains. The synthesized compounds were tested for anti-proliferative assays against the HELA carcinoma cell line. The IC50 values obtained were 98.83 µM for the ligand, 83.09 µM for the Ni(II) complex, and 86.74 µM for the Pd(II) complex, suggesting Ni(II) complex a stronger anti-cancerous agent compared to the Pd(II) complex.Noteworthy, both complexes and standard drugs (ciprofloxacin and nystatin) showed non-cytotoxic behavior towards the normal HEK-293 cell line. The increased efficacy and selective cytotoxicity of the complexes highlight their potential as a candidate for further investigation and development into a potent therapeutic agent as an antimicrobial and anticancer agent.

Crystal structure, spectral characterization, in vitro, molecular docking and DFT studies of pyranopyrazole derivatives

Two Pyranopyrazole derivatives, namely, methyl-11-(2-chlorophenyl)-16-methyl-8-[(4-methylbenzene)sulfonyl], -14-phenyl-12-oxa-8,14,15-triazatetracyclo[8.7.0.02,7.013,17] heptadeca-2(7), 3, 5, 13(17), 15-pentaene-10-carboxylate, C38H37N3S1O5 and butyl‑16-methyl-8-[(4-methylbenzene)sulfonyl]-11,14-diphenyl-12-oxa-8,14,15-triazatetracyclo[8.7.0.02,7.013,17] heptadeca-2(7),3,5, 13(17), 15-pentaene-10-carboxylate, C35 H30 Cl N3 O5 S with phenyl and chlorophenyl substitutions were synthesized successfully, and crystallized by the slow evaporation technique. The pyranopyrazole derivatives were characterized by spectroscopic techniques including UV–visible, FTIR, and mass spectroscopy, and their 3D-structural arrangements were also confirmed by single crystal XRD studies. Both compounds crystallize in the triclinic crystal system with the centrosymmetric space group P-1, which is identified by the X-ray single-crystal structure. These compounds were examined for in vitro and molecular docking studies with the enzymes 1hny, 1pgg, and 4 cox and thus correspond to diabetes and inflammation. The observed results showed better binding energy and inhibition constants for inflammation involving enzymes. The chemical reactivity and electronic arrangement of the compounds have been revealed by DFT studies.

Bio‐evaluation of pyrazolone‐furan derived Schiff base Cr(III), Co(II), Ni(II), Cu(II), and Zn(II) nano‐sized complexes: Design, spectral characterization, antimicrobial efficacy, antioxidant activity, apoptotic activity, and cell cycle analysis

Bio‐evaluation of pyrazolone‐furan derived Schiff base Cr(III), Co(II), Ni(II), Cu(II), and Zn(II) nano‐sized complexes: Design, spectral characterization, antimicrobial efficacy, antioxidant activity, apoptotic activity, and cell cycle analysis

New 2H‐Chromene‐Based Hydrazone Derivatives as Promising Anti‐Breast Cancer Agents: Efficient Synthesis, Spectral Characterization, Molecular Docking, and ADMET Studies

AbstractA new series of 2H‐chromene‐based hydrazones (10 a–w, 12 a–d, and 14 a–d) were efficiently synthesized by the reaction of substituted 2H‐chromene aldehydes (8 a–w) with various hydrazines (9, 11, and 13) in absolute ethanol under microwave irradiation as well as by lemon juice mediated conventional heating. The structures of synthesized target molecules were identified by spectroscopic analysis methods (1H NMR, 13C NMR, FT‐IR, and HRMS). The in vitro anticancer activity of the new 2H‐chromene‐based hydrazones were evaluated on the three breast cancer cell lines (MCF‐7, MDA MB‐231, and MDA MB‐468) by MTT assay. Among these synthesized compounds, 10 r and 12 b exhibited the most potent antiproliferative activities with IC50 values at 9.12±0.45 μM and 10.71±0.67 μM respectively, against MCF‐7 cell. Flowcytometric analysis revealed that these two potent compounds, 10 r and 12 b arrested the cell cycle at the G2/M phase and induced apoptosis of proteins in a dose‐dependent manner. It was further confirmed by Hoechst staining and Annexin V‐FITC assay. Additionally, compounds 10 r and 12 b were examined by in silico molecular docking, which revealed that compound 10 r displayed excellent binding affinity energy of around −10 kcal/mol with human HER2 receptor. Also, the ADME studies validated the hybrid compounds showing promising physicochemical, pharmacokinetic, and drug‐like attributes. Broadly, these results underscored the potential of 2H‐chromene‐based hydrazone derivatives as promising anticancer agents.

Synthesis, Spectral Characterization, and Structural Modelling of Di- and Trinuclear Iron(III) Monensinates with Different Bridging Patterns

In the present study, we report the solid-state isolation and structural characterization of novel iron(III) complexes of the veterinary antibiotic monensin. Monensic acid (MonH × H2O) forms a dinuclear complex of composition with FeCl3 [FeCl(Mon)2]2 (1), while its interaction with FeSO4 leads to the isolation of a triangular oxo-ferric coordination species [Fe3O(Mon × H2O)6(H2O)2(OH)] (2). During the procedure resulting in 2, oxidation of the Fe(II) ions by atmospheric oxygen was observed. In the presence of organic bases, both complexation reactions proceeded to successfully deprotonate the carboxylic function of the ligand. Iron(III) complexes 1 and 2 were characterized by IR, EPR, NMR, and Mössbauer spectroscopies as well as with thermal (TG-DTA/MS) and elemental analyses. In addition, the structures of the two coordination compounds were modelled and selected calculated parameters were compared with the experimental results. The biological assay revealed the enhanced antibacterial potential of the newly obtained complexes against the Gram-positive aerobic microorganisms Bacillus cereus and Bacillus subtilis.

Spectral Characterization of Silver Nanoparticles Biosynthesized from Lysinibacillus fusiformis and its Antibacterial Efficacy Against Multidrug-Resistant Bacteria Isolated from Chronic Wounds

Spectral Characterization of Silver Nanoparticles Biosynthesized from Lysinibacillus fusiformis and its Antibacterial Efficacy Against Multidrug-Resistant Bacteria Isolated from Chronic Wounds

Massively Reconstructing Hydrogen Bonding Network and Coordination Structure Enabled by a Natural Multifunctional Co-Solvent for Practical Aqueous Zn-Ion Batteries.

The practical application of aqueous Zn-ion batteries (AZIBs) is hindered by the crazy Zn dendrites growth and the H2O-induced side reactions, which rapidly consume the Zn anode and H2O molecules, especially under the lean electrolyte and Zn anode. Herein, a natural disaccharide, d-trehalose (DT), is exploited as a novel multifunctional co-solvent to address the above issues. Molecular dynamics simulations and spectral characterizations demonstrate that DT with abundant polar -OH groups can form strong interactions with Zn2+ ions and H2O molecules, and thus massively reconstruct the coordination structure of Zn2+ ions and the hydrogen bonding network of the electrolyte. Especially, the strong H-bonds between DT and H2O molecules can not only effectively suppress the H2O activity but also prevent the rearrangement of H2O molecules at low temperature. Consequently, the AZIBs using DT30 electrolyte can show high cycling stability even under lean electrolyte (E/C ratio = 2.95 µL mAh-1), low N/P ratio (3.4), and low temperature (-12°C). As a proof-of-concept, a Zn||LiFePO4 pack with LiFePO4 loading as high as 506.49 mg can be achieved. Therefore, DT as an eco-friendly multifunctional co-solvent provides a sustainable and effective strategy for the practical application of AZIBs.

Spectral characterization of the impact of modifiers and different prepare temperatures on snow lotus medicinal residue-biochar and dissolved organic matter

This study involved the production of 20 biochar samples derived from secondary medicinal residues of Snow Lotus Oral Liquid, processed within the temperature range of 200–600 °C. Additionally, four medicinal residues, including dissolved organic matter (DOM), from 24 samples obtained using the shaking method, served as the primary source material. The investigation focused on two key factors: the modifier and preparation temperature. These factors were examined to elucidate the spectral characteristics and chemical properties of the pharmaceutical residues, biochar, and DOM. To analyze the alterations in the spectral attributes of biochar and medicinal residues, we employed near-infrared spectroscopy (NIR) in conjunction with Fourier-infrared one-dimensional and two-dimensional correlation spectroscopy. These findings revealed that modifiers enhanced the aromaticity of biochar, and the influence of preparation temperature on biochar was diminished. This observation indicates the stability of the aromatic functional group structure. Comparative analysis indicated that Na2CO3 had a more pronounced structural effect on biochar, which is consistent with its adsorption properties. Furthermore, we utilized the fluorescence indices from UV–visible spectroscopy and excitation-emission-matrix spectra with the PARAFAC model to elucidate the characteristics of the fluorescence components in the DOM released from the samples. The results demonstrated that the DOM released from biochar primarily originated externally. Aromaticity reduction and increased decay will enhance the ability of the biochar to bind pollutants. Those results confirmed the link between the substantial increase in the adsorption performance of the high-temperature modified charcoal in the previous study and the structural changes in the biochar. We investigated the structural changes of biochar and derivative DOM in the presence of two perturbing factors, modifier and preparation temperature. Suitable modifiers were selected. Preparation for the study of adsorption properties of snow lotus medicinal residues.

Spectral Characterization of a Blue Light-Emitting Micro-LED Platform on Skin-Associated Microbial Chromophores

Spectral Characterization of a Blue Light-Emitting Micro-LED Platform on Skin-Associated Microbial Chromophores

Moisture‐Resistant Orange Emitters with Near‐Unity Quantum Yield from Mn2+ Alloyed Vacancy‐Ordered Quadruple Perovskites

AbstractMn2+‐doped metal halide perovskites present remarkable optical properties in optoelectronic applications, although the realization of high efficiency and stability is still a challenge. In this work, a series of highly efficient and stable orange‐emitting Mn2+ alloyed Cs4Cd1‐xMnxBi2Cl12 single crystals are successfully synthesized via a hydrothermal reaction. Combined with the crystal structure and spectral characterization at 7 K, the site occupation of Mn2+ and defect emission are systematically discussed. Benefiting from the effective [BiCl6]3−→[MnCl6]4− energy transfer and lattice distortion, these single crystals exhibit a maximum internal and external quantum yield of ≈97% and ≈65% at 35% heavy doping level. Interestingly, these Mn2+‐alloyed single crystals exhibit remarkably waterproof stability, no decrease in emission intensity is observed after immersion in deionized water for 4 h. After soaking in deionized water for 100 days, the internal quantum yield can still maintain 44%, implying good chemical stability and moisture resistance due to the formation of protective BiOCl layer. This work provides new insights into the optimization mechanism for Mn2+ luminescence and overcoming the downside of their waterproofing in humid conditions.