Space Group Pna21 Research Articles

Facile Synthesis of Potassium Decahydrido‐Monocarba‐closo‐Decaborate Imidazole Complex Electrolyte for All‐Solid‐State Potassium Metal Batteries

AbstractAll‐solid‐state potassium metal batteries have caught increasing interest owing to their abundance, cost‐effectiveness, and high energy/power density. However, their development is generally constrained by the lack of suitable solid‐state electrolytes. Herein, we report a new complex KCB9H10 ⋅ 2C3H4N2, synthesized by grinding and heating the mixture of potassium decahydrido‐monocarba‐closo‐decaborate (KCB9H10) and imidazole (C3H4N2) under mild conditions, to achieve the K‐ion superionic solid‐state electrolyte. The crystal structure was revealed as an orthorhombic lattice with the space group of Pna21 by FOX software. The diffusion properties for K+ in the crystal structure were calculated using the climbing image nudged elastic band (CI‐NEB) method. KCB9H10 ⋅ 2C3H4N2 exhibited a high ionic conductivity of 1.3×10−4 S cm−1 at 30 °C, four orders of magnitude higher than that of KCB9H10. This ionic conductivity is also the highest value of hydridoborate‐based K+ conductors reported. Moreover, KCB9H10 ⋅ 2C3H4N2 demonstrated a K+ transference number of 0.96, an electrochemical stability window of 1.2 to 3.2 V vs. K/K+, and good stability against the K metal coated by a layer of potassium imidazolate (KIm). These great performances make KCB9H10 ⋅ 2C3H4N2 a promising K‐ion solid‐state electrolyte.

Multi-Noncentrosymmetric Polar Order in 2D Hybrid Lead Chloride with Broadband Emission and High-Temperature Second-Harmonic Generation Switching.

Two-dimensional lead halide perovskites represent a fascinating class of hybrid semiconductors for solar cell, light-emitting, nonlinear optical (NLO), and ferroelectric applications. A notable subset within this category is luminescent ferroelectrics, which have garnered considerable attention for their potential in integrated photoelectronic devices. In this study, we employed an organic amine halogenation strategy (also referred to as halogen engineering), which is renowned for its efficacy in inducing polar order through crystal engineering. Consequently, we synthesized a layered Ruddlesden-Popper (RP) lead chloride comprising 3-chloropropylammonium cations (CPA+), with the chemical formula CPA2PbCl4. This compound features as many as four temperature-dependent crystal phases, with phase transitions observed at T1 = 353.1 K (343.9 K), T2 = 211.7 K (208.6 K), and T3 = 182.0 K (178.2 K) in the heating (cooling) cycles. Employing a multitechnique approach─including thermal analysis, X-ray diffraction, dielectric and pyroelectric current measurements, Raman spectroscopy, and second-harmonic generation (SHG) studies─we determined the mechanisms of the structural phase transitions. Our findings demonstrate polar order of phase II (space group Cmc21), phase III (space group Pna21), and phase IV (space group Pca21), while also confirming the centrosymmetric nature of phase I (space group Cmce). X-ray diffraction data revealed that the I to II PT is of a ferroelectric nature, devoid of ferroelastic strain, a conclusion further supported by pyroelectric measurements. CPA2PbCl4 features negative linear thermal expansion and broadband emission, which transitions to white light above 180 K. Remarkably, CPA2PbCl4 also demonstrates high-temperature SHG on-off switching with a high contrast ratio of 300:1 along with good switching stability, as evidenced by SHG cycling studies at heating/cooling rates ranging from 5 to 50 K/min. This SHG study also sets new standards for the field of SHG switching by providing a method to quantify the thermal responsiveness of SHG-switchable materials using the treq (time requirement) parameter. Overall, our findings show that the halogenation strategy has led to the discovery of a rare example of an RP perovskite exhibiting coexistence of white-light emission, SHG on-off thermal bistability, ferroelectricity, and negative linear thermal expansion.

Calorimetry and structural analysis of uranyl sulfates with rare topologies

Abstract Uranyl sulfate minerals are the most rapidly expanding group of uranium minerals, with dozens of species described in the past decade from the localities of White Canyon, U.S.A. and Jáchymov, Czech Republic. Synthetic analogs of a suite of uranyl sulfate minerals were crystallized, characterized, and the standard-state enthalpies of formation (ΔHfo) were determined. Synthetic lussierite is monoclinic, space group Cc, a = 9.2896, b = 28.685, c = 9.6155 Å, β = 93.504°. Synthetic geschieberite is ortho-rhombic, space group Pna21, a = 13.7408, b = 7.2713, c = 11.5844 Å. The standard-state enthalpies of formation from the binary oxides for lussierite, péligotite, shumwayite, geschieberite, and bluelizardite are –3214 ± 78, –2026 ± 33, –587 ± 22, –966.1 ± 10.9, and –2084 ± 21 kJ/mol, respectively, while the standard-state enthalpies of formation of each phase from its elements are –9743 ± 78, –7220 ± 33, –5255 ± 22, –3916 ± 20, and –7117 ± 21 kJ/mol, respectively. The ΔHfo of péligotite was accurately estimated using the ΔHfo of lussierite, bluelizardite, and literature values of the oxide components of each phase. This implies that estimates can be made accurately of the ΔHfo of uranyl sulfates of minerals without synthetic analogs.

Crystal structure, optical properties, Hirshfeld surface analysis and bactericidal activity of a new organic-inorganic hybrid: 4-methyl-1-(2'-nitrobenzyl)pyridinium tetrabromocuprate(II)

In this work, an organic-inorganic hybrid crystal with excellent bactericidal activity, 4-methyl-1-(2'-nitrobenzyl)pyridinium tetrabromocuprate(II) ([4Me2NO2BzPy]2[CuBr4]), was synthesized by the crystal growth by a slow evaporation method and characterized. [4Me2NO2BzPy]2[CuBr4] crystallized in the orthorhombic space group Pna21. Hirshfeld surface analysis indicated that the H···H (28.8%), H···Br/Br···H (27.0%), and O···H/H···O (17.5%) interatomic contacts played a primary role in contributing to the stacking of the crystals. Thermogravimetric analysis showed that the material was stable up to 192.5 °C. The charge transfer interaction between anions and cations was explained by UV-Vis diffuse reflectance spectroscopy. [4Me2NO2BzPy]2[CuBr4] exhibited favorable bactericidal activity against Staphylococcus aureus and Escherichia coli.

Second-Order Nonlinear Switching and Photoluminescence Properties of Cd-Based Hybrid Perovskite with High-Temperature Phase Transition.

Recently, organic-inorganic hybrid perovskites exhibiting facile structural phase transitions have accumulated significant attention due to their switchable second-order nonlinear optical (NLO) properties, which hold significant promise for next-generation intelligent optoelectronic devices. In this study, we present a novel one-dimensional hexagonal hybrid perovskite, (4-methoxypiperidinium)CdCl3, which undergoes a reversible high-temperature structural phase transition at 389 K. Notably, (4-methoxypiperidinium)CdCl3 demonstrates switchable second-order NLO and dielectric properties, accompanied by symmetry breaking from the centrosymmetric Pnma to noncentrosymmetric Pna21 space group. Variable-temperature structure analyses reveal that this transition is mainly driven by the order-disorder transformation of the 4-methoxypiperidinium cations. Furthermore, it also features a promising photoluminescence performance with blue-light emission and a long lifetime of 25.34 ns. It is anticipated that this study will expand the family of hybrid perovskites exhibiting high-temperature phase transitions and offer valuable guidance for the design of new NLO switching materials with superior optoelectronic properties.

Structure and optical properties of LixAg1–xAlSe2

The complete solid solution LixAg1–xAlSe2 was prepared at 850 °C in the form of phase-pure powder samples as well as single crystals. They adopt noncentrosymmetric crystal structures belonging to the tetragonal CuFeS2-type (space group I4‾2d) for x = 0–0.5 and orthorhombic β-NaFeO2-type (space group Pna21) for x = 0.6–1, both being built up from corner-sharing metal-centred tetrahedra and exhibiting complete disorder of Li and Ag atoms. Solid-state 7Li NMR spectra support the presence of unique Li sites. The substitution of Li for Ag atoms allows control of optical band gaps, which increase linearly from 2.7 eV to 3.6 eV. Second harmonic generation responses were measured to evaluate the potential of these compounds as infrared nonlinear optical materials.

Synthesis, structure and photocatalytic performance of {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n and its derivatives

A polynuclear metal-organic framework, {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n (Htza=1H-tetrazole-1-acetic acid), was successfully synthesized and characterized, and its photocatalytic properties, along with those of its derivatives, were investigated. The crystal structure of the compound was determined to belong to the orthorhombic space group Pn ma, featuring a 3D framework comprising cage-like [Bi6(µ3-O)3(µ3-OH)5]7+ clusters. {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n demonstrated significant photocatalytic activity with UV light response within the pH range of 6.0–8.0 and a band gap energy of 3.32 eV. Under optimal conditions, a reduction in chemical oxygen demand (COD) and total organic carbon (TOC) (from 126.90 mg/L to 4.57 mg/L) clearly validated the efficient methyl orange degradation. The main active groups in the degradation process were h+, ·O2− and ·OH, and the catalyst demonstrated reusability for up to six cycles. Moreover, it was hydrolyzed to Bi2O2CO3 and BiOCl under alkaline (pH=9.0–11.0) and acidic (pH=1.0–5.0) conditions, respectively, thus serving as a valuable precursor. Notably, the Bi2O2CO3 and BiOCl derivatives exhibited higher catalytic activities than catalysts synthesized using alternative methods under the same experimental conditions. Therefore, within the pH range of 1.0–11.0, {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n, along with its in situ derivatives BiOCl and Bi2O2CO3, were highly efficient UV light-driven photocatalysts.

Ferroelectric Organic-Inorganic Hybrid Ammonium Halogenobismuthate(III) for Piezoelectric Energy Harvesting.

Halogenobismuthate(III) compounds are of recent interest because of their low toxicity and distinct electrical properties. The utility of these materials as ferroelectrics for piezoelectric energy harvesters is still in its early stages. Herein, we report a hybrid ammonium halogenobismuthate(III) [BPBrDMA]2·[BiBr5], crystallizing in a ferroelectrically active polar noncentrosymmetric Pna21 space group. Its noncentrosymmetric structure was confirmed by the detection of the second harmonic generation response. The ferroelectric P-E hysteresis loop measurements on the thin film sample of [BPBrDMA]2·[BiBr5] gave a saturation polarization (Ps) of 5.72 μC cm-2. The piezoresponse force microscopy analysis confirmed its ferroelectric and piezoelectric nature, showing characteristic domain structures and signature hysteresis and butterfly loops. The piezoelectric energy harvesting attributes of [BPBrDMA]2·[BiBr5] were further probed on its polylactic acid (PLA) composites. The 15 wt % [BPBrDMA]2·[BiBr5]-PLA polymer composite resulted in a high output voltage of 26.2 V and power density of 15.47 μW cm-2. The energy harvested from this device was further utilized for charging a 10 μF capacitor within 3 min.

High-pressure/high-temperature synthesis of a new polymorphic series of lanthanoid cadmium borates, LnCdB6O10(OH)3 (Ln = Sm–Er)

Abstract We report on the synthesis, structure determination, and characterization of a new series of compounds LnCdB6O10(OH)3 (Ln = Sm–Er). Syntheses were carried out in a Walker-type multianvil device at 7 GPa and 650 °C. Structure determinations revealed the coexistence of an orthorhombic and a monoclinic polymorph, depending on the ionic radius of the lanthanoid cation. The orthorhombic structural variants crystallize non-centrosymmetrically in the space group Pna21 (no. 33), while the monoclinic modifications crystallize in space group P21/c (no. 14). Both modifications display a layered crystal structure built up by a repeating [B6O13]8− building block as their main structural feature.

Structural Elucidation of Electrical and Optical Properties in Lead‐free Organic‐Inorganic Copper Bromide [(CH3)4N]2CuBr4 Single Crystals

AbstractOrganic‐inorganic metal halide single crystals have attracted a lot of attention due to their flexible structural design and excellent optoelectronic applications. This study details the synthesis of copper‐based [(CH3)4N]2CuBr4 hybrid metal halide single crystals via a slow evaporation method. The crystal structure, crystal habit, chemical groups, intermolecular interactions, electrical properties of the sample were studied via single crystal x‐ray diffraction, scanning electron microscopy, Raman and Fourier transform infrared spectrometer, Hirshfeld surface analysis, impedance spectroscopy, and modulus spectroscopy, respectively. An orthorhombic crystal system with the non‐centrosymmetric space group Pna21 was identified at room temperature. The deformation in the tetrahedra was calculated by the bond angle and bond length deformation index. The Cole‐Cole plot displayed the existence of depressed semicircles, which indicated the predominant distribution of grains, further confirmed by the SEM image. The deformed semi‐circular arcs on the electric modulus curve undeniably prove that the bulk effect dominates the material‘s electrical properties. Significantly, the compound presents a phase transition at ~240 K and excellent thermal stability up to a temperature of 400 K. Therefore, our research sheds light on the temperature dependence of electrical responses in these hybrid crystals and gives inspiration for the development of single crystal‐based efficient energy devices.

N-(2,4-Difluorophenyl)-2-fluorobenzamide

The title compound N-(2,4-difluorophenyl)-2-fluorobenzamide (Fo24) was synthesized in high yield (1.09 g; 87%) using standard synthetic procedures from the condensation reaction of 2-fluorobenzoyl chloride with 2,4-difluoroaniline. Crystals of Fo24 were grown from CH2Cl2 at room temperature. The Fo24 crystal structure was determined using single-crystal X-ray diffraction methods at 294 (1) K in space group Pn (No. 7). Fo24 is the second regular tri-fluorinated benzamide with the formula C13H8F3N1O1 to be reported and contrasts with the more common difluorinated and tetra-fluorinated analogues. In Fo24, both aromatic rings are effectively coplanar with an interplanar angle of 0.7(2)°. The central amide group plane is oriented by 23.04(18)° and 23.69(17)° from both aromatic rings, forming an intramolecular contact with an ortho-F12 atom with H1⋯F12 = 2.12(4) Å. The primary hydrogen bonds are 1D amide–amide interactions that form along the b-axis direction. In addition, weaker C-H⋯F/O interactions are noted: a R22(12) synthon involving two C-H, a N-H and two C-F groups, with C-F⋯C ring–ring stacking contacts completing the interactions.

Crystal growth, structural, optical, mechanical characterization and quantum chemical analysis by DFT of an organic nonlinear optical single crystal 4-Hydroxy pyridinium succinate for photonic and optoelectronic devices

A new organic nonlinear optical single crystal 4-Hydroxypyridinium Succinate was synthesized and grown successfully by slow evaporation method using methanol as solvent at ambient temperature. Single crystal X –ray diffraction studies on the grown crystal reveals that 4HPS crystallizes into orthorhombic structure with the non-centrosymmetric space group (Pna21). In structural point of view, the 4-Hydroxypyridinium cation is bonded to the hydrogen succinate anion by direct electron conjugation through nitrogen atom. In addition, the UV visible transmittance spectrum implies that the crystal has high transparency domain in the entire UV visible region with a lower cut-off wavelength of 286 nm. The various functional groups present in the crystal and their frequency assignments are derived from FTIR spectral analysis. The Photoluminescence spectrum brings forth that the grown crystal has violet emission property. The microhardness measurements testify that the crystal belongs to soft material category with reasonable hardness parameters. The compound was found to be thermally stable up to 188 °C without any weight loss from the TGA and DTG traces. The detailed quantum chemical calculation done by density functional theory (DFT) indicates the Homo –Lumo energy gap of the molecule is 3. 956 eV and 4. 289 eV for α and β wave functions respectively. The Laser induced damage threshold of the crystal investigated using Nd: YAG laser of 1064 nm radiation was found to be 21. 93 Gw/cm2. The second harmonic generation efficiency of the 4HPS crystal was confirmed by the emission of green light under Kurtz and Perry powder test.

Synthesis, Crystal Structure and Antifungal Activity of 1-(3,3 -Dimethyl-2-oxobutyl)-N-phenyl-1H-1,2,4-triazole-3-carboxamide

Fungicides play a vital role in protecting crops from fungal damage.However, fungicide re-sistance is one of the most important issues in modern agriculture. Hence, it is very neces-sary to develop new fungicides constinuously.Triazole compounds have received consider-able interest in agricultural chemistry due to a novel action mode, extremely high activity against phytopathogenic fungi, low acute toxicity to mammals, and environmentally benign characteristics. The title compound 1-(3,3-dimethyl -2-oxobutyl)-N-phenyl-1H-1,2,4-triazole-3-carboxamide 5, synthesized using methyl 1H-1,2,4 -triazole-3-carboxylate 1 as the start material, was successfully obtained via multi-ple synthesis route and finally characterized by 1H NMR,13C NMR, HRMS and single-crystal X-ray diffraction. Compound 5 (C15H18N4O2, Mr = 287.1500) belongs to the orthorhombic system, space group Pn21a, with a = 14.49451(11)and#197;, b = 20.34686(18)and#197;, c = 10.17021(9)and#197;, V =2999.38(4) and#197;3, Z = 8, Dc= 1.268 g/cm3, T = 293.55(14) K, μ (CuKα) = 0.710 mm-1, F (000) =1216.0, the final R=0.0448, and wR = 0.1260 with Iandgt;=2σ (I). Fur-thermore, the results from biological assays indicated that the title compound exihibited a similar antifungal activity（EC 50 =8.98 mg. L-1）compared to triadimefon (EC50=5.6 mg.L-1)against G. cingulatal. And had different degrees of weak activity against other phy-topathogenic fungi, including A. solani, S. sclerotiorum, G. saubinetii and T. cucumeris. Po-tentially, the result lay the foundation for the development of novel fungicides

STRUCTURAL INVESTIGATION AND HIRSHFELD SURFACE ANALYSIS OF TWO [ONO]-TYPE SCHIFF BASES

Two novel [ONO]-type tridentate Schiff base compounds namely (E)-2-(((2-hydroxyphenyl)imino)methyl)-4,5-dimethoxyphenol, C15H15NO4 (1), and (E)-2-(((5-chloro-2-hydroxyphenyl)imino)methyl)-4,5-dimethoxyphenol, C15H14ClNO4 (2) were synthesized. These compounds were characterized using various spectroscopic techniques, including single crystal X-ray diffraction (XRD), infrared (IR), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), and UV-Vis spectroscopy. The X-ray crystallographic analysis revealed that both compounds 1 and 2 contain two independent molecules within the asymmetric unit. Compound 1 crystallizes in the orthorhombic system with the Pna21 space group, while compound 2 crystallizes in the monoclinic system with the P21/c space group. An important feature observed in the crystal structure of compound 1 is the presence of O–H···N and O–H···O hydrogen bonds. In compound 2, the hydrogen bonding interactions involve C–H···O, O–H···O and O–H···N. Additionally, both compounds exhibit C–H···π interactions. To further understand the bonding interactions in compounds 1 and 2, Hirshfeld surface analyses and 2D fingerprint graphs were performed. The results indicate that the Hirshfeld surfaces are predominantly influenced by H⋯H, O⋯H, and C⋯H contacts.

Dimorphism of [Bi2O2(OH)](NO3) - the ordered Pna21 structure at 100 K.

The re-investigation of [Bi2O2(OH)](NO3), dioxidodibismuth(III) hydroxide nitrate, on the basis of single-crystal X-ray diffraction data revealed an apparent structural phase transition of a crystal structure determined previously (space group Cmc21 at 173 K) to a crystal structure with lower symmetry (space group Pna21 at 100 K). The Cmc21 → Pna21 group-subgroup relationship between the two crystal structures is klassengleiche with index 2. In contrast to the crystal structure in Cmc21 with orientational disorder of the nitrate anion, disorder does not occur in the Pna21 structure. Apart from the disorder of the nitrate anion, the general structural set-up in the two crystal structures is very similar: [Bi2O2]2+ layers extend parallel to (001) and alternate with layers of (OH)- anions above and (NO3)- anions below the cationic layer. Whereas the (OH)- anion shows strong bonds to the BiIII cations, the (NO3)- anion weakly binds to the BiIII cations of the cationic layer. A rather weak O-H⋯O hydrogen-bonding inter-action between the (OH)- anion and the (NO3)- anion links adjacent sheets along [001].

Study of optoelectronics and magnetic properties of GdCrWO6 oxide by ab initio calculations

Using first-principle calculations within the framework of density functional theory (DFT), the full-potential linearized augmented plane-wave (FP-LAPW) method have been performed to investigate structural, electronic, magnetic and optical properties of the aeschynite type GdCrWO6 oxide within both generalized gradient approximation (GGA) and modified Becke Johnson potential (TB-mBJ). GdCrWO6 forms the polar crystal structure (space group Pna21 (#33)) due to the cation ordering of W6+ and Cr3+. Our calculations reveal that the compound GdCrWO6 is a semiconductor by the GGA-PBE and TB-mBJ approximations. The magnetic moment of each magnetic atom is found for two approximations. The imaginary part, real part and the optical conductivity of dielectric function of the compound GdCrWO6 are found by TB-mBJ. GdCrWO6 exhibits a strong absorption coefficient in the ultraviolet region.

Single-crystal structure and theoretical calculations of the second ternary tellurium borate Te2B2O7

We present the high-pressure/high-temperature synthesis (10 GPa, 1073 K) of the second known tellurium borate Te2B2O7. It crystallizes in a unique crystal structure with the lattice parameters a = 1876.54(5) pm, b = 1170.11(3) pm, c = 440.43(1) pm, V = 0.967(1) nm3, and eight formula units (Z = 8) per unit cell in the orthorhombic non-centrosymmetric space group Pna21 (no. 33). The structure contains only corner connected tetrahedral [BO4]5– and bisphenoidal [TeO4]4–units. The structure is discussed in detail and theoretical calculations including a visualization of the electron localization function have been carried out.

Syntheses, crystal structures, optical properties, antibacterial activity and DFT calculations of two tetrachlorocobaltate(II) salts with substituted methyl pyridinium

The syntheses, compositions, and structural analyses of two new organic-inorganic metal halides benzyl-2-methyl pyridinium tetrachlorocobaltate(II) [Bz-2-MePy]2[CoCl4](1) and benzyl-4-methyl pyridinium tetrachlorocobaltate(II) [Bz-4-MePy]2[CoCl4](2) were presented in this paper. Single-crystal X-ray diffraction analyses revealed that 1 and 2 crystallized in the monoclinic space group C2/c and the orthorhombic space group Pna21, respectively, composed of two [Bz-2-MePy]+/[Bz-4-MePy]+ cations and a [CoCl4]2− anion, in which the [CoCl4]2− anion displayed a tetrahedral geometry. Two crystals investigated by TG-DTA technique were stable up to 162.7 °C (1) and 226.3 °C (2), respectively. The HOMO–LUMO energy gaps and UV–vis diffuse reflectance spectra explained the charge transfer interactions between [CoCl4]2− cations and the [Bz-2-MePy]+/[Bz-4-MePy]+ cations. In addition, their low band gap values (1.88 eV in gas state and 1.65 eV in solid state for 1, 1.18 eV in gas state and 1.64 eV in solid state for 2) indicated the appropriateness of the crystals for optical applications. The first hyperpolarizabilities (βtot) of two salts were 459 and 70,000 times higher than the standard KDP crystal (βKDP = 6.85 × 10−31 esu), respectively. The antibacterial experiments demonstrated that both salts exhibited superior bactericidal activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

Synthesis, crystal and energy structure of the Ag8SnS6 crystal

The Ag8SnS6 crystal was synthesized by directly melting a high-purity stoichiometric mixture of elementary Ag, Sn, and S in a sealed quartz ampoule. This argyrodite crystallizes in the orthorhombic structure (Pna21 space group (No. 33)) at room temperature. The theoretical first-principle calculations of the electronic band structure and density of states of a αʹʹ-Ag8SnS6 crystal are estimated by the generalized gradient approximation (GGA) and local density approximation (LDA). A Perdew–Burke–Ernzerhof functional (PBE) and (PBEsol) were utilized for GGA calculation. All calculated parameters correlate well with known experimental data. Based on the electronic band structure, the effective mass of electrons and holes was calculated. The anisotropic behavior of electronic band structure is discussed.

Achiral Au(I) Cyclic Trinuclear Complexes with High‐Efficiency Circularly Polarized Near‐Infrared TADF

AbstractRealizing high photoluminescence quantum yield (PLQY) in the near‐infrared (NIR) region is challenging and valuable for luminescent material, especially for thermally activated delay fluorescence (TADF) material. In this work, we report two achiral cyclic trinuclear Au(I) complexes, Au3(4‐Clpyrazolate)3 and Au3(4‐Brpyrazolate)3 (denoted as Cl−Au and Br−Au), obtained through the reaction of 4‐chloro‐1H‐pyrazole and 4‐bromo‐1H‐pyrazole with Au(I) salts, respectively. Both Cl−Au and Br−Au exhibit TADF with high PLQY (>70 %) in the NIR I (700–900 nm) (λmax = 720 nm) region, exceeding other NIR−TADF emitters in the solid state. Photophysical experiments and theoretical calculations confirmed the efficient NIR−TADF properties of Cl−Au and Br−Au were attributed to the small energy gapΔE(S1‐T2) (S = singlet, T = triplet) and the large spin‐orbital coupling induced by ligand‐to‐metal‐metal charge transfer of molecular aggregations. In addition, both complexes crystallize in the achiral Pna21 space group (mm2 point group) and are circularly polarized light (CPL) active with maxima luminescent dissymmetry factor |glum| of 3.4 × 10−3 (Cl−Au) and 2.7 × 10−3 (Br−Au) for their crystalline powder samples, respectively. By using Cl−Au as the emitting ink, 3D‐printed luminescent logos are fabricated, which own anti‐counterfeiting functions due to its CPL behavior dependent on the crystallinity.