Colorless Crystals Research Articles

Contributions to the stereochemistry of zirconium oxysalts—part VI: syntheses and crystal structures of K2Zr(SO4)3∙2.5H2O, K2Zr(SeO4)3, K2Zr2O(SeO4)4, and Zr(OH)2(SeO4)·H2O

The compounds K2Zr(SO4)3·2.5H2O, K2Zr(SeO4)3, and K2Zr2O(SeO4)4 were synthesized at 200 °C by reaction of Zr2O2(CO3)(OH)2 and KHCO3 with the respective acids H2SeO4/H2SO4 and minor H2O. Zr(OH)2(SeO4)·H2O originates from an analogous experiment at 215 °C without KHCO3. All four phases form colorless crystals up to several tenths of a mm and were investigated by single crystal X-ray diffraction. K2Zr(SO4)3·2.5H2O is monoclinic, space group P21/c (No. 14), with a = 7.295(2) Å, b = 13.925(3) Å, c = 12.579(3) Å, β = 95.32(3)°, V = 1272.3(4) Å3, Z = 4, R1 = 0.025. K2Zr(SeO4)3 and K2Zr2O(SeO4)4 are both triclinic, space group P1¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$P\\overline{1}$$\\end{document} (No. 2), with a = 7.570(1) Å, b = 10.500(1) Å, c = 14.400(1) Å, α = 85.55(1)°, β = 88.04(1)°, γ = 87.82(1)°, V = 1139.7(2) Å3, Z = 4, R1 = 0.049, and a = 5.400(1) Å, b = 7.328(1) Å, c = 9.642(1) Å, α = 95.81(1)°, β = 95.20(1)°, γ = 94.27(1)°, V = 376.74(4) Å3, Z = 1, R1 = 0.020, respectively. Zr(OH)2(SeO4)·H2O crystallizes in the monoclinic space group C2/c (No. 15), with a = 6.684(1) Å, b = 12.998(2) Å, c = 6.792(1) Å, β = 97.37(1)°, V = 585.14(6) Å3, Z = 2, R1 = 0.013.Graphical abstract

Crystallization of [Zn(Pyrazinamide)₂(Cl)₂] Complex and In Vitro Antibacterial Activity of the Complex Against E. coli and S. aureus

A complex of [Zn(pza)2(Cl)2], pza = pyrazinamide, was successfully crystallized from methanol or ethanol solvents with different morphology. The complex was synthesized using the solution method in ZnCl2: pza mol ratios of 1:2 and 1:4 in both ethanol and methanol solvents. FTIR and single crystal XRD analyses were done to confirm the complex. The complex was then used for in vitro antibacterial test against E. coli and S. aureus. Experimental data shows that the type of solvent and metal-to-ligand mol ratio yields the same compound, resulting in colorless crystals that melt at 234-236°C. Large block crystals were obtained from the methanolic solution, while a higher yield was obtained from the use of a higher mol ratio of 1:4. Infrared spectra analysis confirms the presence of characteristic carbonyl and amide groups of the pza ligand. Meanwhile, single crystal XRD screening indicates that unit cell parameters of the crystals from both solvents are identical to a known zinc(II)-pza complex. In vitro antibacterial tests against E. coli and S. aureus show that the complex had much better activity than the ZnCl2 and the free pza. In addition, the complex performs better antibacterial activity toward gram-positive S. aureus than the gram-negative E. coli.

Ultraviolet Nonlinear Optical Single Crystals of A Three‐Dimensional Chiral Covalent Framework Containing Te−O−B−O Bonds

AbstractExtending covalent organic frameworks (COFs) into crystalline carbon‐free covalent backbones is an important strategy to endow these materials with more exotic functions. Integrating metal‐free inorganic and organic components into one covalent framework is an effective way to address the issue of poor thermal/solvent stability in the field of nonlinear optics (NLO). However, constructing such structures is very challenging. Here, we linked 3‐connected nods (BO3) and 2‐connected organic building blocks (Te(Ph)2) together to produce colorless single crystals (size up to 400 μm) of a three‐dimensional (3D) chiral covalent framework (CityU‐22). The single‐crystal X‐ray diffraction (SCXRD) analysis reveals that CityU‐22 has a non‐carbon Te−O−B−O bond‐based network with the srs topology. The chiral CityU‐22 displays good stability under the treatment of different common solvents or heat (the decomposition temperature above 300 °C). Due to its non‐π‐conjugated backbone (−Te−O−B−O−), CityU‐22 shows an ultraviolet NLO behavior with a second‐harmonic generation (SHG) response similar to KH2PO4 (KDP).

Ultraviolet Nonlinear Optical Single Crystals of A Three-Dimensional Chiral Covalent Framework Containing Te-O-B-O Bonds.

Extending covalent organic frameworks (COFs) into crystalline carbon-free covalent backbones is an important strategy to endow these materials with more exotic functions. Integrating metal-free inorganic and organic components into one covalent framework is an effective way to address the issue of poor thermal/solvent stability in the field of nonlinear optics (NLO). However, constructing such structures is very challenging. Here, we linked 3-connected nods (BO3) and 2-connected organic building blocks (Te(Ph)2) together to produce colorless single crystals (size up to 400 μm) of a three-dimensional (3D) chiral covalent framework (CityU-22). The single-crystal X-ray diffraction (SCXRD) analysis reveals that CityU-22 has a non-carbon Te-O-B-O bond-based network with the srs topology. The chiral CityU-22 displays good stability under the treatment of different common solvents or heat (the decomposition temperature above 300 °C). Due to its non-π-conjugated backbone (-Te-O-B-O-), CityU-22 shows an ultraviolet NLO behavior with a second-harmonic generation (SHG) response similar to KH2PO4 (KDP).

New Silver(I) Complexes as Achromatic Sensitizers in Solar Cell Applications

ABSTRACTThe design, synthesis, and spectroscopic characterization of [Ag(P(o‐C6H4OCH3)3)(NO3)]2 (1) and [Ag(P(o‐C6H4OCH3)3)2][NO3] (2) were conducted to investigate the efficiency of the fabricated solar cell devices. The slow evaporation technique proved effective in growing the colorless crystals of the silver(I) complexes. Spectroscopic analyses including Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and ultraviolet–visible (UV–Vis) studies were carried out to elucidate the chemical structure and absorption properties of the compounds. The chemical composition and existence of intermolecular interactions in 1 and 2 were disclosed via the single‐crystal x‐ray diffraction method. The side‐to‐side arrangement of molecules in 1 and 2 was evident from the crystal packing analysis, in which the molecules in both compounds were linked together by C–H···O and C–H···π contacts. The silver(I) complexes exhibited maximum absorption wavelength (287–288 nm) within the ultraviolet region, where both compounds had comparable high energy band gap values ranging from 4.15 to 4.16 eV. Moreover, both compounds possess appropriate HOMO–LUMO energy levels that facilitate effective electron injection and dye regeneration processes in dye‐sensitized solar cell (DSSC) applications. Photophysical characterization techniques, field‐emission scanning electron microscopy (FESEM), and energy‐dispersive x‐ray (EDX) spectroscopy studies were employed to assess the morphological characteristics and elemental composition of the silver(I) complexes on TiO2. Compound 2 exceeded 1 in terms of solar cell efficiency, 2 (η = 3.34%) > 1 (η = 0.66%) due to the complex being in ionic form and composed of the mononuclear [Ag(P(o‐C6H4OCH3)3)2]+ cation [NO3]− anion.

THE U-PB AGE AND HAFNIUM ISOTOPE COMPOSITION OF ZIRCON FROM METAMORPHOZED ANDESITE OF THE CHORTOMLYK FORMATION AND RHYODACITE HYPABYSSAL INTRUSION OF THE SURA COMPLEX, CHORTOMLYK GREENSTONE BELT

Andesites and felsic volcanic rocks are observed at all stratigraphic levels of the Konka and Bilozerka groups, which comprise greenstone structures in the Middle Dnieper Domain. Their nature and age are still poorly known. The youngest felsic volcanic rocks of the Solone Formation of the Konka Group and comagmatic with the tonalite-trondhjemite-granodiorite (TTG) association of the Sura Complex hypabyssal intrusions were pre-viously dated by the U-Pb zircon SHRIMP method at ca. 3.1 Ga. The purpose of this study is to determine the U-Pb zircon age and geochemical features of i) metamorphosed andesites of the Chortomlyk Formation and ii) low-alkaline metarhyodacite hypabyssal intrusions that cut the rocks of the Sura Formation of the Konka Group. In the Chortomlyk Greenstone Belt, the thickness of volcanogenic rocks of the Chortomlyk Formation (dacite-andesite-tholeiite association) reaches 2000 m. The youngest felsic volcanic rocks of the Solone Formation and comagmatic hypabyssal intrusions are located within three large volcanic fields located near the Novomykolaivka* massif. Using the LA-ICP-MS method, U-Pb ages of two zircon populations from metamorphosed andesites of the Chortomlyk Formation were dated. Twenty-three crystals of transparent colourless zircon crystals yielded a concordant age of (3222 ± 6) Ma. The U-Pb age of the second population of large, brown, opaque zircon crystals is 3132–3073 Ma. Interpretation of the obtained ages is not straightforward and at least two options can be proposed: 1). The studied metaandesites are differentiated mafic magmas and the age of their formation is defined by the older zircon population, and the young population corresponds to the time of superimposed thermal processes during later intrusion of plagioclase granitoids of the Novomykolaivka massif; 2). The age of the metaandesite is defined by the younger population, while the older population is inherited from the protolith. We consider the second option as being far more likely. The first option contradicts the stratigraphic position of the dated rock. The studied metaandesite is low in potassium and belongs to the sodium series. Relative to TTG, they have higher Nb (16.2 ppm) and Y (25.9 ppm). Rare earth elements are weakly differentiated, (La/Yb)N = 3.91 with a strongly negative Eu anomaly, Eu/Eu* = 0.44. The U-Pb zircon age from the low-alkaline rhyodacite hypabyssal intrusion that cuts the Sura Formation of the Konka Group is (3085 ± 6) Ma. It has a highly differentiated REE pattern, (La/Yb)N = 16.2 and a positive Eu anomaly, Eu/Eu* = 1.21. The Nb (6.7 ppm) and Y (10.8 ppm) contents are low. They chemically resemble TTGs of the Sura Complex. Based on our data, the andesites of the Chortomlyk Formation of the Konka Group and the low-alkaline rhyodacite hypabyssal intrusions have the same U-Pb age, but different origins. The former were produced by the melting of older crustal rocks, and the latter were formed due to the partial melting of metabasites with garnet-bearing restite. Hafnium isotope composition in zircon from both samples reveals their juvenile nature, i.e., they crystallized from partial melts of rocks with short crustal residence times. Our isotope data agrees with the neodymium isotope composition of the felsic volcanic rocks of the Sura greenstone belt, which yielded εHf values of +1.8. These values are lower than the depleted mantle isotope composition at this time (3200–3000 Ma). *Novomykolaivka massif was formerly known as Chkalove massif.

Synthesis of dual functional Zn(II) MOF for colorimetric detection of norfloxacin and photocatalytic degradation of ornidzole drugs in aqueous medium

Pharmaceuticals widespread use of antibiotics endangers humans and animals. Antibiotic residues in groundwater, rivers, lakes, and other surfaces pose serious health risks. Therefore, the synthesis of high-performance sensors and catalyst materials for the selective and ultra-sensitive detection and removal of antibiotics from water is crucial for community health and environmental quality. This study created [Zn(Cei)] (1) flower-like colourless crystals using bis(2-carboxyethyl) isocyanurate (H2Cei) a simple room-temperature process and tested their photoluminescence sensing and photocatalytic destruction of antibiotics. Physicochemical characterisation of produced (1) was done using analytical and spectroscopic methods. The photoluminescent characteristics of (1) demonstrated that it is very sensitive and selectively detects NFX and NFT in aqueous solution at 0.323 and 0.590 ppm, respectively. However, [Zn(Cei)] (1) showed excellent photocatalytic activity against ODZ and CMP with degradation efficiency of 90.15% and 86.09% within 120 min under UV irradiation, respectively, and good stability by monitoring photocatalyst reusability.

Design of a new palladium(ii) halide complex as a bio-active material: synthesis, physico-chemical studies, DFT-computations and evaluation of anti-inflammatory, antioxidant and anti-gastric damage activities.

Colorless single crystals of the zero-dimensional hybrid compound, (C6H10N2)2[PdCl6]·2H2O were acquired through the slow evaporation technique. The crystal structure was explored using SC-XRD, which demonstrates that the material crystallizes in the centrosymmetric space group P1̄ of the triclinic system. The density functional theory method at the B3LYP/Lan2mb basis set level was employed to establish the optimized geometry and vibrational frequencies of the title compound. An acceptable correspondence was observed between the results obtained through calculation and the experimental data, including the structure, and IR spectra. The optical characteristics revealed a direct band gap energy of 2.35 eV, validating the semiconductor characteristics of this new material. The results suggest strong agreement with the experimental data and validate the involvement of metal orbitals in defining the HOMO-LUMO boundary. Simultaneous TGA-DTA shows that this material remains solid up to 210 °C. Beyond these temperatures, a gradual decomposition process occurs, extending up to 440 °C and unfolding in several steps. This process entails the liberation of diverse compounds, encompassing organic molecules, and the evaporation of chlorine ions, ultimately leading to the formation of palladium oxide (PdO) as the final product. When given to rats with gastric ulcers at a dose of 100 mg kg-1, these compounds inhibit the key enzyme responsible for neutrophil infiltration as myeloperoxidase (MPO) by 38.7%. The compound also alleviates cellular damage induced by free radicals, demonstrated by a notable 48.3% decrease in thiobarbituric acid reactive substance rates (TBARS) compared to untreated rats. Additionally, these compounds bring about a substantial 30.6% reduction in the surface area of ulcers.

Mixed occupancy: the crystal structure of scheelite-type LiLu[MoO4]2

Coarse colorless single crystals of lithium lutetium bis[orthomolybdate(VI)], LiLu[MoO4]2, were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetragonal, space group I41/a) with two formula units per unit cell. The Wyckoff position 4b (site symmetry \overline{4}) comprises a mixed occupancy of Li+ and Lu3+ cations in a 1:1 ratio. In comparison with a previous powder X-ray study [Cheng et al. (2015). Dalton Trans. 44, 18078–18089.] all atoms were refined with anisotropic displacement parameters.

Crystal structure of a three-coordinate lithium complex with monodentate phenyloxazoline and hexamethyldisilylamide ligands

The reaction of lithium hexamethyldisilylamide, [Li{N(Si(CH3)3)2}] (LiHMDS), with 4,4-dimethyl-2-phenyl-2-oxazoline (Phox, C11H13NO) in hexane produced colourless crystals of bis(4,4-dimethyl-2-phenyl-2-oxazoline-κN)(hexamethyldisilylamido-κN)lithium, [Li(C6H18NSi2)(C11H13NO)2] or [Li{N(Si(CH3)3)2}(Phox)2] in high yield (89%). Despite the 1:1 proportion of the starting materials in the reaction mixture, the product formed with a 1:2 amide:oxazoline ratio. In the unit cell of the C2/c space group, the neutral molecules lie on twofold rotation axes coinciding with the Li—N(amide) bonds. The lithium(I) centre adopts a trigonal–planar coordination geometry with three nitrogen donor atoms, one from the HMDS anion and two from the oxazolines. All ligands are monodentate. In the phenyloxazoline units, the dihedral angle defined by the five-membered heterocyclic rings is 35.81 (5)°, while the phenyl substituents are approximately face-to-face, separated by 3.908 (5) Å. In the amide, the methyl groups assume a nearly eclipsed arrangement to minimize steric repulsion with the analogous substituents on the oxazoline rings. The non-covalent interactions in the solid-state structure of [Li{N(Si(CH3)3)2}(Phox)2] were assessed by Hirshfeld surface analysis and fingerprint plots. This new compound is attractive for catalysis due to its unique structural features.

Crystal structure and Hirshfeld surface analysis of 5-hy-droxy-penta-nehydrazide.

Carb-oxy-hydrazides are widely used in medicinal chemistry because of their medicinal properties and many drugs have been developed containing this functional group. A suitable inter-mediate to obtain potential hydrazide drug candidates is the title compound 5-hy-droxy-penta-nehydrazide, C5H12N2O2 (1). The aliphatic compound can react both via the hydroxyl and hydrazide moieties forming derivatives, which can inhibit Mycobacterium tuberculosis catalase-peroxidase (KatG) and consequently causes death of the pathogen. In this work, the hydrazide was obtained via a reaction of a lactone with hydrazine hydrate. The colourless prismatic single crystals belong to the ortho-rhom-bic space group Pca21. Regarding supra-molecular inter-actions, the compound shows classic medium to strong inter-molecular hydrogen bonds involving the hydroxyl and hydrazide groups. Besides, the three-dimensional packing also shows weak H⋯H and C⋯H contacts, as investigated by Hirshfeld surface analysis (HS) and fingerprint plots (FP).

Approach to the "Missing" Diarylsilylene: Formation, Characterization, and Intramolecular C-H Bond Activation of Blue Diarylsilylenes with Bulky Rind Groups.

The treatment of the bulky Rind-based dibromosilanes, (Rind)2SiBr2 (2) [Rind = 1,1,7,7-tetra-R1-3,3,5,5-tetra-R2-s-hydrindacen-4-yl: EMind (a: R1 = Et, R2 = Me) and Eind (b: R1 = R2 = Et)], with two equivalents of tBuLi in Et2O at low temperatures resulted in the formation of blue solutions derived from the diarylsilylenes, (Rind)2Si: (3). Upon warming the solutions above -20 °C, the blue color gradually faded, accompanying the decomposition of 3 and yielding cyclic hydrosilanes (4) via intramolecular C-H bond insertion at the Si(II) center. The molecular structures of the bulky Eind-based 3b and 4b were confirmed by X-ray crystallography. Thus, at -20 °C, blue crystals were formed (Crystal-A), which were identified as mixed crystals of 3b and 4b. Additionally, colorless crystals of 4b as a singular component were isolated (Crystal-B), whose structure was also determined by an X-ray diffraction analysis. Although the isolation of 3 was difficult due to their thermally labile nature, their structural characteristics and electronic properties were discussed based on the experimental findings complemented by computational results. We also examined the hydrolysis of 3b to afford the silanol, (Eind)2SiH(OH) (5b).

Synthesis, characterization and supra-molecular analysis for (E)-3-(pyridin-4-yl)acrylic acid.

The title compound, C8H7NO2, crystallizes as prismatic colourless crystals in space group P , with one mol-ecule in the asymmetric unit. The pyridine ring is fused to acrylic acid, forming an almost planar structure with an E-configuration about the double bond with a torsion angle of -6.1 (2)°. In the crystal, strong O-H⋯N inter-actions link the mol-ecules, forming chains along the [101] direction. Weak C-H⋯O inter-actions link adjacent chains along the [100] direction, generating an R 2 2(14) homosynthon. Finally, π-π stacking inter-actions lead to the formation of the three-dimensional structure. The supra-molecular analysis was supported by Hirshfeld surface and two-dimensional fingerprint plot analysis, indicating that the most abundant contacts are associated with H⋯H, O⋯H/H⋯O, N⋯H/H⋯N and C⋯H/H⋯C inter-actions.

Mckelveyite group minerals – Part 4: Alicewilsonite-(YLa), Na2Sr2YLa(CO3)6 ⋅ 3H2O, a new lanthanum-dominant species from the Paratoo mine, Australia

Abstract. The new mckelveyite group mineral, alicewilsonite-(YLa), Na2Sr2YLa(CO3)6 ⋅ 3H2O, was found together with kamphaugite-(Y), paratooite-(Y), bastnäsite-(La), and decrespignyite-(Y) coating along fractures in dolomite at the Paratoo copper mine, South Australia, Australia. It occurs as pale pink to colourless pseudohexagonal tabular crystals up to 150 µm in size. The streak is white; the lustre is vitreous. The mineral has no cleavage. Dcalc is 3.37 g cm−3. Alicewilsonite-(YLa) is optically biaxial (−), α = 1.556(2), β= 1.582(2), γ= 1.592(2), 2V (meas.) = 60(2)°, 2V (calc.) = 63° (589 nm). The IR spectrum is reported. The composition (wt %, average of seven analyses) is Na2O 7.43, CaO 2.00, SrO 18.43, BaO 1.64, Y2O3 9.59, La2O3 11.74, Pr2O3 1.29, Nd2O3 5.74, Sm2O3 0.44, Eu2O3 0.09, Gd2O3 0.95, Dy2O3 1.15, Ho2O3 0.25, Er2O3 0.89, Yb2O3 0.29, CO2 29.78, H2O 6.18, total 97.88. The empirical formula calculated on the basis of six cations with 3 H2O molecules is as follows: Na2.10Ca0.31Sr1.56Ba0.10Y0.74La0.63Pr0.07 Nd0.30Sm0.03Eu0.01Gd0.04Dy0.05Ho0.01Er0.04 Yb0.01(CO3)5.92(H2O)3. The mineral is triclinic, P1, a= 8.9839(2), b= 8.9728(3), c= 6.7441(2) Å, α= 102.812(2)°, β= 116.424(2)°, γ= 60.128(2)°, and V= 422.17(2) Å3 and Z= 1. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are 6.03(43)(001), 4.355(100)(11‾0, 2‾1‾1, 120), 4.020(30)(1‾11, 210, 1‾2‾1), 3.188(29)(2‾1‾2, 11‾1, 121), 2.819(96)(002, 1‾12, 211, 1‾2‾2), 2.592(40)(3‾01, 030, 3‾3‾1), 2.228(33)(2‾21, 4‾2‾1, 2‾4‾1). 2.011(36)(2‾22, 003, 420, 2‾4‾2), 1.9671(32)(3‾03, 301, 03‾2, 032, 3‾3‾3, 331). The crystal structure was solved and refined from single-crystal X-ray diffraction data (R1= 0.058).

Exploring the physicochemical properties of a new mixed halide 1D hybrid material Zn(C2H8N2)Br1.41Cl0.59 with a non-centrosymmetric structure: Promising material for nonlinear applications

Colorless crystals of a new mixed halide hybrid material, Zn(C2H8N2)Br1.41Cl0.59, were synthesized by the slow evaporation method at room temperature. The crystal structure, thermal behavior, and optical analysis were analyzed to characterize this complex. The crystal structure study revealed that this compound adopts the orthorhombic system and crystallizes in the non-centrosymmetric space group Ima2. Its one-dimensional structure is built from infinite wavy chains of [Zn(C2H8N2)Br1.41Cl0.59]n propagating along the crystallographic a-axis, which are interconnected through NH···Br/Cl hydrogen bonds. Thermogravimetric analysis indicated that this complex remains stable up 251 °C, decomposing in a single step to yield zinc oxide (ZnO) as final product. Differential scanning calorimetry (DSC) revealed an endothermic peak at 195 °C, indicating that the title compound undergoes a phase transition at this temperature. Additionally, the material's suitability for optical application was assessed through UV–Visible absorption and non-linear optical (NLO) techniques. The determined band gap energy of 4.5 eV suggests that this new complex can be classified as a semiconductor material closely resembling an insulator. Furthermore, the second harmonic generation (SHG) efficiency of the grown crystal was analyzed using the Kurtz-Perry powder technique. The IR and Raman spectra confirm the results obtained from X-ray single-crystal structural analyses.

Ag(EtOH){Ph3Bi[O(O)CC5H4N-3]2}(ClO4)]•CHCl3 – A coordination polymer based on a divergent, ditopic metalloligand

Reaction of Ph3Bi[O(O)CC5H4N‐3]2 (1) in CHCl3 and AgClO4 in ethanol, in 1:1 molar ratio, afforded the isolation of colorless crystals of a coordination compound which was proved to be [Ag(EtOH){Ph3Bi[O(O)CC5H4N-3]2}(ClO4)]•CHCl3 (2•CHCl3) by single-crystal X-ray diffraction. A 1D coordination polymer is formed based on bridging triphenylbismuth(V) di(nicotinate) between silver atoms, with trans Ag−N dative bonds [2.183(4), 2.196(5) Å]. Additional Ag•••O interactions are established between the coinage metal atom and an ethanol molecule [2.58(3) Å] as well as a perchlorate anion [2.746(6) Å], respectively. Its supramolecular architecture, based on a variety of non-covalent interactions, i.e. O−H•••O, C−H•••O or C−H•••Cl hydrogen bonds, π•••π , C−H•••π, C−Cl•••π interactions, as well as Ag•••O and Ag•••Cl contacts, is discussed.

Kristjánite, KNa2H(SO4)2, a new fumarolic mineral from Iceland containing the [SO4–H–SO4]3– anion in the crystal structure

Abstract Kristjánite, KNa2H(SO4)2, is a new mineral (IMA2022–131) found in a high-temperature fumarole on Fimmvörðuháls, Iceland. It is monoclinic, P21/n, a = 6.9625(1), b = 9.9953(1), c = 11.0928(2) (Å), β = 105.637(2)° and V = 743.40(2) Å3. Kristjánite forms colourless transparent crystals up to ~100 μm in size in compact aggregates with metathénardite, belomarinaite, aphthitalite, ivsite and an unknown mineral with tentative composition K2NaH(SO4)2, or grows in white globules of smaller grains on their surface. The eight strongest maxima in a powder X-ray diffraction diagram are [d, Å (Intensity)] 4.37 (59), 3.65 (32), 3.48 (78), 3.36 (100), 3.18 (76), 2.83 (43), 2.73 (38) and 2.405 (23). The mineral represents a novel crystal structure type. In it, K is coordinated by eight O atoms, and two symmetrically independent Na atoms by seven O atoms. Two symmetrically independent S atoms are in tetrahedral coordination by O atoms. A close to linear, very short hydrogen bond (2.44 Å), connects the two to a SO4–H–SO4 dimer. K and Na coordination polyhedra share vertices, edges and even faces forming with sulfate tetrahedra a tight structure with narrow [100] channels lined on two opposite sides by hydrogen bonds.

The Molecular Structures of Lithium Trichlate, Li[Cl3CSO3]∙2H2O, and Lithium Tribrate, Li[Br3CSO3]∙2H2O

Lithium trichlate, Li[Cl3CSO3]∙2H2O (triclinic, P1, Z = 2, a = 630.29(3) pm, b = 630.65(3) pm, c = 1246.10(6) pm, α = 100.657(2)°, β = 97.813(2)°, γ = 107.994(2)°) was obtained from the reaction of (H5O2)[Cl3CSO3] and LiOH in aqueous solution. Similarly, colourless single crystals of the tribrate Li[Br3CSO3]∙2H2O (triclinic, P1, Z = 4, a = 634.65(4) pm, b = 636.83(4) pm, c = 2496.8(2) pm, α = 83.518°, β = 86.081(5)°, γ = 72.061(5)°) form in the reaction of aqueous Br3CSO3H and LiOH. The acid (H2O2)[Cl3CSO3] was obtained from the chlorination of CS2, followed by oxidation of the intermediate Cl3CSCl with H2O2. The bromo derivative Br3CSO3H has been prepared by bromination of phenylsulfonate with KOBr and subsequent ion exchange of the obtained potassium salt. Both lithium compounds exhibit molecular dimers according to {Li2(X3CSO3)2/1(H2O)2/1(H2O)2/2} with the Li+ ions in tetrahedral coordination of oxygen atoms. The difference in the crystal structures result from the variation of the orientation of the dimers with respect to each other. The experimental findings for the dimers are in good agreement with DFT calculations.

Exploring novel Cd(II) complexes with 5-methyl-4-imidazolecarboxaldehyde: synthesis, structure, computational insights, and affinity to DNA through switchSense methodology.

A series of four Cd(II) complexes with 5-methyl-4-imidazolecarboxaldehyde (L) with different inorganic anions within or outside the coordination sphere of general formula: [CdCl2L2] (1), [CdBr2L2] (2), [CdI2L2] (3), and [CdL4](PF6)2·3H2O (4) was synthesized through one-step and two-step reactions, respectively. All complexes were obtained as colorless crystals without the need for recrystallization and exhibited solubility in aqueous solutions. Structural analysis revealed different coordination environments for each complex, with variations in bond lengths and angles. The crystal packing of the complexes was stabilized by hydrogen bonding and π-π stacking interactions. FT-IR analysis indicated coordination of the ligand to the metal ion, and UV-Vis studies confirmed the stability of the complexes in solution. Computational analysis has revealed the polar nature of the complexes and their favorable stability constants. Affinity studies with DNA using the switchSense technique demonstrated rapid association and dissociation processes for all complexes, with temperature-dependent binding constants. Thermodynamic analysis suggested spontaneous with positive entropy change and endothermic formation processes for the complexes. Overall, the study underscores the synthesis, examination, and interaction with DNA of Cd(II) complexes, demonstrating their promise within medicinal chemistry.

Stibioclaudetite from the Zlatá Idka Ag-Au-Sb deposit, Spišsko-gemerské rudohorie Mts., Slovakia

A rare mineral, stibioclaudetite, ideally AsSbO3 was discovered at the dump of the Najvyšší Štefan adit at the Zlatá Idka Ag-Au-Sb deposit near Zlatá Idka, Spišsko-gemerské rudohorie Mts., Košice-okolie Co., Košice Region, Slovakia. It occurs as colourless prismatic crystals up 5 mm with perfect cleavage, developed on fractures of quartz gangue with abundant stibnite, arsenopyrite and minor pyrite. The unit-cell parameters of stibioclaudetite from the Zlatá Idka (for the monoclinic space group P21/n) refined from the PXRD data are: a 4.5715(17) Å, b 13.112(2) Å, c 5.4182(15) Å, β 94.97(3) and V 323.55(14) Å3. Its chemical composition corresponds to the average empirical formula As1.09Sb0.91O3.00. Raman spectrum of stibioclaudetite is also given. Stibioclaudetite was formed by the in-situ weathering of primary ore minerals at the base of the supergene zone under the relatively reducing conditions.