Bridging Sulfate Research Articles

(CN3H6)[FeIIFeIII(SO4)3(H2O)3]: A Framework Iron Sulfate with a Mixed S = 2 and S = 5/2 Honeycomb Lattice.

A new guanidinium-templated hydrated iron sulfate, [CN3H6][FeIIFeIII(SO4)3(H2O)3] (1), was prepared from strongly acidic aqueous solutions. Its crystal structure is comprised from FeIIIO6 and FeIIO3(H2O)3 octahedra linked by sulfate bridges forming a [FeIIFeII(SO4)3(H2O)3]- 3D framework with a layer-by-layer ordering of ferric and ferrous cations. The structural topology of the framework is related to the anhydrous rhombohedral mikasaite Fe2(SO4)3. The removal of part of the sulfate tetrahedra and the partial replacement of the Fe3+ cations in the [Fe3+2(SO4)3]0 framework by Fe2+ provide a negative charge and allow the incorporation of the protonated organic species in the voids. The compound 1 has been characterized by single-crystal X-ray diffraction, TG and DSC analyses, UV-vis-NIR spectroscopy, magnetic susceptibility, Mössbauer spectroscopy, IR and Raman spectroscopy, and density functional band-structure calculations. The magnetic behavior of 1 shows an interplay of FeII (S = 2) and FeIII (S = 5/2) sublattices that exhibit different types of antiferromagnetic couplings, one FeIII-FeIII (J1 ∼ 6.1 K) and two FeII-FeIII couplings (J2 ∼ 1 K, J3 ∼ 5.9 K) within corrugated honeycomb layers. These ferrimagnetic layers are coupled antiparallel to each other, resulting in an overall antiferromagnetic order below TN = 31 K.

Crystal structure of catena-poly[[[bis-(1-benzyl-imidazole-κN)copper(II)]-μ-sulfato-κ2 O:O'-[tetra-kis-(1-benzyl-imidazole-κN)copper(II)]-μ-sulfato-κ2 O:O'] N,N-di-methyl-formamide disolvate dihydrate

The title one-dimensional copper(II) coordination polymer, {[Cu(SO4)(C10H10N2)3]·C3H7NO·H2O} n or {[Cu(bzi)3(μ-O2SO2)]·H2O·DMF} n (bzi = 1-benz-yl-imidazole, C10H10N2; DMF = N,N-di-methyl-formamide, C3H7NO), is constructed by monodentate bzi ligands and bridging sulfate anions, leading to chains propagating parallel to the c axis. Within a chain, there are two crystallographic independent CuII ions, each with site symmetry , which form [CuN2O2] and [CuN4O2] polyhedra alternating along the chain direction. The crystal structure is consolidated by weak hydrogen-bonding, C-H⋯π and π-π inter-actions, leading to the formation of a three-dimensional supra-molecular network.

A binuclear copper(II) complex based on hydrazone ligand: Characterization, molecular docking, and theoretical and antimicrobial investigation

AbstractA new binuclear copper(II) complex [Cu2L2(μ‐SO4)(dmf)] with the 2‐acetylpyridinebenzoylhydrazone (HL) ligand was synthesized and characterized by elemental analysis, Fourier transform infrared (FT‐IR), ultraviolet–visible (UV–Vis), single‐crystal X‐ray diffraction, density functional theory (DFT), and molecular docking studies. The crystal structure revealed each copper(II) atom coordinated to the NNO chelating system of the anionic hydrazone ligand and a sulfate bridged. The copper ions are connected by a sulfate bridge, which keeps a distance of 3.292(3) Å between the two copper(II) centers. Additionally, only one of the copper(II) atoms is coordinated to the oxygen atom of the N,N‐dimethylformamide (dmf) solvent molecule, resulting in two different geometry to each metal center. Cu···O interactions are observed for the secondary coordination sphere of Cu1 and Cu2 atoms with distances of 2.545(2) and 2.821(3) Å, respectively. Theoretical studies with DFT were performed to optimize the geometry of the complex and investigate its spectroscopic properties supporting the experimental results. Two different approaches were used in computational calculations, the plane wave using Perdew–Burke–Ernzerhof (PBE) functional and the localized basis set using the following functionals: B3LYP, B3PW91, CAM‐B3LYP, LC‐wPBE, M06‐2X, ωB97‐XD, PBE1PBE, and HSEH1PBE. The in vitro antibacterial potential of the new complex was evaluated against pathogenic bacteria and fungi and compared with the free ligand. The molecular docking was used to predict the inhibitory activity of the ligand and complex against one Gram‐positive bacteria (Enterococcus faecalis), one Gram‐negative bacteria (Enterobacter aerogenes), and one fungi (Candida albicans) species.

Copper(II) complexes based on thiosemicarbazone ligand: Preparation, crystal structure, Hirshfeld surface, energy framework, antiMycobacterium activity, in silico and molecular docking studies

Considering the promising previous results on the remarkable activity exhibited by cobalt(III) and manganese(II) thiosemicarbazone compounds as antibacterial agents, the present study aimed to prepare and then evaluate the antibacterial activity of two different types of Cu(II) complexes based on a 2-acetylpyridine-N(4)-methyl-thiosemicarbazone ligand (Hatc-Me), a monomer complex [CuCl(atc-Me)] and a novel dinuclear complex [{Cu(μ-atc-Me)}2μ-SO4]. The compounds were characterized by infrared spectra, ultraviolet visible and CHN elemental analysis. In addition, the crystalline structures of the complexes were determined by single-crystal X-ray diffraction. In both cases, the Schiff base ligand coordinated in a tridentate mode via the pyridine nitrogen, imine nitrogen and sulfur atoms. The two Cu(II) atoms in the dimer are five coordinate, consisting of three NNS-donor atoms from the thiosemicarbazone ligand connected by a sulfate bridge. The Hirshfeld surface and energy framework of the complexes were additionally analyzed to verify the intermolecular interactions. The biological activity of the Cu(II) salts, the free ligand and its Cu(II) complexes was evaluated against six strains of mycobacteria including Mycobacterium tuberculosis. The complexes showed promising results as antibacterial agents for M. avium and M. tuberculosis, which ranged from 6.12 to 12.73 μM. Furthermore, molecular docking analysis was performed and the binding energy of the docked compound [{Cu(μ-atc-Me)}2μ-SO4] with M. tuberculosis and M. avium strains were extremely favorable (−11.11 and − 14.03 kcal/mol, respectively). The in silico results show that the complexes are potential candidates for the development of new antimycobacterial drugs.

Evolution of fumarolic anhydrous copper sulfate minerals during successive hydration/dehydration

AbstractHydration processes of primary anhydrous minerals as well as dehydration of the hydrated phases are relevant not only for answering geochemical and petrological questions, but are also interesting in the context of the theory of the ‘Evolution of minerals’. Our study of the evolution of anhydrous exhalative sulfates in hydration and dehydration processes has demonstrated the complexity of the processes for a number of minerals from the active high-temperature fumaroles of Tolbachik volcano (chalcocyanite Cu(SO4), dolerophanite Cu2O(SO4), alumoklyuchevskite K3Cu3AlO2(SO4)4 and itelmenite Na2CuMg2(SO4)4). Hydration and dehydration experiments were carried out for all four minerals using powder X-ray diffraction. A typical structural characteristic of several anhydrous copper sulfate minerals of fumarolic origin is the presence of oxygen-centred OCu4 tetrahedra. These are absent in the structures of all known hydrated minerals or synthetic compounds of the class under consideration. Hydration of minerals initially containing O2– anions as part of oxocomplexes, proceeds with sequential formation of a large series of hydroxysalts. On the contrary, hydration of itelmenite with its relatively complex ‘initial’ structure, but without additional oxygen atoms that are strong Lewis bases, results in formation of simpler hydrates. The lower the temperature and the larger the excess of water, the stronger the tendency of the cations to adopt higher hydration numbers thus outcompeting the sulfate anions as ligands. Ultimately, the water molecules completely expel the bridging sulfate anions from the metal coordination sphere yielding relatively simple fully hydrated structures.

Copper(II) hydrazone complexes with different nuclearities and geometries: Synthesis, structural characterization, antioxidant SOD activity and antiproliferative properties

New copper(II) hydrazone complexes with (Z)-2-(phenyl(2-(pyridin-2-yl)hydrazono)methyl)pyridine (L) were synthesized and characterized using various physicochemical methods. The geometries of the complexes can be classified as mononuclear and binuclear. The complex 1, [Cu(L)(Cl)2], is mononuclear whereas the solid-state structure of complex 2 contain a mixture of co-crystals of the mono- and binuclear complexes 2a, [Cu(L)(H2O)(SO4)], and 2b, [Cu2(L)2(μ-SO4)2]. The unit cell of 2 contains two units of the mononuclear complex 2a and one units of the binuclear complex 2b. The copper atoms contained in all the mono- and binuclear complexes are in a distorted square pyramidal geometry. The present study indicates that complexes having different nuclearities and geometries can be achieved by changing the synthetic conditions and methods. Variable temperature magnetic susceptibility measurements of the complexes have shown the presence of weak anti-ferromagnetic interactions. These interactions are mediated by intermolecular hydrogen bonding in 1 and through a symmetric sulfate bridge in 2. The EPR spectra in the polycrystalline state for 1 and 2 exhibited a broad signal at ~ 2.149 due to spin–spin interactions between two copper(II) ions. The cyclic voltammograms of complexes 1 and 2 in DMSO gave two irreversible redox waves. Density functional theory (DFT) calculations were evaluated in the study, involving the molecular specification with the use of B3LYP/LANL2DZ formalism for the copper atoms and B3LYP/6-31G for the remaining atoms. Both complexes catalyzed the dismutation of superoxide (O2∙-). Furthermore, the copper complexes and the ligand were tested to explore their anticancer properties. Promising cytotoxicity of the synthesized compounds was observed against the selected cancerous cell lines of neuroblastoma, lung carcinoma, hepatocellular carcinoma and breast cancer.

Water-sulfate anion interplay in the evolution of solid state architectures and emission properties of Zn and Cd coordination networks with four azine ligands

Reactions of zinc and cadmium sulfates with 1,2-bis(pyridin-3-ylmethylene)hydrazine (3-bphz), 1,2-bis(pyridin-4-ylmethylene)hydrazine (4-bphz), and two methylated derivatives, 1,2-bis(1-(pyridin-3-yl)ethylidene)hydrazine (3-bpmhz) and 1,2-bis(1-(pyridin-4-yl)ethylidene)hydrazine (4-bpmhz) resulted in eight coordination compounds. For Zn(II) the structural landscape includes binuclear complexes and two-dimensional coordination polymers, [Zn2(3-bphz)(H2O)10](SO4)2.4H2O (1), [Zn2(SO4)2(3-bphz)(H2O)4]n (2), [Zn2(3-bpmhz)3(H2O)8](SO4)2 (3), and {[Zn(SO4)(4-bpmhz)(H2O)2].1.5(H2O)·0.25(4-bpmhz)}n (4). For Cd(II) two- and three-dimensional coordination networks, {[Cd(SO4)(4-bpmhz)(H2O)1.32]·1.2(H2O)}n (5), [Cd(SO4)(3-bpmhz)(H2O)]n (6), {[Cd(SO4)(4-bphz)(H2O)]·(H2O.C2H5OH)}n (7), and [Cd3(SO4)3(3-bphz)3(H2O)2]n (8) are reported. The extension of crystal structures up to two- and three-dimensional coordination networks has been achieved via bidentate bridging neutral azine ligands, and bi- and tridentate bridging sulfate anions that provide the metal-sulfate inorganic scaffolds in the forms of different one- and two-dimensional coordination arrays. The new crystalline solids were studied by X-ray single crystal and powder diffraction, spectroscopic and thermogravimetric analytical methods. The water-sulfate-anion interplay, similarities and dissimilarities in the coordination networks' topologies, the inherent chiralities of coordination networks, an impact of ligands’ methylation on solvent uptake, and the emission events accompanying the thermal stress are demonstrated and discussed.

Copper(II) Hydrazone Complexes with Different Nuclearities and Geometries: Synthesis, Structural Characterization, Antioxidant Sod Activity and Antiproliferative Properties

New copper(II) hydrazone complexes with (Z)-2-(phenyl(2-(pyridin-2-yl)hydrazono)methyl)pyridine (L) were synthesized and characterized using various physicochemical methods. The geometry of complexes can be classified as mononuclear and binuclear. The complex 1 [Cu(L)Cl2] is mononuclear whereas solid-state structures of complex 2 contains a mixture of co-crystals of mono- and binuclear complexes 2a [Cu(L)(H2O)(SO4)] and 2b [(L)Cu-(SO4)2-Cu(L)]. The molecular structure of 2 contains two units of mononuclear complex 2a and two units of binuclear complex 2b. Copper contains in all mono- and binuclear complexes are in a distorted square pyramidal geometry. The present study indicates that complexes having different nuclearities and geometries can be achieved by changing synthetic conditions and methods. Variable temperature magnetic susceptibility measurements of the complexes have shown a weak anti-ferromagnetic interaction. The presence of weak anti-ferromagnetic interactions is mediated by intermolecular hydrogen bonding in 1 and by symmetric sulfate bridge in 2, respectively. The Epr spectra in polycrystalline state of 1 and 2 exhibited a broad signal at 2.149 due to the spin-spin interactions between two copper(II) ions. The cyclic voltammograms of complexes 1 and 2 in DMSO gave two irreversible redox waves. Density functional theory (DFT) calculations were evaluated in the study involved the molecular specification for the use of B3LYP/LANL2DZ formalism for copper atom and B3LYP/6-31G for the remaining atoms. Both complexes catalyzed the dismutation of superoxide ( 02). Furthermore, copper complexes and ligand were tested to explore the anticancer properties. Promising cytotoxicity of synthesized compounds was observed on the selected cancerous cell line of neuroblastoma, lung carcinoma, hepatocellular carcinoma and breast cancer.

The varied structures of cobalt(II)-pyridine (py)-sulfate: [Co(SO4)(py)4] n , [Co2(SO4)2(py)6] n , and [Co3(SO4)3(py)11] n.

The solid-state structures of two cobalt-pyridine-sulfate compounds, namely catena-poly[[tetra-kis-(pyridine-κN)cobalt(II)]-μ-sulfato-κ2 O:O'], [Co(SO4)(C5H5N)4] n , (1), and catena-poly[[tetra-kis-(pyridine-κN)cobalt(II)]-μ-sulfato-κ3 O:O',O''-[bis-(pyridine-κN)cobalt(II)]-μ-sulfato-κ3 O,O':O''] n , [Co2(SO4)2(C5H5N)6] n , (2), are reported. Compound (1) displays a polymeric structure, with infinite chains of CoII cations adopting octa-hedral N4O2 coordination environments that involve four pyridine ligands and two bridging sulfate ions. Compound (2) is also polymeric with infinite chains of CoII cations. The first Co center has an octa-hedral N4O2 coordination environment that involves four pyridine ligands and two bridging sulfate ligands. The second Co center has an octa-hedral N2O4 coordination environment that involves two pyridine ligands and two bridging sulfate ions that chelate the Co atom. The structure of (2) was refined as a two-component inversion twin.

More crystal field theory in action: the metal-4-picoline (pic)-sulfate [M(pic)x]SO4 complexes (M= Fe, Co, Ni, Cu, Zn, and Cd).

Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal-4-picoline (pic)-sulfate complexes of the form [M(pic)x]SO4 are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-μ-sulfato-κ2O:O'], [M(SO4)(C6H7N)4]n, where the metal/M is iron, cobalt, nickel, and cadmium, di-μ-sulfato-κ4O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2O:O'], [Zn(SO4)(C6H7N)2]n, and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2O:O'], [Zn(SO4)(C6H7N)3]n. The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of MII ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square-pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.

Heterometallic Hexanuclear [Ln4Cr2] Cluster-Based Three-Dimensional Sulfate Frameworks as a Magnetic Refrigerant and Single Molecular Magnet

Three heterometallic 3d-4f cluster-based, three-dimensional sulfate frameworks, [Ln4Cr2(μ4-O)2(μ3-OH)4(H2O)9(SO4)5]·3H2O (Ln = Gd/Tb/Dy), were obtained. They are built from the hexanuclear [Ln4Cr2] cluster and sulfate bridge, showing a 6-connected pcu topology network. The [Gd4Cr2]-based compound displays a large magnetocaloric effect of −ΔSm = 38.33 J kg–1 K–1, making it a hopeful magnetic cooler at low temperature, while the Tb- and Dy-containing compounds display interesting single-molecule magnet behavior, indicating that they are potential materials to make spintronic devices.

Arraying Octahedral {Cr2Dy4} Units into 3D Single-Molecule-Magnet-Like Inorganic Compounds with Sulfate Bridges.

Two novel 3D pure inorganic compounds based on [Cr2Dy4(μ4-O)2(μ3-OH)4]10+ cluster units and sulfate anions are presented. Both complexes exhibit single-molecule-magnet (SMM)-like behavior. Permutation of the magnetic moment direction among SMM-like cluster units has a significant effect on the performance of molecular nanomagnets, and directional consistency shows obvious advantages.

The crystal structures of iron and cobalt pyridine (py)-sulfates, [Fe(SO4)(py)4] n and [Co3(SO4)3(py)11] n.

The solid-state structures of two metal-pyridine-sulfate compounds, namely catena-poly[[tetra-kis-(pyridine-κN)iron(II)]-μ-sulfato-κ2O:O'], [Fe(SO4)(C5H5N)4] n , (1), and catena-poly[[tetra-kis-(pyridine-κN)cobalt(II)]-μ-sulfato-κ2O:O'-[tetra-kis-(pyridine-κN)cobalt(II)]-μ-sulfato-κ3O,O':O''-[tris-(pyridine-κN)cobalt(II)]-μ-sulfato-κ2O:O'], [Co3(SO4)3(C5H5N)11] n , (2), are reported. The iron compound (1) displays a polymeric structure, with infinite chains of FeII atoms adopting octa-hedral N4O2 coordination environments that involve four pyridine ligands and two bridging sulfate ligands. The cobalt compound (2) displays a polymeric structure, with infinite chains of CoII atoms. Two of the three Co centers have an octa-hedral N4O2 coordination environment that involves four pyridine ligands and two bridging sulfate ligands. The third Co center has an octa-hedral N3O3 coordination environment that involves three pyridine ligands, and two bridging sulfate ligands with one sulfate chelating the cobalt atom.

The role of sulfate in the chemical synthesis of graphene oxide

In this work we carried out both a theoretical and experimental study of the interactions between the sulfate species with graphene sheets, in order to understand the possible formation mechanisms behind the graphene oxide (GO) synthesis. As the results, it is shown a series of theoretical structures which were found in our conformational searches via quantum methods, such as the well-known epoxy group and the cyclic sulfate bridges, a new species that, up until now, was not reported for this kind of system. These results were also compared with the data acquired from a sequence of chemical tests and spectroscopic analyses of a GO prepared using the modified Hummers method. Finally, it was possible to give some answers to open questions that can guide future experiments in the GO synthesis.

Synthesis, crystal structure and characterization of new three-dimensional Cu(II) coordination polymer based on 1,3,5-tris(imidazol-1-ylmethyl)benzene

The title Cu(II) coordination polymer of 1,3,5-tris(imidazol-1-ylmethyl) benzene, namely {Cu(SO4)(C18H18N6)(C2H6O2)}n, was synthesized and characterized by elemental analysis, infrared spectra (IR), thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. Single crystal structure analysis shows that the title complex possesses a three-dimensional (3D) architecture with a very rare (3,4,6)-connected (4.62)2(42.68.83.102)(64.82) topology . There are two kinds of crystallographically independent CuII centres, each lying on a centrosymmetric position and having a similar six-coordinated octahedral structure. One is coordinated by four N atoms from four 1,3,5-tris(-imidazol-1-yl)methyl benzene (timb) ligands and two O atoms from two different bridging sulfate anions. The second is surrounded by two timb N atoms and four O atoms, two from sulfate anions and two from two ethane-1,2-diol ligands. The tripodal timb ligand bridges neighbouring CuII centres to generate a two-dimensional layered structure. Adjacent layers are further bridged by sulfate anions, resulting in a three-dimensional structure. X-ray powder diffraction studies of the title complex confirm that there is no impurity phase in the bulk material since experimental diffraction patterns match well with the simulated ones. In addition, their thermal stabilities have also been investigated.

Topological study of diverse hydrogen-bonded patterns found in a system of a nickel(II) complex and the sulfate anion.

A nickel(II) coordination complex, bis[2,6-bis(1H-benzimidazol-2-yl-κN3)pyridine-κN]nickel(II) sulfate, [Ni(C19H13N5)2]SO4 or [Ni(H2L)2]SO4, having four peripheral tetrahedrally oriented N-H donor units, combines with sulfate bridges to create hydrogen-bonded structures of varied dimensionality. The three crystal structures reported herein in the space groups P212121, I-4 and Pccn are defined solely by strong charge-assisted N-H...O hydrogen bonds and contain disordered guests (water and dimethylformamide) that vary in size, shape and degree of hydrophilicity. Two of the compounds are channelled solids with three-dimensional structures, while the third is one-dimensional in nature. In spite of their differences, all three present a striking resemblance to the previously reported anhydrous relative [Guo et al. (2011). Chin. J. Inorg. Chem. 27, 1517-1520], which is considered as the reference framework from which all three title compounds are derived. The hydrogen-bonded frameworks are described and compared using crystallographic and topological approaches.

First-row transition metal-pyridine (py)-sulfate [(py)xM](SO4) complexes (M = Ni, Cu and Zn): crystal field theory in action.

The crystal structures of three first-row transition metal-pyridine-sulfate complexes, namely catena-poly[[tetrakis(pyridine-κN)nickel(II)]-μ-sulfato-κ2O:O'], [Ni(SO4)(C5H5N)4]n, (1), di-μ-sulfato-κ4O:O-bis[tris(pyridine-κN)copper(II)], [Cu2(SO4)2(C5H5N)6], (2), and catena-poly[[tetrakis(pyridine-κN)zinc(II)]-μ-sulfato-κ2O:O'-[bis(pyridine-κN)zinc(II)]-μ-sulfato-κ2O:O'], [Zn2(SO4)2(C5H5N)6]n, (3), are reported. Ni compound (1) displays a polymeric crystal structure, with infinite chains of NiII atoms adopting an octahedral N4O2 coordination environment that involves four pyridine ligands and two bridging sulfate ligands. Cu compound (2) features a dimeric molecular structure, with the CuII atoms possessing square-pyramidal N3O2 coordination environments that contain three pyridine ligands and two bridging sulfate ligands. Zn compound (3) exhibits a polymeric crystal structure of infinite chains, with two alternating zinc coordination environments, i.e. octahedral N4O2 coordination involving four pyridine ligands and two bridging sulfate ligands, and tetrahedral N2O2 coordination containing two pyridine ligands and two bridging sulfate ligands. The observed coordination environments are consistent with those predicted by crystal field theory.

Sulfate‐Assisted Interfacial Engineering for High Yield and Efficiency of Triple Cation Perovskite Solar Cells with Alkali‐Doped TiO2 Electron‐Transporting Layers

AbstractFacile electron injection and extraction are two key attributes desired in electron transporting layers to enhance the efficiency of planar perovskite solar cells. Herein it is demonstrated that the incorporation of alkali metal dopants in mesoporous TiO2 can effectively modulate electronic conductivity and improve the charge extraction process by counterbalancing oxygen vacancies acting as nonradiative recombination centers. Moreover, sulfate bridges (SO42−) grafted on the surface of K‐doped mesoporous titania provide a seamless integration of absorber and electron‐transporting layers that accelerate overall transport kinetics. Potassium doping markedly influences the nucleation of the perovskite layer to produce highly dense films with facetted crystallites. Solar cells made from K:TiO2 electrodes exhibit power conversion efficiencies up to 21.1% with small hysteresis despite all solution coating processes conducted under ambient air conditions (controlled humidity: 25–35%). The higher device efficiencies are attributed to intrinsically tuned electronic conductivity and chemical modification of grain boundaries enabling uniform coverage of perovskite films with large grain size.

2D polymeric cadmium(II) complexes containing 1,3-imidazolidine-2-thione (Imt) ligand, [Cd(Imt)(H2O)2(SO4)]n and [Cd(Imt)2(N3)2

The present study aims at preparing and carrying out the structural investigation of two polymeric cadmium(II) complexes of imidazolidine-2-thione (Imt) based on sulfate or azide ions, [Cd(Imt)(H2O)2(SO4)]n (1) and [Cd(Imt)2(N3)2]n (2). The structures of the complexes were determined by single crystal X-ray analysis. Both compounds, 1 and 2 crystallize in the form of 2D coordination polymers and the cadmium(II) ion is six-coordinate having a distorted octahedral geometry in each compound. In 1, the metal ion is bonded to one sulfur atom of Imt and five oxygen atoms with two from water and three of bridging sulfate ions. In 2, the cadmium coordination sphere is completed by two Imt molecules binding through the sulfur atoms and four nitrogen atoms of bridging azide ions. The crystal structures are stabilized by intra and intermolecular hydrogen bonding interactions. The complexes were also characterized by IR and NMR spectroscopy and the spectroscopic data is consistent with the binding of the ligands.

Crystal structure of fluorosulfate complex compounds of indium(III) M2[InF3(SO4)H2O] (M = K, NH4)

The crystal structures of isostructural mixed-ligand fluorosulfate complex compounds of indium(III) M2[InF3(SO4)H2O] (M = K, NH4), formed of K+ cations, NH4 + respectively, and complex [InF3(SO4)H2O]2– anions are determined. In the complex anion, the indium atom surrounded by three F atoms, the oxygen atom of the coordinated H2O molecule, and two oxygen atoms of the bridging sulfate group forms a slightly distorted octahedron (CN 6). Via alternating bridging SO4 groups, the polyhedra of In(III) atoms are arranged in polymer chains. The O–H•••F hydrogen bonds organize the chains in a three-dimensional network. The K+ and NH4 + cations are located in the structure framework and additionally strengthen it.