Enhancing Photostability of Complex Lead Halides through Modification with Antibacterial Drug Octenidine.

The high power-conversion efficiencies of hybrid perovskite solar cells encourage many researchers. However, their limited photostability represents a serious obstacle to the commercialization of this promising technology. Herein, we present an efficient method for improving the intrinsic photostability of a series of commonly used perovskite material formulations such as MAPbI, FAPbI, CsFAPbI, and CsMAFAPbI through modification with octenidine dihydroiodide (), which is a widely used antibacterial drug with two substituted pyridyl groups and two cationic centers in its molecular framework.

Synthesis and Properties of Ethylene/propylene and Ethylene/propylene/5-ethylidene-2-norbornene Copolymers Obtained on -Et(2-MeInd)ZrMe/Isobutylaluminium Aryloxide Catalytic Systems.

Ethylene/propylene (E/P) and ethylene/propylene/5-ethylidene-2-norbornene (E/P/ENB) copolymers were obtained on -Et(2-MeInd)ZrMe activated by a number of isobutylaluminium aryloxides: (2,6-BuPhO-)AlBu (1-DTBP) (2,6-Bu,4-Me-PhO-)AlBu (1-BHT), (2,4,6-BuPhO-)AlBu (1-TTBP), (2,6-Bu,4-Me-PhO-)AlBu (2-BHT), (2,6-BuPhO-)2AlBu (2-DTBP), [(2-Me,6-Bu-CHO)AlBu] (1-MTBP), [(2,6-Ph-PhO)AlBu] (1-DPP). This study shows how the structure of an activator influences catalytic activity and polymer properties, such as the copolymer composition, molecular weight characteristics, and thermophysical and mechanical properties. It has been shown that both the introduction of a bulky substituent in the para-position of the aryloxy group and the additional aryloxy group in the structure of an activator lead to a significant decrease in activity of the catalytic system in all studied copolymerization processes.

Exploring the Limits: Degradation Behavior of Lead Halide Perovskite Films under Exposure to Ultrahigh Doses of γ Rays of Up to 10 MGy.

Herein, we show that thin films of MAPbI, FAPbI, (CsMA)PbI, and (CsMAFA)PbI, where MA and FA are methylammonium and formamidinium cations, respectively, tolerate ultrahigh doses of γ rays approaching 10 MGy without significant changes in their absorption spectra. However, among the studied materials, FAPbI was the only one that did not form metallic lead due to its extreme radiation hardness. Infrared near-field optical microscopy revealed the radiation-induced depletion of organic cations from the grains of MAPbI and their accumulation at the grain boundaries, whereas FAPbI on the contrary lost FA cations from the grain boundaries.

Magnetically bistable cobalt-dioxolene complexes with a tetradentate N-donor base.

Synthesis and magnetic characterization of a family of cobalt-dioxolene complexes [(MeTPA)Co(36-DBCat)] (1), [(MeTPA)Co(36-DBCat)](PF) (2) and [(MeTPA)Co(diox-(OMe))](BPh) (3) (MeTPA = bis(6-methyl-2-pyridyl)methyl-(2-pyridylmethyl)amine; 36-DBCat = dianion of 3,6-di--butylcatechol; diox-(OMe) - 2,5-di--butyl-3,3,4-trimethoxy-6-oxocyclohexa-1,4-dienolate) is reported. The neutral complex 1 is found to form hexa- (CoON, 1a) and pentacoordinated (CoON, 1b) isomers. Variable temperature single crystal X-ray diffraction analysis of 1a and 1b clearly indicates the presence of the high-spin divalent metal ion and the dianionic catecholate form of the dioxolene ligand.

Spin-Crossover and Slow Magnetic Relaxation Behavior in Hexachlororhenate(IV) Salts of Mn(III) Complexes [Mn(5-Hal-sal323)][ReCl] (Hal = Cl, Br).

The cationic complexes of Mn(III) with the 5-Hal-sal323 (Hal = Cl, Br) ligands and a paramagnetic doubly charged counterion [ReCl] have been synthesized: [Mn(5-Cl-sal323)][ReCl] () and [Mn(5-Br-sal323)][ReCl] (). Their crystal structures and magnetic properties have been studied. These isostructural two-component ionic compounds show a thermally induced spin transition at high temperature associated with the cationic subsystem and a field-induced slow magnetic relaxation of magnetization at cryogenic temperature, associated with the anionic subsystem.

Nanoscale Visualization of Photodegradation Dynamics of MAPbI Perovskite Films.

Herein, we report the nanoscale visualization of the photochemical degradation dynamics of MAPbI (MA = CHNH) using infrared scattering scanning near-field microscopy (IR s-SNOM) combined with a series of complementary analytical techniques such as UV-vis and FTIR-spectroscopy, XRD, and XPS. Light exposure of the MAPbI films resulted in a gradual loss of MA cations starting from the grain boundaries at the film surface and slowly progressing toward the center of the grains and deeper into the bulk perovskite phase. The binary lead iodide PbI was found to be the major perovskite photochemical degradation product under the experimental conditions used.

Abrupt Spin-State Switching in Mn(III) Complexes with BPh Anion: Effect of Halide Substituents on Crystal Structure and Magnetic Properties.

Three tetraphenylborates of mononuclear Mn(III) cation complexes with hexadentate ligands, the products of the reaction between a N,N'-bis(3-aminopropyl)ethylenediamine and salicylaldehydes with the different haloid substitutions at the 5 or 3,5 positions, have been synthesized: [Mn(5-F-sal-N-1,5,8,12)]BPh (1), [Mn(3,5-diCl-sal-N-1,5,8,12)]BPh (2) and [Mn(3,5-Br,Cl-sal-N-1,5,8,12)]BPh (3). Their crystal structure, dielectric constant (ϵ) and magnetic properties have been studied. Ligand substituents have a dramatic effect on the structure and magnetic properties of the complexes.

Temperature Dynamics of MAPbI and PbI Photolysis: Revealing the Interplay between Light and Heat, Two Enemies of Perovskite Photovoltaics.

Regardless of the impressive photovoltaic performances demonstrated for lead halide perovskite solar cells, their practical implementation is severely impeded by the low device stability. Complex lead halides are sensitive to both light and heat, which are unavoidable under realistic solar cell operational conditions. Suppressing these intrinsic degradation pathways requires a thorough understanding of their mechanistic aspects.

Biomimetic Water Oxidation Catalyzed by a Binuclear Ruthenium (IV) Nitrido-Chloride Complex with Lithium Counter-Cations.

The lithium salt of the binuclear nitrido complex of ruthenium (IV) Li(RuNCl·2HO) was synthesized. Using UV spectroscopy and voltammetry, we studied complex behavior in aqueous solutions. It was found that in dilute solutions of this compound, Cl ions are replaced by HO molecules, and the intra-sphere redox reaction between Ru (IV) and HO, as well as the oxidation of water with the formation of oxygen and the acidic dissociation of coordinated water molecules also have been taking place.

Synthesis and study of -substituted methylthio derivatives of cobalt bis(dicarbollide).

The -methylthio derivatives of cobalt bis(dicarbollide) were synthesized by reaction of anhydrous CoCl with -carborane [7-MeS-7,8-CBH] and isolated as a mixture of -[1,1'-(MeS)-3,3'-Co(1,2-CBH)] and -[1,2'-(MeS)-3,3'-Co(1,2-CBH)] isomers. The structures of both isomers were studied using DFT quantum chemical calculations. The most preferable geometry of rotamers and the stabilization energy of -methylthio derivatives of cobalt bis(dicarbolide) were calculated.

The First Conducting Spin-Crossover Compound Combining a Mn Cation Complex with Electroactive TCNQ Demonstrating an Abrupt Spin Transition with a Hysteresis of 50 K.

We present herein the synthesis, crystal structure, and electric and magnetic properties of the spin-crossover salt [Mn(5-Cl-sal-N-1,5,8,12)]TCNQ ⋅2 CH CN (I), where 5-Cl-sal-N-1,5,8,12=N,N'-bis(3-(2-oxy-5-chlorobenzylideneamino)propyl)-ethylenediamine, containing distinct conductive and magnetic blocks along with acetonitrile solvent molecules. The Mn complex with a Schiff-base ligand, [Mn(5-Cl-sal-N-1,5,8,12)] , acts as the magnetic unit, and the π-electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ ) is the conducting unit. The title compound (I) exhibits semiconducting behavior with room temperature conductivity σ ≈1×10  ohm  cm and activation energy Δ ≈0.

Evidence of field induced slow magnetic relaxation in cis-[Co(hfac)(HO)] exhibiting tri-axial anisotropy with a negative axial component.

We report a combined experimental characterization and theoretical modeling of the hexa-coordinated high-spin Co(ii) complex cis-[Co(hfac)(HO)] (I). The magnetic static field (DC) data and EPR spectra (measurements were carried out on the powder samples of diluted samples cis-[CoZn (hfac)(HO)]) were analyzed with the aid of the parametric Griffith Hamiltonian for the high-spin Co(ii) supported by the ab initio calculations of the crystal field (CF) parameters, g-factors and superexchange parameters between H-bonded Co(ii) ions in the neighboring molecules in a 1D network. This analysis suggests the presence of the easy axis of magnetic anisotropy and also shows the existence of a significant rhombic component.

Single-Ion Magnet EtN[Co(hfac)] with Nonuniaxial Anisotropy: Synthesis, Experimental Characterization, and Theoretical Modeling.

In this article we report the synthesis and structure of the new Co(II) complex EtN[Co(hfac)] (I) (hfac = hexafluoroacetylacetonate) exhibiting single-ion magnet (SIM) behavior. The performed analysis of the magnetic characteristics based on the complementary experimental techniques such as static and dynamic magnetic measurements, electron paramagnetic resonance spectroscopy in conjunction with the theoretical modeling (parametric Hamiltonian and ab initio calculations) demonstrates that the SIM properties of I arise from the nonuniaxial magnetic anisotropy with strong positive axial and significant rhombic contributions.

Singularity of proton transport in salts of orthoperiodic and orthotellurium acids: theoretical modeling using density functional calculations.

Density functional B3LYP calculations have been performed to investigate proton transport in orthoperiodic and orthotellurium acids, their salts MIO(6)H(4)(M = Li, Rb, Cs) and CsH(5)TeO(6), dimers of the salt*acid type MIO(6)H(4)*H(5)IO(6)(M = Rb, Cs), CsIO(6)H(4)*H(6)TeO(6), CsHSO(4)*H(6)TeO(6), Cs(2)SO(4)*H(6)TeO(6), and also in double-substituted and binary salts Rb(2)H(3)IO(6) and Rb(4)H(2)I(2)O(10). It has been shown that the energy of salt dimerization is 33-35 kcal mol(-1) and the activation barrier for proton migration between the neighboring octahedrons of the salt*acid --> acid*salt type is calculated to be 3-13 kcal mol(-1). The activation energy of the proton migration along the octahedron, 20-30 kcal mol(-1), is comparable with the barrier for water molecule separation.