Iodide Salts Research Articles

Synthesis, X-ray structures, Hirshfeld surface analysis, and redox behaviour of 2-substituted-1H-perimidine derivatives

Peri-naptho fused pyrimidine derivatives, known as 1H-perimidines or 1H-benzo[d,e]quinazolines, have recently been studied for a diverse range of applications. A series of 2-substituted-1H-perimidine compounds (1A–1F) have been synthesized by the condensation reaction of 1,8-diaminonaphthalene with the appropriate aldehyde. The 2-substituted-1H-perimidinium iodide salts (1A+I––1F+I–) were obtained by methylating 1H-perimidine using methyl iodide in the presence of a mild base K2CO3. The perimidinium salts were reduced using NaBH4 in methanol to obtain 2-substituted-2,3-dihydro-1H-perimidine compounds (1AH–1FH). The compounds were characterized by 1H, 13C-NMR and UV–Vis absorption spectroscopy, elemental analysis, and in the case of compounds 1C, 1B+I–, 1C+I–, 1E+I–, 1F+I–, and 1BH–1EH, their molecular structures have been determined using single crystal X-ray analysis and compared to those of related 1H-perimidine derived species. The crystal packings from the solid-state structures of 1C, 1C+I–, and 1CH were compared and revealed further stability of the molecule 1C through intermolecular NH···N hydrogen bonding and π···π stacking interactions, while in the case of molecules 1C+I–, and 1CH through short interatomic CH···C contacts between two adjacent perimidine rings. To further quantify the intermolecular interactions and investigate their contributions to the crystal packing in each molecule, Hirshfeld surface analysis was performed. The redox properties of the perimidinium salts 1A+I––1F+I–, and the hydride reduced species 1AH–1FH were studied using cyclic voltammetry, and compared to that of N-DMBI-H ((4-(1,3-dimethyl-2,3-dihydro-1H-benzo[d]imidazole-2-yl)phenyl)dimethylamine). The salts exhibit an irreversible reduction wave, like those of 2-substituted-1,3-dimethyl-1H-benzo[d]imidazolium salts, while the hydrides undergo a reversible oxidation process, with the peak ratio (Ipc/Ipa) > 0.5. This shows the chemical stability of the 1H•+ species at a scan rate of 100 mV s–1.

A predictive approach for the compositional and temperature representation of thermal conductivity in multicomponent molten salt systems for advanced energy applications

This study presents a theoretical model, based on kinetic theory, for accurately predicting thermal conductivity in molten salt mixtures, a vital factor in designing advanced energy systems such as concentrating solar power, thermal energy storage, and advanced nuclear reactors. Applicable to non-complex, non-reciprocal systems, the model represents thermal conductivity with respect to composition and temperature. We evaluated the model using molecular dynamics simulations on binary systems from fluoride, chloride, bromide, iodide salt families. The model predictions were also compared against existing experimental datasets for those families as well as binary nitrates and carbonates. The model demonstrated an improvement in predictive accuracy over the ideal linear estimation and showed reasonable agreement with the reliable experimental data. Deviations from ideal conductivity, analyzed using the Redlich-Kister method, pointed to the molecular weight and thermal conductivity of individual compounds as primary influencing factors. When applied to predict the thermal conductivity of higher order eutectic salt mixtures relevant to energy applications, the model showed predictive accuracy comparable to empirical methods. The model was further applied to generate compositional mapping to quantify deviations from ideality over the compositional space. This advance enhances new molten salt mixtures evaluation efficiency and extends the model to complex mixtures.

Tuning 2D Perovskite Passivation: Impact of Electronic and Steric Effects on the Performance of 3D/2D Perovskite Solar Cells

AbstractSurface passivation with 2D perovskites is a powerful strategy to achieve improved stability and performance in perovskite solar cells (PSCs). Various large organic cations have been successfully implemented, led by phenylethylammonium (PEA+) and its derivatives. However, systematic studies on large sets of cations to understand the effect of substituent position on 2D perovskite passivation and device performance are lacking. Herein, a collection of halogenated PEA+ iodide salts (x‐XPEAI where x: ortho (o), meta (m), para (p), X: F, Cl, Br) are synthesized by a facile method and deposited on top of 3D perovskite. The 2D perovskite layer formation is confirmed by X‐ray diffraction (XRD) and grazing‐incidence wide‐angle X‐ray scattering analyses for all cations, regardless of the nature and position of the halogen. Density functional theory analysis reveals that lower formation energies and higher interfacial dipoles achieved by m‐substituted cations are responsible for enhanced performance compared to their o‐ and p‐ counterparts. While the m‐BrPEAI‐treated device shows a champion efficiency of 23.42%, (VOC=1.13 V, FF=81.2%), considering average efficiencies, stability, and reproducibility, the treatment with m‐ClPEAI salt yields the best overall performance. This comprehensive study provides guidelines for understanding the influence of large cation modification on performance and stability of 3D/2D PSCs.

Scalable, solution-based dye-sensitized photovoltaic fibers with an electrolytic solid-state ion conductor

We have created a textile with solid-state dye-sensitized photovoltaic fibers (DSPFs) fabricated using a unique combination of inexpensive, commercial-off-the-shelf materials and solution-based processing deposition techniques. DSPFs were made possible by macroscopic support of liquid state components in both the electrolyte and photoanode of the DSPFs. A plastic crystal system of succinonitrile was doped with iodide salts to achieve a solid-state ion-conducting electrolyte. Similarly, utilization of a mesoporous TiO2 photoanode created an adsorptive scaffold for photoactive dyes in a liquid solution. An inexpensive pairing of coated carbon and stainless steel, replacing the traditional and expensive platinum-based counter electrode, was used as a catalytic counter electrode. A solid-state DSPF including both electrodes aligned in comparative orientations provided peak power of up to 0.4 µW/mm with open-circuit voltage (VOC) of 0.7 V. A module of solid-state DSPFs was then incorporated into a simple weave in a mini-loom to demonstrate textile capability. Solid-state DSPFs woven and connected in series in the loom produced peak power of over 50 µW and VOC of 4.5 V. Creation of the flexible DSPFs was achieved through a series of simple and scalable solution-based coating processes, and to the best of our knowledge, has not been previously reported in literature to produce fully encapsulated solid-state dye-sensitized photovoltaic cells with a fiber form factor. Low cost, high throughput processing of this technology can potentially support the manufactural transition for the next generation of commercial energy harvesting wearable electronics.

Double‐Side Passivation of Perovskite Solar Cells for High Performance and Stability

AbstractPerovskite solar cells (PSCs) are in the spotlight as promising renewable energy devices by their appealing properties. However, they face challenges both in power conversion efficiency (PCE) and long‐term stability. The presence of surface defects in the PSCs is a significant obstacle to achieving both high efficiency and stability, as these defects cause nonradiative recombination and degradation. Herein, a novel double‐side surface passivation method using phenyltrimethylammonium iodide (PTMAI) salt is applied to remove electronic defects effectively. Furthermore, double‐side passivation with PTMAI contributes to the enhancement of the perovskite crystallinity with the relaxed non‐uniform distribution of local strains. Finally, the efficiency of PSC is significantly improved by double‐side passivation with PTMAI, achieving a PCE of 21.87%. Furthermore, the passivated cell exhibited enhanced long‐term stability, maintaining over 80% of initial PCE after 1860 and 1030 h under 60 °C and 1 sun illumination, respectively.

Decarboxylative Cross-Electrophile Coupling of (Hetero)Aromatic Bromides and NHP Esters.

Aryl bromides are known to be challenging substrates in the decarboxylative cross-electrophile coupling with redox-active NHP esters-the majority of such processes utilize aryl iodides. Herein, we describe the development of conditions that are suitable for the decarboxylative cross-electrophile coupling of NHP esters and a wide range of (hetero)aryl bromides. The key advances that allowed for the use of aryl bromides in this reaction are (1) the identification of ligand L3 as an optimal ligand for the use of electron-neutral and deficient aryl bromides and (2) the significant improvement in yield that iodide salts and excess heterogenous zinc impart to this reaction. A wide variety of NHP esters perform well under the optimized conditions, including methyl, primary, secondary, and several strained tertiary systems. Likewise, a variety of aromatic and heteroaromatic bromides relevant to medicinal chemistry perform well in this transformation, including an aryl bromide precursor to the known drug dapagliflozin.

Influence of humidity on accuracy of QCM – IR780-based GUMBOS sensor arrays

Herein, hydrophobic coating materials are reported for QCM detection of VOCs under dry and humid conditions. In this study, IR780-based GUMBOS ([IR780][OTf] and [IR780][NTf2]) were synthesized using an ion exchange reaction and the anions trifluoromethanesulfonimide ([OTf]) and bisperfluoromethanesulfonimide ([NTf2]). The parent iodide salts and GUMBOS ([IR780][I]), [IR780][OTf], and [IR780][NTf2]) were characterized using several analytical techniques. These salts were then employed as sensor coatings on quartz crystal resonators using an electrospray coating method. These sensors were exposed to four flow ratios of five common VOCs in the absence and presence of 10 vol% water. Fundamental frequency responses were recorded and further employed as input variables to develop highly accurate multi-sensor arrays (MSAs). Accuracy was better than 78.3% without water, and better than 91.7% in the presence of water. When multi-harmonic responses were evaluated as input variables to assess discrimination ability for each sensor, highly accurate virtual sensor arrays (VSAs) were developed using each GUMBOS coating. In the case of [IR780][NTf2], a slight improvement in discrimination was achieved in the presence of water (95%) versus the absence of water. Moreover, this study highlights development of readily synthesized hydrophobic coatings of IR780-based GUMBOS for potential detection and discrimination of VOCs in aqueous systems.

Ion Diffusion Management Enables All-Interface Defect Passivation of Perovskite Solar Cells.

Perovskite solar cells (PSCs) have demonstrated over 25% power conversion efficiency (PCE) via efficient surface passivation. Unfortunately, state-of-the-art perovskite post-treatment strategies can solely heal the top interface defects. Herein, we propose an ion diffusion management strategy to concurrently modulate the top interfaces, buried interfaces, and bulk interfaces (i.e., grain boundaries) of perovskite film, enabling all-interface defect passivation. Specifically, this method is enabled by applying double interactive salts of octylammonium iodide (OAI) and guanidinium chloride (GACl) onto the three-dimensional (3D) perovskite surface. We reveal that the hydrogen-bonding interaction between OA+ and GA+ decelerates the OA+ diffusion and therefore forms dimensionally broadened 2D capping layer. Additionally, the diffusion of GA+ and Cl- determines the composition of the bulk and buried interface of PSCs. As a result, we can obtain n-inter-i-inter-p, i.e., 5-layer structured PSCs with a champion PCE of 25.43% (certified 24.4%). This approach also enables the substantially improved operational stability of perovskite solar cells. This article is protected by copyright. All rights reserved.

Phenoxazine‐benzimidazolium ionic hole transport material for perovskite solar cells

AbstractA novel organic ionic material, hole transport material‐1 (HTM‐I), was synthesized and characterized as a hole transport material for perovskite solar cells (PSCs), with the aim of replacing 2,2',7,7'‐Tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9'‐spirobifluorene (Spiro‐OMeTAD). HTM‐I was designed to incorporate both phenoxazine and benzimidazolium iodide salt structures, and its chemical structure was confirmed using 1H NMR and high‐resolution mass spectrometry. Differential scanning calorimetry measurements revealed that HTM‐I maintained an amorphous phase throughout the temperature range of −60 – 200 °C, and thermogravimetric analysis showed good thermal stability up to 220 °C. To evaluate its potential as a hole transport layer, perovskite solar cells were fabricated using a fluorine‐doped tin oxide (FTO)/compact‐TiO2/(Cs/FA/MA)Pb(I/Br)3/hole transport layer/Au configuration. The resulting n–i–p planar structure exhibited a power conversion efficiency of 10.4%.

New Insights into the Phototoxicity of Anthracene-Based Chromophores: The Chloride Salt Effect†.

Unraveling the causes underlying polycyclic aromatic hydrocarbon phototoxicity is an essential step in understanding the harmful effects of these compounds in nature. Toward this end, we have studied the DNA interactions and photochemistry of N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride in the presence and absence of NaF, KF, NaCl, KCl, NaBr, KBr, NaI, and KI (350 nm hν, pH 7.0). Exposing pUC19 plasmid to UV light in solutions containing 400 mM KCl formed significantly more direct strand breaks in DNA compared to no-salt control reactions. In contrast, NaCl increased DNA damage moderately, while the sodium(I) and potassium(I) fluoride, bromide, and iodide salts generally inhibited cleavage (I- > Br- > F-). A halide anion-induced heavy-atom effect was indicated by monitoring anthracene photodegradation and by employing the hydroxyl radical (•OH) probe hydroxyphenyl fluorescein (HPF). These studies revealed that among no-salt controls and the eight halide salts, only NaCl and KCl enabled the anthracene to photosensitize the production of high levels of DNA-damaging reactive oxygen species (ROS). Pre-irradiation of N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride at 350 nm increased the amounts of chloride salt-induced •OH detected by HPF in subsequent anthracene photoactivation experiments. Taking into consideration that •OH and other highly reactive ROS are extremely short-lived, this result suggests that the pre-irradiation step might lead to the formation of oxidized anthracene photoproducts that are exceedingly redox-active. The fluorometric probes HPF and Singlet Oxygen Sensor Green revealed that KCl concentrations ranging from 150 to 400 mM and from 100 to 400 mM, respectively, enhanced N1-(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride photosensitized •OH and singlet oxygen (1O2) production over no-salt controls. Considering the relatively high levels of Na+, K+, and Cl- ions that exist in the environment and in living organisms, our findings may be relevant to the phototoxic effects exhibited by anthracenes and other polycyclic hydrocarbons in vivo.

Structural, Optical, and Electrical Parameters of Doped PVA/PVP Blend with TPAI or THAI Salt.

The 70% polyvinyl alcohol/30% polyvinyl pyrrolidone (PVA/PVP) polymer blends, with different weight ratios of tetrapropylammonium iodide (TPAI) or tetrahexylammonium iodide (THAI) salt, were prepared using dimethyl sulfoxide (DMSO) as a solvent. The X-ray diffraction technique was used to trace the crystalline nature of the formed blends. The SEM and EDS techniques were applied to figure out the morphology of the blends. The variation in the FTIR vibrational bands was used to investigate the chemical composition and the effect of different salt doping on the functional groups of the host blend. The influence of the salt type (TPAI or THAI) and its ratio on the linear and nonlinear optical parameters for the doped blends were investigated in detail. Absorbance and reflectance are highly enhanced in the UV region reaching a maximum for the blend with 24% TPAI or THAI; so, it can be employed as shielding materials for UVA and UVB types. The direct (5.1 eV) and indirect (4.8 eV) optical bandgaps were reduced continuously to (3.52, 3.63 eV) and (3.45, 3.51 eV) while increasing the content of TPAI or THAI, respectively. The blend doped with 24% wt TPAI exhibited the highest refractive index (around 3.5 in 400-800 nm). The DC conductivity is affected by the content and type of salt, its dispersion, and blend-salt interaction. The activation energies of different blends were obtained by applying the Arrhenius formula.

Effects of Gamma Irradiation on Optical Properties of Poly(ethylene oxide) Thin Films Doped with Potassium Iodide

In this study, the effect of gamma irradiation on the optical properties of thin films of polymer electrolytes was investigated. The thin films were composed of poly(ethylene oxide) (PEO) doped with different concentrations of potassium iodide (KI) salt. The optical absorption spectrum of each film was measured using a UV–Vis spectrophotometer over a range of 300 to 800 nm. The PEO thin-film samples were subjected to gamma irradiation at two different doses of 100 and 200 Gy generated by a Co-60 source. It was found that the optical properties of the thin films were significantly influenced by the KI dopant concentration and gamma irradiation. Increasing both the KI concentration and the gamma irradiation dose resulted in a reduction in the energy gap and an increase in the absorption coefficient, extinction coefficient, refractive index, and dielectric constant of the PEO electrolyte. These findings have potential applications in the optimization of polymers for use in optical devices and energy storage systems.

Cu(I)-catalyzed Synthesis of Symmetrical Perfluoroterphenyl Analogues; Fluorescence, Antioxidant and Molecular Docking studies.

Pentafluoroaryl analogues have been found to exhibit para specific nucleophilic aromatic substitution (SN Ar). Herein, we describe the use of SN Ar chemistry to create luminous perfluorinated symmetrical terphenyls. Both of SN Ar chemistry and Cu(I)-catalyzed decarboxylative cross-coupling were applied for the synthesis of those perfluorinated symmetrical terphenyls in high yields from the corresponding derivatives of aryl iodide and potassium salt of fluorobenzoate. A series of perfluorinated symmetrical terphenyls with different para alkoxy chains were synthesized. The synthesized perfluorinated terphenyl adducts were confirmed via elemental analysis, FT-IR, 1 H/13 C NMR, and 19 F NMR spectra. The absorbance and fluorescence spectra showed solvatochromic activities. The new synthesized fluoroterphenyl hybrids were screened against antioxidant inspection over DPPH performance, in assessment to Vitamin C and BHT as standard drugs exposed that fluoroterphenyl hybrid covering decyl hydrocarbons exhibited highest effectiveness through IC50 values 21.74 μg/mL. Additionally, molecular docking procedures of the synthesized fluoro-terphenyl hybrids were employed by using (PDB ID: 5IKQ) protein. The docking simulation was displayed convenient and recognized findings with the antioxidant examination.

Leaching of Copper Concentrate with Iodized Salts in a Saline Acid Medium: Part 1—Effect of Concentrations

One of the main problems in processing chalcopyrite ore with hydrometallurgical methods is its refractoriness, which is due to the formation of a layer that inhibits the contact of the ore with the leaching solution, thus reducing the dissolution rate. The main objective of this paper is to evaluate the leaching potential of iodide ions in copper extraction from chalcopyrite concentrate in an acidic seawater medium. Leaching tests were carried out in glass reactors stirred at 45 °C. Parameters such as iodide salt concentration and acidity were evaluated in ranges of 0-5000 ppm and 0-1.0 M, respectively. According to the results obtained, adding iodide ions to a medium acid enhances the leaching kinetics in the chalcopyrite concentrate, observing that it improves copper extraction at low concentrations of 100 ppm KI compared to high concentrations of 5000 ppm KI. As a result, part of the iodide required to oxidize copper tends to sublimate or is associated with other ions producing iodinated compounds such as CuI. Copper extraction reached 45% within the first 96 h, while at 216 h, it reached an extraction of close to 70% copper. The recovery rate improves at potentials between 600 and 650 mV, while at lower potentials, the copper extraction decreases. The mineral surface was analyzed using SEM/EDS and XRD analyses for the identification of precipitates on the surface, finding porous elemental sulfur and precipitated jarosite. An increase in iodide ions improves the leaching kinetics in the chalcopyrite concentrate, observing that it improves copper extraction at low concentrations of 100 ppm KI compared to high concentrations of 5000 ppm KI. As a result, part of the iodide required to oxidize copper tends to sublimate or is associated with other ions producing iodinated compounds such as CuI. Copper extraction reached 45% within the first 96 h, while at 216 h, it reached an extraction of close to 70% copper. The recovery rate improves at potentials between 600 and 650 mV, while at lower potentials, the copper extraction decreases. The mineral surface was analyzed using SEM/EDS and XRD analyses for the identification of precipitates on the surface, finding porous elemental sulfur and precipitated jarosite.

Efficiency enhancement of dye-sensitized solar cell with PVdF-HFP:MPII:NaI quasi-solid-state electrolyte

Quasi-solid-state polymer electrolyte (QSSPE) based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) was prepared using sodium iodide (NaI) salt, 1-methyl-3-propylimidazolium iodide (MPII) ionic liquid, propylene carbonate (PC) and 1,2-dimethoxyethane (DME) plasticizers. This paper discusses the effects of using a binary mixture of large (MPII) and small (NaI) cation alkaline salts on enhancing the performance of DSSCs with gel polymer electrolytes. The amount of NaI was varied while the other components were kept constant to study the dependence of dye-sensitized solar cell (DSSC) performance on NaI amount. The incorporation of NaI in PVdF-HFP-MPII-PC-DME has enhanced the efficiency of DSSC. DSSC with 0.6 M MPII and 0.4 M NaI showed the highest efficiency of 4.16 % and short circuit current density (J sc) of 13.63 mAcm−2. Additionally, the roles of TBP and GuSCN as co-additives in the electrolytes were also discussed in this paper. The presence of 4-tert-butylpyridine (TBP) and guanidine thiocyanate (GuSCN) further enhanced the efficiency from 4.16 to 6.95 %.

Elucidating the mixing effect of dual polymers via physical blending on its physicochemical, thermal and electrical properties for dye-sensitized solar cells

Blending two different polymers through a physical blending is a wise alternative to create a new polymer with desired properties showing a synergistic effect of the individual polymers. In this work, polyacrylonitrile (PAN) and poly (1-vinylpyrrolidone-co-vinyl acetate) P(VP-co-VAc) were blended in a fixed amount of binary organic solvent of ethylene carbonate and propylene carbonate. The weight ratios were varied to 30:70, 50:50 and 70:30 wt%, respectively. Polymer electrolytes in a gel and solid form are safer than liquid ones. Thus 50:50PP and 70:30PP samples were selected and incorporated with iodide/triiodide redox mediators such as sodium iodide salt, 1-methyl-3-propylimidazolium iodide (MPII) ionic liquid and iodine for dye-sensitized solar cells (DSSC) application. Polymer electrolytes containing 50 wt.% of both PAN and P(VP-co-VAc) with iodide/triiodide redox mediator (50:50PP-IL) has achieved maximum ionic conductivity, short-circuit (JSC) current and power conversion efficiency (PCE, η) of 6.10 ×10−3 S cm−1, 11.1 mA cm−1 and 5.35%, respectively.

2-Amino-1,3-benzothiazole: Endo N-Alkylation with α-Iodo Methyl Ketones Followed by Cyclization.

Reactions of 2-amino-1,3-benzothiazole with aliphatic, aromatic and heteroaromatic α-iodoketones in the absence of bases or catalysts have been studied. The reaction proceeds by N-alkylation of the endocyclic nitrogen atom followed by intramolecular dehydrative cyclization. The regioselectivity is explained and the mechanism of the reaction is proposed. A number of new linear and cyclic iodide and triiodide benzothiazolium salts have been obtained and their structure proved by NMR and UV spectroscopy.

Dependence of Transition-Metal Telluride Phases on Metal Precursor Reactivity and Mechanistic Implications.

Modern bottom-up synthesis to nanocrystalline solid-state materials often lacks the reasoned product control that molecular chemistry boasts from having over a century of research and development. In this study, six transition metals including iron, cobalt, nickel, ruthenium, palladium, and platinum were reacted with the mild reagent didodecyl ditelluride in their acetylacetonate, chloride, bromide, iodide, and triflate salts. This systematic analysis demonstrates how rationally matching the reactivity of metal salts to the telluride precursor is necessary for the successful production of metal tellurides. The trends in reactivity suggest that radical stability is the better predictor of metal salt reactivity than hard-soft acid-base theory. Of the six transition-metal tellurides, the first colloidal syntheses of iron and ruthenium tellurides (FeTe2 and RuTe2) are reported.

Dual-side interfacial passivation of FAPbI3 perovskite film by Naphthylmethylammonium iodide for highly efficient and stable perovskite solar cells

Interfacial passivation has been considered as an effective strategy to improve the performance of perovskite solar cells (PSCs) by modifying defect trap states between perovskite and charge transport layers. Here, we apply Naphthylmethylammonium Iodide (NMAI) salt to passivate the double-side interfaces from the perovskite/electron transport layer (ETL) and perovskite/hole transport layer (HTL). It demonstrates that using NMAI to suppress the interface defects from perovskite film can effectively decrease non-radiative recombination, extend the carrier recombination lifetime (from 4 to 113 ns), and boost PSCs device performance. Additionally, the judicious control of the interaction between perovskite and NMAI molecules can further optimize the homogenous morphology and crystallinity of the perovskite absorber layer. The double-side NMAI passivated device achieved a decent 22.97 % power conversion efficiency (PCE) with 1.11 V of open-circuit voltage (VOC), 80.35 % fill factor (FF) and short-circuit current (JSC) of 25.77 mA cm−2, compared to the control device (19.56 % PCE in conjunction with an VOC of 1.01 V, FF of 79.67 %, and JSC of 24.37 mA cm−2). Moreover, the unencapsulated devices with double-side NMAI passivation layers maintain 73 % of initial PCE after 432 h, at room temperature, under a nitrogen atmosphere, and in dark conditions. This study proposes a facile and effective method to passivate the perovskite/ETL and perovskite/HTL interfaces via NMAI spin-coating process.

High-resolution structural study on pyridin-3-yl ebselen and its N-methylated tosylate and iodide derivatives.

The crystal structure of the pyridine-substituted benzisoselenazolinone 2-(pyridin-3-yl)-2,3-dihydro-1,2-benzoselenazol-3-one (C12H8N2OSe, 2), related to the antioxidant ebselen [systematic name: 2-phenyl-1,2-benzoselenazol-3(2H)-one, 1], is characterized by strong intermolecular N...Se(-N) chalcogen bonding, where the N...Se distance of 2.3831 (6) Å is well within the sum of the van der Waals radii for N and Se (3.34 Å). This strong interaction results in significant lengthening of the internal N-Se distance, consistent with significant population of the Se-N σ* antibonding orbital. Much weaker intermolecular O...Se chalcogen bonding occurs between the amide-like O atom in 2 and the less polarized C-Se bond in this structure. Charge density analysis of 2 using multipole refinement of high-resolution data allowed the electrostatic surface potential for 2 to be mapped, and clearly reveals the σ-hole at the extension of the Se-N bond as an area of positive electrostatic potential. Topological analysis of the electron-density distribution in 2 was carried out within the Quantum Theory of Atoms in Molecules (QTAIM) framework and revealed bond paths and (3,-1) bond critical points (BCPs) for the N...Se-N moiety consistent with a closed-shell interaction; however, the potential energy term is suggestive of electron sharing. Analysis of the electron localization function (ELF) for the strong N...Se and the weak O...Se chalcogen-bonding interactions in the structure of 2 suggest significant electron sharing in the former interaction, and a largely electrostatic interaction in the latter. Conversion of 2 to its N-methylated derivatives by reaction with methyl iodide [1-methyl-3-(3-oxo-2,3-dihydro-1,2-benzoselenazol-2-yl)pyridin-1-ium iodide, C13H11N2OSe+·I-] and methyl tosylate [1-methyl-3-(3-oxo-2,3-dihydro-1,2-benzoselenazol-2-yl)pyridin-1-ium toluenesulfonate trihydrate, C13H11N2OSe+·C7H7O3S-·3H2O] removes the possibility of N...Se chalcogen bonding and instead structures are obtained where the iodide and tosylate counter-ions fulfill the role of chalcogen-bond acceptors, with a strong I-...Se interaction in the iodide salt and a weaker p-Tol-SO3-...Se interaction in the tosylate salt.