Organic Salts Research Articles

Recovery of organic nutrients from biogas slurry using decolorized ultra filtration membrane compared with nanofiltration membrane

Membrane separation technology has played a crucial role in concentrating biogas slurry (BS) for efficient water discharge. However, a membrane that selectively separates organic molecules and inorganic ions for the recovery of organic nutrients from BS for its valorization has not yet been reported. In this study, we investigated the use of decolorized ultra filtration membrane (DUFM) for the separation of organic molecules and inorganic ions from BS, compared it with the commonly used commercial nanofiltration (NF). The results showed that DUFM concentrated approximately 63 % of the COD content, which was 24 % lower than that achieved by NF. However, the concentrated BS using DUFM exhibited higher levels of protein-like substances (9 %), aromatic humic-like substances (14 %), and pigments (8 %) compared to NF, as indicated by absorbance of λ254, λ420 and λ560. In terms of inorganic ions, NH4+, Ca2+, HCO3-, and PO43- constituated approximately 88 %, 90 %, 80 %, and 70 % in the permeate side of DUFM, respectively. In constrast, NF allowed only about 70 % of NH4+ and 67 % of HCO3- to pass through, with almost complete rejection of PO43- and Ca2+. The mix-charged DUFM (500 Da) demonstrated superior separation of organic molecules and inorganic salts with low energy consumption compared to NF (150 Da) with negative charges. The DUFM with mix-charged performance increases organic molecules rejection by Donnan effect via electrostatic exclusion and with 500 Da reinforces inorganic ions’ permeation by size exclusion. Additionally, DUFM exhibited tolerance for large molecular dissolved organic matter in BS due to its membrane’s high surface hydrophilicity and smoothness. In conclusion, this study suggests DUFM, with its mix-charged characteristics, could serve as a promising membrane for the selective separation of organic molecules and inorganic ions, facilitating the recovery of organic nutrients for BS valorization.

Surface engineering of FAPbI3 based organic–inorganic hybrid perovskite for memristors

Organic–inorganic hybrid perovskites (OIHPs) have been spotlighted as emerging solution-processed electronics and show promise as economical, flexible, and stretchable emerging memristors. However, OIHPs suffer from considerable defects derived from solution processing; thus, post-processing is often required to alleviate such shortcomings. Treating alkyl ammonium organic salt on OIHP films is a representative approach to efficiently mediate the defect density. Here, we adopted n-octyl ammonium chloride (OACl) in our post-processing agent for organometal perovskite memristors (OPMs). The OACl-incorporated OPM showed an enlarged ON/OFF resistance ratio of 520 compared to OPM without passivation (3.91). Thin film analysis revealed that the synergistic insulating/passivating layer from OACl post-treatment retarded the interaction with the electroactive electrode (Ag). Additionally, the combined effects from the lower-dimensional OIHP induced by OA, including the p-doping of lead by chloride, enhanced the energetic barrier with Ag electrode to reduce the parasitic current at the high resistance state. This study offers deeper insights into the surface passivation of OIHPs and its effects on memristic performance.

Crystal structure and Hirshfeld surface analysis of 2-bromo-ethyl-ammonium bromide - a possible side product upon synthesis of hybrid perovskites.

This study presents the synthesis, characterization and Hirshfeld surface analysis of a small organic ammonium salt, C2H7BrN+·Br-. Small cations like the one in the title compound are considered promising components of hybrid perovskites, crucial for optoelectronic and photovoltaic applications. While the incorporation of this organic cation into various hybrid perovskite structures has been explored, its halide salt counterpart remains largely uninvestigated. The obtained structural results are valuable for the synthesis and phase analysis of hybrid perovskites. The title compound crystallizes in the solvent-free form in the centrosymmetric monoclinic space group P21/c, featuring one organic cation and one bromide anion in its asymmetric unit, with a torsion angle of -64.8 (2)° between the ammonium group and the bromine substituent, positioned in a gauche conformation. The crystal packing is predominantly governed by Br⋯H inter-actions, which constitute 62.6% of the overall close atom contacts.

Ascorbic acid-induced porous iodide layer for a high-purity two-step solution-processed tin-lead mixed perovskite photodetector

Tin (Sn)-lead (Pb) mixed halide perovskites have attracted widespread interest due to their wider response wavelength and lower toxicity than lead halide perovskites. Among the preparation methods, the two-step method more easily controls the crystallization rate and is suitable for preparing large-area perovskite devices. However, the residual low-conductivity iodide layer in the two-step method can affect carrier transport and device stability, and the different crystallization rates of Sn- and Pb-based perovskites may result in poor film quality. Therefore, Sn-Pb mixed perovskites are mainly prepared by a one-step method. Herein, a MAPb0.5Sn0.5I3-based self-powered photodetector without a hole transport layer is fabricated by a two-step method. By adjusting the concentration of the ascorbic acid (AA) additive, the final perovskite film exhibited a pure phase without residues, and the optimal device exhibited a high responsivity (0.276 A W−1), large specific detectivity (2.38 × 1012 Jones), and enhanced stability. This enhancement is mainly attributed to the inhibition of Sn2+ oxidation, the control of crystal growth, and the sufficient reaction between organic ammonium salts and bottom halides due to the AA-induced pore structure.

Ambient-atmosphere fabricated perovskite solar cells with formamidinium iodide passivation for enhanced light absorption

The exceptional photoelectric characteristics and high conversion efficiency have positioned metal halide perovskite as a significant breakthrough in recent thin-film photovoltaic technology. Despite these advantages, perovskite crystalline lattices often contain defects like interstitials, vacancies, and impurities at grain boundaries and surfaces, along with dangling bonds, contributing to the nonradiative recombination processes among photocarriers, which hamper device performance and stability. In this context, we present a simple method to mitigate electronic defects occurring at the interface between perovskite (Cs0.17FA0.83Pb(I0.83Br0.17)3 films and the hole transport layer by applying organic salt, namely formamidinium iodide (FAI), in an eco-friendly isopropanol (IPA) antisolvent to treat the perovskite surface. Incorporating FAI reduces grain boundaries, enhances carrier transportation, and boosts power conversion efficiency from 13.59 % to 15.10 % under 1 sun measurement with an active area of 0.09 cm2. Similarly, under 1000 lx illumination, efficiency improves from 26.70 % to 28.69 %, with enhanced stability. This study offers a cost-effective and low-temperature method via the utilization of carbon electrodes to fabricate highly efficient planar perovskite solar cells under an air atmosphere, showcasing the potential for stable and economically viable photovoltaic solutions.

Synthesis methods of 1,2,4-triazole-3-thiones: review

1,2,4-Triazole-containing compounds are unique heterocyclic compounds present in an array of pharmaceuticals and biologically important compounds used in drug-discovery studies against cancer cells, microbes, and various types of diseases in the human body. The aim of the study was to analyze in detail and combine the available literature materials to study the reactions associated with the formation of different classes of derivatives of 1,2,4-triazole-3-thione and to study their physical-chemical properties. Various innovative methods have been proposed and explored for synthesizing different classes of 1,2,4-triazole compounds, each with distinct applications and potential medicinal benefits. When analyzing the outcomes of studies aimed at obtaining new 1,2,4-triazole-3-thiones, it’s crucial to recognize the multiple stages involved in their synthesis. These stages typically include the esterification of carboxylic acids, hydrazinolysis, the formation of carbothioamides, and thiones through alkaline cyclization. Subsequently, reactions involving the S-function are conducted, leading to the formation of various classes of derivatives of 1,2,4-triazole. The study by a team of scientists introduced a novel method for synthesizing imidazolyl- and imidazole-1,2,4-triazoles, targeting the design of safer analgesic and anti-inflammatory agents. Moreover, researchers have successfully synthesized derivatives of 3-[2-(5-thio-4-aryl-4H-1,2,4-triazole-3-yl)ethyl]quinoxalin-2(1H)-one, N-(3-thio-5-aryl-[1,2,4]triazole-4-yl)acylamides, 5-alkylthio-4-amino-3-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-thiomethyl)-1,2,4-triazole and 3-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-thiomethyl)-6-aryl-5,6-dihydrogen-1,2,4-triazole-[3,4-b]-1,3,4-thiadiazole, 5,5’-(alkyldiyl-bis(sulfandiyl))bis(N-(arylidene)-3-thiophen-2-ylmethyl)-4H-1,2,4-triazole-4-amines, 3-(arylsulfonyl)-4-phenyl-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole, expanding the scope of 1,2,4-triazole-based, compounds with potential pharmacological activities. Furthermore, the synthesis of molecules containing two 1,2,4-triazole and two benzole rings has gained traction, offering new avenues for drug development. Mannich bases were synthesized from the corresponding thiones through a reaction with N-methylpiperazine or N-phenylpiperazine in dimethylformamide in the presence of formaldehyde. Additionally, the synthesis of salts derived from 1,2,4-triazole highlights its importance in pharmaceutical formulations, with studies focusing on both organic and inorganic salts for potential therapeutic applications. Conclusions. The analysis of the above-mentioned publications indicates that the search for new biologically active compounds among derivatives of 1,2,4-triazole-3-thiones is promising. Many 1,2,4-triazole-3-thiones exhibit a wide spectrum of biological activity with little toxicity.

Preparation, crystallographic feature, synthon investigation and Hirshfeld surface analysis of both 3D supramolecular anhydrous organic salts constructed by triphenylmethylamine, 3-nitrophthalic acid and 5-nitroisophthalic acid

Preparation, crystallographic feature, synthon investigation and Hirshfeld surface analysis of both 3D supramolecular anhydrous organic salts constructed by triphenylmethylamine, 3-nitrophthalic acid and 5-nitroisophthalic acid

The effectiveness of rehabilitation in vulvovaginal atrophy

Objective: to evaluate the effectiveness and safety of rehabilitation programmes in patients with vulvovaginal atrophy (VVA).Material and methods. The study involved 350 patients with VVA in surgical (n=140) and natural (n=140) menopause, the control group included 70 women without VVA. Patients with VVA were distributed into groups receiving complex “active” rehabilitation (surgical menopause: group 1A, natural menopause: group 2A) and “passive” rehabilitation (surgical menopause: group 1B, natural menopause: group 2B). Body mass index (BMI), vaginal pH, carbohydrate profile with calculation of insulin resistance index (HOMA-IR), inflammatory markers leptin, interleukin-6, tumour necrosis factor alpha, serum magnesium, and safety profile with evaluation of adverse events related to rehabilitation measures were assessed over 24 months.Results. BMI decreased significantly in groups 1A and 2A. Vaginal pH at 1-year follow-up decreased in groups 1A and 2A, but increased in groups 2A and 2B. BMI was higher than normal in all patients with VVA, as well as in the control group, demonstrating preobesity (groups 1A, 2A, control group) or first-degree obesity (initially in group 1B and throughout follow-up in group 2B). HOMA-IR initially reflected postoperative insulin resistance in groups 1A and 2A, but in those receiving complex “active” rehabilitation the dynamics of its reduction was the most pronounced. The concentration of inflammatory markers was initially increased compared to the control group and decreased over time in groups 1A and 1B, but only leptin levels reached the control group values by the end of the study. Serum concentration of magnesium levels was 0.71±0.12 mmol/l in group 1A, 0.71±0.10 mmol/l in group 2A, 0.76±0.08 mmol/l in group 1B, 0.72±0.17 mmol/l in group 2B (magnesium deficiency). When organic magnesium salts in combination with pyridoxine were supplemented in groups 1A and 1B, serum magnesium levels were restored to normal from the 3rd month of follow-up. No adverse events were registered.Conclusion. The personalised programme of complex “active” rehabilitation in patients with VVA is more effective than “passive” rehabilitation with comparable safety profile. Its implementation into routine practice will contribute to the improvement of the quality of health care for such patients.

A 3D ordered hierarchical crystalline porous organic salt for large-sized enzyme immobilization

Crystalline porous organic salts (CPOSs) are an emerging class of promising materials with intrinsic highly polar nanoconfined microporosity. However, their single microporous structure greatly hinders their development in the field of catalysis and adsorption. Constructing a hierarchical porous structure can effectively reduce the mass transport resistance, thus expanding the scope of their applications. Herein, we report the synthesis of a three-dimensional (3D) ordered macro-/microporous hierarchical CPOS (HCPOS-1) using a template-assisted approach for the first time. The as-synthesized HCPOS-1 prepared from a polystyrene colloidal crystal template showcases a 3D ordered macroporous structure while also preserving the microporous structure. The 3D ordered macroporous structure in such a hierarchical structure, together with its hydrophilic surface, endows HCPOS-1 with the ability to immobilize large-sized enzymes through physical adsorption under mild conditions. The resulting catalase/HCPOS-1 showcases a high enzyme immobilization capacity and avoids undesired conformational changes of enzymes during the immobilization process, thus exhibiting excellent catalytic activity for the decomposition of hydrogen peroxide.

Grouping of short alkyl-chain branched carboxylic acids for developmental toxicity

Read-across (RAx) and grouping of chemicals into categories are well-known concepts in toxicology. Recently, ECHA proposed a grouping approach for branched-chain carboxylic acids (BCAs) including more than 60 branched-chain saturated carboxylic acids for hazard identification. Grouping was based only on structural considerations. Due to developmental effects of two members, ECHA postulated that “all short carbon chain acids … are likely reproductive and developmental toxicants”. This work analyzes available data for BCAs. The number of compounds in the group can be significantly reduced by eliminating metal and organic salts of BCAs, compounds of unknown or variable composition, and complex reaction products or biological materials (UVCB compounds). For the resulting reduced number of compounds, grouping is supported by similar physicochemical data and expected similar biotransformation. However, analysis of adverse effects for compounds in the group and mechanistic information show that BCAs, as a class, do not cause developmental effects in rats. Rather, developmental toxicity is limited to selected BCAs with specific structures that share a common mode of action (histone deacetylase inhibition). Thus, the proposed grouping is unreasonably wide and the more detailed analyses show that structural similarity alone is not sufficient for grouping branched-chain carboxylic acids for developmental toxicity.

Macrocyclic thiol ligand additive engineering for stable and efficient perovskite solar cells

Perovskite solar cells have a rapid development speed and excellent prospects, but still face performance and stability problems for practical applications. Excessive Pb2+ defects often accompany the preparation of perovskite, which greatly affect the performance and stability of perovskite solar cells. Herein, a macrocyclic thiol ligand (DXPSH) is introduced as an additive for organic amine salt. It effectively reduces the defect density of perovskite, induces better crystal orientation of perovskite, and improves carrier lifetime. As a result, the optimized DXPSH-modified PSCs achieves a maximum power conversion efficiency of 24.03 % and good long-term stability in ambient air.

Machine learning-assisted chemical design of highly efficient deicers

The use of deicers in urban areas, on runways and aircrafts has raised concerns about their environmental impact. Understanding the ice-melting mechanism is crucial for developing environmentally friendly deicers, yet it remains challenging. This study employs machine learning to investigate the ice penetration capacity (IPC) of 21 salts and 16 organic solvents as deicers. Relationships between their IPC and various physical properties were analysed using extreme gradient boosting (XGBoost) and Shapley additive explanation (SHAP). Three key ice-melting mechanisms were identified: (1) freezing-point depression, (2) interactions between deicers and H2O molecules and (3) infiltration of ions into ice crystals. SHAP analysis revealed different ice-melting factors and mechanisms for salts and organic solvents, suggesting a potential advantage in combining the two. A mixture of propylene glycol (PG) and sodium formate demonstrated superior environmental impact and IPC. The PG and sodium formate mixture exhibited higher IPC when compared to six commercially available deicers, offering promise for sustainable deicing applications. This study provides valuable insights into the ice-melting process and proposes an effective, environmentally friendly deicer that combines the strengths of organic solvents and salts, paving the way for more sustainable practices in deicing.

Surface Passivation with Tailoring Organic Potassium Salt for Efficient FAPbI3 Perovskite Solar Cells and Modules

AbstractPassivating surface defects on perovskite films with tailored functional materials has emerged as one of the most effective strategies for achieving high‐performance perovskite solar cells (PSCs). Among existing material selections, potassium salts stand out for their effective passivation of defects surrounding perovskite grain boundaries. However, the widely used potassium salts are inorganic and only soluble in highly polar solvents, which limits their practical application for surface passivation. Herein, a novel organic potassium salt (KCFSO), with multiple organic functional groups and good solubility in low polar isopropanol, is reported to function as a post‐treatment agent for perovskite. Combined with experimental results and theoretical calculations, the formed multiple intermolecular interactions between KCFSO and perovskite are revealed to play a vital role in determining the defect passivation effect. Thus, the KCFSO‐modified film shows a more uniform surface potential distribution, dramatically decreased defect density, and improved charge transfer, leading to a champion power conversion efficiency (PCE) of 25.11%, and good stability for the derived PSCs. As a demonstration of scalability, the centimeter‐sized PSCs and 5 cm × 5 cm mini‐modules also demonstrate impressive PCEs of 24.17% and 20.18%, respectively. These findings provide insights into passivator design principles to achieve efficient and stable perovskite photovoltaics.

The Utilization of Chicken Egg White Waste-Modified Nanofiber Membrane for Anionic Dye Removal in Batch and Flow Systems: Comprehensive Investigations into Equilibrium, Kinetics, and Breakthrough Curve.

This study investigated the use of chicken egg white (CEW) waste immobilized on weak acidic nanofiber membranes for removing the anionic acid orange 7 (AO7) dye in batch and continuous flow modes. Different experiments were conducted to evaluate the effectiveness of CEW-modified nanofiber membranes for AO7 removal, focusing on CEW immobilization conditions, adsorption kinetics, and thermodynamics. The CEW-modified nanofiber membrane (namely NM-COOH-CEW) exhibited a maximum AO7 adsorption capacity of 589.11 mg/g within approximately 30 min. The Freundlich isotherm model best represented the equilibrium adsorption data, while the adsorption kinetics followed a pseudo-second-order rate model. Breakthrough curve analysis using the Thomas model and the bed depth service time (BDST) model showed that the BDST model accurately described the curve, with an error percentage under 5%. To investigate AO7 elution efficiency, different concentrations of organic solvents or salts were tested as eluents. The NM-COOH-CEW nanofiber membrane exhibited promising performance as an effective adsorbent for removing AO7 dye from contaminated water.

4F-Phenethylammonium chloride as a key component for interfacial engineering of wide-bandgap perovskite absorber

The development of high-efficiency and stabilized tandem solar cells and solar cells for indoor light harvesting relies heavily on the fabrication of wide-bandgap (WBG) perovskite solar cells (PSCs) that exhibit exceptional efficiency and stability. In this study, we introduce an effective method for enhancing the optoelectronic properties of a 1.74 eV WBG perovskite absorber by interfacial engineering. Specifically, we utilize 4F-Phenethylammonium Chloride (4F-PEACL) as a key component for the surface treatment of perovskite layer. The treatment of perovskite with 4F-PEACL alters the surface stoichiometry, promoting self-doping and surface passivation, reducing surface recombination, and improving the optoelectronic properties of perovskite. Consequently, PCSs with perovskite treated with 4F-PEACL exhibit a notable power conversion efficiency of 20.27 %. Furthermore, the devices subjected to 4F-PEACL treatment demonstrate enhanced stability compared to the control devices across a range of testing settings. The findings of our study indicate that the utilization of organic salt perovskite passivation holds great potential in the development of efficient and stable WBG PSCs.

Mapping Hydrogen Positions along the Proton Transfer Pathway in an Organic Crystal by Computational X-ray Spectra.

Understanding proton transfer (PT) dynamics in condensed phases is crucial in chemistry. We computed a 2D map of N 1s X-ray photoelectron/absorption spectroscopy (XPS/XAS) for an organic donor-acceptor salt crystal against two varying N-H distances to track proton motions. Our results provide a continuous spectroscopic mapping of O-H···N↔O-··· H+-N processes via hydrogen bonds at both nitrogens, demonstrating the sensitivity of N 1s transient XPS/XAS to hydrogen positions and PT. By reducing the O-H length at N1 by only 0.2 Å, we achieved excellent theory-experiment agreement in both XPS and XAS. Our study highlights the challenge in refining proton positions in experimental crystal structures by periodic geometry optimizations and proposes an alternative scaled snapshot protocol as a more effective approach. This work provides valuable insights into X-ray spectra for correlated PT dynamics in complex crystals, benefiting future experimental studies.

Residual Stress Mitigation in Perovskite Solar Cells via Butterfly-Inspired Hierarchical PbI2 Scaffold.

Residual stress in metal halide perovskite films intimately affects the photovoltaic figure of merit and longevity of perovskite solar cells. A delicate management of the crystallization kinetics is critical to the preparation of high-quality perovskite films. Only very limited methods, however, are available to regulate the residual stress of a perovskite film in a controllable manner, particularly for a perovskite film fabricated by a two-step method. Here, we demonstrate the construction of a hierarchical PbI2 scaffold inspired by Archaeoprepona demophon butterfly by combining an interlayer guided growth of porous structure and nanoimprinting. The hierarchically structured PbI2 that emulates the physical structure of the butterfly wing scale permits unimpeded permeation of organic amine salts and sufficient space for volume expansion during the crystallization process, accompanied by preferential perovskite growth of a defectless (001) crystal plane. The optimized perovskite film outperforms the control with reduced residual stress and defect density. Consequently, perovskite solar cells with a respectable power conversion efficiency reaching 23.4% (certified 23%) and an impressive open-circuit voltage of 1.184 V can be achieved. The target device can maintain 80% of initial efficiency after maximum power point tracking under illumination for 700 h. This work expands the range of engineering toward PbI2 by exploring a simultaneously tailored morphology and crystallinity and highlights the significance of a hierarchical PbI2 scaffold as an alternative choice to mitigate residual stress in a two-step processed perovskite active layer and boost the longevity of perovskite solar cells.

Depollution of Polymeric Leather Waste by Applying the Most Current Methods of Chromium Extraction.

The leather industry is one of the most polluting industries in the world due to the large amounts of waste following raw hide processing but also due to the high content of chemical substances present in leather waste. The main problem with chromium-tanned leather solid waste is related to the storage, due to the ability of chromium to leach into soil or water, and also owing to the high ability of trivalent chromium to oxidize to its toxic form, hexavalent chromium. The purpose of this article is to present the most current methods of chromium extraction from solid tanned leather waste in order to obtain non-polluting leather, which can constitute secondary raw material in new industrial processes. The extraction methods identified in the present study are based on acid/basic/enzymatic hydrolysis and substitution with the help of organic chelators (organic acids and organic acid salts). In addition, this study includes a comparative analysis of the advantages and disadvantages of each identified extraction method. At the same time, this study also presents alternative chromium extraction methods based on the combination of conventional extraction methods and ultrasound-assisted extraction.

Vapor Pressure and Enthalpy of Vaporization of Guanidinium Methanesulfonate as a Phase Change Material for Thermal Energy Storage.

This paper reports the vapor pressure and enthalpy of vaporization for a promising phase change material (PCM) guanidinium methanesulfonate ([Gdm][OMs]), which is a typical guanidinium organomonosulfonate that displays a lamellar crystalline architecture. [Gdm][OMs] was purified by recrystallization. The elemental analysis and infrared spectrum of [Gdm][OMs] confirmed the purity and composition. Differential scanning calorimetry (DSC) also confirmed its high purity and showed a sharp and symmetrical endothermic melting peak with a melting point (Tm) of 207.6 °C and a specific latent heat of fusion of 183.0 J g-1. Thermogravimetric analysis (TGA) reveals its thermal stability over a wide temperature range, and yet three thermal events at higher temperatures of 351 °C, 447 °C, and 649 °C were associated with vaporization or decomposition. The vapor pressure was measured using the isothermogravimetric method from 220 °C to 300 °C. The Antoine equation was used to describe the temperature dependence of its vapor pressure, and the substance-dependent Antoine constants were obtained by non-linear regression. The enthalpy of vaporization (ΔvapH) was derived from the linear regression of the slopes associated with the linear temperature dependence of the rate of weight loss per unit area of vaporization. Hence, the temperature dependence of vapor pressures ln Pvap (Pa) = 10.99 - 344.58/(T (K) - 493.64) over the temperature range from 493.15 K to 573.15 K and the enthalpy of vaporization ΔvapH = 157.10 ± 20.10 kJ mol-1 at the arithmetic mean temperature of 240 °C were obtained from isothermogravimetric measurements using the Antoine equation and the Clausius-Clapeyron equation, respectively. The flammability test indicates that [Gdm][OMs] is non-flammable. Hence, [Gdm][OMs] enjoys very low volatility, high enthalpy of vaporization, and non-flammability in addition to its known advantages. This work thus offers data support, methodologies, and insights for the application of [Gdm][OMs] and other organic salts as PCMs in thermal energy storage and beyond.

Hirshfeld surface analysis, experimental and theoretical evaluation of a new monohydrated organic salt of 2-amino-4‑hydroxy-6-methylpyrimidine (AHMP) and 4-acetamidobenzoic acid (AMBA) for nonlinear optical applications

The organic crystal (AHMP+.AMBA−) of the AHMP and AMBA organic compounds was successfully synthesized and grown by the slow evaporation solution process. The present work focuses on the crystal structure, Hirshfeld surface, spectroscopic and DFT analyses of the title salt. The crystal geometry of AHMP+.AMBA− monohydrated salt was characterized by the single-crystal XRD technique. The synthesized salt crystallizes in the triclinic crystal system and P-1 space group. The identification of the functional groups of the compound has been done by FTIR spectroscopy and DFT/B3LYP-D3/6–311++G(d,p) level of theory. Further, Hirshfeld surface mapping and its associated two-dimensional fingerprint plots predict that the O⋅⋅⋅H and H⋅⋅⋅H interactions are dominant for stabilizing the crystal structure. TG-DTA reveals the crystal is thermally stable up to 168 ºC. The optical studies have been performed by the time-dependent DFT (TD-DFT) and UV–Vis spectroscopic methods. Moreover, the Z-scan experiment has been done to obtain third-order NLO properties. Additionally, the HOMO-LUMO energy gap, MEP maps and theoretical NLO parameters have also been calculated.