Bond Formation Research Articles

Cellulose acetate-decorated and siloxane-modified hydrophobic melamine foam with excellent selectivity and durability for efficient oil/water separation

The construction of hydrophobic porous adsorption materials, which are cost-effective, green, stable, and efficient, are urgently demanded for the large-scale and effective oily wastewater treatment. Herein, a facile and low-cost two-step fabrication strategy of hydrophobic melamine foam (MF) was demonstrated, including cellulose acetate (CA) decoration and siloxane modification. Cellulose acetate initially assembled on the skeleton of MF with the aid of hydrogen bond formation between the hydroxyl groups of CA and imimo groups of MF. At an optimal concentration of CA, the as-prepared composite foam (CA/MF) exhibited good hydrophobicity. To further improve the oil/water selectivity, the above foam was enhanced by chemical vapor deposition (CVD) of methyltrimethoxysilane (MTMS). The successful silicification reaction between CA/MF and MTMS decreased the surface energy and improved the surface topological structure, leading to excellent hydrophobicity (water contact angle of 147.4°) and superoliophilicty. Such hydrophobized cellulose acetate/melamine foam (H-CA/MF) presented low density, favorable porosity (97.78%), and distinguished pore volume (88.66 mL/g), leading to a high oil adsorption capacity of up to 56.6 g/g. Due to the excellent mechanical elasticity of H-CA/MF, the oil absorption and recovery can be achieved easily by a simple manual adsorption-squeezing method and lab-made pump-assisted separation device with satisfactory recyclability. Moreover, H-CA/MF displayed marvelous stability and environmental adaptability in different harsh environment, further enlarging its practical application scenarios. Along with the green and cost-effective preparation process, the present study provides a facile strategy to fabricate hydrophobized melamine-based foam, which is of great significance for scalable and efficient oil/water separation.

Quantification of Interfacial Voids Using Positron Annihilation Spectroscopy for Mechanism Study on SiCN Bonding and SiN Bonding

Abstract Hybrid bonding for 3D integration requires reliable direct bonding interface of dielectrics. Lately, the spotlight has focused on SiCN/SiCN bonding considering its superior bonding performance by the dangling bonds-facilitated nanovoid closure mechanisms, but it is reported to be sensitive to reactive species especially under the high temperatures. Recent work proposed SiN/SiO2 asymmetric bonding showing a void-free bonding interface and bond energy higher than 2.5 J/m2 as a promising candidate for direct bonding applications. Interestingly, we observed opposite bonding behaviors between SiCN and SiN in corresponding symmetric bonding pair and asymmetric bonding pair (with SiO2). Thus, a comprehensive fundamental understanding on the bonding of different dielectrics is needed to guide the specifications of the bonding layer for enabling a void-free and highly reliable bonding interface. In this study, we systematically quantified the nanovoids in the bonding interface of SiCN/SiCN, SiCN/SiO2, and SiN/SiO2 through positron annihilation spectroscopy and simulation, dangling bond formation by electron spin resonance, and the film passivation property by quasi-steady-state photoconductance. By correlating the film properties and bonding performance, the model of SiCN bonding is extended towards its SiCN/SiO2 asymmetric bonding, and a new model of the nanovoid closure mechanism in SiN bonding is first-time proposed.

Monitoring Glutathione Content of the Endoplasmic Reticulum under Scrap Leather-Induced Endoplasmic Reticulum Stress via an Endoplasmic Reticulum-Targeted Two-Photon Fluorescent Probe.

Maintaining tissue homeostasis necessitates the coordinated efforts of various cell types to regulate inflammation. Endoplasmic reticulum (ER) stress, a hallmark of inflammation, exacerbates tissue pathology in various human diseases. Glutathione (GSH), a pivotal regulator of cellular redox balance, controls disulfide bond formation in the ER, thereby shielding cells from oxidative stress. In this study, we developed a two-photon fluorescent probe, ER-GSH, with specific ER targeting and demonstrated its high sensitivity and rapid response to GSH. Experiments conducted on BV2 cells and a mice model of neuroinflammation induced by scrap leather revealed that inflammatory reactions led to ER stress and a substantial reduction in GSH levels. Notably, the anti-inflammatory drug NS-398 effectively inhibited cell inflammation and ER stress by maintaining GSH levels. These findings underscore the potential therapeutic significance of modulating GSH levels to alleviate the impact of neuroinflammation.

Programmable Plasma-Microdroplet Cascade Reactions for Multicomponent Systems.

The concept of programmable cascade reactions in charged microdroplets is introduced using carbon-carbon (C-C) bond formation via uncatalyzed Michael addition in a three-tier study culminating in programmable Hantzsch multicomponent, multistep reactions. In situ generated reactive oxygen species (ROS) from nonthermal plasma discharge are fused with charged water microdroplets (devoid of ROS) in real time for accelerated chemical reactions. This plasma-microdroplet fusion platform utilizing a coaxial spray configuration enabled product selection while avoiding unwanted side reactions. Hydrogen abstraction via ROS facilitated the formation of enolate anions without strong base use. Reaction enhancement factors >103 were calculated for plasma-microdroplet fusion versus microdroplet-only reactions. The platform programmability was showcased through (i) uncatalyzed 1,4-Michael addition of α,β-unsaturated carbonyls, (ii) novel C-C bond formation via the use of pro-electrophilic amine and alcohol substrates─activated through collisions in the microdroplet environment to serve as Michael acceptors, and (iii) selective Hantzsch cascade reaction with cross-coupling products, avoiding side reactions including N-alkylation and self-coupling product formation. Milligram quantity product collection is achieved, showcasing plasma-microdroplet fusion as an effective tool for preparative-scale synthesis. Thus, the controlled generation of ROS via plasma discharge during charged water microdroplet evolution establishes a green synthetic method for uncatalyzed C-C bond formation.

Hybrid Metal Catalysts as Valuable Tools in Organic Synthesis: An Overview of the Recent Advances in Asymmetric C─C Bond Formation Reactions.

Carbon-carbon bond formation represents a key reaction in organic synthesis, resulting in paramount importance for constructing the carbon backbone of organic molecules. However, traditional metal-based catalysis, despite its advantages, often struggles with issues related to efficiency, selectivity, and sustainability. On the other hand, while biocatalysis offers superior selectivity due to an extraordinary recognition process of the substrate, the scope of its applicable reactions remains somewhat limited. In this context, Artificial Metalloenzymes (ArMs) and Metallo Peptides (MPs) offer a promising and not fully explored solution, merging the two fields of transition metal catalysis and biotransformations, by inserting a catalytically active metal cofactor into a customizable protein scaffold or coordinating the metal ion directly to a short and tunable amino acid (Aa) sequence, respectively. As a result, these hybrid catalysts have gained attention as valuable tools for challenging catalytic transformations, providing systems with new-to-nature properties in organic synthesis. This review offers an overview of recent advances in the development of ArMs and MPs, focusing on their application in the asymmetric carbon-carbon bond-forming reactions, such as carbene insertion, Michael additions, Friedel-Crafts and cross-coupling reactions, and cyclopropanation, underscoring the versatility of these systems in synthesizing biologically relevant compounds.

Programmable and flexible wood-based origami electronics

Natural polymer substrates are gaining attention as substitutes for plastic substrates in electronics, aiming to combine high performance, intricate shape deformation, and environmental sustainability. Herein, natural wood veneer is converted into a transparent wood film (TWF) substrate. The combination of 3D printing and origami technique is established to create programmable wood-based origami electronics, which exhibit superior flexibility with high tensile strength (393 MPa) due to the highly aligned cellulose fibers and the formation of numerous intermolecular hydrogen bonds between them. Moreover, the flexible TWF electronics exhibit editable multiplexed configurations and maintain stable conductivity. This is attributed to the strong adhesion between the cellulose-based ink and TWF substrate by non-covalent bonds. Benefiting from its anisotropic structure, the programmability of TWF electronics is achieved through sequentially folding into predesigned shapes. This design not only promotes environmental sustainability but also introduces its customizable shapes with potential applications in sensors, microfluidics, and wearable electronics.

Adsorption of thiotepa on B12N12, Mg12O12, and Si12C12 fullerene-like cages: A DFT study

We examined the adsorption of thiotepa (TTP) on the outer surface of B12N12, Mg12O12, and Si12C12 fullerene-like cages using density functional theory (DFT) calculations. The computations were carried out at the Perdew-Burke-Ernzerhof level with the D3 dispersion correction (PBE-D3) in a water solvent. The adsorption mechanism of TTP through N-head and S-head on the external surface of Si12C12 involves a covalent interaction (binding energy ∼ −1.31 eV) with the carrier surface. In contrast, the adsorption of the TTP molecule through N-head and S-head on the outer surfaces of B12N12 (binding energy ∼ −0.75 eV) and Mg12O12 (binding energy ∼ −0.62 eV) fullerene-like cages is driven by electrostatic interactions. Therefore, due to their low values of recovery time, both B12N12 and Mg12O12 fullerene-like cages can serve as carriers for TTP in the treatment of cancer. Thermodynamic parameters (Gibbs free energy and enthalpy energy) demonstrate that these interactions are exothermic and spontaneous. The results further reveal the significant disparity in the calculated HOMO and LUMO energies at the computational level. The formation of intricate bonds between the drug and the fullerene-like cages is attributed to the charge transfer dynamics that occur during their interactions. Through computational analysis and examination of the total density of state (TDOS) plots, it is evident that B12N12 and Si12C12 fullerene-like cages exhibit a high degree of sensitivity to the TTP drug. The adsorption process can increase the electrical conductivity of B12N12 and Si12C12, while having minimal effect on Mg12O12. This suggests that B12N12 could potentially serve as a suitable biosensor for detecting TTP.

Long-term cooperative relationships among vampire bats are not strongly predicted by their initial interactions.

In many group-living animals, survival and reproductive success depend on the formation of long-term social bonds, yet it remains largely unclear why particular pairs of groupmates form social bonds and not others. Can social bond formation be reliably predicted from each individual's immediately observable traits and behaviors at first encounter? Or is social bond formation hard to predict due to the impacts of shifting social preferences on social network dynamics? To begin to address these questions, we asked how well long-term cooperative relationships among vampire bats were predicted by how they interacted during their first encounter as introduced strangers. In Study 1, we found that the first 6h of observed interactions among unfamiliar bats co-housed in small cages did not clearly predict the formation of allogrooming or food-sharing relationships over the next 10 months. In Study 2, we found that biologger-tracked first contacts during the first 4-24h together in a flight cage did not strongly predict allogrooming rates over the next 4 months. These results corroborate past evidence that social bonding in vampire bats is not reducible to the individual traits or behaviors observed at first encounter. Put simply, first impressions are overshadowed by future social interactions.

Mechanism of microwave-assisted coal desulfurization with urea peroxide

To effectively remove organic sulfur from coal for higher resource efficiency, an innovative microwave-assisted urea peroxide for desulfurization system was designed. The experimental group with different microwave frequencies and the conventional pyrolysis control group were set up to prove the desulfurization effect of microwave in coordination with urea peroxide. The experimental results showed that under 1000 W microwave irradiation and the promotion of urea peroxide, the desulfurization efficiency can reach 67.29 %, with an increase of 38.32 % while the conventional pyrolysis is only 28.97 %. According to the Fourier transform infrared (FTIR) analysis, the effectiveness of microwave coordination with urea peroxide for desulfurization is explained from macroscopic point of view. Benzylidene thiol, dibenzyl sulfide, and dibenzyl disulfide were selected as model compounds for the quantum chemical calculation. The simulation results demonstrated that the changes in the pathway energy barriers for desulfurization align with the experimental material transformations, confirming the accuracy of the simulation. The sulfur-containing bonds of mercaptans will be destroyed to form hydrogen sulfide, and the undestroyed bonds will remain in the organic matter. After being oxidized, the sulfur-containing bond will break to form a water-soluble sulfonic acid free radical. The unoxidized sulfur bonds of thioethers will be destroyed to generate unstable phenyl free radicals and free sulfur radicals. To achieve stability, phenyl free radicals can pair to form diphenylethane or combine with other radicals (such as •H). In contrast, sulfur free radicals can only react with hydrogen radicals to form hydrogen sulfide. However, the limited availability of hydrogen radicals in the system restricts the desulfurization efficiency. After oxidation by urea peroxide, the thioethers will form sulfones. The sulfur-containing bonds will be fractured and directly generate phenyl and sulfur dioxide, which reduces the dependence on hydrogen free radicals. The three-dimensional desulfurization path of microwave collaboration with urea peroxide experiment was simulated and converted to the analytical bond breaking and formation mechanism. This study proved that microwave synergizes with urea peroxide can intensify the desulfurization process. It provides a high-efficiency method for the clean and green utilization of coal, which is conducive to supporting environmentally sustainable development.

Synthesis of Diketopyrrolopyrrole Based Photoactive Materials via Photoredox C−H Activation

AbstractThe synthesis of diketopyrrolopyrrole (DPP) derivatives followed the well‐known conventional cross‐coupling methods such as Suzuki, Stille, Sonogashira, and Negishi cross‐coupling reactions. However, these methods required unfavorable reaction conditions, organometallic precursors, and high temperatures. In addition, the synthesis of conventional cross‐coupling partners including organoboranes, stannane, and acetylenes required drastic reaction conditions and strong bases. In this work, a wide variety of thiophene‐diketopyrrolopyrrole (TDPP)‐based semiconducting materials (36 compounds) were synthesized via Pd‐catalysed photoredox methodology by using N‐hydroxyphthalimide (NHP) based coupling partners, which can be readily prepared from N‐hydroxyphthalimide and carboxylic acid or aldehyde derivatives via single step C−O bond formation reactions with good yield (80–90 %). This methodology minimizes additional synthetic steps, harsh reaction conditions, and high temperature (100–150 °C). Optoelectronic studies suggest that the synthesized materials have suitable band gap, HOMO and LUMO levels for variety of optoelectronic applications. To the best of our knowledge, this is the first report on the synthesis of TDPP‐based π‐conjugated materials via the photoredox method.

Heterogeneous visible-light photoredox catalysis with NiCl2@g-C3N4 for induced C(sp2)-H/N[sbnd]H cross-dehydrogenative coupling

A novel photoactive NiCl2@g-C3N4 catalyst system, which effectively drives C(sp2)-H/NH bond formation between quinolin-2(1H)-ones, primary and secondary aliphatic amines under blue light irradiation. The NiCl2@g-C3N4 composite with a NiCl2 loading of 0.7wt% had the highest photoactivity, and the calculated band gap energy value is 2.56 eV The nickel ion could act as an electron acceptor enhancing carrier separation and transfer efficiency, greatly enhanced the photoreaction efficiency of g-C3N4. Preliminary mechanistic studies indicate upon visible light irradiation, the photo-generated electrons and holes act as oxidants, thereby generating amine radicals in the absence of external chemical oxidants. This provides a straightforward and efficient approach for directly 3-aminating quinoxalines-2(1H)-ones. Moreover, the heterogeneous catalyst can be recycled at least six times without significant activity loss.

Programmable C-N Bond Formation through Radical-Mediated Chemistry in Plasma-Microdroplet Fusion.

Non-thermal plasma discharge produced in the wake of charged microdroplets is found to facilitate catalyst-free radical mediated hydrazine cross-coupling reactions without the use of external light source, heat, precious metal complex, or trapping agents. A plasma-microdroplet fusion platform is utilized for introduction of hydrazine reagent that undergoes homolytic cleavage forming radical intermediate species. The non-thermal plasma discharge that causes the cleavage originates from a chemically etched silica capillary. The coupling of the radical intermediates gives various products. Plasma-microdroplet fusion occurs online in a programmable reaction platform allowing direct process optimization and product validation via mass spectrometry. The platform is applied herein with a variety of hydrazine substrates, enabling i) self-coupling to form secondary amines with identical N-substitutions, ii) cross-coupling to afford secondary amine with different N-substituents, iii) cross-coupling followed by in-situ dehydrogenation to give the corresponding aryl-aldimines with two unique N-substitutions, and iv) cascade heterocyclic carbazole derivatives formation. These unique reactions were made possible in the charged microdroplet environment through our ability to program conditions such as reagent concentration (i.e., flowrate), microdroplet reactivity (i.e., presence or absence of plasma), and reaction timescale (i.e., operational mode source). The selected program is implemented in a co-axial spray format.

Facile and Metal‐Free Synthesis of Isoflavones Using α‐Aryl‐β,β‐Ditosyloxy Ketones

AbstractConsidering the drawbacks associated with available synthetic methodologies of isoflavones, herein we have reported a metal‐free and eco‐friendly approach to these natural products. In the present study, we have carried out the synthesis of eight isoflavone derivatives 7a–7h using α‐aryl‐β,β‐ditosyloxy ketone protocol. Initially, we have protected the 2’‐hydroxy group of respective chalcone moiety in order to remove its interference under reaction conditions. The protected chalcones were then subjected to 1,2‐aryl migration by being treated with hydroxy(tosyloxy)iodobenzene (HTIB) reagent in a non‐nucleophilic solvent (CH2Cl2). This migration furnished the formation of α‐aryl‐β,β‐ditosyloxy ketones via C−C bond formation from their corresponding chalcones in moderate to good yields (55–82 %). The ambiguity regarding the exact molecular structure of the α‐aryl‐β,β‐ditosyloxy ketones was examined through the single crystal X‐ray diffraction data. At last, the synthesis of isoflavones was carried out in moderate to good yields (50–80 %) by performing the reaction of α‐aryl‐β,β‐ditosyloxy ketones with sodium hydroxide in aqueous methanol.

Photo‐Induced Sulfonylation/Trifluoromethylation‐Peroxidation of Alkenes via EnT‐Mediated N−S Bond Homolysis of N‐Sulfonyl Ketimines

AbstractPhotocatalytic sulfonylation/trifluoromethylation‐peroxidation of alkenes with N‐sulfonyl ketimines and tert‐butyl hydroperoxide is reported. The transformation is initiated by the EnT‐driven homolytic S−N bond cleavage of N‐sulfonyl ketimines. The sulfonyl‐peroxides were obtained when alkyl sulfonyl radicals were captured by alkene via sequential C−S and C−O bond formation, while a thermodynamically favored release of SO2 from trifluoromethane sulfonyl radical generated CF3 radical and afforded the trifluoromethyl‐peroxides.

Oriented Synthesis of Glycine from CO2, N2, and H2O via a Cascade Process

AbstractAir contains carbon, hydrogen, oxygen, and nitrogen elements that are essential for the constitution of amino acids. Converting the air into amino acids, powered with renewable electricity, provides a green and sustainable alternative to petrochemical‐based methods that produce waste and pollution. Here, taking glycine as an example, we demonstrated the complete production chain for electrorefining amino acids directly from CO2, N2, and H2O. Such a prospective Scheme was composed of three modules, linked by a spontaneous C−N bond formation process. The high‐purity bridging intermediates, separated from the stepwise synthesis, boosted both the carbon selectivity from CO2 to glycine of 91.7 % and nitrogen selectivity from N2 to glycine of 98.7 %. Under the optimum condition, we obtained glycine with a partial current density of 160.8 mA cm−2. The high‐purity solid glycine product was acquired with a separation efficiency of 98.4 %. This work unveils a green and sustainable method for the abiotic creation of amino acids from the air components.

Analysis of Energy Flow to the Interface Microstructure and Its Effect on Weld Strength in Ultrasonic Additive Manufacturing

Ultrasonic additive manufacturing (UAM) is a process used for the three-dimensional printing of metal foil stock that can produce near-net-shaped metallic parts. This work details the development of an energy-based tool to identify the relationships between input energy, energy stored in the interface microstructure, and the strength of the weld interface in UAM. The stored energy in the grain boundaries of the crystallized grains in the interface microstructure are estimated using the Read–Shockley relationship. The energy stored in the interface is found to be positively correlated with the resulting weld strength. An energy flow diagram is developed to map the flow of energy from the welder to the workpiece and quantify the key participating energies such as the energy of plastic deformation, energy stored in the interface microstructure, energy required for asperity collapse, and heat generation. A better understanding of the flow of energy in UAM can assist in optimizing the process to maximize the portion of energy input by the welder that is used for bond formation.

Crystal structure, Chemical Bonding, and Magnetism of α-Fe6Ga5: How Local Interactions Shape the Structure and Properties of Intermetallic Compounds.

α-Fe6Ga5 was synthesized from the elements as a polycrystalline powder. Its crystal structure was redetermined by high-resolution powder X-ray diffraction, which showed a complex monoclinic structure of the Fe6Ge5 type. The determined lattice parameters (a = 10.08380(6) Å, b = 7.97071(5) Å, c = 7.70489(5) Å, and β = 108.3062(2)°) differ notably from the previous reports. Despite possessing the same structure type as Fe6Ge5, α-Fe6Ga5 displays several distinctive features, such as short Ga-Ga bonds and distorted Fe layers. According to magnetization measurements, α-Fe6Ga5 is a soft ferromagnet with a high Curie temperature of 760 K, which is in stark contrast to the antiferromagnetic behavior of Fe6Ge5 reported in the literature. The electronic structure of α-Fe6Ga5 was studied theoretically using density functional theory-calculations, which showed the pronouncedly covalent character of the short Fe-Ga and Ga-Ga bonds. Similar calculations were performed for Fe6Ge5, which revealed stronger Fe-Ge interactions, which preclude the formation of short Ge-Ge bonds. In both cases, the theoretical calculations showed ferromagnetic instability, which leads to ferromagnetic ordering only in the case of α-Fe6Ga5, likely due to the different nature of Fe-Ga-Fe and Fe-Ge-Fe superexchange interactions.

Selective C-N Bond Cleavage in Unstrained Pyrrolidines Enabled by Lewis Acid and Photoredox Catalysis.

Cleavage of inert C-N bonds in unstrained azacycles such as pyrrolidine remains a formidable challenge in synthetic chemistry. To address this, we introduce an effective strategy for the reductive cleavage of the C-N bond in N-benzoyl pyrrolidine, leveraging a combination of Lewis acid and photoredox catalysis. This method involves single-electron transfer to the amide, followed by site-selective cleavage at the C2-N bond. Cyclic voltammetry and NMR studies demonstrated that the Lewis acid is crucial for promoting the single-electron transfer from the photoredox catalyst to the amide carbonyl group. This protocol is widely applicable to various pyrrolidine-containing molecules and enables inert C-N bond cleavage including C-C bond formation via intermolecular radical addition. Furthermore, the current protocol successfully converts pyrrolidines to aziridines, γ-lactones, and tetrahydrofurans, showcasing its potential of the inert C-N bond cleavage for expanding synthetic strategies.

Kinetics and Mechanism Study of Different Types of Surface‐Imprinted Polymers for CO2 Adsorption

ABSTRACTThe increased level of CO2 in the atmosphere has led to global warming and climate change. To mitigate these problems, solid adsorbents have become attractive materials for capturing excess CO2 in the post‐combustion method. Molecularly imprinted polymer (MIP) can be applied to prepare highly selective adsorbents that could capture CO2 molecules. The MIP was prepared using the surface imprinted polymer technique in this preliminary work. Only two types of support materials were used (graphite and silica gel) to screen the best support material that could enhance the CO2 adsorption capacity of the resulting adsorbent, which was analyzed using a fixed‐bed column reactor. Graphite‐imprinted polymer (GMIP) was found to be a good potential for CO2 adsorption. The Avrami model best described the adsorption system, while the fixed‐bed curve data fit the Yoon–Nelson model well. The semi‐empirical method was used to assess the interaction mechanism of the molecularly imprinted polymer with CO2 during adsorption. This investigation involved testing four different ratios of the template complex to functional monomers. The ratio of 1:4 (CO2:Allylthiourea) demonstrated the highest binding energy, with a higher formation of hydrogen bonds. Film diffusion and intraparticle diffusion were the main rate‐limiting steps that played vital roles at different stages of CO2 adsorption. This preliminary work has enhanced the development of MIP for CO2 adsorption and showcased the integration of computational approaches in tailoring specific MIPs.

Synthetic Control of Water-Stable Hybrid Perovskitoid Semiconductors.

Hybrid metal-halide perovskites and their derived materials have emerged as the next-generation semiconductors with a wide range of applications, including photovoltaics, light-emitting devices, and other optoelectronics. Over the past decade, numerous single-crystalline perovskite derivatives have been synthesized and developed. However, the synthetic methods for these derivatives mainly rely on acidic crystallization conditions. This approach leads to crystals comprising metal halide building blocks, which show problematic stability when directly exposed to water. In this study, a methodology is developed for synthesizing hybrid metal-halide compounds using lead iodide and the zwitterionic bifunctional molecule cysteamine (CYS), to form various perovskitoid structures under a broad pH range. Interestingly, the different pH conditions alter the coordination environment of lead halides, leading to lead-sulfide and lead-nitride covalent bond formation. This modification significantly enhances their stability when in direct contact with water, lasting for months. Photoluminescence measurements and first principal density functional theory (DFT) calculations reveal that the perovskitoids synthesized under basic and acidic pH conditions exhibit a direct bandgap nature, while those synthesized under neutral conditions display an indirect bandgap. This approach opens new avenues for manipulating synthetic methods to develop water-stable hybrid semiconductors suitable for a wide range of applications, such as solid-state light emitters.