Structure-stability Relationship Research Articles

Stabilization mechanism of arsenic-sulfide slag by density functional theory calculation of arsenic-sulfide clusters

Stabilization of arsenic sulfur slag (As‒S slag) is of high importance to prevent the release of deadly As pollutants into environment. However, the molecular understanding on the stability of As‒S slag is missing, which in turn restricts the development of robust approach to solve the challenge. In this work, we investigated the structure-stability relationship of As‒S slag with adopting various As‒S clusters as prototypes by density functional theory (DFT). Results showed that the configuration of S multimers-covering-(As2S3)n is the most stable structure amongst the candidates by the analysis of energies and bonding characteristics. The high stability is explained by orbital composition that the 4p-orbital (As) binding with 3p-orbital (S) decreases energy level of highest occupied molecular orbital (HOMO). Inspired from the calculations, an excess-S-based hydrothermal method was successfully proposed and achieved to promote the stabilization of As‒S slag. Typically, the As concentration from the leaching test of stabilized As‒S slag is only 0.8 mg/L, which is much lower than the value from other stabilized slag.

Explainable machine learning for materials discovery: predicting the potentially formable Nd-Fe-B crystal structures and extracting the structure-stability relationship.

New Nd-Fe-B crystal structures can be formed via the elemental substitution of LA-T-X host structures, including lanthanides (LA), transition metals (T) and light elements, X = B, C, N and O. The 5967 samples of ternary LA-T-X materials that are collected are then used as the host structures. For each host crystal structure, a substituted crystal structure is created by substituting all lanthanide sites with Nd, all transition metal sites with Fe and all light-element sites with B. High-throughput first-principles calculations are applied to evaluate the phase stability of the newly created crystal structures, and 20 of them are found to be potentially formable. A data-driven approach based on supervised and unsupervised learning techniques is applied to estimate the stability and analyze the structure-stability relationship of the newly created Nd-Fe-B crystal structures. For predicting the stability for the newly created Nd-Fe-B structures, three supervised learning models: kernel ridge regression, logistic classification and decision tree model, are learned from the LA-T-X host crystal structures; the models achieved maximum accuracy and recall scores of 70.4 and 68.7%, respectively. On the other hand, our proposed unsupervised learning model based on the integration of descriptor-relevance analysis and a Gaussian mixture model achieved an accuracy and recall score of 72.9 and 82.1%, respectively, which are significantly better than those of the supervised models. While capturing and interpreting the structure-stability relationship of the Nd-Fe-B crystal structures, the unsupervised learning model indicates that the average atomic coordination number and coordination number of the Fe sites are the most important factors in determining the phase stability of the new substituted Nd-Fe-B crystal structures.

Boron cage effects on Nd–Fe–B crystal structure’s stability

In this study, we investigate the structure-stability relationship of hypothetical Nd-Fe-B crystal structures using descriptor-relevance analysis and the t-SNE dimensionality reduction method. 149 hypothetical Nd-Fe-B crystal structures are generated from 5967 LA-T-X host structures in the Open Quantum Materials Database by using the elemental substitution method, with LA denoting lanthanides, T denoting transition metals, and X denoting light elements such as B, C, N, and O. By borrowing the skeletal structure of each of the host materials, a hypothetical crystal structure is created by substituting all lanthanide sites with Nd, all transition metal sites with Fe, and all light element sites with B. High-throughput first-principle calculations are applied to evaluate the phase stability of these structures. Twenty of them are found to be potentially formable. As the first investigative result, the descriptor-relevance analysis on the orbital field matrix (OFM) materials' descriptor reveals the average atomic coordination number as the essential factor in determining the structure stability of these substituted Nd-Fe-B crystal structures. 19 among 20 hypothetical structures that are found potentially formable have an average coordination number larger than 6.5. By applying the t-SNE dimensionality reduction method, all the local structures represented by the OFM descriptors are integrated into a visible space to study the detailed correlation between their characteristics and the stability of the crystal structure to which they belong. We discover that unstable substituted structures frequently carry Nd and Fe local structures with two prominent points: low average coordination numbers and fully occupied B neighboring atoms. Moreover, there are only three popular forms of B local structures appearing on all potentially formable substituted structures: cage networks, planar networks, and interstitial sites. The discovered relationships are promising to speed up the screening process for the new formable crystal structures.

Comparison of the Thermal Stabilities of Diazonium Salts and Their Corresponding Triazenes

A range of diazonium salts and their corresponding triazenes have been prepared in order to directly compare their relative thermal stabilities (via initial decomposition temperature) from differential scanning calorimetry (DSC) data. A structure–stability relationship has been explored to investigate trends in stability, depending on the aromatic substituent and the structure of the secondary amine component of the diazonium salts and triazenes. All of the triazenes investigated show significantly greater stability (many are stable above 200 °C) compared with the corresponding diazonium salts, which show varying stabilities.

No such thing as a free lunch: interaction costs and the structure and stability of mutualistic networks

Different modelling approaches have been used to relate the structure of mutualistic interactions with the stability of communities. However, inconsistencies arise when we compare modelling outcomes with the patterns of interactions observed in empirical studies. To shed light on these inconsistencies, we explored the network structure–stability relationship by incorporating the cost of mutualistic interactions, a long ignored feature of mutualisms, into population dynamics models. We assessed the changes in the relationship between network structure (species richness, connectance, modularity) and community stability (species persistence, resilience), and between network structure and community structural attributes (average abundance), using models with increasing levels of cost for mutualistic communities. We found that adding the potential cost of mutualistic interactions affected the strength of the network structure–stability relationship. Our results revive the question of whether the structure of mutualistic networks determines community stability.

Recent Progress of Atmospheric Water Harvesting Using Metal-Organic Frameworks

Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas. To efficiently harvest vapor from the air, sorbents are required to have considerable adsorption capacity, easy regeneration and high stability. With the advantages of porous structure, tunable pore size and tailorable hydrophilicity, metal-organic frameworks (MOFs) have demonstrated excellent performance in vapor adsorption and water generation. In this review, we first discuss the degradation mechanisms of MOFs exposed to water and summarize the structure-stability relationship; by centering on the adsorption isotherms, the connection between the structure of MOFs and the water adsorption property is illuminated; finally, some prospects are suggested in order to push forward the progress of this technology.

Experimental confounding factors affecting stability, transport and metabolism of flavanols and hydroxycinnamic acids in Caco-2 cells.

Studying bioavailability of polyphenols is essential to understand the health effects of these compounds. Human epithelial cells are commonly used in intestinal absorption and transport experiments but the changes polyphenols undergo during incubation, due to their chemical instability under the cell culture conditions, are scarcely known and might lead to inaccurate conclusions. Based on abundance of flavanols and hydroxycinnamic acids in the diet, epicatechin, epicatechin-3-gallate and procyanidin B2 as flavanols along with 5-caffeoylquinic and 3,5-dicaffeoylquinic acids as hydroxycinnamic acids were selected to comparatively evaluate their absorption and metabolism using an in vitro Caco-2 cell model. Special emphasis was paid to the structure-stability relationship of these phenolic compounds in Dulbecco's Modified Eagle's Medium (DMEM) under the cell culture conditions. The tested compounds were scarcely absorbed and minimally metabolized by the intestinal epithelium cells. The cell transport study showed prevalent efflux for flavanols opposite to absorption for hydroxycinnamates. Intestinal metabolism revealed that hydroxycinnamates were preferentially hydrolyzed and subsequently methylated, whereas hydrolysis of flavanols could not be confirmed, being mostly conjugated to sulfate, methyl- and methyl-sulfate derivatives. It is noteworthy that methyl derivatives of procyanidin-B2 were detected inside Caco-2 cells, confirming its absorption. In addition, culture medium influenced phenol isomerization to a higher extent than cells. In conclusion, hydroxycinnamates were better absorbed than flavanols although their bioavailability was limited in this intestinal cell model.

Structural properties and isomerisation of simple S-nitrosothiols: ab initio studies with a simplified treatment of correlation effects

Despite the enormous biological significance, the structure-stability relationship in S-Nitrosothiols (RSNOs) that govern their activity in vivo is not well understood. We provide useful structural properties (bond length, vibrational frequency, dissociation energy, and interconversion barrier) of the -SNO group in RSNOs ( and ) using the recently suggested computationally cost-ffective multireference ab initio method which includes electron correlation effects by means of the perturbation theory using a multiconfigurational zero-order wave function. A sizable rotation barrier of cis-trans RSNO interconversion imply a partial S-N double-bond like nature. The low stretching frequency, elongated length, and small dissociation energy indicate that this bond is relatively weak and labile. Although the study of S– bond in RSNOs is a challenging case even for the current generation computational approaches, IVO-SSMRPT method (having several appealing features) employed here is competent to reproduce the structure and stability of RSNO isomers in close agreement with the reference high-level estimates.

Building nanoparticle-stacking MoO2-CDs via in-situ carbon dots reduction as high-performance anode material for lithium ion and sodium ion batteries

In this work, we report a new type anode material, MoO2 combined carbon dots (CDs) with nanoparticle-stacking structure via a facile hydrothermal route. Herein, CDs is introduced as the reductant which in-situ reduces MoVI to MoIV. It is further confirmed that the particles of MoO2 with evenly distributed beset of carbon dots form a nanoparticle-stacking structure. Thanks to this specific structure, the as-made MoO2-CDs manifest high performance in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The capacities maintain 854 and 236 mAh g−1 at 0.50 A g−1 after 300 cycles for LIBs and 600 cycles for SIBs, respectively. Furthermore, we explored the structure-stability relationship by the electrochemical measurement and morphology, found the mechanisms of charge/discharge composed of dominant redox reaction and auxiliary intercalation reaction, and explained the characteristics of a high rate performance through kinetic issues and extrinsic pseudocapacitance contributions. This green synthetic method of anode material could make it possible to obtain high-performance alkali-ion batteries and other energy storage devices.

Atomically Resolved Anisotropic Electrochemical Shaping of Nano-electrocatalyst.

Catalytic properties of advanced functional materials are determined by their surface and near-surface atomic structure, composition, morphology, defects, compressive and tensile stresses, etc; also known as a structure–activity relationship. The catalysts structural properties are dynamically changing as they perform via complex phenomenon dependent on the reaction conditions. In turn, not just the structural features but even more importantly, catalytic characteristics of nanoparticles get altered. Definitive conclusions about these phenomena are not possible with imaging of random nanoparticles with unknown atomic structure history. Using a contemporary PtCu-alloy electrocatalyst as a model system, a unique approach allowing unprecedented insight into the morphological dynamics on the atomic-scale caused by the process of dealloying is presented. Observing the detailed structure and morphology of the same nanoparticle at different stages of electrochemical treatment reveals new insights into atomic-scale processes such as size, faceting, strain and porosity development. Furthermore, based on precise atomically resolved microscopy data, Kinetic Monte Carlo (KMC) simulations provide further feedback into the physical parameters governing electrochemically induced structural dynamics. This work introduces a unique approach toward observation and understanding of nanoparticles dynamic changes on the atomic level and paves the way for an understanding of the structure–stability relationship.

176 - Metabolism of stilbenoids in cancer cells

The stability of stilbenoids in DMEM cell culture, human plasma, Milli Q water and HSA solution are compared. It was found that stilbenoids showed different stability in different solutions, and their stability is as follows: MilliQ water > HSA > human plasma > DMEM cell culture. The structure-stability relationship of stilbenoids in DMEM cell culture is determined as follows: (i) An additional hydroxyl group on ring B will reduce the stablity; (ii) The stability of resorcinol-type stilbenoids is higher than that of catechol-type stilbenoids; (iii) The methoxylation and glycosylationon of resveratrol improves the stability. The interaction between stilbenoids with plasma proteins is beneficial to enhance the stability. We further investigate metabolites of stilbenoids when incubated with several cells (cancer and normal) and its related mechanism.

273 - Dietary flavonoids as anti-cancer agents: what are the bioactive compounds?

We have comprehensively investigated the structure-stability relationship of natural polyphenols in DMEM medium without cells. Polyphenols with catechol or pyrogallol structure were evidently instable in DMEM medium without cells. Herein, we further investigate metabolites of quercetin and luteolin when incubated with several cells (cancer and normal) and its related mechanism. After incubated with SK-28, Caco-2, HepG2, MCF-7, A549, 231, LO2, and LX2 cells at 37 °C in 5% CO2 for 24-72 h, the new products of quercetin and luteolin were found to quite different from different cells. It is time to investigate what really happened for polyphenols and the new products of polyphenols in various cells, as well as the related mechanism. It is very important to further check the bioactivity of these new products, which will avoid erroneous conclusions for what’s the really bioactive compounds.

Advances in alkaline stable guanidinium based anion exchange membranes

Anion exchange membranes (AEMs) are solid polymer electrolytes that contain cationic groups covalently bound to or embedded in a polymer backbone. They act as key role of hydroxide conduction and separator between two electrodes in anion exchange membrane fuel cells (AEMFCs). To achieve high performance in AEMFCs, ideal AEMs should own high ion conductivity and good alkaline stability. Considering to the alkaline stability of AEMs, ionic groups play very important role in determining the overall stability for the AEMs apart from polymer backbones. To date, various ion conductive moieties have been investigated as new tethered ionic groups to replace conventional quaternary ammoniums (QAs) in AEMs because of the multiple degradation pathways under alkaline conditions including: (1) nucleophilic substitution (SN2), (2) Hoffmann elimination (E2), or (3) nitrogen ylide formation. Guanidiniums are found to be a kind of novel ionic groups for the application of AEMs. In the structure of guanidinium, the positive charge is uniformly distributed over the central carbon atom and three nitrogen atoms, leading to stabilized charge delocalization and good thermal and chemical stability. There are six substitutions distributed over three N atoms which can be easily tuned by a mature and feasible route. Additionally, the kinetics of hydrogen evolution/oxidation reaction (HER/HOR) and ORR catalyzed by Pt and carbon-based non precious metal could be greatly enhanced through using guanidiniums. Guanidinium cations can be introduced into the polymer backbone easily by the synthetic methods as follows: (1) halomethylation of a phenyl group and subsequent amination with pentalkylguanidine; (2) nucleophilic substitution of a Vilsmeier salt and a secondary amine; (3) activated fluoroamine reaction; (4) nucleophilic substitution of alkyl halid and guanidine to prepare guanidinium functional monomer; (5) polycondensation between guanidine hydrochloride and diamine. Recently, several types of guanidinium-functionalized AEMs have been explored including benzylic guanidinium AEMs, alkylic guanidinium AEMs and phenylic guanidinium AEMs. Some of the AEMs have been proven to possess excellent ion conductivity, and some have been used in AEMFCs and show good electrochemical performance. Considering to degradation mechanism of guanidinium, it can be concluded as a nucleophilic addition-elimination reaction: firstly the center C atom is attacked by OH- and an intermediate is obtained (addition reaction); then one of N atoms combines with the H atom and eliminates from the intermediate (elimination reaction); finally the degradation products urea and amine are formed. It is worth noting that the degradation process of guanidinium is evidently different from quaternary ammoniums. Their degradation reaction sites only occur at the central carbon atom rather than the benzyl carbon which indicate the promising stability for guanidinium. Though the stabilities of guanidiniums are under debate by now, the usability of guanidiniums as ionic group is still a topic worthy of study. On the one hand, almost all of the studies are confined to guanidiniums with methyl groups substituted at the N1 and N3 positions, hence comprehensive and systematic analysis of the structure-stability relationship of guanidinium cations in alkaline media is still rarely developed. On the other hand, the degradation process of guanidiniums is only speculated by a few studies in theoretical way, more specific experimental studies of this process are badly needed to prove it. Therefore, revealing the structure-stability relationship and the detailed degradation mechanism are vital to design alkaline stable guanidinums which can be applied to AEMs preparation in the future. In addition, the polymer backbone is also very important to improve the stability of guanidiniums based AEMs. More guanidiniums based AEMs with various structures should be designed and prepared. The ion conductivity, alkaline stability and cell performace should be assessed comprehensively to figure out the relationship between the structures and properties of AEMs, and finally the preparation of high performance anion exchange membranes can be achieved.

Structure-stability relationship of anthocyanins under cell culture condition

This work aims to evaluate the structure-stability relationship of anthocyanins in cell culture. An early degradation time (CT10) and half-degradation time (CT50) were used to characterise the stability of 10 of the most common anthocyanins, incubated with DMEM at 37 °C, pH = 7.4, 5% CO2 for different time periods. According to the glycosylation, the glycosylated forms were more stable than the not glycosylated forms. The methylation at 3’' or 5' position at ring B enhanced their stability; contrarily, the hydroxylation at 3' or 5' position at ring B weakened their stability. Glycosylated forms were much more stable in water than in the culture medium. Although not glycosylated forms were also instable in water, their stability was improved compared with culture medium. Together with the cell culture experiments and, in order to avoid artefacts, stability tests of polyphenols should be performed in parallel experiments with DMEM.

Fusicoccane-Derived Diterpenoids from Alternaria brassicicola: Investigation of the Structure-Stability Relationship and Discovery of an IKKβ Inhibitor.

The structure-stability relationships of 1-6 were investigated to show that 1 converted to 5 via a kinetic, solution-mediated autoxidation. In addition, alterbrassicene A (7), a fusicoccane-derived diterpenoid bearing an unprecedented 5/9/4-fused carbocyclic skeleton with a rare fused 2-cyclobuten-1-one motif, was characterized from Alternaria brassicicola. Its absolute structure was elucidated by spectroscopic analyses and quantum chemical calculations. Compound 7 was the first fusicoccane derivative acting as a potent IKKβ inhibitor in the NF-κB signaling pathway.

Past and potential future effects of habitat fragmentation on structure and stability of plant-pollinator and host-parasitoid networks.

Habitat fragmentation is a primary threat to biodiversity, but how it affects the structure and stability of ecological networks is poorly understood. Here, we studied plant-pollinator and host-parasitoid networks on 32 calcareous grassland fragments covering a size gradient of several orders of magnitude and with amounts of additional habitat availability in the surrounding landscape that varied independent of fragment size. We find that additive and interactive effects of habitat fragmentation at local (fragment size) and landscape scales (1,750 m radius) directly shape species communities by altering the number of interacting species and, indirectly, their body size composition. These, in turn, affect plant-pollinator, but not host-parasitoid, network structure: the nestedness and modularity of plant-pollinator networks increase with pollinator body size. Moreover, pollinator richness increases modularity. In contrast, the modularity of host-parasitoid networks decreases with host richness, whereas neither parasitoid richness nor body size affects network structure. Simulating species coextinctions also reveals that the structure-stability relationship depends on species' sensitivity to coextinctions and their capacity for adaptive partner switches, which differ between mutualistic and antagonistic interaction partners. While plant-pollinator communities may cope with future habitat fragmentation by responding to species loss with opportunistic partner switches, past effects of fragmentation on the current structure of host-parasitoid networks may strongly affect their robustness to coextinctions under future habitat fragmentation.

Stability of dietary polyphenols: It's never too late to mend?

We have comprehensively investigated the structure-stability relationship of natural polyphenols in DMEM medium without cells. Polyphenols with catechol or pyrogallol structure were evidently instable in DMEM medium without cells. Herein, we further investigate stability of polyphenols when incubated with cancer cells and its related mechanism. After incubated with SK-28 cells and A549 cells at 37 °C in 5% CO2 for 72 h, the new products of quercetin and 5,7,3′,4′-tetrahydroxyflavone were found to quite different from different cells. It is time to investigate what really happened for polyphenols and the new products of polyphenols in cancer cells, as well as the related mechanism. It is very important to further check the bioactivity of these new products, which will avoid erroneous conclusions for what's the really bioactive compounds.

Non-additive stabilization by halogenated amino acids reveals protein plasticity on a sub-angstrom scale.

It has been a long-standing goal to understand the structure-stability relationship of proteins, as optimal stability is essential for protein function and highly desirable for protein therapeutics. Halogenation has emerged as a minimally invasive strategy to probe the physical characteristics of proteins in solution, as well as enhance the structural stabilities of proteins for therapeutic applications. Although advances in synthetic chemistry and genetic code expansion have allowed for the rapid synthesis of proteins with diverse chemical sequences, much remains to be learned regarding the impact of these mutations on their structural integrity. In this contribution, we present a systematic study of three well-folded model protein systems, in which their structural stabilities are assessed in response to various hydrogen-to-halogen atom mutations. Halogenation allows for the perturbation of proteins on a sub-angstrom scale, offering unprecedented precision of protein engineering. The thermodynamic results from these model systems reveal that in certain cases, proteins can display modest steric tolerance to halogenation, yielding non-additive consequences to protein stability. The observed sub-angstrom sensitivity of protein stability highlights the delicate arrangement of a folded protein core structure. The stability data of various halogenated proteins presented herein should also provide guidelines for using halogenation as a strategy to improve the stability of protein therapeutics.

Metallophilic interactions and structure-stability relationship with secondary interactions in [ZnX]− based hybrid derivatives

To scrutinize the role of the weak interactions in structure-stability of zinc based metal-organic compounds a series of seventy derivatives were analyzed through single crystal X-ray crystallographic data obtained from IUCr. The structural parameters obtained from the cif file were simulated for molecular dynamics to calculate the weak interactions in series of zinc chloride, zinc bromide, zinc iodide and zinc fluoride based metal-organic composites. The structural frameworks depict that the metal halides are holding the organic moieties within the inorganic patterns through XH … A, CH … π, π … π, halogen-halogen and Metallophilic secondary interactions. The different structural motifs from 1D chain, 2D ribbons and 3D dimmer patterns were observed in the selected series. The comprehensive structural statistics results that the average Zn-X bond distance = 2.375 (4)Å [ZnCl2 = 2.465 (4)Å, ZnBr2 = 2.396 (4)Å, ZnI2 = 2.557 (6)Å, ZnF2 = 2.019 (5)Å] and X-Zn-X bond angles lie in the range of 64.77–126.45° in these compounds. The XH … A hydrogen bond calculations result the average H … A bond length = 2.38 Å [ZnCl2 = 2.37 Å, ZnBr2 = 2.44 Å, ZnI2 = 2.65 Å, ZnF2 = 2.28 Å] and the average XH … A bond angle = 125.5° [ZnCl2 = 139°, ZnBr2 = 130.5°, ZnI2 = 119.5°, ZnF2 = 133.5°]. This indicates that these hydrogen interactions are in the category of strong to moderate type of hydrogen bonds. The minimum value of H … π = 2.800 (4) Å is observed in ZnBr17 at symmetry position -x, 1-y, 1-z shows that such interactions are stabilizing the organic moieties within the metal-organic derivatives. It is observed that the minimum value of halogen … halogen weak interaction is 2.382 (2)Å for ZnF1 at symmetry position -x, 0.5-y, 0.5-z and the minimum value of metallophilic interaction distance is observed as 2.508 (6)Å in ZnBr32 at symmetry position,1 + x, y, z, which are linking the inorganic components of metal-organic derivatives. The IR and Raman spectra tensors were calculated for the selected series of derivatives which indicates that IR, Raman and Hyper-Raman modes are dominant in ZnCl2 based derivatives as compared to ZnBr2, ZnI2 and ZnF2 based metal-organic compounds. The structural and spectroscopic parameters reveal that such weak interactions can be used to design the materials with spectroscopic applications.

High-Throughput Survey of Ordering Configurations in MXene Alloys Across Compositions and Temperatures.

2D transition metal carbides and nitrides known as MXenes are gaining increasing attention. About 20 of them have been synthesized (more predicted) and their applications in fields ranging from energy storage and electromagnetic shielding to medicine are being explored. To facilitate the search for double-transition-metal MXenes, we explore the structure-stability relationship for 8 MXene alloy systems, namely, (V1-xMox)3C2, (Nb1-xMox)3C2, (Ta1-xMox)3C2, (Ti1-xMox)3C2, (Ti1-xNbx)3C2, (Ti1-xTax)3C2, (Ti1-xVx)3C2, and (Nb1-xVx)3C2, with 0 ≤ x ≤ 1, using high-throughput computations. Starting from density-functional theory calculated formation energies, we used the cluster expansion method to build quick-to-compute interactions, enabling us to scan through the formation energies of millions of alloying configurations. For the Mo-rich MXenes, (M11-xMox)3C2 (where M1: Ti, V, Nb, Ta) Mo atoms prefer to occupy the surface layers, and ordering persists to high temperatures, based on our Monte Carlo simulations. When Ti is alloyed with Nb or Ta, in the Ti-rich MXenes, Ti atoms prefer the surface layers (e.g., Ti-C-Nb-C-Ti sequence), and in the Nb- or Ta-rich MXenes, Ti occupies only one surface layer and the other two layers are Nb or Ta (e.g., Ti-C-Nb-C-Nb), exhibiting asymmetric ordering. However, alloying Ti with V results in solid solutions across all compositions. (Nb1-xVx)3C2 phase separates at lower temperatures but forms solid solutions at synthesis temperatures. Postsynthesis annealing at moderate temperatures (800 to 1000 K) increases the ordering for all the compositions. Lastly, by investigating the stability of their precursor MAX phases and surface-terminated MXenes, we discuss the synthesis possibilities of highly ordered MXenes.