Relative Enthalpies Research Articles

Magnetic field improvement of the germination of brown rice in the absence/presence of gibberellin: Changes in α-amylase activity and starch structural and physicochemical properties

Germination could improve the sensory and nutritional value of brown rice (BR), and magnetic field (MF) is considered as a promising technique for enhancing germination. However, the mechanism underlying MF-enhanced germination of BR remains unclear. Therefore, in this study, BR was exposed to MF (10 mT, 60 min, 25 °C), germinated in the absence/presence of gibberellin (GA) solution (20 mg/L, 30 °C) for 36 h, and subsequently the mechanism was explored by assessing germination index, endogenous GA content, relevant gene expression, α-amylase activity, and α-amylase action on rice starch. Results indicated that with MF treatment, the shoot and root length of BR increased by 10.4% and 22.9%, respectively. MF treatment upregulated the gene expression related to α-amylase by 0–110.2%, activated α-amylase by 11.0%, led to the hydrolysis of starch into more reducing sugars by 9.2% and thus provided additional energy for BR germination. Post-germination, pores appeared on BR starch surface, and there was a decrease in its relative crystallinity, pasting temperature, and enthalpy. Compared with MF, the combination of MF and GA treatments (GM) showed a more pronounced effect on germination, which further confirmed that MF might enhance BR germination by activating α-amylase through the GA pathway. Overall, this study extended the knowledge of MF-assisted germination, which provided a guidance for the applications of MF in food and agricultural industries.

Effects of galactomannans of varied structural features on the functional characteristics and in vitro digestibility of wheat starch

This study explores the effects of four natural galactomannans (GMs) with varying degrees of branching (fenugreek gum, guar gum, tara gum and locust bean gum) on the functional properties and in vitro digestibility of wheat starch (WS). Results from rapid viscosity analysis (RVA) and low-field nuclear magnetic resonance (LF-NMR) analysis revealed that GMs with lower branching degrees were correlated with higher paste viscosity, peak viscosity, and greater water-holding capacity in the WS-GM mixtures. Additionally, these lower branching GMs more effectively inhibited amylose leaching during starch gelatinization, leading to a softer gel texture and increased transparency of the mixtures. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis demonstrated that starch mixtures containing lower branching GMs exhibited reduced relative crystallinity and enthalpy values during aging. Furthermore, the incorporation of lower branching GMs resulted in decreased starch digestibility in vitro, thereby enhanced resistant starch content. These findings highlight the potential of selectively branched GMs to modulate the functional properties and nutritional profile of WS, providing a promising approach for the development of starch-based products with improved health benefits.

Mechanical and electrical properties of two-dimensional BN doped with carbon group elements: first-principles calculations

Abstract Research of low-dimensional nanomaterials provides a direction for solving the problems of energy and environmental pollution. In this work, the regulation mechanism of doping carbon group elements X (X = C, Si, Ge, Pb, Sn) on mechanical and electrical properties of 2D monolayer BN are investigated by first-principles calculations. Two doping sites were selected, replace B atoms (B15N16X) or N atoms (B16N15X). Lower relative enthalpies and the elastic constants, which conforming to the mechanical stability standard, fully prove the stability of the doping system. Compared with B15N16X, B16N15X has larger structural distortion, smaller elastic constants and modulus, and is more inclined to ductility. With the increase of atomic radius, the deformation degree increases and the elastic parameters decrease. C-doped by replacing B atoms improves the elastic mechanical properties of monolayer BN. Sn-doped and Pb-doped modulate the monolayer BN into ductility. More importantly, all doped configurations exhibit magnetism. The indirect band gap of the undoped system can also be modulated into a direct band gap, B15N16C, B16N15Si and B16N15Ge all have direct band gaps in the spin-down direction. Asymmetric impurity energy levels DOS further verify the magnetism of the reference system.

In-depth quantitative and theoretical study of ambident electrophilies of 2-bromo-3-X-5-nitrothiophenes

As part of our continuing studies into the electron deficient nature of five-membered ring heterocycles, specifically 2‑methoxy-3-X-5-nitrothiophenes and 3-X-5-nitrothiophene, we report here a kinetic study of σ-complexation reactions involving 2‑bromo-3,5-dinitrothiophene 1 and various nitroalkyl anions in aqueous solution at 20 °C. Theoretical calculations at the density functional theory (DFT) level were performed to confirm the proposed mechanism. From the previously reported nucleophilicity parameters N and sN for the nucleophiles 2 and the derived second-order rate constants, the electrophilicity parameter (E) at the C-4 position of thiophene 1 was quantified according to the linear free enthalpy relationship log k (20 °C) = sN (E + N). Mayr's approach accurately predicted the rate constants for the reactions of this thiophene 1 with a series of para-substituted phenoxide anions in water at 20 °C. A reasonable correlation between calculated global electrophilicity index ω values and experimental electrophilic reactivities was observed and discussed.

Cellulose-reinforced foam-based phase change composites for multi-source driven energy storage and EMI shielding

To address the increasingly serious environmental pollution and energy crisis, there is an urgent need to develop multi-source-driven energy storage materials, the field of new energy sources, such as solar thermal power generation, but electromagnetic pollution has become a primary problem that needs urgent resolution. Therefore, the development of multifunctional phase change composites (CPCMs) with multi-source drive capabilities and excellent electromagnetic shielding integration is crucial. In this study, polypyrrole (PPy)-coated conductive fibers were crosslinked with polyvinyl alcohol (PVA) to form a three-dimensional network, which was then combined with metal foam to prepare Ni–F/PPy@CNF-PVA (PCN) dual-network carriers with high electrical conductivity by vacuum-assisted adsorption and freeze-drying methods. Polyethylene glycol (PEG) was subsequently encapsulated via vacuum impregnation to get the shape-stable PEG/Ni–F/PPy@CNF-PVA (PPCN) phase change composites. The PPCN exhibited good stability and high energy storage density (melt enthalpy up to 126.18 J/g, relative enthalpy efficiency over 99 %). Benefiting from its outstanding electrical conductivity (186680 S/m for PPCN-3), light-absorbing properties, and magnetism, the PPCN also exhibits highly efficient photothermal, electrothermal, and magnetothermal conversion capabilities. The electromagnetic interference shielding efficiency reaches up to 110.37 dB within the X-band frequency range (8.2–12.4 GHz). In conclusion, PPCNs are significant for multi-source-driven energy storage and electromagnetic shielding.

Phase change composite based on lignin carbon aerogel/nickel foam dual-network for multisource energy harvesting and superb EMI shielding

With the increasingly rapid pace of updates and iterations in electronic devices, electronic equipment/systems are becoming progressively intricate, aiming to achieve swift responsiveness through higher packaging density, which leads to electromagnetic interference and brings along with it heat accumulation, the creation of new composite phase change materials with efficient thermal management capabilities integrated with excellent electromagnetic interference shielding capabilities is imminent. In this study, nickel foam/lignin/rGO dual network scaffolds (LGN) with high electrical conductivity were prepared by vacuum-assisted adsorption, freeze-drying, and thermal annealing, and then PEG was encapsulated in LGN by vacuum impregnation to obtain shape-stabilized PEG/NiF/LN-rGO (PLGN) composite phase change material. The results demonstrate that the prepared PLGNs exhibit robust stability, exceptional thermal management capabilities, and commendable electromagnetic interference (EMI) shielding effectiveness (SE). Among these composites, PLGN-3 stands out with a notably high energy storage density, featuring a melting enthalpy of 140.95 J/g and a relative enthalpy efficiency of 98.72%. Benefiting from its outstanding electrical conductivity (1597.5 S/cm for PLGN-3) and superior light absorption, the PLGN composite phase change material also demonstrates highly effective photothermal and electrothermal conversion capabilities. In addition, the EMI shielding effectiveness reaches up to 69.9 dB at 8.2–12.4 GHz. In conclusion, the synthesized PLGN composite phase change material demonstrates considerable promise for mitigating electromagnetic interference and facilitating thermal energy management in electronic devices.

Unveiling the unique potential of MXene with and without graphene nanoplatelet for thermal energy storage applications.

Solar thermal energy storage (TES) is an outstanding innovation that can help solar technology remain relevant during nighttime and cloudy days. TES using phase change material (PCM) is an avant-garde solution for a clean and renewable energy transition. The present study unveils the unique potential of MXene as a performance enhancer in lauric acid (LA), which functions as a base PCM. The addition of graphene nanoplatelet (GNP) into the LA-MXene composite is prepared to comprehend and evaluate the benefits and detriments of adding carbon-based nanomaterial into the PCM via a two-step homogenizing method. A similar weight percentage of MXene and GNP at 0.75 was used for composite synthesis. The study found that the enthalpy of LA-MXene is comparable to LA at 169.87 J/kg and greater than LA-MXene/GNP, which has 137.53 J/kg. Regarding thermal storage performance, LA-MXene exhibited outstanding performance compared to LA-MXene/GNP in terms of enthalpy efficiency (λ) and relative enthalpy efficiency (η), achieving 95.4% and 96.1%, respectively. This is supported by the XPS spectra, which show that the crosslinking structure acted as a barrier, reinforcing the material and preventing further thermal degradation. This has resulted in robust and denser shells that significantly improved light absorption, enhancing both the photothermal conversion and thermal energy storage efficiency of LA/MXene. The present study reveals that LA-MXene is a promising and optimal candidate for the feasibility and reliability of TES in solar renewable energy applications. It was observed that the incorporation of exclusive MXene may effectively address the limitations of LA as a conventional PCM and surpass the traditional role of GNP. This study offers valuable insights into the superior performance of MXene alone, eliminating the need for doping with various nanomaterials and thereby reducing the complexity in synthesizing the PCM.

Ethynyl Radical Hydrogen Abstraction Energetics and Kinetics Utilizing High-Level Theory.

The ethynyl radical, C2H, is found in a variety of different environments ranging from interstellar space and planetary atmospheres to playing an important role in the combustion of various alkynes under fuel-rich conditions. Hydrogen-atom abstraction reactions are common for the ethynyl radical in these contrasting environments. In this study, the C2H + HX → C2H2 + X, where HX = HNCO, trans-HONO, cis-HONO, C2H4, and CH3OH, reactions have been investigated at rigorously high levels of theory, including CCSD(T)-F12a/cc-pVTZ-F12. For the stationary points thus located, much higher levels of theory have been used, with basis sets as large as aug-cc-pV5Z and methods up to CCSDT(Q), and core correlation was also included. These molecules were chosen because they can be found in either interstellar or combustion environments. Various additive energy corrections have been included to converge the relative enthalpies of the stationary points to subchemical accuracy (≤0.5 kcal mol-1). Barriers predicted here (2.19 kcal mol-1 for the HNCO reaction and 0.47 kcal mol-1 for C2H4) are significantly lower than previous predictions. Reliable kinetics were acquired over a wide range of temperatures (50-5000 K), which may be useful for future experimental studies of these reactions.

Flame-retardant shape-stabilized phase change composites with superior solar-to-thermal conversion

Building thermal management is responsible for over 40 % of total energy use, of which about 20 % is directly related to the operation of heating. Materials saving energy to heat buildings would contribute substantially to sustainability. In this study, we have developed a series of flame-retardant shape-stabilized phase change composites (PCCs) by incorporating MXene@PTA and flame-retardant phytic acid dicyandiamide (PD) into a waterborne polyurethane framework using a simple vacuum impregnation technique, and their thermophysical properties, photothermal conversion, and flammable retardant performance were systematically studied. It was found that the resulting composite, termed PMWP PCCs, achieved an enthalpy efficiency and relative enthalpy efficiency of 68.66 % and 99.7 %, respectively. And it maintained excellent shape stability even after 180min at 70 °C, which demonstrates effective inhibition of leakage of phase change material. Furthermore, the maximum temperature of PCCs without modified MXene was observed to be around 37 °C, which rose to more than 45 °C after adding modified MXene, indicating higher photothermal conversion performance. Most importantly, compared to pure PEG, the peak heat release rate and total heat release value of the modified phase change composites were found to be reduced by 6.7–35.8 % and 13.2–19 %, respectively. The results suggest that the combination of MXene and PD exhibits a synergistic flame retardant effect, enhancing the flame retardancy. These outcomes underscore the promising application potential of PMWP PCCs in the fields of thermal management and energy storage.

EVAPORATIVE AIR COOLER THERMAL PERFORMANCE FOR RESIDENTIAL USE

This paper investigates an Evaporative Air Cooler (EAC) thermal performance and energy efficiency, when reducing the air temperature. EAC equipment typically consists of fan, small hydraulic pump and cooling pads. That device is able to provide ventilation only or air cooling trough water evaporative process that increases the air humidity (absolute and relative) and, as consequence, air temperature decreases (dry and wet bulb). The methodology adapts some aspects from ABNT - Brazilian Technical Standards Normative, for air conditioning devices. During tests, the fan rotor operates in 3 (three) angular speeds (RPM) in different ambient conditions for inlet air. Appropriate instrumentation and measurements registration allow to register the behavior of thermal parameters as: dry and wet bulb temperatures (Tdb and Twb, °C), air relative humidity (RH, %), enthalpy (kJ.kg-1), and water mass flow (kg.s-1). Thus, main results are for overall efficiency (η, %) considering the energy conversion from electricity to air flow hydraulic power, and cooling effectiveness (ε, %) is based on heat exchange between water evaporation and airflow rate. As main conclusions, we point out that: a) ↓Tdb for ↓mAir, reaching ΔT~5.0°C and corresponding ΔΦ~20%, when comparing outlet and inlet airflow parameters; b) EAC efectiveness reaches maximum values for lower rotor angular speeds (εEAC ~90%@1300 RPM), in comparison to higher ones; c) For a constant rotor angular speed, EAC performance (CP, εEAC and others) is strongly dependent on air ambient conditions; mAir increases from ~13.8 kg.s-1 up to ~16.5 kg.s-1 when rotor angular speeds goes from 1300 RPM to 1500 RPM.

High-throughput design of three-dimensional carbon allotropes with Pmna space group

284 carbon allotropes with Pmna space group (No. 53) are proposed based on high-throughput calculations and density functional theory. Out of 14,285 initially identified candidates, 284 carbon allotropes are confirmed by structure optimization, removal of repetitive structures, calculation of relative enthalpies, and verification of the mechanical and thermal stabilities. Among them, 135 are metals, 55 are direct band gap semiconductors (in 15 cases with a band gap between 1.0 and 1.5 eV), 46 have three-dimensional conductive channels, 32 are superhard, and 3 are type-I Dirac semimetals.

Unravelling Irreversible Adsorbate Thermodynamics through Adsorption-Assisted Desorption.

Strongly bound surface species like alkylamines adsorbed on the Brønsted acid site of aluminosilicate zeolites exhibit negligible rates of molecular desorption, preventing them from achieving an equilibrated state on experimentally relevant time scales that limit the measurement of their adsorption thermodynamics. Through adsorption-assisted desorption, whereby distinct alkylamines facilitate desorption from Brønsted acid sites, we demonstrate that equilibrated states are achieved. Breakthrough adsorption measurements reveal that while 2-butylammonium on a Brønsted acid site is irreversibly adsorbed, it readily undergoes molecular desorption when exposed to a distinct alkylamine like 2-propanamine. As a result, two-adsorbate equilibrium was achieved when the Brønsted acid sites of aluminosilicate zeolites were exposed to a binary vapor-phase alkylamine mixture. By varying relative vapor-phase partial pressures and temperatures, we demonstrate the ability to experimentally measure the adsorption enthalpy and entropy of alkylammonium adsorbates on mostly isolated Brønsted acid sites in H-ZSM-5 (Si/Al = 140). A multiadsorbate Langmuir isotherm was found to quantitatively describe the coadsorption of alkylamines varying in size and basicity over a wide range of conditions through which the relative adsorption enthalpy and entropy of alkylamines were measured. Across a homologous family of sec-alkylamines (C3-C5) adsorbed on isolated Brønsted acid sites, a fixed contribution to the enthalpy (19 ± 4 kJ mol CH2-1) and entropy (25 ± 4 J mol CH2-1 K-1) of adsorption per methylene unit was found to exist, likely resulting from electrostatic interactions between the alkyl chain and the surrounding pore environment.

The impact of parboiling on physical structure, physicochemical properties and zinc status of Zn-fortified germinated brown rice

The structural and physicochemical properties, cooking quality and zinc retention ratio of Zn-fortified germinated brown rice were investigated with different parboiling times (4–20 min). The brown rice grains exhibited visually more yellowish-brown colour and cracks on the surface with the germination and longer parboiling, and the micrographs clearly displayed wrinkles after these processes. Germination and the increase of parboiling time exacerbated the disruption of microstructure and the decrease in relative crystallinity and enthalpy change. The relaxation time (T2) increased in Zn-fortified germinated brown rice and parboiled samples compared to brown rice. Cooking time of Zn-fortified germinated brown rice was reduced from 36 min to 27 min with longer parboiling. Parboiling treatment longer than 4 min improved the palatability. There was no significant difference of Zinc retention ratio at different parboiling times. Sixteen min parboiling was recommended to obtain the brown rice product, which requires a short cooking time with desired palatability, as well as acceptable colour and zinc content. Overall, parboiling is an effective technique to modify the physical structure and physicochemical properties and improve cooking quality of Zn-fortified germinated brown rice.

Effects of sourdough on bread staling rate: From the perspective of starch retrogradation and gluten depolymerization

In the present study, we investigated the effects of sourdough on the staling rate of bread from the perspectives of starch retrogradation during storage and gluten depolymerization in bread dough. Three sourdough types, which were fermented using Weissella cibaria, Latilactobacillus sakei, and Fructilactobacillus sanfranciscensis strains, were added to bread dough at a 25% ratio. Compared with regular bread, sourdough bread (SDB) exhibited a lower hardness value and slower staling rate during a 7-day storage period. The relative crystallinities and enthalpies revealed that sourdough addition inhibited amylopectin recrystallization. Furthermore, sourdough-induced acid conditions promoted glutenin macropolymer depolymerization; and the dough containing sourdough (SD-D) showed a decrease in viscoelastic properties and changes on microstructure, reflecting a weakened gluten network structure. Among the three sourdough types, L. sakei-fermented sourdough exhibited the lowest staling rate; this might be owing to its higher gluten depolymerization degree, lower α-helix and intermolecular β-sheet contents, and decreased viscoelastic properties. Our study findings provide a theoretical basis for using sourdough fermentation with different strains to develop clean label bread and improve bread quality in the future.

A superhard orthorhombic carbon allotrope: Cmca-C16

A novel three-dimensional sp3 hybrid carbon allotrope, namely Cmca-C16, is predicted through structure searching within density functional theory (DFT) calculations. The structural, electronic, relative formation enthalpy and mechanical properties including bulk, shear, Young's modulus, ideal strength and Vickers' hardness are systematically investigated. The obtained results demonstrated that Cmca-C16 exhibiting excellent mechanical and dynamic stability. The calculations of ideal strength indicate that the failure mode occurs along the [100] direction, with the lowest peak stress of 80.8 GPa. The theoretical hardness of Cmca-C16 is calculated to be 88.6 GPa, which is comparable to that lonsdaleite (90.5 GPa) and C14-carbon (89.7 GPa), but higher than most other known carbon phases.

Potassium tert‐Butoxide‐Catalyzed Selective Synthesis of 1,4‐Benzodioxepines via 7‐exo/7‐endo‐dig Cyclization of Alkynol: Experimental and DFT Study

AbstractA new method utilizing base catalysis is outlined for the synthesis of 1,4‐benzodioxepines, introducing a unique scaffold containing a seven‐membered ring heterocycle. The reaction proceeded under thermal conditions, with no waste was generated during the transformation, highlighting its remarkable atom efficiency and environmental friendliness. A straightforward metal‐free reaction condition utilizing 2‐propynyloxy benzyl alcohols as starting material and a catalytic amount of t‐BuOK in mesitylene at 100 °C for 1 hour was employed for this intramolecular cyclization transformation, resulting in the formation of 1,4‐Benzodioxepines in good to excellent yields and high regio‐ and diastereo‐selectivity. The density functional theory (DFT) calculations yielded the relative internal energy (U), enthalpy (H), and Gibbs free energy (G) values for all possible products, aligning closely with our experimental data.

Valorization of coconut peat to develop a novel shape-stabilized phase change material for thermal energy storage

Coconut peat (CP) is a product derived from coconut husks and it has been recognized as a valuable resource for the removal of heavy metals, as an oil-sorbent material, and for agricultural purposes. However, large quantities of coconut husks are still discarded yearly, leading to environmental pollution. In this study, a series of CP/polyethylene glycol (CP/PEG) composites were prepared as novel shape-stabilized phase change materials (SSPCMs) by vacuum impregnation to demonstrate a potential new application of CP in the area of thermal energy storage. The composites were investigated by thermogravimetric (TG) analysis, differential scanning calorimeter (DSC), scanning electron microscopy, attenuated total reflection-Fourier transform infrared spectrometer, leakage test, and thermal cycling testing. The results revealed that the CP/PEG composites exhibit minimal leakage of PEG while the composite with a CP/PEG mass ratio of 3:7 has a high latent heat storage of 108.5 J/g and relative enthalpy efficiency of 91.7%. Meanwhile, TG results indicated that it has good thermal stability up to 150 °C and the thermal cycling test showed that it has excellent thermal reliability even after 100 thermal cycles. The heat harvesting and releasing performance of the sample was evaluated as well to understand its thermoregulation capability. Therefore, the obtained CP/PEG composite demonstrates that it can potentially be utilized for thermal storage applications such as in wallboard or building materials for passive cooling, thus fostering a cleaner process by realizing energy savings.

Mixed Enthalpy-Entropy Descriptor for the Rational Design of Synthesizable High-Entropy Materials Over Vast Chemical Spaces.

The practically unlimited high-dimensional composition space of high-entropy materials (HEMs) has emerged as an exciting platform for functional material design and discovery. However, the identification of stable and synthesizable HEMs and robust design rules remains a daunting challenge. Here, we propose a mixed enthalpy-entropy descriptor (MEED) that enables highly efficient, robust, high-throughput prediction of synthesizable HEMs across vast chemical spaces from first-principles. The MEED is based on two parameters: the relative formation enthalpy with respect to the most stable competing compound and the spread of the point-defect formation energy spectrum. The former measures the relative synthesizability of an HEM to its most stable competing phase, going beyond the conventional thermodynamic understanding. The latter gauges the relative entropy forming ability of an HEM, entailing no sampling over numerous alloy configurations. By applying the MEED to two structurally distinct representative material systems (i.e., 3D rocksalt carbides and 2D layered sulfides), we not only successfully identify all experimentally reported HEMs within these systems but also reveal a cutoff criterion for assessing their relative synthesizability within each system. By the MEED, tens of new high-entropy carbides and 2D high-entropy sulfides are also predicted, which have the potential for a wide variety of applications such as coating in aerospace devices, energy conversion and storage, and flexible electronics.

Construction of MXene-enhanced rigid polyurethane foam/polyethylene glycol phase change composites for solar thermal conversion and storage

In this study, various rigid polyurethanes foams (PUFs) with different morphologies were prepared and subsequently used for encapsulating the phase change material, polyethylene glycol (PEG). To address the low photothermal conversion efficiency of polyurethane-based phase change materials, MXene was successfully synthesized via an in-situ hydrofluoric acid (HF) etching method and incorporated into the PEG to obtain MXene@PEG composite material. Finally, a series of innovative MXene@PEG-PUF phase change composites were successfully fabricated by utilizing PUFs as the supporting matrix and the MXene@PEG composite as the phase change component through a vacuum impregnation technique, and their thermophysical properties and photothermal conversion performance were systematically studied. The results show that PUF is the ideal capsulation material for PEG. And MXene@PEG-PUF demonstrates a high PCM loading rate (>80 wt%) and a high latent heat storage enthalpy (>140 J/g) with a relative enthalpy efficiency of 99.5%, maintaining excellent shape stability and relative enthalpy efficiency of 95.58% after 150 thermal cycles. This highlights its superior thermal reliability, making it suitable for practical building energy-saving applications. Most importantly, the incorporation of MXene into PUF@PEG significantly enhances solar-to-thermal conversion capability, attributed to the exceptional photothermal characteristics of MXene.

Novel Derivatives of Phenylisoxazole‐3/5‐Carbaldehyde Semicarbazone: Synthesis, Characterization, and Computational Studies

Six novel phenylisoxazole semicarbazone derivatives 1–6 were synthesized by reaction of the corresponding phenylisoxazole‐3/5‐carbaldehyde derivatives with semicarbazide hydrochloride. The synthesized compounds were characterized by ESI‐MS, FT‐IR, and NMR (1H, 13C) spectroscopic techniques. The two‐dimensional 1H‐1H NOESY NMR (in acetone‐d6) data revealed that compound 1 exists in the E isomeric form. The computational study of the energetic, structural, and electronic properties, carried out at B3LYP/6‐311G++(d,p) level of theory, showed that the most stable conformer for the all synthesized compounds, in both gas and liquid (acetone and DMSO) phases, has a cisE geometrical configuration. This evidence found is in good agreement with the spectrometric results. The geometrical parameters, frontier molecular orbital (FMO), molecular electrostatic potential (MEP), Mulliken atomic charges, and natural bonding orbital (NBO) analysis were also performed at the same level of theory. Taking into account the relative enthalpies ΔH computed, we can establish for tautomeric structures of each of the compounds, the following stability order: I (cisE) > II (E′E) > III (cisE). The MEP descriptors indicate that the oxygen atom of the carbonyl group C=O is susceptible to electrophilic attack, while the hydrogen atoms of the amide and hydrazone fragments are sensitive to nucleophilic attack. The calculated HOMO‐LUMO gap energies Eg indicate that 5 (in gas phase) and 6 (in liquid phase) are the most stable and less reactive compounds, while 1 is the less stable and the most reactive compound. From the NBO analysis, it becomes evident that the presence of the hydrazone fragment produces stabilizing effects due to hyperconjugative interactions.