Physical & Theoretical Chemistry
Exploring Iridium's Catalytic Role in Redox Reactions: A Concise Review
Transition metals exhibit a remarkable capacity to catalyse redox processes playing a crucial role in various natural biological and chemical transformations. Among all the elements in the periodic table iridium stands out with the broadest range of oxidation states. With its electronic configuration of 5d76s2 iridium displays a range of oxidation states fluctuating from -3 in [Ir (CO)3]3- to +9 in [IrO4]2+. The utilization of iridium as a catalyst stems from its capability to adopt these variable oxidation states. Notably Iridium (III) complexes exhibit significant catalytic activity in both acidic and basic environments facilitating a diverse array of organic and inorganic chemical transformations. The catalytic mechanism adapts according to the specific conditions under which the catalysts are employed. Iridium's catalytic efficiency is notably enhanced in an acidic environment as highlighted in this review compared to its performance in a basic medium. Iridium stands as the sole reported catalyst with the capability to harness sunlight and transform it into chemical energy offering promising prospects for application in artificial energy systems. The high surface-to-volume ratio of IrNPs contributes to their excellent catalytic performance. As research in Nanocatalysis continues to evolve iridium remains a key player in shaping the future of sustainable and efficient chemical processes.
Investigation of the Effects of Different Phases of TiO2 Nanoparticles on PVA Membranes
PVA/TiO2 nanocomposite membranes are prepared by solution casting technique where different phases of TiO2 nanoparticles like brookite brookite-rutile and rutile are dispersed in PVA matrix. Sol-gel method was employed to prepare TiO2 nanoparticles while different phases of TiO2 have been obtained by controlling the calcination temperature.
PVA/TiO2 nanocomposite membranes were characterized by XRD FTIR AFM TEM UV-visible and PL techniques. XRD results confirmed the presence of different phases of TiO2 exhibiting 3.3 nm 8.4 nm and 35.7 nm mean crystalline size. The XRD studies also confirmed that TiO2 nanoparticles became properly dispersed to the PVA matrix leading to increased PVA crystallinity after doping of different phases of TiO2 nanoparticles. UV-visible analysis revealed an increase in absorption intensity and peak position shifts slightly towards longer wavelengths which indicates that nanofillers tuned the band gap of PVA. The doping of the TiO2 (brookite) phase in the PVA matrix results in a decreased in PL intensity.
This suggests that the PVA/TiO2 (brookite) membrane exhibits a greater degree of photocatalytic activity in comparison to the other two composites. According to the FTIR investigation the hydroxyl (OH) groups present in PVA interact with the dopants Ti+ ions via intra- and intermolecular hydrogen bonds to produce charge transfer complexes (CTC). The AFM study shows surface roughness details for PVA and PVA/TiO2 composite membranes. The average grain size of TiO2 nanoparticles calculated from TEM images is in good agreement with the grain size calculated by XRD.
By adjusting the phase of TiO2 nanoparticles into PVA matrix composites can be developed that are optimized for a variety of applications such as water purification UV protection self-cleaning surfaces lithium-ion batteries and optoelectronic devices.
A Kinetic and Mechanistic Study of Ir (III)-Catalyzed Oxidation of Methionine by HCF (III) in an Aqueous Alkaline Medium
The kinetic study of Ir (III) chloride-catalyzed oxidation of methionine by hexacyanoferrate (abbreviated as HCF) III ions in aqueous alkaline medium was performed spectrophotometrically at constant ionic strength of 0.5 moldm-3 and temperature of 35±0.1°C.
The progress of the reaction was found to be first-order rate dependence kinetics with respect to [HCF (III)] [OH-] and [IrCl3]. The rate of reaction was found to decrease with an increased concentration of methionine. The ionic strength of the reaction mixture showed a positive salt effect on the reaction rate. Different activation parameters were also evaluated by studying the reaction at four different temperatures. The stoichiometry of the reaction showed Methionine: HCF (III) = 1:4.
The oxidation product of the reaction was found to be methionine sulphone which was identified by an organic solvent method and IR Spectroscopy. Further a suitable mechanism was proposed to explain all the experimental results.
It is assumed that the reaction proceeded through complex formation between substrate (oxidant) and iridium trichloride. A rate law was derived which verified the results.
CH3-S-(CH2)2-CH (NH2)-COO- + 4HCF (III) 
CH3-SO2-(CH2)2-CH-(NH2)-COO- + 4HCF (II)
Ionic Liquid-Based Green Solvents for Extraction and Purification of Natural Plant Products
This research paper explores the environmental sustainability of ionic liquid-based green solvents in the extraction and purification of natural plant products with a focus on their entire life cycle. The objectives of the study were to assess the environmental impact of ionic liquid synthesis energy consumption water usage emissions recycling rates policy effects and stakeholder perceptions.
Methodologically we conducted a comprehensive Life Cycle Assessment (LCA) that involved primary data collection through field surveys and interviews with key stakeholders in the ionic liquid production and usage industry across various regions in India. The data were analyzed using specialized LCA software tools to quantify environmental impacts. Key findings include the identification of synthesis as a major contributor to environmental impact emphasizing the need for greener synthesis methods.
The study revealed the significant carbon footprint energy consumption and water usage during production highlighting opportunities for improvement. Emissions data underscored the importance of emission control measures particularly for greenhouse gases and volatile organic compounds. Recycling and reuse were identified as environmentally friendly disposal methods. Policy compliance varied among stakeholders indicating room for stricter regulations. Stakeholder perceptions varied with researchers having the most positive outlook. Implications of the findings extend to sustainable chemistry practices emphasizing interdisciplinary collaboration and the importance of considering the entire life cycle of chemical processes.
This research contributes to a deeper understanding of green solvents and provides a foundation for promoting sustainable practices in industrial processes in India and globally.
Spectrophotometric Determination of Curcumin using 3-Methyl-2-benzothiazolinone Hydrazone Hydrochloride Hydrate as Electrophilic Coupling Agent
Nutraceuticals are products derived from food sources that provide extra health benefits in addition to the basic nutritional value found in foods. Spectrophotometric methods for the determination of curcumin were developed which are simple sensitive selective rapid and reliable.
The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium. Spectrophotometric methods for the determination of curcumin were developed which are simple sensitive selective rapid and reliable. The methods are based on the reduction of iron (III) to iron (II) by 3-Methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) which is an electrophilic coupling agent and subsequent reaction with curcumin in mild hydrochloric acid medium.
The reaction produces a bluish–green complex with maximum absorbance at 670 nm. The colour complex can be extracted into chloroform. The methods obey Beer’s law in the range 0.3-7.0 and 0.2-7.0 (µg mL-1).
10 common anions and cations were added and the method was tested and no interference was observed. The proposed methods offered the advantages of having good reproducibility and were satisfactorily worked out to estimate the amount of curcumin in various turmeric samples.
Thermo-Gravimetric Studies and Specific Heat Capacity Estimations of the Products of Biginelli Reaction using TGA-DSC
In this work the thermal behavior and specific heat capacities of nine derivatives which were obtained via Biginellipyrimidone synthesis reaction have been experimentally determined using thermal gravimetry analysis and differential scanning calorimetry and the obtained results have been thoroughly analyzed and discussed. The influence of the structural variation on the thermal analysis has been discussed along with the influence of the structure of the derivatives of pyrimidines on the specific heat capacity.
To date heterocycles have successfully been switched from synthetic organic chemistry laboratory to the core of a variety of biomolecules conducting devices and so on. Derivatives of 2-hydroxypyrimidine or pyrimidines have a wide window of pharmaceutical applications. Therefore attempts have been made to understand the thermal response of these organic frameworks.
The main objective of this study was to explore thermal methods to understand heat-induced structural interactions as well as the specific heat capacity (Cp) as a function of temperature for the synthesized derivatives of 2-hydroxy pyrimidine or pyrimidones.
Room temperature condensation of ethyl acetoacetate urea and variety of aldehydes or ketones has been optimized in ionic liquids for the formation of pyrimidones. Thereafter the thermal profiles of the synthesized derivatives of pyrimidines have been studied thoroughly and the thermal response of the synthesized derivatives of pyrimidones gives sound information about thermal stability of these heterocycles.
In the present work the effect of substituents on the thermal behavior of the synthesized derivatives of pyrimidines has been investigated with the help of TGA-DSC analysis. Specific heat capacity (Cp) data as a function of temperature for the synthesized derivatives of pyrimidones have been reported for the first time.
The specific heat capacity data of the molecules of high commercial and biological relevance such as pyrimidines like organic frameworks play a subtle role in the development of the computational methods and molecular modelling to comprehend the fundamentals of these molecular frameworks and effectively explore the pharmaceutical as well as materialistic potentials of these heterocyclic frameworks via simulation.
Exploring Structural and Optical Properties of Nanoparticles of Barium Titanate and Iron doped Barium Titanate and Their Potential Application in Antibacterial Activity
Barium Titanate (BaTiO3) is a good candidate for a variety of applications due to its excellent dielectric ferroelectric and piezoelectric properties.
Pure and doped Barium Titanate (BTO) nanoparticles have been synthesized by the sol-gel method. Barium hydroxide octahydrate (Ba (OH)2.8H2O) and titanium (IV) iso-propoxide (Ti {OCH[CH3]2}4) were used as starting materials. Apart from pure Barium Titanate nanoparticles Fe-doped BaTiO3 nanoparticles of three different concentrations: 0.1 0.2 and 0.3 in mol% were prepared and characterized using X-ray diffraction (XRD) UV visible spectroscopy Fourier Transform Infrared Spectroscopy (FTIR).
From the X-ray diffraction pattern the particle size was found to be varied in a range of 17-25nm. By using UV visible spectroscopy it was observed that the band gap energy of pure BaTiO3 NP is 3.2eV. As the pure BaTiO3 nanoparticles are doped with 0.1% Fe the band gap reduces to 3.175eV. For BaTiO3 doped with 0.2% and 0.3% Fe the band gap energy values are 2.709 and 2.652 respectively. FTIR spectra were used to analyze the vibrational modes of BaTiO3. From the result obtained from FTIR we can see that the absorption spectrum ranges from 450cm-1-4000cm-1. The prominent peak of pure BaTiO3 is at 500cm-1 which is due to the vibration of the Ti-O band in crystal lattice. For BaTiO3 doped with Fe2O3 the wave number of the absorption peak is shifted from 500cm-1 in pure BaTiO3. The antibacterial studies were conducted on Pseudomonas aeruginosa Staphylococcus aureus and Escherichia coli.
Both pure and iron-doped Barium Titanate showed significant antibacterial properties confirming the antibacterial property of Barium Titanate nanoparticles.
Spectrophotometric Analysis of Edible Salt for Iodate Quantities
The Spectrophotometric method was used to identify iodate by utilizing a class of antidepressants known as imipramine hydrochloride (IPH) desipramine hydrochloride (DPH) clomipramine hydrochloride (CPH) and trimipramine hydrochloride (TPM).
Iodate in nano amounts can be measured using this method in an acidic medium with 3-methyl-2-benzothiazolinone hydrazone hydrochloride hydrate (MBTH) acting as an electrophilic coupling reagent. The MBTH-IPH/DPH/CPH/TPM method had a blue with a maximum absorbance at 630 nm. Beer 's law was followed and the blue color that was produced remained stable for up to 24 hours at room temperature (270C).
The boundaries depending on the situation for the assessment of the strategy like molar absorptivity and Sandell's sensitivity gave various qualities with various reagents. The method was tested with interference from common 11 cations and 8 anions and the results obtained were within a reasonable range.
The procedure was used for the determination of iodate in iodized edible salts because iodate is one of the common ions in iodized salt. It was found that the method is reliable and can be used effectively for the determination.
The Dynamic Impact of Synthetic Dyes on the Physicochemical Parameters of Cationic and Anionic Surfactants
The interaction of dyes (crystal violet malachite green and congo red) with cationic (cetrimide) and anionic surfactants (sodium dodecyl sulfate) in the aqueous medium were studied via conductometric and UV-visible spectroscopy.
The critical micelle concentration (CMC) of both cetrimide and SDS upsurges in all the selected dyes on increasing the temperature. Thermodynamic parameters like change in Gibb’s free energy of micellization () change in enthalpy of micellization () as well as change in entropy of micellization () were calculated by employing mass action model.
The values obtained are positive with and values being negative signified that the phenomenon of micellization is spontaneous as well as exothermic in nature. Moreover the more negative in water as well as in the presence of dyes signify the presence of electrostatic forces of attraction between the oppositively charged dyes and surfactant moieties. UV-spectroscopy reveals that spectral changes occur because of the interaction of surfactants with dye molecules.
By analyzing shifts in absorption peaks changes in intensity and alterations in band shape insights into the nature of surfactant-dye complexes and their potential applications in various industries can be assessed. This understanding can help in the design and optimization of products and processes involving surfactants and dyes.
Modulation of Solid-state Thermal Reaction of Iron(III)Citrate by a Co-precursor Studied using Thermogravimetry: Evaluation of Kinetic and Thermodynamic Parameters and Nucleation Rate
Background: Solid state reaction of iron(III)citrate leads to a range of ironbased oxides by varying the reaction conditions e.g. the presence of co-precursor. The influence of reaction conditions on the kinetics of the solid-state reaction of iron(III)citrate needs to be investigated. Objective: Kinetic analysis of the solid-state reaction of iron(III)citrate in the presence of a co-precursor has been explored to realize the influences of the co-precursor on the reaction process as well as decomposed material. Methods: Non-isothermal thermogravimetry profiles are deconvoluted to individual reaction steps. The model-free kinetic methodology is utilized to estimate step-wise activation energy and hence the reaction mechanism along with the reaction rate. Conversiondependent thermodynamic parameters and nucleation rate are estimated. XRD analysis has been used to characterize the decomposed material. Results: Thermogravimetry profiles obtained for an iron(III)citrate and malonic acid mixture are deconvoluted into six steps. The decomposed nanomaterial is identified as magnetite (size 10 nm). The observed reaction mechanisms associated with each step are different where the activation/reaction rate is conversion-dependent. A good fit between the experimental and reverse-constructed conversion profiles is obtained. The nucleation rate at higher temperatures is affected by both the extent of conversion and the heating rate. A possible reaction pathway is proposed. The study elucidates the role of malonic acid as a co-precursor in modifying the thermal reaction of iron(III)citrate and product formation. Conclusion: This investigation proposes the applicability of suitable co-precursors as a potential controlling factor for preparing iron oxides from iron-based compounds.
Biopolymers and their Nanocomposites: Current Status and Future Prospects
For many years petroleum-based polymers have been successfully enhanced by the addition of nanoparticles as additives. Carbon nanotubes graphene nanoclays 2-D layered materials and cellulose nano whiskers are a few of the several nanoreinforcements that are currently being researched. In comparison to unmodified polymer resin the use of these nanofillers with bio-based polymers could improve a wide range of physical properties including barrier flame resistance thermal stability solvent uptake and rate of biodegradability. This nano-reinforcement is a very appealing method to create new functional biomaterials for a variety of applications because these enhancements are typically achieved at minimal filler content.
Modulation of Triton X-100 Aqueous Micelle Interface by Ionic Liquid: A Molecular Level Interaction Studied by Time-resolved Fluorescence Spectroscopy
Background: Self-assembly structure is an important area of research for understanding biological systems owing to its resemblance to the membrane structure of the phospholipid bilayer. In a self-assembly medium chemical reactions and chemical or physical processes are dramatically different than the bulk phase. Understanding this process in synthesizing self-assembly structures may allow us to explore various biological processes occurring in cell membranes. Objective: The study aimed to understand water dynamics in the TX-100 micellar interface via steady state and a time-resolved fluorescence spectroscopy study. The objective was also to determine the two different ionic liquids (ILs) namely 1-butyl-3-methyl imidazolium tetrafluoroborate ([bmim][BF4]) and 1-decyl-3-methyl imidazolium tetrafluoroborate ([dmim][BF4]) inducing surfactant aggregation changes at the molecular level. Also the focus was on determining the hydration and its dynamics at the palisade layer of TX-100 micelle in the presence of two different ionic liquids. Methods: Steady state and time-resolved fluorescence spectroscopy have been used to study TX-100 micellar systems. Employing time-resolved spectroscopy two chemical dynamic processes solvation dynamics and rotational relaxation dynamics have been studied to investigate structural changes in TX100 by adding ILs. Solvation dynamics was studied by measuring the time-dependent Stokes shift of the fluorescent probe. From the Stokes shift time-resolved emission spectra were constructed to quantify the solvation dynamics. Also using the polarization properties of light time-resolved anisotropy was constructed to explore the rotation relaxation of the probe molecule. Results: The absorption and emission spectra of C-153 in TX-100 were red-shifted in the presence of both the ILs. Also the C-153 experienced faster solvation dynamics and rotational relaxation with the addition of both ILs. In our previous study we observed a significantly increased rate of solvation dynamics with the addition of [bmim][BF4] (J. Phys. Chem. B 115 6957-6963) [38]. However with the addition of the same amount of [dmim][BF4] the IL rate of solvation enhancement was more pronounced than with [bmim][BF4]. The faster solvation and rotational relaxation have been found to be associated with the penetration of more free water at the TX100 micellar stern layer leading to increased fluidity of the micellar interface. Conclusion: Upon incorporating ILs in TX100 micelle substantially faster solvation dynamics of water as well as rotational relaxation dynamics of C-153 have been observed. By decreasing surfactant aggregations [bmim][BF4] ILs facilitated more water molecules approaching the TX-100 micellar phase. On the other hand [dmim][BF4] ILs comprising mixed micelles induced even more free water molecules at the palisade layer yielding faster solvation dynamics in comparison to pure TX-100 micelle or TX100 micelle + [bmim][BF4] ILs systems. Time-resolved anisotropy study has also supported the finding and strengthened the solvation dynamics observation.
pH-Sensitive Polymers with their Important Applications (A Review)
Materials that modify their chemical or physical characteristics in reaction to diverse stimuli such as moisture heat water or pH are commonly known as smart materials or stimuli-responsive polymers. Typical applications for these polymers include catalysis finishing and coating processes. Tissue engineering drug delivery and gene transportation are additional applications that have emerged in the past two decades. As a result their potential use extends to a wider range of applications encompassing chemical processes drug delivery body-site targeting separation membrane activity sensing and actuation and agriculture. Recently pH-responsive polymers have garnered considerable interest for implementation in membrane and 4D printing. The current review work encompasses previously published research through 2022 with a particular focus on the critical application of pH-sensitive polymers.
Kinetic and Mechanistic Pathway of Electron Transfer React ions: Pyridine Oxidation by Peroxomonophosphoric Acid in Acidic Aqueous Medium
The kinetic and mechanistic pathways of pyridine oxidation by peroxomonophosphate has been studied in an acidic aqueous medium. Reactions of peroxomonophosphoric acid are the least exploited kinetically. This reaction has been attempted to understand the role of oxidation of pyridine and the reactivity pattern of peroxomonophosphate. The reaction has been second order and First-order concerning the oxidant and substrate respectively. The reaction rate showed a decreasing effect with increasing hydrogen ion concentration. Considering peroxomonophosphate reactions as non-chain reactions and all the results a feasible mechanism for the reaction has been suggested. The calculated energy of activation and entropy of activation has been observed conventionally to be 80 ± 5 kJ mol-1 and – 45 ± 6 JK-1 mol-1. The oxidation product was pyridine-N-oxide in this reaction.
Study of Selected Patents on the Manufacture of Activated Carbon as Electrodes in Power Storage Devices
The field of activated carbon has attracted many researchers. Our study of selected patents on the mentioned subject reveals an interesting fact such as including the pore characteristics of the electrode material in the claims of a patent specification. The parameters such as power density energy density capacitance and charge-recharge cycles are mentioned for the various embodiments in the patent specification. The technolegal aspects of patenting in this field are concerned with the source of the carbon the active material with which it is composited or activated the process of treatment which includes time temperature and method the resulting energy storage device and the process of making such a device.
Doping Induced Optical Band Gap Modification of Potassium Dihydrogen Phosphate
Aim: Potassium dihydrogen phosphate (KDP) is an excellent nonlinear optical material that has many potential applications such as laser frequency conversion Qswitches Pockels cells 3-D optical data storage devices etc. Doping enhances various optical parameters of KDP. Doping changes in the absorbance and dopants such as aspartic acid succinic acid glycine and L-alanine improved the optical band gap of the sample. Background: KDP is a non-linear optic material that has many important applications. Many researchers all over the world are trying to improve its optical properties. Objective: To synthesise pure KDP and KDP doped with aspartic acid succinic acid glycine and L-alanine. Also to study the temperature stability of the grown samples using TGA DTA and DSC analysis. Methods: Growth from solution at low temperatures is used for the growth of crystals. TGA DTA and DSC are used to analyse the stability of the samples against temperature variations. Results: KDP crystals of good quality were grown using the slow cooling solution growth technique. Determined their band gap using the Tauc Plot. Significant variations in the optical bandgap are noticed. Also the TGA DTA and DSC characterizations were done. Conclusion: KDP solution and grown crystals of good quality were synthesized. The variation in the bandgap on doping is a significant result as the modifications in bandgap enable the sample to be used in a more enhanced applications. Also the doped samples were stable for variations in temperature like the pure KDP.
Drug Polymorphism: An Important Pre-formulation Tool in the Formulation Development of a Dosage Form
Polymorphism permits solids to have two or multiple crystal structures with varying orientations or conformations and polymorph drug dissolution and solubility vary. Polymorphism influences drug efficacy bioavailability and toxicity. Various parameters can regulate polymorph crystallization including supersaturation phase temperature stirring rate solvent addition rate seed crystal additives and pH. To characterize and monitor polymorphs various analytical approaches are available including powder X-Ray diffraction / X-Ray diffraction (PXRD/XRD) also called as Gold Standard method differential scanning calorimetry (DSC) Infrared spectroscopy (IR) and microscopical studies. To prevent polymorphic change during production distribution and storage formulation with the most stable form in the marketed product is considered. In addition by monitoring each phase of raw material processing polymorphisms can be controlled during dosage form manufacturing. The objective of this review is to provide concise information on drug polymorphism their characterization process their effect on the stability of dosage forms factors controlling polymorphism in the crystallization process some case studies on polymorphs control of polymorphism during the formulation of successful dosage forms and some of the regulatory considerations regarding polymorphs. Various databases like Pubmed/Medline Google Scholar and Web of Science of all English language articles were searched and relevant information was collected regarding the importance of polymorphism in formulation development. From a vast literature survey it was found that polymorphism is a very important tool in a pre-formulation study that provides information about the fate of a drug molecule in its journey. From the present study it was concluded that the polymorphism property of a drug should be taken into consideration at the pre-formulation stage since it is a very important tool for the formulation of a successful dosage form with stability and efficacy.
Effect of Laterally Substituted Methoxy Group on the Liquid Crystalline Behavior of Novel Ester Molecules
Background: The aim of this research is to study the effect of length-to-width ratio on mesomorphism to enhance the understanding of its potential applications. This will be achieved by synthesizing a unique and innovative series of identical ester molecules including lateral methoxy groups and terminal ethyl benzoate groups. In this research we aim to find new insights into the relationship between molecular structures and mesomorphic behaviors which could have significant implications for the development of advanced materials with adapted properties. The objective of the study is to investigate the mesophase behavior of new ester mesogens and determine how they are influenced by lateral methoxy groups. By identifying the underlying perspectives and relationships between these variables we hope to better understand the unique properties and potential applications of these materials. Method: In this research work the focus is on the synthesis of ethyl(E)-4-((3-(4-alkoxy-3- methoxyphenyl)acryloyl)oxy)benzoate which is prepared from Steglich esterification method by using (E)-3-(4-alkoxy-3-methoxyphenyl)acrylic acid and ethyl 4- hydroxybenzoate. Synthesis processes involve precise reaction sequences designed to ensure maximum yield and purity of the final product. By providing a detailed report on the experimental process this study contributes to the ongoing research efforts aimed at the development of innovative compounds with various applications in liquid crystals. Result: A new set of liquid crystal derivatives has been synthesized and studied to investigate the effect of molecular structure on the behavior of liquid crystals with particular attention to the group -OCH3 located laterally. This series was composed of 12 derivatives (C1-C16). Among them the first six derivatives (C1-C6) did not have the characteristics of a liquid crystal while the remaining derivatives (C7 and C8) had a monotropic behavior and C10-C16 had an enantiotropic smectogenic liquid crystal behavior without exhibition of the nematic phase. The average thermal stability of the smectic property was 87.33 °C and the mesophase range was 2 °C to 14 °C. The molecular structure was confirmed by analytical and spectral analysis. The properties of liquid crystals of this new series were compared with those of other known structurally similar homologous series. The transition temperatures were determined with an optical polarizing microscope equipped with a heating phase. Conclusion: The mesomorphic thermal and optical properties of the compounds have been validated by DSC and POM techniques. The result shows that the length of the alkyl chain has a significant influence on the mesomorphic characteristics and thermal stability of the different mesophases. Evaluation of the compounds studied indicates that the molecules are sensitive to their lateral substituent which influences the thermal characteristics and stability of the mesophase.