HOMO-LUMO Plot Research Articles

Battling hazardous gas molecules with kekulene surfaces: A computational study

A Density Functional Theory were used to investigate the interactions between kekulene and various noxious gases, including methane(CH4), carbon dioxide (CO2), hydrogen(H2), ammonia(NH3), and sulfur dioxide(SO2). The adsorption energies and bond distances were computed, indicating successful molecular interactions with kekulene, particularly notable in the exothermic nature of the adsorption process. Enthalpy calculations further confirmed the exothermic nature of the reactions, suggesting spontaneous adsorption. The analysis of frontier molecular orbitals revealed distinctive electronic characteristics, with HOMO-LUMO plots indicating a significant energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Chemical descriptors derived from these calculations provided insights into the reactivity and polarizability of the compounds. Furthermore, the molecular electrostatic potential (MEP) surface maps illustrated the electrostatic potential distribution, aiding in predicting the molecule’s reactivity. Overall, the study highlights the potential of kekulene as a selective adsorbent for toxic gas (SO2), offering valuable insights into its chemical and electronic properties for various applications, particularly in environmental and industrial settings.

The impact of anchoring groups on the efficiency of dye-sensitized solar cells: 2-Cyanoacrylic acid vs. ethyl 2-cyanoacrylate

Due to their promising performance, coumarin-based dyes have been widely used in third-generation dye-sensitized solar cells (DSSCs) and as nonlinear optical (NLO) materials. In this study, we have designed and synthesized coumarin-based sensitizers in conjugation with common phenyl as a π-linker and ethyl-2-cyanoacrylate (SPDSSC 7) and 2-cyanoacrylic acid (SPDSSC 8) as an anchor and determined their DSSC performance. Photovoltaic results showed that 2-cyanoacrylic acid-based sensitizer (SPDSSC 8) performed better than ethyl-2-cyanoacrylate-based sensitizer (SPDSSC 7) which improves with a thicker coating of TiO2. Density functional theory (DFT) results showed an inverse relationship between band-gap (BG) and chemical potential and electrophilicity index but a direct relationship between BG and hardness and hyperhardness. Time dependent-DFT (TD-DFT) showed a similar trend as observed in the experiment. It was also found that first-order hyperpolarizability (β0) and second-order hyperpolarizability (γ) and PCE is related directly through CT properties. Furthermore, calculations of sensitizers@TiO2 revealed that sensitizer with ethyl-2-cyanoacrylate was linked as unidentate and 2-cyanoacrylic acid linked bidentatly to TiO2 clusters. Furthermore, quantitative analysis of the HOMO-LUMO and MEP plots revealed that SPDSSC 8 showed more efficient electron transfer from the sensitizer to the TiO2 cluster than SPDSSC 7. These results were consistent with the calculated Eadsorption for both sensitizers. The monodentate binding of SPDSSC 7 to TiO2 results in inferior charge transfer in the semiconductor’s conduction band, ultimately negatively impacting DSSC performance.

Evaluation of structure-reactivity correlation of efficient corrosion inhibitor ionic liquids for mild steel in acidic medium

The synthesis and characterization of Imidazolium cation-based ionic liquids having different anions were reported in the present article. The physicochemical and spectral analyses were used to characterized these ionic liquids. The theoretical studies using the B3LYP method provide optimized structure, HOMO–LUMO plots, thermodynamic parameters, and quantum descriptors. The anti-corrosive property of Imidazolium cation-based ionic liquids was observed in 0.5 M H2SO4 corrosive medium at 303, 313, 323, and 333 K temperatures by various strategies like gravimetric studies, electrochemical impedance spectroscopy, potentiodynamic polarization studies, and scanning electron microscopy (SEM). The interesting feature of this article is that both ionic liquids follow different adsorption isotherms. IL-1 ionic liquid shows physisorption adsorption behavior, and IL-2 exhibits mixed adsorption (chemisorptions and physiorption). The electrochemical strategies and E gap value obtained from DFT reveal the maximum inhibition efficiency of IL-2 for the corrosion process in an acidic medium on mild steel. Potentiodynamic polarization studies reveal the mixed type behavior for ionic liquid inhibitors. EIS results indicate that the inhibition efficiency improved by enhancing ionic liquids concentration. The protective layer formation or adsorption of ionic liquid on metallic surface was confirmed by SEM. In the present article, the proposed mechanism shows the blockage of anodic and cathodic sites by ionic liquids to inhibit the corrosion process on mild steel in an acidic medium.

Scrutinizing the optical limiting action of a novel carbonyl guanidinium hippurate for laser safety device applications

A new organic Carbonyl Guanidinium Hippurate [CGH] crystal is grown and its crystal structure was solved for first time in literature. Structural stability via hydrogen bond interactions and the structural parameters were investigated and weighted up with the theoretical interpretation. FT-IR and Raman spectroscopic behavior was expended to recognize the various functional groups accommodated in CGH. The diverse inter contacts existing within the crystal were visualized through 3D Hirshfeld surface analysis and 2D fingerprint plot of CGH ensures the percentage of interactions takes place in. The natural bond orbital evaluation interprets all the possible inter and intra molecular interactions appear in the crystal structure for stabilization. The CGH specimen has thermal stability up to 183 °C and the lesser defect nature for the better NLO effect has been confirmed with diminish dielectric constant and dielectric loss at higher frequencies. The linear optical studies reveal that the material has high transmission window in the region of 280–1100 nm and low band gap with green emission tendency. HOMO-LUMO plot and MESP map indicates the ICT interactions present in the molecule. Intensity dependent open aperture z-scan confirms the sequential two photon absorption arising from excited state absorption and thus CGH crystal can be used for developing nonlinear absorption based laser safety devices.

Unravelling the interaction between boron nitride nanosheets and organic pesticides through density functional theory studies

In recent years, the concerns over the contamination of water resources due to pesticides and their residues have risen. To address this issue, the present study investigates the adsorption of some commonly used pesticides (acetamiprid, clothianidin, imidacloprid, thiacloprid and tri-allate) on monolayer boron nitride nanosheets (BNNs) from wastewater based on the first-principle density functional theory. A standard B3LYP model and 6-311G basis set were used to obtain the electrostatic potential maps, the density of states plot and HOMO-LUMO energy distributions. The feasibility of adsorption was confirmed from the adsorption energy calculations. The recovery time values were evaluated to examine the recovery of BNNs sheets after the adsorption. The electrostatic potential maps examined the local electron density distribution over the pesticides before and after adsorption. Quantum mechanical descriptors were evaluated to understand the chemical activity of the species involved in the process. The HOMO-LUMO distribution and DOS plots indicated that HOMOs of pesticides play an important role in the interactions. The quantum descriptors indicated weak interactions between pesticides and BNNs. The RDG and NCI plots confirmed the dominance of Van der Waals forces during adsorption interactions and showed that the forces operate to a greater extent during adsorption of imidacloprid.

Synthesis, crystallization, XRD, Hirshfeld surface, vibrational spectra, and quantum chemical studies and Computational investigation of Caffeinium bisulfate: a new noncentrosymmetric form

Crystals of caffienium bisulfate were grown by solution growth technique. The vibrational spectra were scaled by adopting FT-IR and FT-Raman spectroscopy with the wide range, between 4000-400 cm−1. X-ray diffraction study exhibited that the functional group such as N-H….O hydrogen bonds played an effective role in generating hydrogen-bonded crystal packing, pre-dominant. The examined molecules showed an interconnection of anions, by the O-H…O hydrogen bonds, establishing a chain C (4) motif, extending along the b-axis of the unit cell. Further, anions have shown interaction with cations, through N-H…O hydrogen bond, resulting from a ring R1 2 (4) motif. The formed ring and chain motifs manifested an alternate hydrophilic stratum at z = ¼ and ¾. Geometrical optimization of tester molecule was done with Density Functional Theory (DFT) employing B3LYP function along with Hartree-Fock (HF) using 6-311++G(d,p) level basis set. Optimum molecular geometry and calculated database on the vibrational spectra were critically analyzed by comparing with experimental findings, resulting in a good correlating exhibited among them. Natural Bond Orbital (NBO) study revealed that hyper conjugation affinities and intermolecular charge transfer (ICT). An advanced technique such as HOMO-LUMO plot was performed to understand the chemical hardness, electro negativity and chemical efficacy of the tested molecules. The results showed that the occurrence of lower band gap value in the frontier orbital was responsible for the possible biological activities of the study materials. Bioinformatics analysis is applied for analyzing the biological activity of CAFSUL against Alzheimer's disease through computational methods. Communicated by Ramaswamy H. Sarma

Experimental, and theoretical investigations on the structure and vibrational spectral analysis of oxalate complex of nicotinamide and computational scrutiny against prostate cancer

This investigation involved oxalate salt of B vitamin experimental and theoretical spectra analysis. Docking studies and molecular dynamic simulation analysis were also carried out against the target protein involved in prostate cancer. At room temperature, the infra-red and Raman spectra results were chronicled in at range 4000–400 cm–1. In the crystalline environment along with the shifting of some spectral bands, the effect of hydrogen bonding force is detected. HF and DFT/B3LYP were employed to estimate the optimized geometry with the basis set of 6-311++G (d,p). Hypothetical wavenumbers presented a respectable agreement with the investigational values. The various genuine modes are observed and some of them are perceived in the experimentally observed spectra. Hyperconjugative interaction and intramolecular charge transfer (ICT) values were calculated with the help of the natural bond orbital (NBO) study. HOMO-LUMO plot technique was employed to examine the compound's hardness of chemical, chemical potential, and electro-negativity. The molecules' bioactivity and therapeutic efficacy were estimated through the lower band gap value of the frontier orbitals. In silico analysis was performed, to analyse the therapeutic efficacy of oxalate complex of Nicotinamide against Prostate cancer through Molecular docking and dynamics study. ADME/T analysis revealed the pharmaceutical efficacy of the oxalate complex of Nicotinamide by satisfying Lipinski’s Rule of Five, BBB, HOA, etc. Highlights of the work Comparative studies of theoretical and experimental vibrational spectra of the B vitamin Theoretical wavenumber numbers were showed good agreement with the experimental values Theoretical bond lengths and bond angles were slightly deviated from the experimental values Theoretical calculations shows that B vitamin exists in a Cocrystal Number of modes calculated from the factor group method is match with the theoretical method

Comprehensive DFT calculations on protonated metallic hexa halide anions [formula omitted](M=Ni, Pd, Pt; X=F, Cl)

We propose a new series of superacids by protonation of hexa-halide anions MX6−(M ​= ​Ni, Pd, Pt & X ​= ​F, Cl) by using combination of DFT/B3LYP method and SDD basis set. The strength of superacid is calculated by their Gibbs free energies of deprotonation. The acidity of these superacids is not only related to electronic stability of corresponding metallic anions MX6− but also on topology of protonated metallic anions. We have noticed that these base anions have very high vertical detachment energy (VDE), which indicates that they belong to superhalogenic family. A rough correlation (R2 ​= ​0.62) is found in between VDE of MX6−and acidity of protonatedMX6−. The AIM analyses of HMX6 help to understand its superacidic behaviour. Some electronic parameters of HMX6 are also calculated by using same level theory. We have also discussed the optimized structure of NiF6Li supersalt. The HOMO LUMO plots are used to describe chemical reactivity as well as the binding nature of HMX6 superacids and LiNiF6 salt.

Implementation of biomolecular logic gate using DNA and electrically doped GaAs nano-pore: a first principle paradigm.

One of the emerging areas of today's research arena is molecular modeling and molecular computing. The molecular logic gate can be theoretically implemented from single-strand DNA which consists of four basic nucleobases. In this study, the electronic transmission characteristics of DNA chain are investigated to form the logic gate. This biomolecular single-strand DNA chain is passed through an electrically doped gallium-arsenide nano-pore to achieve reasonably improved transmission along <1 1 1> direction. Current-voltage characteristic and device density of states with HOMO-LUMO plot of the device are explained along with the conductivity of the device to confirm the characteristics of some important logic gates like a universal gate. Ultimately the property of resistivity proves the law of Boolean logic of AND gate and universal logic gate, viz., NAND and NOR gate. All the electronic properties of the Boolean logic gate are explored based on the first principle approach by non-equilibrium Green's function coupled with density functional theory in room temperature.

Enhancement of nonlinearity by a parasubstituted compounds - it's spectroscopic analysis

By slow cooling solution growth technique, transparent single crystals of 4-pyridone 4-nitrophenol (4PNP) were grown using ethanol as solvent. The harvested crystals were subjected to various characterization studies. Single crystal XRD reveals that the grown crystal crystallizes in orthorhombic system. The grown crystals were characterized by FTIR/Raman to ascertain the fundamental functional groups. Theoretical analysis predicts that 324 possible optical modes of vibrations. Bandgap and refractive index were obtained from the UV–Vis optical studies,. Fluorescence spectrum shows an emissive peak at 340 nm. HOMO-LUMO plot reports the energy gap on the basis of molecular orbital energy levels.

Thermal smearing in DFT calculations: How small is really small? A case of La and Lu atoms adsorbed on graphene

The thermal smearing is an efficient tool to accelerate self-consistent field (SCF) convergence, and therefore widely employed in the modern computational materials science. One of the values most frequently used is 0.005 Ha. However, the fact that its equivalent temperature of 1578.9 K goes far beyond conditions of the very stability for most systems studied in the conventional materials science rises concerns on credibility of the data obtained. In the present report, we studied the effect of variable smearing values on different calculated parameters of selected lanthanide atoms (Ln = La and Lu) interacting with cluster and periodic graphene models, using Perdew-Burke-Ernzerhof (PBE) functional in conjunction with the empirical long-range dispersion correction by Grimme. In the cluster calculations for the La and Lu complexes with the supercoronene model for graphene, only the use of thermal smearing of the order of 10−4 Ha or below (down to Fermi occupancy) can yield convergent total energies, Ln…C interatomic distances, charge and spin of Ln atom, spin density and HOMO-LUMO plots. The results of periodic calculations were less sensitive to the choice of the smearing value. In this case, the smearing values at which convergent results can be obtained for total energies, Ln…C interatomic distances, charge and spin of Ln atom, as well as DOS plots are from 0.00004 to 0.001 Ha. In both cluster and periodic calculations, the value of 0.005 Ha was too high for reliable computed parameters to be obtained.

Synthesis, molecule growth, characterization, theoretical studies and nonlinear optical properties of new chalcone derivative containing thiophene moiety for optical device applications

A new organic nonlinear optical chalcone derivative-1-(5-bromothiophene-2-yl)-3-(3-methoxyphenyl) prop-2-en-1-one (3MO5B2SC) molecule has been grown by slow evaporation technique. Theoretically DFT method was used to study optimized structure of the molecule and compare with reported XRD data. The structure of the molecule has been confirmed by the experimental and computed FTIR and H1 NMR spectrum studies. The melting point (117 °C) and thermal stability (273 °C) of the molecule have been determined using DSC, TGA, DTA and DTG. The optical absorption spectrum revels that molecule has lower optical cut-off wavelength of 410 nm recorded by UV–Vis–NIR spectrophotometer and 480 nm calculated by DFT. The band gap calculated from experimental data and theoretical HOMO–LUMO plots is same (3.3 eV). The global chemical reactivity descriptor (GCRD) of the sample has been calculated. The nonlinear parameters such as nonlinear absorption coefficient (β ~ 10−4 cm/W), nonlinear refraction index (n2 ~ 10−8 cm2/W) and third-order nonlinear susceptibilities (χ(3) ~ 10−6 esu) and molecular hyperpolarizability (γh ~ 10−26 esu) were measured under diode-pumped continuous wave Nd:YAG laser at 532 nm wavelength. The static electric dipole moment (μ), polarizability (α), first hyperpolarizability (β), static and dynamic second hyperpolarizability (γh) have been calculated theoretically and compared with experimental values. The experimental and theoretical nonlinear parameters are many times higher than urea molecule. The mean polarizability, total polarizability, first-order hyperpolarizability and static second hyperpolarizability value of the molecule is 20, 7.5, 17 and 91 times higher than standard urea, respectively. The nonlinearity exhibited by this molecule exploited for studying its optical limiting behaviour. The structure and its corresponding properties prompt that it can be used as nonlinear optical devise applications.

Structural, optical and thermal analysis of creatininium borate – A new semiorganic nlo single crystal

The main focus of this work is to synthesize creatininium borate (CRB) single crystal by using slow evaporation technique and to analyse the physiochemical properties. The grown single crystal is subjected to Single Crystal X-ray Diffraction analysis (SXRD) and the structural parameters were assigned. The various interactions present in the synthesized material have been visualized by Hirshfield surface analysis. The transmittance ability was studied by using UV Visible spectral analysis and the optical constants such as band gap energy, extinction coefficient and refractive index were calculated. HOMO-LUMO and MEP plots were successfully generated and analysed. The emission behaviour of creatininium borate was analysed by photoluminescence spectral analysis. Theoretical NLO calculations were performed to calculate the dipole moment, polarizability, first order hyperpolarizability and second order hyperpolarizability. Third order optical non linearity was confirmed by Z scan analysis. The second harmonic generation was confirmed by Kurtz and Perry powder technique. The optical limiting behaviour and laser damage threshold analysis suggests the material in laser assisted devices. Thermal behaviour of the material has been analysed by TG/DTA analysis.

Xrd, Quantum Chemical, Vibrational, Thermal and Antifungal Activity Analysis on 3-Nitroanilinium Hydrogen Oxalate

3-nitroanilinium hydrogen oxalate has been crystallized successfully by solvent evaporation method. Optimized molecular geometrical parameters and the vibrational assignments of 3NAOX has been calculated by using Hartree-Fock (HF) and density functional method (B3LYP) with 6-311++G (d, p) basis set. The computational analysis showed good agreement with the experimental data. The energy and various parameters were obtained by HOMO–LUMO plot. The apparent pharmaceutical/biological activity of the salt confirmed by lower band gap value obtain from the Frontier Molecular Orbital (FMO) analysis. Thermal properties of 3NAOX were analyzed by TGA/DTA. The grown crystals were involved in an antimicrobial activity against certain potentially threatening microbes which shows that grown crystal screened the bacteria.

A New Organic Dye Cordia sebestena Sensitized Solar Cell with Current-Voltage Characteristics

Titanium dioxide nanoparticles have been synthesized by a novel modified sol-gel for the fabrication of natural dye sensitized solar cells. The natural photo sensitizer extracted from Cordia sebestena flower was mixed with the precursor solution. The flower dye has put the effort of a surfactant which has resulted colourized TiO2 instead of white TiO2. Whencompared to the conventional sol-gel method, this modified process has enhanced the properties of TiO2 like, morphology, uniformity in dye absorption. It has reduced the agglomeration of TiO2 and dye aggregation significantly. The optimized molecular geometry of sebestenoid D, the major pigment of Cordia sebestena and HOMO-LUMO plot are found using density functional theory. The TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies which showed improved properties in modified sol-gel process. Ecofriendly and low-cost natural dye sensitized solar cells (DSSC) were fabricated using conventional and pre-dye treated TiO2 sensitized by Cordia sebestena flower extract. The I-V studies showed the solar light photon to electron conversion efficiencies of 0.87 and 1.28 % for sol-gel and modified sol-gel methods, respectively. There has been an enhancement in efficiency by 47 % in modified sol-gel method which is very much promising in terms of efficiency for natural dye sensitized solar cells.

Structural, IR spectra NBO, TDDFT, AIM calculation, biological activity and docking property of [1,2,4]-triazolo[3,4-b][1,3,4] thiadiazole

In this paper a complete quantum chemical study of [1,2,4]-triazolo [3,4-b][1,3,4] thiadiazole has been done with the combination of DFT/B3LYP method and 6-311G(d, p) basis set. The vibrational assignments are calculated with the help of PED. By using quantum theory of atoms in the molecule (QTAIM) we have calculated topological parameters at BCP point by which the nature of several intermolecular hydrogen bondings are studied. Electronic properties are calculated with the help of HOMO-LUMO plot. Chemical active sites of title molecule are described by FF, chemical hardness, chemical softness etc. UV spectra are calculated with the help of TDDFT using optimized parameters. NBO analysis gives idea about transfer of charge between bonding and antibonding electrons. Biological activity analysis suggests that the molecule can be used in anti- inflammatory drugs to explore new drugs. The molecule is docked with MBNL1 receptor with the help of Swiss-Dock online server with Full fitness score of −541.58 a.u.

Structural, spectral, computational, thermal and antibacterial studies on a co-crystal: 2-Aminopyrazine phthalic acid

In the present work, the crystal growth of a new co-crystal of aminopyrazine with phthalic acid (APPA) and the corresponding structural, vibrational, thermal and antibacterial characteristics have been reported. Crystals of aminopyrazine phthalicacid (PAPA) were grown by slow solvent evaporation technique. Single crystal X-ray diffraction analysis revealed that the present crystal structure is monoclinic system with P21/n space group. In the crystal structure, molecules were connected via NH⋯O and OH⋯N intermolecular hydrogen bonds with R22(8) and R44(18) ring motifs thus forming a C22(10) chain motif along the b axis. The crystal structure was dominated by NH⋯O and weak OH⋯N interactions and it was quantitatively analyzed by Hirshfeld surface and fingerprint analysis. The molecular geometry of the grown crystal was optimized theoretically by using density functional theory with B3LYP/cc-PVTZ basis set. The optimized molecular geometry and computed vibrational spectra were compared with experimental results which showed noteworthy agreement. Thermal stability was determined as 148 °C for APPA crystal using TG/DTA study. The atomic charge distribution on atoms of APPA molecule has been calculated by Mulliken charge analysis. Energy gap, ionization potential and chemical hardness of the APPA molecule were carried out by HOMO–LUMO plot. In which, the frontier orbitals has lower band gap value indicating the possible bio activity of the molecule. The natural bond orbital analysis was carried out to interpret the stability of the molecule and charge delocalization within the molecule. The antibacterial activity of the compound was tested and found increased significantly against all bacteria. Enhanced antibacterial activity of the APPA was attributed to the synergistic effects of intermolecular hydrogen-bonding interactions NH⋯O and OH⋯N between APZ and PA. The molecular docking study supported the antibacterial activity and exhibiting the binding energy.

Theoretical investigation of organotin(IV) complexes of substituted benzohydroxamic acids

The complexing abilities of para-substituted benzohydroxamates to the tin metal center of organotin(IV) ions have been investigated using DFT, since organotin(IV) compounds have been touted as promising anti-cancer agents. We have studied the coordination structures of Sn(IV) complexes (R2SnL2) with organoligands (R = Me, Et, n-Bu) and para-substituted benzohydroxamate ligands (L) so as to study the effect of electron withdrawing (Cl, F, NO2) and electron donating substituents (OCH3, NH2) in the ligand as well as in the alkyl group of the organotin compound. The structures of all the complexes are found to be intermediate between distorted octahedron and bicapped tetrahedron, in agreement with experiment. We have analyzed all the complexes in detail, using their Mayer bond orders, ESP charges, HOMO-LUMO plots and Fukui indices. Of all the complexes, the one having methyl as the alkyl group and the para-amino benzohydroxamate ligand is found to be the most stable. This is owing to the stronger ionic and covalent interaction of Sn(IV) with the para-amino benzohydroxamate ligand and methyl group, respectively.

Spectroscopic characterization of hydroxyquinoline derivatives with bromine and iodine atoms and theoretical investigation by DFT calculations, MD simulations and molecular docking studies

In the present work, spectroscopic characterization of 5,7-dibromo-8-hydroxy quinoline (DBHQ(1)) and 5,7-diiodo-8-hydroxy quinoline (DIHQ(2)) has been obtained theoretically and experimentally. On the basis of potential energy distribution of vibrational modes, complete assignments of wavenumbers were performed yielding good agreement between experimental and theoretical wavenumbers. The HOMO-LUMO plots in the title molecules show the charge transfer in the molecular system through the conjugated paths. The electrophilic and nucleophilic sites are revealed from the molecular electrostatic potential maps. Experimental investigation encompassed spectroscopic characterization by FT-IR and Raman techniques while computational studies included DFT calculation, molecular dynamics (MD) simulations and molecular docking studies. MD simulations provided insights into the reactivity with water and with selected proteins. The molecular docking studies reveal that the ligands bind at the active site of the macromolecule and could restrict or block the functioning of Plasmodium falciparum dihydrofolatereductase-thymidylate synthase (PfDHFR-TS), there by acting as antiprotozoal agents. Drug activity and binding affinity of halogen positional changes in the title molecules with target protein were reported and this study thesaurus the effects of bio-efficiency in the molecule.

Structural, Spectroscopic Investigation and Computational Study on Nitrate and Hydrogen Oxalate Salts of 2-Aminopyrimidine.

The proton transfer salts of 2-aminopyrimidine with nitric acid (2APNO) and oxalic acid (2APOX) were synthesized and crystallized successfully by solvent evaporation solution growth technique. The crystal packing is stabilized through intricate three dimensional hydrogen bonded network. Both, the molecular structures were optimized with Density Functional Theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311++G(d,p) basis set. Optimized molecular parameters between the methods were compared for the cation showing appreciable agreement. The computed vibrational spectra are compared with experimental result which clearly demonstrates the strong N-H··· O vibrational behaviour. Thermal stability of the crystals were analyzed with TGA/DTA and the melting points of the salts, viz. 2APNO and 2APOX, were identified at 189.5 and 210.9 °C, respectively. The chemical hardness, electronegativity, chemical potential and electrophilicity index of the two crystals were determined by HOMO-LUMO plot. The lower band gap value obtained from the Frontier Molecular Orbital (FMO) analysis favours the possible pharmaceutical/biological activity of the salts.