Assignment Of Vibrational Modes Research Articles

Investigation of spectroscopic characterization, crystal structure, and antitumor activity of a novel 2ATP molecule

In this section, the spectroscopic characteristics of 2-amino-toysl-pyridine (2ATP) are fully examined, using both experimental and computational investigations guided by density functional theory (DFT). It will facilitate our computational research using the B3LYP approach to use the basis set 6–311++G(d,p). Comprehensive assignments of vibrational modes were obtained from the vibrational spectra, which comprised FT-Raman and FT-IR spectroscopy and were recorded in the region of 3500–400 cm−1 and 4000–500 cm-1, respectively, using the Vibrational Energy Distribution Analysis (VEDA) approach. The net atomic charges inside the molecule were ascertained by using Mulliken population analysis, natural atomic charges, and electrostatic potentials (CHELPG). The structural conformations of 2ATP were determined using NMR spectroscopy in a CDCl3 solvent. The donor-acceptor interactions of the 2ATP molecule at the 6–311++G(d,p) level were studied by means of a Natural Bond Orbital (NBO) study. Studies of the ultraviolet (UV) spectrum in ethanol were used to assess the effects of the solvent. An assessment was made of the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) in order to understand charge transfer processes that suggest the molecule may have biological activity. Molecular electrostatic potential (MEP) surfaces were used to predict the nucleophilic and electrophilic sites in molecules. The non-covalent interactions were evaluated using the reduced density gradient (RDG) approach. The Multiwfn software was used to analyze the topological properties of the 2ATP, including the Localized Orbital Locator (LOL) and Electron Localization Function (ELF). Further attention was drawn to the compound's exceptional pharmacological potential when its ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) characteristics were evaluated. Not to add, molecular docking experiments were carried out to evaluate the feasibility of 2ATP as a bioactive material with possible uses in the pharmaceutical business.

Terahertz spectroscopic study of the dehydration process and hydrogen bonding network of DL-glutamic acid and its monohydrate

The dehydration process involves the dissociation and reorganization of hydrogen bonds, and for the characterization of the dehydration process of amino acid-based hydrates, the analysis of their molecular vibrational modes and hydrogen bonds is still challenging nowadays. In this paper, the dynamic process of the dehydration of DL-glutamic acid monohydrate was monitored using terahertz spectroscopy. Quantitative simulations were performed on DL-glutamic acid and its monohydrate, with vibrational mode assignments and hydrogen bonding network analysis based on Density Functional Theory (DFT) for terahertz absorption peaks. The results show that the hydrogen bond stretching vibration is intermixed with atomic vibration. Specifically, the intermolecular hydrogen bond O4-H9···O2 of DL-glutamic acid exhibits a stronger vibration at 2.43 THz. Furthermore, the intramolecular hydrogen bond O5-H11···O4 in DL-glutamic acid monohydrate shows significant changes in bond length and bond angle at 1.85 THz. These findings validate the effectiveness of terahertz spectroscopy in monitoring the transformation process of the hydrate and the analysis of the hydrogen bond.

Multi-wavelength Raman microscopy of nickel-based electron transport in cable bacteria.

Cable bacteria embed a network of conductive protein fibers in their cell envelope that efficiently guides electron transport over distances spanning up to several centimeters. This form of long-distance electron transport is unique in biology and is mediated by a metalloprotein with a sulfur-coordinated nickel (Ni) cofactor. However, the molecular structure of this cofactor remains presently unknown. Here, we applied multi-wavelength Raman microscopy to identify cell compounds linked to the unique cable bacterium physiology, combined with stable isotope labeling, and orientation-dependent and ultralow-frequency Raman microscopy to gain insight into the structure and organization of this novel Ni-cofactor. Raman spectra of native cable bacterium filaments reveal vibrational modes originating from cytochromes, polyphosphate granules, proteins, as well as the Ni-cofactor. After selective extraction of the conductive fiber network from the cell envelope, the Raman spectrum becomes simpler, and primarily retains vibrational modes associated with the Ni-cofactor. These Ni-cofactor modes exhibit intense Raman scattering as well as a strong orientation-dependent response. The signal intensity is particularly elevated when the polarization of incident laser light is parallel to the direction of the conductive fibers. This orientation dependence allows to selectively identify the modes that are associated with the Ni-cofactor. We identified 13 such modes, some of which display strong Raman signals across the entire range of applied wavelengths (405-1,064 nm). Assignment of vibrational modes, supported by stable isotope labeling, suggest that the structure of the Ni-cofactor shares a resemblance with that of nickel bis(1,2-dithiolene) complexes. Overall, our results indicate that cable bacteria have evolved a unique cofactor structure that does not resemble any of the known Ni-cofactors in biology.

FT-IR, FT-raman and UV spectra and ab initio HF and DFT study of conformational analysis, molecular structure and properties of ortho- meta– and para–chlorophenylboronic acid isomers

In this study, the FT-IR, FT-Raman, and UV–Vis spectroscopic properties of three monosubstituted phenylboronic acid derivatives: ortho-chlorophenylboronic acid (o-ClPhBA), meta-chlorophenylboronic acid (m-ClPhBA) and para-chlorophenylboronic acid (p-ClPhBA) molecules are investigated both experimentally and theoretically using Density Functional Theory (B3LYP) and Hartree Fock (HF). In order to find the stable possible conformations of the compounds, the conformational analysis was carried out by running potential energy surface (PES) scan by means of rotation of two structural parameters, the dihedral angles indicated as φ2 (C6–B–O1–H1A) and φ3 (C6–B–O2–H2A), varying from −180° to 180° with an increment of 10° using B3LYP/6-31G level of theory. Also, to determinate the most stable conformer for all the molecules, potential energy curve (PEC) the stable possible conformations on PES scan were investigated as a function of φ1 (C1-C6–B–O1) dihedral angle from 0° up to 180° with an increment of 10° using B3LYP/6–311++G(d,p) and HF/6–311++G(d,p) level of theory. For all the studied compounds, two conformational structures (conformer anti-anti, syn-syn) that did not have imaginary frequency values outside the equilibrium state (conformer anti-syn) were detected theoretically at the both methods.Due to their conformational flexibility, the relative stabilities of the anti-syn, anti-anti, and syn-syn conformers of o-ClPhBA, m-ClPhBA, and p-ClPhBA are 0.0, 4.66, and 6.76 kcal/mol, respectively, at the B3LYP/6–311++G(d,p) level of theory. For the HF/6–311++G(d,p) level of theory, the relative stabilities are 0.00, 4.54, and 6.11 kcal/mol for o-ClPhBA; 0.00, 3.98, and 1.51 kcal/mol for m-ClPhBA; and 0.00, 4.10, and 1.44 kcal/mol for p-ClPhBA, respectively. Some of the determined stable conformations of these molecules are different in symmetry groups. It was observed that the increase in the symmetry was effective in the of molecular properties, especially for vibrational frequencies. The structural parameter, dipole moments (μ), vibrational frequencies, polarizability (α), hyperpolarizability (β), the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) of the stable conformers were calculated by using Ab initio HF/6–311++G(d,p) and DFT/B3LYP/6–311++G(d,p) level of theory. The assignments of fundamental vibrational modes of the studied molecule were performed based on total energy distribution (TED) analysis.

Tutton K2Zn(SO4)2(H2O)6 salt: Structural-vibrational properties as a function of temperature and ab initio calculations

In this work, a thorough study of Tutton K2Zn(SO4)2(H2O)6 crystal was performed. Structural, electronic, vibrational, and thermal properties were analyzed and discussed. Calculations based on the density functional theory (DFT) were performed to provide a correct assignment of vibration modes (90 active Raman and 93 active IR), and analyses of band structure and density of states. Powder X-ray diffraction (PXRD) at 300 K showed that the Tutton crystallizes in monoclinic symmetry with space group P21/a. An electronic bandgap of 4.66 eV, typical of insulating material, was estimated by band structure calculation. The thermal analysis in the 300–700 K range by coupled TG-DTA thermogram revealed two endothermal events and one exothermal. Such events were investigated by PXRD and Raman spectroscopy as a function of temperature, where three phase changes associated with dehydration and crystallization were observed. The new phase structures were determined by the Le Bail and Rietveld methods. The thermal-structural findings suggest that the K2Zn(SO4)2(H2O)6 Tutton can be considered a promising thermochemical compound for residential heat storage devices due to a low onset for the dehydration temperature (≈327 K) and a high enthalpy of dehydration (77.4 kJ/ mol H2O).

Pressure dependence on Raman spectra of the molecular crystal 4-(benzenesulfonyl)-morpholine

The structural and vibrational properties of 4-(benzenesulfonyl)-morpholine, C10H13NO3S, have been studied using multinuclear (1H and 13C) NMR, IR and Raman spectroscopy techniques at pressures up to 3.2 GPa, as well as molecular modeling and vibrational mode assignment using DFT calculations with B3LYP functional and 6-31G (d,p) basis set and potential energy distribution (PED). Experimental and calculated spectra were compared and showed good accuracy. The sample was subjected to high pressure in the range of 0 to 3.2 GPa. The pressure measurements suggest a conformational transition for values around 0.7, 1.7 and 2.5 GPa, which was observed in some spectral regions, mainly in the high energy vibrational bands.

Spectroscopic characterization (FT-IR, RAMAN and UV–VIS), thermogravimetric analysis, XPD and DFT calculations of highly stable hydroxy-functionalized chalcone: (2E)-1-(4-hidroxyphenyl)-3-(4-methoxyphenil)-prop-2-en-1-one

(2E)-1-(4-hydroxyphenyl)-3-(4-methoxyphenyl)‑prop-2-en-1-one, a hydroxy‑functionalized chalcone has been characterized by FT-IR, RAMAN and UV–VIS spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and DFT calculations. The detailed assignments of vibrational modes are compared with the literature and supported by theoretical calculations. The calculated energy gap at B3LYP/6–311++G(2d,2p) level shown values of 2.97 eV and 2.8 eV for experimental data. The intermolecular interaction in the solid state is responsible for the small differences between theoretical optimized geometry and experimental parameters. Thermogravimetric analysis shows very high thermal stability, and the spectroscopic UV–VIS shows that the compound under analysis has the potential for possible applications in organic LEDs.

Label-Free identification of fentanyl analogues using surface-enhanced Raman scattering and machine learning algorithm

The identification and analysis of drug abuse is crucial for controlling and combating this global public health problem. In this regard, surface-enhanced Raman spectroscopy (SERS) is a highly sensitive detection technique that is fast, non-destructive, and widely used in various fields. In this study, Ag@Au nanowires (Ag@Au NWs) were synthesized using the seed growth method. The SERS performance of Ag@Au NWs was evaluated using R6G as a probe molecule, and the minimum detection concentration of R6G was found to be 10−9 M. Similarly, the minimum detection concentration of fentanyl was observed to be 10−7 M. Furthermore, the study also involved performing routine Raman detection on 10 fentanyl analogs that were structurally similar. Additionally, density functional theory (DFT) calculations were carried out to distinguish between these substances. The Raman spectra calculated by DFT provided vibrational frequencies and normal mode assignments for each species. By comparing normal Raman spectra, SERS and DFT calculated spectrogram data, we assigned characteristic peaks of 10 substances. Finally, principal component analysis was used to reduce the dimension of the data, and support vector machine were further used to classification of SERS spectral data of the above 10 substances, with an accuracy of 96.4%.

Molecular structure, spectroscopic, electronic and physicochemical properties of 7,8-dihydroxyflavone hydrate compound using first theory principle

The present investigation involves the structure-based drug design and the functional evaluation of flavone based compound that can be utilized for breast cancer therapy, and it provides a way to create platforms for chemotherapy of breast cancer treatments. The 7,8-dihydroxyflavone hydrate (7DHFH) molecule was structurally characterized by spectroscopic techniques such as FT-IR/Raman, and EPR spectral analysis, which were compared with the DFT methods using Gaussian09 software packages. The complete assignments of the fundamental vibrational modes were obtained using potential energy distribution.The DFT results show a good agreement with the all experimental results. A DFT study on frontier molecular orbital analysis is used to calculate the HOMO- LUMO energies and charge transfer or conjugative interaction taking place within the molecular system and also other molecular parameters, viz. chemical hardness, softness, ionization potential, electron affinity, electrophilicity index, and electronegativity. Furthermore, the drug likeness properties were also calculated, thus allowing us to identify the present compound as a potential anticancer agent. Molecular docking results revealed the bioactive candidate displayed the best free-energy score towards the target proteins through forming strong hydrogen bonds with the amino acid residues. Finally, the cytotoxic activity of the 7DHFH confirms the anticancer activity against human breast cancer cell lines by MTT assays.

Development of an electrochemical surface‐enhanced Raman spectroscopic biosensor for the direct detection of glutathione

AbstractGlutathione is an important biological free radical scavenger, aiding in the prevention of oxidative stress in living organisms. A decrease in glutathione concentration in cells or bodily fluids is associated with serious health issues including certain cancers and Alzheimer's disease. Rapid detection and quantification of salivary glutathione could play a crucial role in healthcare monitoring as well as in therapeutic progress. This paper reports on the development of a direct electrochemical surface‐enhanced Raman spectroscopic (EC‐SERS) method for the monitoring of glutathione deposited via drop casting from a prepared aqueous stock solution and measured in 0.1‐M sodium fluoride and in artificial saliva. The detection platform for this study is constructed by modifying the working electrode of a carbon screen‐printed electrode with silver nanoparticles of approximately 30 nm in diameter, followed by potassium chloride treatment to remove interfering citrate anions prior to analysis. The coupling of SERS and an applied electrochemical potential resulted in a significantly enhanced spectrum for glutathione compared with those previously reported. Vibrational mode assignment confirmed that glutathione was indeed in close proximity to the surface of the working electrode and had varying anchor points as the potential was stepped anodically. Quantitative analysis of glutathione in artificial saliva showed that the 653 cm−1 marker peak intensity varies linearly (R2 = 0.990) over the concentration of 0.005–1.00 mM on the modified electrode surface. The signal limit of detection of glutathione using EC‐SERS in artificial saliva was determined to be 5 μM. This direct and rapid EC‐SERS detection platform is promising for point‐of‐care diagnostics.

Vibrational spectroscopic studies, DFT, and molecular docking investigations of 4-fluoro- 3-methyl benzophenone

Potential energy distribution was used to describe the optimum molecular geometry, FT-IR, FT-Raman, and UV-Vis spectra, vibrational frequency bands, and assignment of suitable vibrational modes of 4-fluoro-3-methyl benzophenone. Utilizing DFT/B3LYP with a 6–31 +G level, spectroscopic investigations are conducted. The findings of the computation were utilized to model 4-fluoro-3-methyl benzophenone, which has a very good correlation with the spectra that were observed. The TDFT was used so that oscillator strengths could be determined. In order to determine how much charge was transferred by the molecule, HOMO and LUMO analyses were performed. Through the use of the NBO analysis, it was feasible to determine the existence of internal charge transfer, hyperconjugation, and stabilizing energy. DFT techniques were applied to investigate Mulliken's charges and hyperpolarizability characteristics. In the molecular docking investigation, the 4-Fluoro-3-methylbenzophenone molecule was docked with Prostaglandin H2 Synthase-1 and Prostaglandin H2 Synthase-2. Due to their hormone-like properties, the phospholipid molecules known as prostaglandins (PGs) play a crucial part in the body's pain and inflammatory responses. These compounds are composed of fatty acids, which are prevalent in cell membranes. Membrane-associated enzyme cyclooxygenase (COX) is responsible for this process. There are two isoforms of this enzyme: COX-1 and COX-2.

Determination of the molecular structure and spectroscopic properties of capsaicin

In this study, the ground state molecular structure and spectroscopic features of cis- and trans-forms of capsaicin were investigated using DFT (B3LYP) invoking 6–311++G(d,p) basis set. The optimized geometry of capsaicin was determined for the isolated molecule in a vacuum, and then the vibrational spectra –IR and Raman-were obtained, and the assignments of fundamental vibrational modes were done. By applying the GIAO method, proton and carbon chemical shifts were computed for the gas and solvated phases. Besides using the TD-DFT, the Hirshfeld surface and Molecular Electrostatic Potential surfaces were obtained and evaluated to understand the electronic properties. The Total and partial density of state (TDOS and PDOS) spectra were also examined. All obtained computational results were compared with the previously reported experimental data. A high accuracy was obtained for the ground state geometrical structure, and thus, the vibrational frequencies especially lie on the finger print region are predicted also with a high correlation. Similarly, the optimization of chemical shift values calculated by considering solvent effects with experimental data were found as high R2 values of 0.9953 and 0.9455 for C and H atoms, respectively. This comparison shows that the DFT method precisely predicts capsaicin's molecular and spectroscopic characteristics.

Structural correlations of nitrogenase active sites using nuclear resonance vibrational spectroscopy and QM/MM calculations.

The biological conversion of N2 to NH3 is accomplished by the nitrogenase family, which is collectively comprised of three closely related but unique metalloenzymes. In the present study, we have employed a combination of the synchrotron-based technique of 57Fe nuclear resonance vibrational spectroscopy together with DFT-based quantum mechanics/molecular mechanics (QM/MM) calculations to probe the electronic structure and dynamics of the catalytic components of each of the three unique M N2ase enzymes (M = Mo, V, Fe) in both the presence (holo-) and absence (apo-) of the catalytic FeMco clusters (FeMoco, FeVco and FeFeco). The results described herein provide vibrational mode assignments for important fingerprint regions of the FeMco clusters, and demonstrate the sensitivity of the calculated partial vibrational density of states (PVDOS) to the geometric and electronic structures of these clusters. Furthermore, we discuss the challenges that are faced when employing NRVS to investigate large, multi-component metalloenzymatic systems, and outline the scope and limitations of current state-of-the-art theory in reproducing complex spectra.

Vibrational spectra of human tissues: Experimental data and density functional theory calculations comparison

Biophotonics techniques enabling molecular sensing of tissues and biological samples of had been widely applied to biomedical problems. Vibrational spectroscopy technologies like Fourier-Transform Infrared (FTIR) spectroscopy is a well-reported example. However, the correct interpretation of measured vibrational spectra of macromolecules and tissues emerging from the complexity of structures is a challenge. Computer simulations can be used as a strategic method to understand interactions between specific parts of a macromolecule. Here we present two implementations of vibrational calculations based on diagonalization of Hessian matrix obtained via Density Functional Theory calculations using Car-Parrinello Molecular Dynamics (CPMD package), Born-Oppenheimer Molecular Dynamics quickstep GPW (CP2K package), and a molecular dynamics calculations based on tight binding (CP2K-TB) was also employed to obtain FTIR spectra via electric dipole correlation function. These calculations were proposed to capture vibrational pieces of information related to FTIR of the human oral mucosa. Eleven models of peptide which represents collagen type I macromolecule including confined water molecules (ranging from 0 to 8 waters), were tested. CPMD and CP2K methods presented an excellent agreement of vibrational bands positions and maximum intensity to experimental data (goodness-of-fit R2 ∼ 0.90). On the other hand, this agreement was very poor for the CP2K-TB case in spite of the correct overall relative spectral intensity with respect to experimental data. We found that the peptide model enclosing eight waters (labeled C8) in CPMD calculations presented the highest value of R2 = 0.99. The CPMD method, despite some limitations, outperformed the CP2K calculation in our case. Here we only used a collagen cutout and confined water, but it is possible to add other molecules such as proteoglycans to investigate and characterize a tissue. The short collagen mimetic peptide has implications for the conformational behavior of native collagen. The method itself can be used for other macromolecules. Furthermore, we assignment of vibrational modes in the high-wavenumber region ( > 2, 000▒cm−1) is also presented.

Structure/function relationships of a new stannate (IV) complex based on 5,7-dichloro-8-hydroxyquinolinium, accomplished with DFT calculations

In this work, a novel compound bis(5,7-dichloro-8-hydroxyquinolinium) hexachlorostannate (II) dihydrate, formulated as (C9H6Cl2NO)2[SnCl6]·2H2O, has been synthesized and characterized by single crystal X-ray diffraction (XRD), Hirshfeld surface analysis, thermal studies, IR and UV-Vis spectroscopies, photoluminescence properties and in vitro biological activities. Stannate complex crystallizes in the triclinic system with space group P1¯. It is built of [SnCl6]2− anions and (C9H6Cl2NO)+ cations in the 1/2 ratio. The crystalline structure is stabilized by intermolecular and intramolecular hydrogen bonds and offset π-π stacking interactions. Intermolecular interactions were investigated by Hirshfeld surfaces. In addition, the optimized molecular structure and vibrational frequencies were calculated by the Density Functional Theory (DFT) method using the B3LYP function with the LanL2DZ basis set. On the basis of the comparison between calculated and experimental results, assignments of the fundamental vibrational modes are discussed. Subsequently, the nucleophilic and electrophilic binding site regions are elucidated using the molecular electrostatic potential (MEP). The thermal behavior was studied by TG-DTG-SDTA analyses. Moreover, the optical properties of the crystal were studied using optical absorption UV-visible and photoluminescence (PL) spectroscopy. To investigate microscopic third order non-linear optical behaviour of the examined complex, the electric dipole μtot, the polarizability αtot and the hyperpolarizability 〈γ〉 were computed using DFT//B3LYP/6-31G(d,p) and DFT//B3LYP/LanL2DZ methods for organic cation and hybrid compound, respectively. According to our calculation, the title compound exhibits non-zero 〈γ〉 value revealing microscopic third order nonlinear optical behaviour. In addition, the antioxidant activities of the complex were also investigated through scavenging effect on DPPH radicals, total antioxidant activity and reducing power.

Synthesis, Photoluminescence and Vibrational Properties of Aziridinium Lead Halide Perovskites.

Three-dimensional lead halide perovskites are known for their excellent optoelectronic properties, making them suitable for photovoltaic and light-emitting applications. Here, we report for the first time the Raman spectra and photoluminescent (PL) properties of recently discovered three-dimensional aziridinium lead halide perovskites (AZPbX3, X = Cl, Br, I), as well as assignment of vibrational modes. We also report diffuse reflection data, which revealed an extended absorption of light of AZPbX3 compared to the MA and FA counterparts and are beneficial for solar cell application. We demonstrated that this behavior is correlated with the size of the organic cation, i.e., the energy band gap of the cubic lead halide perovskites decreases with the increasing size of the organic cation. All compounds show intense PL, which weakens on heating and shifts toward higher energies. This PL is red shifted compared to the FA and MA counterparts. An analysis of the PL data revealed the small exciton binding energy of AZPbX3 compounds (29-56 meV). Overall, the properties of AZPbX3 are very similar to those of the well-known MAPbX3 and FAPbX3 perovskites, indicating that the aziridinium analogues are also attractive materials for light-emitting and solar cell applications.

Structural, Spectroscopic, and Molecular Docking Analysis of Benzophenone N(4)-methyl-N(4)-phenyl Thiosemicarbazone Using Density Functional Theory

A new thiosemicarbazone derivative, benzophenone N(4)-methyl-N(4)-phenyl thiosemicarbazone (BMPT) is synthesized using benzophenone and N(4)-methyl-N(4)- phenylthiosemicarbazide as precursors. Synthesized ligand is characterized by Fourier Transform Infrared spectra (FTIR) and FT-Raman spectra. Complete quantitative assignments of vibrational modes are presented in terms of potential energy distribution (PED) using quantum chemical calculations using the density functional theory (DFT) approach. Natural bond orbital (NBO) and molecular electrostatic potential (MEP) surface analysis are used to estimate the correlation between molecular structure and biological activity at the electronic level. Hirshfeld surface analysis is used to interpret the intermolecular interactions and also to provide information about the percentage contribution of various intermolecular contacts in the crystal structure. Besides the above, molecular docking studies of BMPT ligand with 3RGF and 3EWD proteins are also performed to confirm the ability of BMPT ligand as an active pharmaceutical ingredient (API) of potential anticancer and antimalarial drugs.

Density functional theoretical calculation of vanadium naphthalocyanine structure and vibrational spectrum

A theoretical investigation of molecular, electronic structures and vibrational spectrum for vanadium naphthalocyanine (VONc) was performed based on the optimized geometry at UB3LYP/6–31G(d) level. Unlike the symmetry (D4h) of NiNc, CuNc and ZnNc, the point group of VONc is C4v. By comparing with metallonaphthalocyanines, the order of the bond lengths of the M–N bonds is computed to be NiNc < CuNc < ZnNc < VONc. The Mulliken atomic charges of the central M vary in the same order as the bond lengths. Of the four molecules, VONc has the smallest HOMO–LUMO gap (1.80 eV). Furthermore, accurate and detailed assignment of the vibrational modes were obtained with both calculated potential energy distribution (PED) and assistance of animated pictures produced based on the normal coordinates. In order to make the assignment of the vibrational spectrum more concise and clear, a brand new symbol system was adopted. Experimental incorrect or missed assignments of vibrational modes were corrected or supplemented by comparison of the experimental and computed results of VONc.

Experimental (FT-IR, UV-Vis) spectroscopic analysis and molecular docking investigations of anti-cancer drugs Alkeran and Bicalutamide

According to the World Health Organization reports, cancer is the leading cause of death around the globe. Infectious diseases, parasitic infections, and cardiovascular diseases are in the following order. It is accounted that in 2021, 19.8 million individuals had been treated for cancer, indicating how widespread cancer has grown. Even after all the efforts in these years, research into cancer's medical implications is still an exciting area of profound investigation. In pursuit of such fundamental scientific efforts, this investigation summarizes, the assignment of specific vibrational modes of Alkeran and Bicalutamide using standard FT-IR spectral analysis and employing molecular docking techniques have identified an exact atomic level itinerary mechanism of the Alkeran and Bicalutamide and target Cellular Tumor Antigen P53 (DNA Binding) protein and Androgen Receptor binding protein, respectively. To ascertain the molecules’ bioactivity and charge transit between their frontier orbitals, the UV-Vis spectra of the molecules were examined, and the associated energy intervals were estimated by employing quantum computations of wavelength–energy relations. Molecular docking studies of Alkeran and Bicalutamide with Cellular Tumor Antigen P53 (DNA Binding) protein and Androgen Receptor binding protein, respectively, have identified binding energy and RMSD, as well as the kinds of bonds and the meticulous path taken by the drug molecule and the receptor, which can be used to improve anticancer medication action mechanisms, effectiveness, and efficacy, as well as the establishment of innovative anticancer agents.

Facile Synthesis of Porous Ag Crystals as SERS Sensor for Detection of Five Methamphetamine Analogs.

Porous noble metal nanomaterials have attracted extensive attention due to their high specific surface area and surface plasmon resonance effect. However, it is difficult to form porous structures due to the high mobility and low reduction potential of noble metal precursors. In this article, we developed a facile method for preparing porous Ag with a controllable structure at room temperature. Two kinds of Ag crystals with different porous structures were successfully prepared by using AgCl cubes as sacrificial templates. Through the galvanic replacement reaction of Zn and AgCl, Ag crystals with a sponge-like porous structure were successfully prepared. Additionally, using NaBH4 as the reducing agent, we prepared granular porous Ag cubes by optimizing the amount of reducing agent. Both the sponge-like and granular porous Ag cubes have clean and accessible surfaces. In addition, we used the prepared two porous Ag cubes as substrate materials for SERS detection of five kinds of methamphetamine analogs. The experimental results show that the enhancement effect of granular porous Ag is better than that of sponge-like porous Ag. Furthermore, we probed the hot spot distribution of granular porous Ag by Raman mapping. By using granular porous Ag as the substrate material, we have achieved trace detection of 5 kinds of methamphetamine analogs including Ephedrine, Amphetamine, N-Methyl-1-(benzofuran-5-yl)propan-2-amine (5-MAPB), N-Methyl-1-(4-methoxyphenyl)propan-2-amine (PMMA) and N-Methyl-1-(4-fluorophenyl)propan-2-amine (4-FMA). Furthermore, to achieve qualitative differentiation of analogs with similar structures we performed density functional theoretical (DFT) calculations on the Raman spectra of the above analogs. The DFT calculations provided the vibrational frequencies, Raman activities, and normal mode assignment for each analog, enabling the qualitative differentiation of the above analogs.