The research focused on investigating and optimizing the interaction of the hormone Norepinephrine (Noradrenaline), which acts as a neurotransmitter, with Mg+2 atoms at the molecular level. To do this, we used GaussView 6.0.16 to generate the molecular structure. Then, it employed Gaussian 09: AS64L-G09RevD.01 program to optimize the molecular structures of Norepinephrine using the DFT method and SDD basis set, and the Mg atom doped molecule using the DFT method and LanL2MB basis set. Various quantum mechanical calculations were conducted on the molecule, including Fourier Transform Infrared spectroscopy (FT-IR), Nuclear Magnetic Resonance Spectroscopy (NMR), HOMO-LUMO structure with the energy level diagram, UV-visible absorption, and density of states (DOS). These calculations provide important insights into the behavior and properties of the Norepinephrine-Mg+2 complex at the molecular level.

Norepinephrine plays an important role in many processes such as stress response, attention, alertness, blood pressure regulation, neurotransmission and emotional states. In this study, the molecule was optimized in order to get knowledge about the formation of the Ca+2 doped norepinephrine complex and the functions of norepinephrine in neurotransmission or other cellular processes by interacting with calcium. Quantum mechanical calculations such as FT-IR, Nuclear Magnetic Resonance (NMR), HO-MO-LUMO structure with the energy level diagram, UV-visible absorption, The density of states (DOS) of the optimized molecule were performed. The physical and chemical structure characteristics of the norepinephrine molecule and the change of its structural properties by molecular bonding with Ca+2 were investigated.

In this study, the structural and electronic properties of the compound 3-(2-furyl)-1 H-pyrazole-5-carboxylic acid have been theoretically investigated by Density Functional Theory (DFT). The most stable geometry of the molecule was optimized and vibrational frequencies were calculated at the B3LYP/6-31G(d) level. Geometry optimization results indicate that the molecule adopts a planar conformation, meaning all constituent atoms lie within the same geometrical plane. This confirms that the atomic arrangement is not spatially random or dispersed in three dimensions, but instead exhibits a well-defined two-dimensional planar geometry. In addition to geometric optimization, quantum chemical calculations show that the molecule has high electronic stability and low reactivity, and also reveal its potential for optoelectronic applications with strong absorption properties in the UV. These analyses contribute to the structural confirmation of the compound and provide important information on the chemical reactivity of the functional sites. The results obtained show that the compound has significant potential for optoelectronic, pharmaceutical and sensor applications.

2-Acetoxy benzoic acid (2ABA) can produce structural changes in the molecule when dissolved in different solvents depending on factors such as solvent polarity, Hydrogen bonding and solvent interactions. Therefore, quantum chemical calculations were performed using Gaussian 09: AS64L-G09RevD.01 software. The structural changes of the 2ABA molecule in the presence of solvents were recorded by Fourier Transform Infrared (FT-IR) Spectroscopy in the 4000-0 cm-1 range. Additionally, Nuclear Magnetic Resonance (NMR) Spectroscopy was employed to examine changes in chemical shift values associated with the dissolution of the molecule. In another phase of the study, the geometric parameters of the optimized molecules, atomic charges, intensities of the vibrational bands, and vibrational frequencies were calculated using Density Functional Theory (DFT). These calculations were performed at the DFT/B3LYP level with the LanL2DZ basis set, providing a detailed analysis of solvent effects at the molecular level. This study offers significant insights into the interactions of solvent environments with molecular structures and contributes to potential drug development processes.

In this study, the K-Serotonin structure formed by adding potassium to Serotonin (5-HT) was investigated by quantum chemical methods. 5-hydroxytryptamine is a neurotransmitter that affects mood, making people feel happy and energetic. 5-HT and 5-HT-potassium were optimized with some base sets to find the optimal band gap using the density function theory (DFT) and Hartree-Fock (HF) method. The most suitable DFT/LanL2DZ was selected for the structure with and without additives. By calculating the values for 5-HT and K-5-HT, the effects of potassium on 5-HT binding were compared.