International Journal of Advances in Scientific Research and Engineering (ijasre) E-ISSN : 2454-8006 DOI: 10.31695/IJASRE.2019.33455 Volume 5, Issue 8 August - 2019 www.ijasre.net Page 102 Licensed Under Creative Commons Attribution CC BY-NC Effects of Solvents on the Electronic and Molecular Properties of 4- ((2-Methyl-4-Nitrophenyl) Imino Methyl)Phenol A.A Akande 1 , N.O Obi-Egbedi 2 and N.D Ojo 3 1-3 Department of Chemistry University of Ibadan Ibadan, Oyo State Nigeria. ABSTRACT Schiff bases are known to possess antiviral, antifungal, antibacterial, enzymatic and other significant biological properties. They also chelate metals to form complexes that have been used in industrial processes. Schiff bases are also important in modern energy applications due to their photometric and thermochemical properties. The basis of their applications depends on the molecular and electronic properties hence it is important to study how solvents perturb these properties. Therefore, this work is aimed at studying the electronic and molecular properties of a Schiff base. The effects of solvents on 4-(((2-methyl-4- nitrophenyl)imino)methyl)phenol was investigated both experimentally and theoretically. Experimentally, the UV-Visible spectrophotometer was used to obtain the absorption spectra of the compound in tetrahydrofuran, dichloromethane, propan-2-,ol, propan-1-ol, ethanol and methanol. Time-Dependent Density Functional Theory (TDDFT) and B3LYP with the 6-311++G(d,p) basis set was used to model and calculate the dipole moment, polarizability and excitation energies in vacuum, cyclohexane, methanol and ethanol using a computational software. In the experimental studies, four bands were observed and designated I, II, III and IV in methanol and ethanol. However three bands were observed in propan-1-ol and propan-2-ol, and two bands in dichloromethane and tetrahydrofuran. A red shift was observed in Bands I and II while a blue shift was observed for Band III as solvent polarity increases. The intensity of the bands increased with increase in solvent polarity. The dipole moment and polarizability calculated using TDDFT increased with increasing solvent polarity. This may indicate ease of charge separation and distortion of the electron cloud of the molecule as polarity of solvent increases. On the basis of the observations of the transition energy and wavelength with solvent polarity, the compound can be classified to have both n→ * and → * transitions. Key words: Solvents, Oscillator strength, Dipole moment, Time-Dependent Density Functional Theory, Polarity. 1. INTRODUCTION Schiff bases are formed from the condensation reaction between an aldehyde (or ketone) and a primary amine. The aldehydes and ketones contain a carbonyl group, C=O and this group is replaced with the C=N-R present in the Schiff bases. This reaction may occur either through an acid or base catalyzed pathways. Although if an acid pathway is followed, it must be at mild pH to avoid hydrolysis of the product. These compounds are often called Schiff bases when they are used as ligands to form coordination complexes with metal ions. These complexes may occur naturally or may be synthesised artificially. When used as ligands, they have strong coordinative ability and are good chelating agents. Since, they mostly are polydentate ligands, almost all of the Schiff bases can form 1:1 complexes with transition metals and these complexes are very stable. Due to this, a number of Schiff base ligands have been used as cation carriers in potentiometric sensors, good ion carriers for anion selective sensors as effective corrosion inhibitors, in enzyme preparation and as catalysts in certain biological systems [1]. Schiff bases are becoming increasingly important in the medical and pharmaceutical fields. This is because they show variety of biological activities. They are known for their anti-inflammatory, anticancer, antioxidant, anticonvulsant, analgesics, among many others. The imine functional group plays a unique role in the biological activities of the compound. It is suspected that the nitrogen atom of the azomethine is involved in the formation of a hydrogen bond with the active centres of a cell constituents and this allows the compound to interfere with the normal cell processes thereby bringing about the biological activities [2]. Schiff bases and its metal complexes synthesised have been used as mordants in dyeing techniques. Abuamer et al synthesised dyes using salicylaldehyde and 2-aminobenzyl alcohol or o-aminophenol in hot ethanolic solution as starting materials. A yellow and orange solid Schiff