#HOMO VS LUMO PC#

The average value of energy gap of PT, P3TAA, PPY and Chlo were 1.23 eV, 1.08 eV, 2.23 eV and 1.10 eV respectively. The LUMO energy levels of PT, P3TAA PPY and Chlo were 5.84 eV, 5.34 eV, 1.10 eV and 3.85 eV respectively, while HOMO energy levels of PT, P3TAA PPY and Chlo were 4.61 eV, 4.25eV, 3.70 eV and 5.93 eV. The species activity of Chlo was exhibited irreversible electrochemical behavior where only the oxidation process was obviously appeared at range of 0.80 V to 0.95 V. PYY species reaction was exhibited irreversible electrochemical behavior where two oxidation states occur within -0.145 V to -0.202 V and 0.870 V to 1.63 V respectively.

#HOMO VS LUMO PC#

The reaction of P3TAA species was exhibited reversible electrochemical behavior, where the range value of oxidation, DE pa and reduction, DE pc were in range of 0.825 V to 1.120 V and -0.230 V to 0.131 V respectively. Vaikka näiden kahden tyypin välillä on useita eroja, Homo: n ja Lumo: n tärkein ero on, että Homo lahjoittaa elektroneja, kun taas Lumo vastaanottaa elektroneja. So that the reaction of PT species was exhibited irreversible electrochemical behavior. Raja-alueen molekyyliorbitaaliteoria selittää HOMO- ja LUMO-tyyppisten molekyyliorbitaalien muodostumisen. Other examples include the reaction of alkenes with H-X, where the HOMO is the p MO of the alkene and the LUMO is the H-X s orbital. The formal reduction potential, E o ¢ is 0.83 (positive) meaning that oxidation process was dominant. The interaction stabilizes the unshared pair of the oxygen, while simultaneously breaking the CH 3-Cl bond because the interaction is with the antibonding orbital. The result of voltammogram is showed that the activity of PT species were produced three oxidation and one reduction processes. The working electrode used is indium tin oxide (ITO). The current-voltage measurements for these solutions are performed using cyclic voltammetry method on input voltage from -2.0 V to 2.0 V. PT, P3TAA, PPY and Chlo solutions were prepared in a solvent of acetonitrile at the concentration range of 10 -2 to 10 -4 M. The purpose of this study is to determine the level energy of high occupied molecule orbital (HOMO) and low unoccupied molecule orbital (LUMO) in polythiophene (PT), Poly (3-thiophene acetic acid) (P3TAA), polypyrrole (PPY) and chlorophyll (Chlo) through oxidation and reduction of molecular ions by cyclic voltammetry method. Also, by looking at the evolving shapes of the levels, the intented structural modifications may be easily interpreted.Cyclic voltammetry can be used to investigate the chemical reactivity of species ion via oxidation and reduction process. A good strategy for understanding the meaning of a HOMO-LUMO gap is to construct a qualitative Walsh Diagram, which monitors the energy of the frontier levels along some specific coordinate (e.g., bond elongation or a relevant angle) and allows establishing how much the gap is controlled by geometry. For instance, population of a LUMO, which is antibonding between two bonded atoms, may trigger bond elongation or even cleveage cause a change in the molecular geometry. Define the three major intermolecular forces (IMF) that can exist in condensed phases: dipole-dipole, H-bonding, and dispersion (London, van der Waals, induced. Even half population of the LUMO may induce a geometric rearrangement, depending on the character of the LUMO, hence the hosted electrons have an effect. Recognize that based on MO theory constructive interference of atomic orbitals yields lower energy MO (bonding) while destructive interference leads to higher energy MO (anti-bonding). A large gap implies good thermodynamic stability of the compound, whereas a small gap suggests an easy electronic transition. The magnitute of the HOMO-LUMO gap has very important chemical implications, even if qualiatively evaluated.