Normal view MARC view ISBD view

Density functional theory (B3LYP and CAM-B3LYP) study on the electronic spectral properties of selected polyyne metabolities / Julian Andrei D. Monteclaro. 6

By: Julian Andrei D. Monteclaro. 4 0 16, [, ] | [, ] |

Contributor(s): 5 6 [] |

Language: Unknown language code Summary language: Unknown language code Original language: Unknown language code Series: ; June 2022.46Edition: Description: 28 cm. 83 ppContent type: text Media type: unmediated Carrier type: volumeISBN: ISSN: 2Other title: 6 []Uniform titles: | | Related works: 1 40 6 []Subject(s): -- 2 -- 0 -- -- | -- 2 -- 0 -- 6 -- | 2 0 -- | -- -- 20 -- | | -- -- -- -- 20 -- | -- -- -- 20 -- --Genre/Form: -- 2 -- Additional physical formats: DDC classification: | LOC classification: | | 2Other classification:

Contents:

Action note: In: Summary: ABSTRACT: Density Functional Theory (DFT) is the most widely utilized computational method for understanding the ground and excited state properties organic compounds and Time Dependent Functional Theory (TDDFT) an extension of DFT, allows for the calculation of emission and absorption spectra. TDDFT is the most widely used and cost-effective approach for studying excited states and predicting UV-Vis and ECD spectra among the techniques used to compute electronic transitions. In this study, a DFT study on the electronic spectral properties of ten (10) polyyne metabolities have been conducted. The structure and the UV-Vis profiles of the samples were obtained from literature. Two (2) density functionals were employed, namely B3LYP and CAM-B3LYP. The basis set used for both functionals is def2-TZVP for computational convenience. The 3D structures employed underwent geometry optimizations. The length of conjugation and HOMO-LUMO energy gap was correlated to the calculated experimental lambda max. It was found that as the length of conjugation increases, the value of the lambda max increases as well. On the other hand, a low value for the HOMO-LUMO energy gap will yield a lower value for the lambda max. The molecular electrostatic potential (MESP) maps were also generated and analysed. It was found that the linear chains of the polyyne metabolites have neutral potentials. Following geometry optimization, TDDFT techniques was applied in order to compute the excited states of the polyyne metabolites and to generate their UV-Vis absorption spectrum. The lambda max values calculated from the B3LYP and CAM-B3LYP functionals were compared to literature values. After calculating the percent relative deviations, it was found that CAM-B3LYP produced values with close similarity to literature with a %R.D. of -0.66%, while B3LYP yielded a %R.D. value of 9.76%. It can be therefore concluded that the CAM-B3LYP/def2-TZVP level of theory can be employed in predicting the electronic spectral properties of polyynes and pollen-like compounds. Other editions:

Tags from this library: No tags from this library for this title. Log in to add tags.

Average rating: 0.0 (0 votes)

Holdings ( 1 )
Title notes
Comments ( 0 )

Item type	Current location	Home library	Collection	Call number	Status	Date due	Barcode	Item holds
Book	PLM	PLM Filipiniana Section	Filipiniana-Thesis	T QD1.M66.2022 (Browse shelf)	Available		FT7672

Total holds: 0

Thesis (Bachelor of Science in Chemistry) - Pamantasan ng Lungsod ng Maynila, 2022. 56

ABSTRACT: Density Functional Theory (DFT) is the most widely utilized computational method for understanding the ground and excited state properties organic compounds and Time Dependent Functional Theory (TDDFT) an extension of DFT, allows for the calculation of emission and absorption spectra. TDDFT is the most widely used and cost-effective approach for studying excited states and predicting UV-Vis and ECD spectra among the techniques used to compute electronic transitions. In this study, a DFT study on the electronic spectral properties of ten (10) polyyne metabolities have been conducted. The structure and the UV-Vis profiles of the samples were obtained from literature. Two (2) density functionals were employed, namely B3LYP and CAM-B3LYP. The basis set used for both functionals is def2-TZVP for computational convenience. The 3D structures employed underwent geometry optimizations. The length of conjugation and HOMO-LUMO energy gap was correlated to the calculated experimental lambda max. It was found that as the length of conjugation increases, the value of the lambda max increases as well. On the other hand, a low value for the HOMO-LUMO energy gap will yield a lower value for the lambda max. The molecular electrostatic potential (MESP) maps were also generated and analysed. It was found that the linear chains of the polyyne metabolites have neutral potentials. Following geometry optimization, TDDFT techniques was applied in order to compute the excited states of the polyyne metabolites and to generate their UV-Vis absorption spectrum. The lambda max values calculated from the B3LYP and CAM-B3LYP functionals were compared to literature values. After calculating the percent relative deviations, it was found that CAM-B3LYP produced values with close similarity to literature with a %R.D. of -0.66%, while B3LYP yielded a %R.D. value of 9.76%. It can be therefore concluded that the CAM-B3LYP/def2-TZVP level of theory can be employed in predicting the electronic spectral properties of polyynes and pollen-like compounds.

There are no comments for this item.

to post a comment.