Comparison of Different Theory Models and Basis Sets in Calculations of TPOP24N-Oxide Geometry and Geometries of meso-Tetraphenyl Chlorin N-Oxide Regioisomers 


Vol. 33,  No. 9, pp. 2861-2866, Sep.  2012
10.5012/bkcs.2012.33.9.2861


PDF
  Tumbnail

  Abstract

Results of the comparisons of various density functional theory (DFT) methods with different basis sets for predicting the molecular geometry of TPOP24N-Oxide macrocycle, an oxoporphyrin N-oxide, are reported in this paper. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-31G*, 6-31+G (d, p), 6-311+G (d, p), and 6-311++G (d, p), are also considered. The M06-2X/6-31G* level is superior to all other density functional methods used in predicting the geometry of TPOP24N-Oxide. The geometries of regioisomeric chlorin N-oxide and oxoporphyrin N-oxide are reported using M06-2X/6-31G* method. The geometry effects of oxoporphyrin and chlorin N-oxide regioisomers are increased β-β bond lengths by N-oxidation because the bond overlap index due to charge transfers is decreased. In N-oxidation ring (II, III), angles that include β-β bond length increase as the bond overlap index of β-β bond is decreased by N-oxidation. The potential energy surfaces of chlorin N-oxide and oxoporphyrin N-oxide are explored by M06-2X/6-31G*, and single-point calculations are performed at levels up to M06-2X/6-311++G (d, p). Total and relative energies are then calculated. The results indicate that chlorin 24 N-oxides are more stable than chlorin 22 N-oxides in chlorin N-oxide regioisomers. Moreover, TPOP24N-Oxide is less stable than TPOP22N-Oxide.

  Statistics
Cumulative Counts from November, 2022
Multiple requests among the same browser session are counted as one view. If you mouse over a chart, the values of data points will be shown.


  Cite this article

[IEEE Style]

S. J. Choe, "Comparison of Different Theory Models and Basis Sets in Calculations of TPOP24N-Oxide Geometry and Geometries of meso-Tetraphenyl Chlorin N-Oxide Regioisomers," Bulletin of the Korean Chemical Society, vol. 33, no. 9, pp. 2861-2866, 2012. DOI: 10.5012/bkcs.2012.33.9.2861.

[ACM Style]

Sang Joon Choe. 2012. Comparison of Different Theory Models and Basis Sets in Calculations of TPOP24N-Oxide Geometry and Geometries of meso-Tetraphenyl Chlorin N-Oxide Regioisomers. Bulletin of the Korean Chemical Society, 33, 9, (2012), 2861-2866. DOI: 10.5012/bkcs.2012.33.9.2861.

Search
(IN TITLE, AUTHOR, ABSTRACT,KEYWORDS)

Advanced Search ▼

POPULAR KEYWORDS
(TOP 10 KEYWORDS)

Recent Publications
(LAST 3 YEARS)

ISSN(Print) 0253-2964
ISSN(Online) 1229-5949