Estimating the angle of total pi-electron energy

Date

2004-01-23

Author

Gutman, I
Türker, Burhan Lemi

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

108
views

0
downloads

The angle theta of total pi-electron energy of an alternant hydrocarbon is defined via: E-pi = 2rootne cos theta, where 2n or 2n + 1 is the number vertices and e the number of edges of the molecular graph, and E-pi is the respective HMO total pi-electron energy. The angle theta is sensitive to the structural differences between isomeric alternant hydrocarbons. Recently [J. Mol. Struct. (Theochem) 584 (2002) 183] an identity cos theta = [(e + n)/(2rootne)](1 + alpha - rootalpha2 + 2alpha) has been deduced, with alpha being a topology-dependent parameter, whose value is much less than unity. We now establish lower and upper bounds for alpha in terms of n and e. By this, the structure-dependence of angle theta and the range of its variation are better understood.

Subject Keywords

Physical and Theoretical Chemistry, Biochemistry, Condensed Matter Physics

URI

https://hdl.handle.net/11511/62453

Journal

JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM

DOI

https://doi.org/10.1016/j.theochem.2003.10.033

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Theoretical investigation of hydroxytyrosol and its radicals Erkoc, F; Keskin, N; Erkoç, Şakir (Elsevier BV, 2003-05-05) The structural and electronic properties of hydroxytyrosol, its three radical isomers, and its three analogues hydroxytyrosol-dihydroxyl isomers have been investigated theoretically by performing semi-empirical self-consistent field molecular orbital theory calculations. The geometry of the systems have been optimized and the electronic properties have been calculated at the level of AMI method.
Theoretical investigation of melatonin and its hydroxy isomers Erkoc, A; Erkoc, F; Keskin, N (Elsevier BV, 2002-07-05) The structural and electronic properties of melatonin and its six hydroxy isomers have been investigated theoretically by performing semi-empirical and ab initio molecular orbital theory calculations. The geometry of the systems has been optimized considering the semi-empirical molecular orbital theory at the level of AM I, and the electronic properties of the systems have been calculated by ab initio RHF including full MP2 correlation correction in their ground state. Conclusions were drawn by comparing wi...
Theoretical investigation of quercetin and its radical isomers Erkoc, E; Erkoc, F; Keskin, N (Elsevier BV, 2003-08-01) The structural and electronic properties of quercetin and its five radical isomers have been investigated theoretically by performing semi-empirical molecular orbital theory calculations. The geometry of the systems have been optimized and the electronic properties of the systems considered have been calculated by semi-empirical self-consistend-field molecular orbital theory at the level AM1 within UHF formalism in their ground state. Conclusions have been drawn by comparing with experimental results.
The positional effect of dodecagonal holes on C-56 structure Türker, Burhan Lemi (Elsevier BV, 2004-05-14) Some C-56 isomers obtained theoretically from C-60 structure by deleting two C-2 units and bonds adjacent to those have been subjected to AM1 (UHF) type semiempirical quantum chemical calculations. Positional effects of dodecagonal (cyclododecahexaene rings) holes on the stabilities are discussed in the case of neutral as well as monovalent cationic form of these species which are all stable but endothermic in nature.
Calculation of the Raman Linewidths of Lattice Modes Close to the alpha-beta Transition in Quartz Lider, Mustafa Cem; Yurtseven, Hasan Hamit (Walter de Gruyter GmbH, 2012-12-01) The Raman frequencies of the lattice modes (147 cm(-1) and 207 cm(-1)) are analyzed for the alpha-beta transition in quartz according to a power-law formula with the critical exponent by using the experimental data. The temperature dependence of the Raman frequency is associated with the order parameter (polarization P) for this transition in the quartz crystal.

Citation Formats

I. Gutman and B. L. Türker, “Estimating the angle of total pi-electron energy,” JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, pp. 119–121, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62453.