Pseudocyclacene electronic circuits - an ab initio treatment

Türker, Burhan Lemi
Pseudocyclacene structure has been considered for ab initio type calculations (3-21G and 6-31G). The unrestricted Hartree-Fock approach was used throughout the calculations. The pseudocyclacene structure having cyclobutadienic peripheral circuits is estimated to be more stable by 3-21G and 6-31G type calculations. Although, 3-21G type calculations predict discernible stability of transoid form over cisoid form, the 6-31G type cannot differentiate in between these two forms. On the other hand, the total energy calculations at 3-21G and 6-3 1 G levels with MP2 approach point to the biradicalic transoid form to be more stable than the others. (C) 2002 Elsevier Science, B.V. All rights reserved.


Cycled-fused-borazines - MNDO and AMI treatments
Türker, Burhan Lemi (Elsevier BV, 2003-11-17)
The Huckel type cycled-fused-borazines which are analogous to cyclacenes are considered for the semiempirical molecular orbital treatment at the level of MNDO and AMI type calculations. The structures having 3-10 arenoid rings (R) are considered. It has been found that they should be thermally stable and exogenic. Moreover, these properties get more and more as R increases. The systems exhibit no cryptoannulenic effect on any of the properties presently studied, showing that the peripheral circuits, unlike ...
Electronic properties of carbon nanotoroidal structures
Yazgan, E; Tasci, E; Malcıoğlu, Osman Barış; Erkoc, S (Elsevier BV, 2004-07-26)
Electronic properties of five carbon nanotori (C-170, C-250, C-360, C-520, and C-750) have been investigated by performing Extended-Huckel type calculations. Carbon nanotori considered is of Fonseca type having five-fold symmetry. It has been found that highest occupied molecular orbital-lowest occupied molecular orbital gaps of nanotori considered are very small, thus they may contain mobile electrons; pentagons and heptagons in the knee-regions act as an electron trap; and all the nanotori have a DOS dist...
Quantum chemical treatment of nitroguanidine and its mono ionic forms
Türker, Burhan Lemi (Elsevier BV, 2004-07-26)
Nitroguanidine and its mono ionic forms have been subjected to AM1 (UHF) type semiempirical as well as 6-31G** (UHF) type ab initio molecular orbital calculations. The stability order has been found to be anion > neutral > cation. The calculations have revealed that contrary to some other explosive chemicals, the charge development are accompanied by only moderate changes in bond lengths and bond angles in the case of nitroguanidine.
A theoretical study on certain iron-sulfur and iron-selenium clusters
Turker, L; Erkoç, Şakir (Elsevier BV, 2003-04-04)
[Fe4S4], [Fe4S3Se] and [Fe4Se4] type iron-sulfur and iron-sulfur-selenium and iron-selenium clusters, all having four cysteinyl moieties as ligands have been considered for ab initio quantum chemical analysis at the level of 6-31G (RHF). All the structures are found to be stable and the stability of Se containing structures increases as the number of Se atoms increases. The inter frontier molecular orbital energy gaps and the HOMO energies follow the same order.
An ab initio treatment on some isomeric structures of a small pseudocyclacene
Türker, Burhan Lemi (Elsevier BV, 2003-10-03)
At the level of 6-31G (RHF) type ab initio calculations, some structures isomeric with the pseudocyclacene are considered. Some structures have the same or almost the same energy values. This situation causes the pseudocyclacene structure to be vague at the level of calculations.
Citation Formats
B. L. Türker, “Pseudocyclacene electronic circuits - an ab initio treatment,” JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, pp. 87–92, 2003, Accessed: 00, 2020. [Online]. Available: