Cyclopentadienyl System: Solving the Secular Determinant, π Energy, Delocalization Energy, Wave Functions, Electron Density and Charge Density

In this study, characteristics of Hückel strategy, were abused so as to acquire some significant outcomes, through a theoretical technique with which it is conceivable to get secular equations, π energy, wave functions, electron density and charge density, as an account of cyclopentadienyl system i.e. C5H5+ (cation), C5H5- (anion), and C5H5. (radical) and permitting the expression of delocalization energy of conjugated cyclopentadienyl ring framework. Here, it was presented the secular determinant of the Hückel technique and applied to cyclopentadienyl system framework so as to communicate their orbital energies of cyclopentadienyl system, also to communicate its electron and charge density in terms of stable configuration of a system. It is settled by the Hückel strategy and applied by the assumptions for nearby comparability such as coulomb integrals, exchange integrals and overlap integrals. This simple way hypothetical strategy will allow to graduate and post graduate understudies to understanding the investigation of stable configuration, electron and charge density and also other parameters.

Delocalization energy retrieved from the current density tensor

The anisotropy of the magnetically induced current density tensor can be computed by its original formulation, known in the literature as ACID, or by its revised definition, AACID, which takes into account the asymmetric nature of the tensor. In polycyclic aromatic hydrocarbons, the excess of the integrated value of AACID over that computed for isolated ethylenes correlate with the Hückel delocalization energy.

The Role of Linear Alkyl and Alkoxy Side Chains in the Modulation of the Structure and Electrical Properties of Bithiophene:a Theoretical Study

In the present work, we have studied from a theoretical perspective the geometry and electronic properties of 2,2′-bithiophene (BT) and its derivatives 3,4′-alkyl-2,2′-bithiophene (3,4′ABT) and 3,4′-alkoxy-2,2′-bithiophene (3,4′OABT). Properties such as planarity, bond lengths, electron density, highest occupied molecular orbital → lowest unoccupied molecular orbital (HOMO → LUMO) excitation energy and π-delocalization energy, which are related to the electrical conductivity, were calculated and analyzed as a function of both the nature and length of the substituent. The oxidation process was also studied for the single-polaronic state. The ionization potential and the intramolecular reorganization energy were calculated following the semiclassical Marcus treatment. As a conclusion, the introduction of alkoxy chains in 3,4′-positions improves the electrical properties with respect to the bithiophene molecule and the corresponding alkyl derivatives.

The close relation between cyclic delocalization, energy effects of cycles and aromaticity

New evidence questioning the multidimensionality of the aromaticity phenomenon exemplified in what is called orthogonality between the classical (structural and energetic) and magnetic aromaticity indices and measures is reported. For this purpose, the recently proposed methodologies for the quantitative characterization of the energy benefits associated with the cyclic arrangement of mobile π-electrons in polycyclic aromatic hydrocarbons are compared with the indices characterizing the extent of cyclic delocalization in the corresponding conjugated circuits. The reported close correlation between both types of indices implies that no discrepancies between classical and magnetic aromaticity measures exist provided the comparison is based on the indices of inherently local nature and/or the interfering contributions of contaminating conjugated circuits is properly taken into account in the description of aromaticity measures like topological resonance energy (TRE) or nucleus independent chemical shift (NICS).