Theoretical studies on the structure and thermochemistry of cyclicparaphenylenediazenes

Ali, Mohamad Akbar; Alam, Mohammad A.

doi:10.1039/c7ra06409h

Cited by 5 publications

(1 citation statement)

References 55 publications

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“…The same computational approach was used to ascertain that the optimized structures correspond to local minima on the potential energy surface by conducting vibrational frequency calculations on the optimized structures; no arbitrary frequencies were observed, as shown in Tables S1–S7 of the Supporting Information (SI). For benchmarking and method selection, geometry optimization was performed using the DFT/ωB97XD, DFT/B3LYP, M06-2X, and MP2 methods using the 6-311++G(d,p) aug-cc-pVDZ, and aug-ccpVTZ basis sets. , Following the approach by refs − , the ring strain energies of the respective molecules with reference to their acyclic counterparts were calculated. In all cases, the corrected ZPVE was utilized in the ring strain calculation.…”

Section: Computational Detailsmentioning

confidence: 99%

Meta-Hybrid Density Functional Theory Prediction of the Reactivity, Stability, and IGM of Azepane, Oxepane, Thiepane, and Halogenated Cycloheptane

et al. 2022

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The application of plain cycloalkanes and heterocyclic derivatives in the synthesis of valuable natural products and pharmacologically active intermediates has increased tremendously in recent times with much attention being paid to the lower cycloalkane members. The structural and molecular properties of higher seven-membered and nonaromatic heterocyclic derivatives are less known despite their stable nature and vast application; thus, an insight into their structural and electronic properties is still needed. Appropriate quantum chemical calculations utilizing the ab initio (MP2) method, meta-hybrid (M06-2X) functional, and long-range-separated functionals (ωB97XD) have been utilized in this work to investigate the structural reactivity, stability, and behavior of substituents on cycloheptane (CHP) and its derivatives: azepane, oxepane, thiepane, fluorocycloheptane (FCHP), bromocycloheptane (BrCHP), and chlorocycloheptane (ClCHP). Molecular global reactivity descriptors such as Fukui function, frontier molecular orbitals (FMOs), and molecular electrostatic potential were computed and compared with lower members. The results of two population methods CHELPG and Atomic Dipole Corrected Hirshfeld Charges (ADCH) were equally compared to scrutinize the charge distribution in the molecules. The susceptibility of intramolecular interactions between the substituents and cycloalkane ring is revealed by natural bond orbital analysis and intramolecular weak interactions by the independent gradient model (IGM). Other properties such as atomic density of states, intrinsic bond strength index (IBSI), and dipole moments are considered. It is acclaimed that the strain effect is a major determinant effect in the energy balance of cyclic molecules; thus, the ring strain energies and validation of spectroscopic specificities with reference to the X-ray crystallographic data are also considered.

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