Theoretical Study of 1,3,4,6,7,9,9b-Heptaazaphenalene and Its Ten Derivatives

Abstract

CH 2 , and -CtCH) at the B3LYP/aug-cc-pVDZ level of theory. Geometry studies show that all of the compounds have a highly symmetric structure with a planar and rigid heteroring. Calculation results confirm that there exists considerable conjugation over the parent ring, which is an advantage to the stabilities of these compounds. Substituent effects on the geometry, electronic structure, conjugation, HOMO, and LUMO of the parent ring are discussed in detail. Vibrational frequency studies indicate that the parent ring has a characteristic frequency and the substitution of all of the substituents makes it shift to a lower wavenumber. Moreover, our study shows that some of our discussed compounds may be potential candidates for highenergy density materials (HEDMs).

A Density Functional Study of Furofuran Polymers as Potential Materials for Polymer Solar Cells

“…The charge density P (r) and Laplacian ( ) at the BCP were also listed in Table 1. and inspect the changes in electronic accumulation, 38 and large charge density (more positive) and Laplacian ( ) (more negative) at BCPs imply large local populations of charges in those bonds. The of P3HT is negative, which indicates that the two atoms in central bond are relatively accumulated due to shared interactions.…”

Rb3[C6N7(NCN)3]·3H2O and Cs3[C6N7(NCN)3]·3H2O – Synthesis, Crystal Structure and Thermal Behavior of Two Novel Alkali Melonates

“…[35] the cyanamide sidearms cause a widening of the adjacent angles and an elongation of the adjacent C-N bonds and hence a slight distortion of the s-heptazine core. The sidearms can be approximately accounted cyanamide groups -N-C≡N, as indicated by the terminal C-N bond lengths (117 pm) which correspond to triple bonds.…”

The Structure And Tautomerism Of Cyameluric Acid*

“…As expected, the protonation of the peripheral N atoms N1, N3 and N5 does not significantly disturb the conjugated system of 20 π-electrons over the tricyclic heptazine core. Complete planarity of the C 6 N 7 X 3 unit was predicted theoretically [2,3] and observed for alkali cyamelurates M 3 [C 6 N 7 O 3 ] [16] as well as for all other heptazine derivatives investigated so far [7 -13].…”