Журнал "Макрогетероциклы"

М. А. Elistratova,^a@ I. B. Zakharova,^b and О. Е. Kvyatkovskii^a

^aIoffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia

^bPeter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia

^@Corresponding author E-mail: marina.elistratova@mail.ioffe.ru

DOI: 10.6060/mhc190552e

Macroheterocycles 2019 12(4) 370-374

The optimal geometry of molecules of tetraphenylporphyrin (H₂TPP), its zinc complex (ZnTPP) and their dimers and trimers, as well as the HOMO-LUMO energy gap and the binding energies of the complexes, and some other parameters were calculated by quantum chemical method. The calculations of the electronic structure of (MeTPP)_n complexes were carried out in the framework of the density functional theory with the B3LYP hybrid functional using MOLCAO SCF with atomic sets of basic Gaussian functions 6-311G (2df, 2pd) with polarizing d and f functions. The difference in energy gain during the formation of dimers and trimers gave an explanation of the self-organization features of different types of porphyrins. The connection between configurations of the basic states of trimers and self-organization properties of selected materials is presented. An explanation of the relationship between the type of porphyrin and its self-organization properties is given. The ground states of the ZnTPP and H₂TPP trimers have different geometry configuration – “Zig-zag” for ZnTPP and “Stairs” for H₂TPP. Due to this fact these materials have different ability to form linear self-organized structures. The energy gain during the formation of the ZnTPP trimer with the optimal configuration is 13.23 kcal/mol, and for H₂TPP is 7.79 kcal/mol. It was concluded that ZnTPP is not prone to self-organization into linear structures under normal crystallization conditions. Whereas the ground state of (ZnTPP)₃ has a “Zig-zag” geometry, it tends to form planar structures. The large difference between ground and minor states makes it difficult to control self-organization and the growth of nanostructures. The ground state in the geometry of the “Stairs” and the small energy difference between other (H₂TPP)₃ configurations, on the contrary, allows growing various modifications of structures, including nanowires, with simple technological changes.