Photochemical Behavior of Beryllium Complexes with Subporphyrazines and Subphthalocyanines

Abstract

Structures of beryllium subphthalocyanines and beryllium subporphyrazines complexes with different substituents are explored for the first time. Their photochemical properties are studied using time-dependent density functional theory calculations and compared to boron-related compounds for which their photochemical activity is already known. These beryllium compounds were found to be thermodynamically stable in a vacuum and present features similar to those of boron-containing analogues, although the nature of bonding between the cation and the macrocycle presents subtle differences. Most important contributions to the main peak in the Q-band region arise from HOMO to LUMO transitions in the case of subphthalocyanines and alkyl subporphyrazine complexes, whereas a mixture of that contribution and a HOMO-2 to LUMO contribution are present in the case of thioalkyl subporphyrazines. The absorption in the visible region could make these candidates suitable for photochemical devices if combined with appropriate donor groups.

Beryllium subphthalocyanines self-assembling properties

“…26 As expected, BeSubPc interacts with water as BePc does (see Figure 5A), similarly also to the arrangement showed with fluorine or chlorine as axial substituents. 22 The distance between Be and O from water is 1.760 Å and the N-Be-N angle 103.8º, in the same range of values found with the previously mentioned axial groups.These molecules could be able to trap other small molecules present in the environment when forming aggregates, such as solvent molecules, as previously Figure 5B (see also Table S2). In view of these structures, it is reasonable to think that BeSubPc might as well coordinate other similar molecules such as 4-Mepy, as observed for the phthalocyanine derivative (CSD Refcode WIJYUK).…”

“…22 The BeSubPz core is identical to that of BeSubPc, but lacks of peripheral benzene rings. For these BeSubPzH 2 O aggregates, we looked at the directionality of the structure, the dipole moment and the complexation energies.…”

“…This is also the case for beryllium subphthalocyanine and subporphyrazine (SubPz) complexes, as recently reported in the literature. 22 As mentioned in the Introduction, BePc observed stacked structures will be used as a starting point for our studies, for which no Be aza-N interactions seem to exist (CSD Refcode ZZZNHK01). 26 To confirm this point for an isolated dimer in vacuum, we have fully optimized the geometry of the simplest BePc dimer, containing hydrogen atoms as peripheral substituents.…”

“…[16][17][18][19][20][21] In this direction, very recently, beryllium subphthalocyanines were shown to be able of absorbing light in the visible region. 22 This fact is a new evidence of the chemical versatility of beryllium, whose ability to behave as an effective Lewis acid, by forming beryllium bonds, opens a door to modulate or completely modify the intrinsic physicochemical properties of its conjugated Lewis base. …”

A computational investigation on core‐expanded subphthalocyanines

“…All calculations were performed with Gaussian 09 Rev E.01 version program package in vacuum. Hybrid density functional B3LYP and 6‐31+G(d) basis sets were chosen to optimize geometry structures along with their corresponding vibration analysis, which allows us to determine whether they are minimum on the potential energy surface . B3LYP has been proven to be able to reproduce experimental structures accurately .…”