The chemical space of B, N-substituted polycyclic aromatic hydrocarbons: Combinatorial enumeration and high-throughput first-principles modeling

Abstract

Combinatorial introduction of heteroatoms in the two-dimensional framework of aromatic hydrocarbons opens up possibilities to design compound libraries exhibiting desirable photovoltaic and photochemical properties. Exhaustive enumeration and first-principles characterization of this chemical space provide indispensable insights for rational compound design strategies. Here, for the smallest seventy-seven Kekulean-benzenoid polycyclic systems, we reveal combinatorial substitution of C atom pairs with the isosteric and isoelectronic B, N pairs to result in 7,453,041,547,842 (7.4 tera) unique molecules. We present comprehensive frequency distributions of this chemical space, analyze trends and discuss a symmetry-controlled selectivity manifestable in synthesis product yield. Furthermore, by performing high-throughput ab initio density functional theory calculations of over thirty-three thousand (33k) representative molecules, we discuss quantitative trends in the structural stability and inter-property relationships across heteroarenes. Our results indicate a significant fraction of the 33k molecules to be electronically active in the 1.5-2.5 eV region, encompassing the most intense region of the solar spectrum, indicating their suitability as potential light-harvesting molecular components in photo-catalyzed solar cells.

Data-Driven Modeling of S0 -> S1 Excitation Energy in the BODIPY Chemical Space: High-Throughput Computation, Quantum Machine Learning, and Inverse Design

“…However, since the unsubstituted BODIPY framework has the C 2v point group symmetry [82,83], this number drops when redundant entries are eliminated. For such symmetry constrained enumerations, Pólya [84][85][86] has suggested an algebraic strategy that has been used for non-constructive enumeration of chemical compound spaces [87]. With in the constraints of C 2v , the total number of molecules in the BODIPYs chemical space considered here amounts to 253 × 10 9 , as reported in Table.…”

A systematic analysis of excitonic properties to seek optimal singlet fission: the BN-substitution patterns in tetracene

“…The final set of selected BN-tetracene molecules comprises 60 different doping configurations out of the 77 theoretically possible configurations. 46 Their chemical structure is represented in Figure S1 of the Supporting Information (SI).…”

Modelling aromatisation of (BN)nH2n azabora-annulenes

“…21 Recently, this protocol of molecular design by successive substitution has been implemented on an impressive scale; substitution of C2 pairs with BN in all possible ways in 77 Kekulean benzenoids generated >7 x 10 12 distinct distinct hypothetical azaborabenzenoid hybrids, of which many were suggested as possible leads for application in light harvesting. 22 A natural question arises. If borazine and its neutral congeners are non-aromatic, is there a systematic way to convert them into aromatics?…”