General Design Strategy of Anti‐aromatic Porphyrinoids

Abstract

A systematic investigation to arrange the typical anti-aromatic porphyrinoids in sequence was performed. Based on density functional theory calculations, six rules are summarized to obtain the high-performance anti-aromatic porphyrinoids: (1) when two atoms are deleted/added on the 18π electron current ring flowing pipe, we will immediately obtain a 16π/20π electron anti-aromatic system; (2) it is a good idea to increase the number of pyrrole/thiophen/furan units on the π-electron current ring flowing pipe; (3) the heteroatom selecting order is À OÀ (optimal choice), À NHÀ (second choice), and À SÀ (last choice); (4) it is worth noting that the CÀ C=CÀ C unit is not beneficial for the anti-aromatic properties; (5) it is very significant to avoid the crowded environment in the core space of an anti-aromatic molecule. In this view, À OÀ is much better than À SÀ and À NHÀ ; (6) the "circular" skeleton is much better than an "ellipse-like", "rectangular", or "parallelogram-like" one.