Recent advances in subphthalocyanines and related subporphyrinoids

Subporphyrinoids constitute a class of extremely versatile and attractive compounds. Herein, a comprehensive review of the most recent advances in the fundamentals and applications of these cone-shaped aromatic macrocycles is presented.

A theoretical study on electronic spectra of a novel series of metal substituted boron subphthalocyanine chloride

Boron subphthalocyanine chloride has been extensively studied by experimentalists and computational chemists due to its unique optical and electronic properties. It has been practical to modify the optical and physical properties of subphthalocyanine through axial, peripheral, and center substitutions or ring expansion. However, there have been few investigations on the substitution of central boron atom. In the present work, a new metal-substituted (center substitution of boron atom) series of boron subphthalocyanine chloride (metal = Fe, Co, Ni, Cu, and Zn) are theoretically designed utilizing modern density functional theory. The optimized results of this series in gas phase and with polarizable continuum model show that they may be chemically stable, and the predicted order of the stability of MSubPC is Fe>Cu>Ni>Co>Zn. Also, this new series of MSubPC molecules all becomes more non-planar and has much smaller dipole moments, which imply that they may be feasible for blend with organic acceptors. The HOMO-LUMO energy gaps of MSubPC (M=Co, Ni, Cu) are smaller than that of subPC. Furthermore, the wavelength of simulated absorption peaks of ZnSubPC and NiSubPC is red-shifted with respect to prototype subPC molecule in the visible region, and FeSubPC has noticeably stronger absorption strength than subPC because its excitation involves more orbital transitions and d electrons. The work here shows a new way to design photoelectric materials based on subphthalocyanine with center metal substitution.

A computational study of the effects of axial halogen substitutions of boron subphthalocyanines on their electronic spectra in solution and in the solid state

Non-planar boron subphthalocyanine chloride is a talented photoelectric material and has been widely applied. In this paper, we have investigated the effects of axial halogen substitutions on electronic spectra of boron subphthalocyanines by combining DFT/TDDFT calculations and available experimental data in solution and in the solid state. We utilize long range separated density functional and polarizable continuum model to obtain the electronic structure and absorption spectra. The computed frontier molecular orbital energy matches well with experiment in dichloromethane and the simulated spectra correctly reproduce the trend of experiment in toluene. Furthermore, we model two configurations (convex-to-convex and concave-to-concave) of dimers of boron subphthalocyanines based on experimental structures in thin film: From F to Cl to Br substitution, the simulated wavelength of absorption peaks in the visible region slightly increases; in contrast, the absorption strength decreases. Moreover, our calculated results suggest that the convex-to-convex configurations of dimers may be the main contributors to the absorption spectra of X-BsubPC (X = F, Cl, Br) in thin film, though no experimental spectra of thin film of X-BsubPC (X = F, Br) yet. Finally, we find that CAM-B3LYP is able to reproduce the energy of frontier molecular orbitals quite well.