Synthesis, Characterization, and Singlet Oxygen Sensitization by Antimony (III/V) Corrole Complexes

Abstract

The synthesis, structural, spectroscopic characterization, and DFT/TD‐DFT calculations of antimony corroles are reported herein. The studied complexes can be described as [(Corr)SbIII] and [(Corr)(oxo)SbV]2, where Corr is the trianion of corrole. All these complexes are diamagnetic in nature as is evident from sharp peaks with normal chemical shifts in the 1H NMR spectra. Single crystal XRD analysis reveals that the antimony(V) corrole complex is the bis‐μ‐oxo‐bridged dinuclear antimony(V). Both the tetra and hexa‐coordinated [(Corr)SbIII] and [(Corr)(oxo)SbV]2 antimony complexes adopt domed‐structure with weak d‐π electron coupling. The Sb−O bond distances in the co‐facial dimer of [(Corr)(oxo)SbV]2 are 1.9802(16) Å (DFT: 2.0141 Å) (for Sb1−O1), and 1.9639(17) Å (DFT: 1.9957 Å) (for Sb2−O2) respectively. We observed that even though iodosobenzene is frequently used to oxidize [(Corr)SbIII] species, the oxidation of [(Corr)SbIII] is indeed very facile in nature and it even occurred in the air‐equilibrated CHCl3 solution while storing for few days. Excitation of these antimony (III/V) corrole complexes in DCM/MeOH (1 : 1) at 77 K results in red emission with maxima at 640–720 nm. The singlet oxygen production of [(Corr)(oxo)SbV]2 has a quantum yield of 69 % and is two times higher than the analogous [(Corr)SbIII] derivatives.

First application of antimony(iii) corrole for electrocatalytic hydrogen evolution

“…The synthesis of antimony corrole may be traced back two decades ago. 21 Contemporary research on antimony corrole encompasses photocatalytic oxidation, [22][23][24][25][26] photodynamic inactivation of mold spores, 27 and electrocatalytic oxygen evolution reactions. 28 However, the application of antimony corrole in the electrocatalytic HER has not been reported so far.…”

Sb(v) dihalide corroles: efficient singlet oxygen photosensitisers

“…10 Additionally, Sb( v ) corroles have been researched with respect to their spectroscopic properties and their role in sensitising ground state triplet oxygen ( 3 O 2 ) to 1 O 2 . Previous studies demonstrated the impressive ability of Sb( v ) corroles to facilitate the generation of sulfoxides through singlet oxygen pathways 11,12 or to serve in the photoinactivation of mold spores and green algae. 11…”