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Tungsten(VI) Complex of N‐Fused Porphyrin Absorbing Near‐Infrared Light beyond 1000 nm
Author(s) -
Yamamoto Takaaki,
Abraham Jibin Alex,
Mori Shigeki,
Toganoh Motoki,
Shimizu Soji,
Ishida Masatoshi,
Furuta Hiroyuki
Publication year - 2020
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.202000014
Subject(s) - homo/lumo , porphyrin , tungsten , crystallography , magnetic circular dichroism , photochemistry , circular dichroism , octahedron , spectroscopy , materials science , band gap , chemistry , molecule , physics , crystal structure , spectral line , optoelectronics , organic chemistry , quantum mechanics , astronomy
Abstract Incorporating tungsten into the N3 core of a N‐fused porphyrin (NFP; 1 ) affords high‐valent tungsten(VI)‐NFP complexes, WClO 2 ‐1 and 21‐chlorinated WClO 2 ‐3 . The X‐ray structure of WClO 2 ‐1 reveals a distorted octahedral geometry with sitting atop metal coordination. The absorption spectrum of WClO 2 ‐1 displays bathochromically shifted Q‐like bands beyond 1000 nm, indicating an inherently narrow HOMO‐LUMO energy gap. DFT calculations show that the degeneracy of the LUMO and LUMO+1 pair of 1 is significantly resolved by the tungsten(VI) coordination. Conclusively, magnetic circular dichroism (MCD) spectroscopy and cyclic voltammetry provide a rationale for the narrow HOMO‐LUMO energy gap in the “16‐electron” d 0 tungsten(VI)‐NFP complexes.