Fine Tuning between Radical versus Nonradical States of Azoheteroarenes on Selective Osmium Platforms.
Inorg Chem
; 63(26): 12175-12189, 2024 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-38870544
ABSTRACT
The article highlights the cooperative impact of azoheteroarenes [abbt 2,2'-azobis(benzothiazole), L1-L3; bmpd (E)-1,2-bis(1-methyl-1H-pyrazole-3-yl) diazene, L4] and coligands [bpy 2,2'-bipyridine; pap 2-phenylazopyridine] in tuning radical (N-Nâ¢-) versus nonradical (NâN0) states of L on selective OsII-platforms in structurally/spectroscopically characterized monomeric [1]ClO4-[6]ClO4 and [1](ClO4)2-[2](ClO4)2/[7](ClO4)2-[8](ClO4)2, respectively. The preferred syn-configuration of L in the complexes prevented obtaining ligand bridged dimeric species. It revealed that {Os(bpy)2} facilitated the stabilization of both nonradical ([1](ClO4)2-[2](ClO4)2) and radical ([1]ClO4-[2]ClO4) states of L1/L2, while it delivered exclusively the radical form for L3 in [3]ClO4. In contrast, {Os(pap)2} generated radical states of L1-L3 in [4]ClO4-[6]ClO4, respectively, without any alteration of the redox state of OsII and azo (NâN0) function of the pap coligand. The neutral state of L4 was, however, ascertained in [7](ClO4)2 or [8](ClO4)2 irrespective of the nature of the metal fragment {Os(bpy)2} or {Os(pap)2}, respectively. Switching between radical and nonradical forms of L in the complexes as a function L and coligand could be addressed based on their relative FMO (frontier molecular orbital) energies. Multiple close redox steps of the complexes extended a competitive electron transfer scenario between the redox active components including metal/L/bpy/pap, leading to delicate electronic forms in each case.
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01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article