Binuclear Coordination Assemblies of Metal Tetraphenylporphyrins (M = Mn, Fe, and In) with Anionic Thioindigo Bridges as Promising Magnetic Systems with Tunable Properties

• Published in: Inorganic chemistry 2024-12, Vol.63 (48), p.22677-22687
• Main Authors: Nazarov, Dmitry I., Faraonov, Maxim A., Nations, Sean M., Gutsev, Lavrenty G., Yakushev, Ilya A., Kuzmin, Alexey V., Khasanov, Salavat S., Otsuka, Akihiro, Yamochi, Hideki, Kitagawa, Hiroshi, Konarev, Dmitri V.
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X; 1520-510X
• DOI: 10.1021/acs.inorgchem.4c02477

A series of hybrids comprising two metal (Mn, Fe, and In) tetraphenylporphyrins axially substituted with anionic bidentate trans-thioindigo ligands (TI) were obtained. Substitution of the axial chloride anion by an oxygen atom of the dye forms short M–O bonds. Crystalline binuclear assemblies (TI•–)·{[MnIITPP]0·[MnIIITPP] + }·xC6H4Cl2 (x = 2 for 1 or 1 for 2) and (TI2–)­{[MIIITPP]+}2·xC6H4Cl2 (M = Fe and x = 2 for 3, M = In and x = 1 for 4) were synthesized. The thioindigo (TI2–) dianion and metal (FeIII and InIII) atoms in TPPs maintain their initial charge states during the formation of 3 and 4, allowing the separation of paramagnetic FeIII or diamagnetic InIII ions by a diamagnetic TI2– bridge. Strong antiferromagnetic coupling is observed between FeIII (S = 5/2) centers in complex 3. Partial reduction of MnIII to MnII occurs upon the formation of 1 and 2, leading to assemblies containing three paramagnetic centers: MnII (S = 5/2), MnIII (S = 2), and TI•– radical anion (S = 1/2). Orthogonal arrangement of TPP and TI molecules in 1 provides strong ferromagnetic coupling. Weak antiferromagnetic coupling is realized in 2 due to the rotation of the TI bridge.