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

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 •- )·{[Mn II TPP] 0 ·[Mn III TPP] + }· x C 6 H 4 Cl 2 ( x = 2 for 1 or 1 for 2 ) and (TI 2- ){[M III TPP] + } 2 · x C 6 H 4 Cl 2 (M = Fe and x = 2 for 3 , M = In and x = 1 for 4 ) were synthesized. The thioindigo (TI 2- ) dianion and metal (Fe III and In III ) atoms in TPPs maintain their initial charge states during the formation of 3 and 4 , allowing the separation of paramagnetic Fe III or diamagnetic In III ions by a diamagnetic TI 2- bridge. Strong antiferromagnetic coupling is observed between Fe III ( S = 5/2) centers in complex 3 . Partial reduction of Mn III to Mn II occurs upon the formation of 1 and 2 , leading to assemblies containing three paramagnetic centers: Mn II ( S = 5/2), Mn III ( 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.