Observation of Carbodicarbene Ligand Redox Noninnocence in Highly Oxidized Iron Complexes

Abstract

To probe the possibility that carbodicarbenes (CDCs) are redoxa ctive ligands,a ll four members of the redox series [Fe(1) 2 ] n+ (n = 2-5) were synthesized, where 1 is aneutral tridentate CDC.Through acombination of spectroscopya nd DFT calculations,t he electronic structure of the pentacation is shown to be [Fe III (1C + ) 2 ] 5+ (S = 1 = 2 ). That of [Fe(1) 2 ] 4+ is more ambiguous,b ut it has significant contributions from the open-shell singlet [Fe III (1)(1C + )] 4+ (S = 0). The observed spin states derive from antiferromagnetic coupling of their constituent low-spin iron(III) centres and cation radical ligands.T his marks the first time redox activity has been observed for carbones and expands the diverse chemical behaviour knownf or these ligands.

Isolation of a Uranium(III)‐Carbon Multiple Bond Complex

“…The treatment of 1 with one equivalent of ferrocenium afforded the corresponding U(IV) complex, [(Cp*) 2 U(CDP)](BPh 4 ) 2 ( 2 ), which was obtained as dark‐red blocks in 43 % crystalline yield. Notably, oxidation of 2 with stronger oxidants, such as Ag + and (NO) + , did not afford the U(V) analogue or carbon centered radicals [14] …”

“…Notably, oxidation of 2 with stronger oxidants, such as Ag + and (NO) + , did not afford the U(V) analogue or carbon centered radicals. [14] …”

A New Tetradentate Mixed Aza-Thioether Macrocycle and Its Complexation Behavior towards Fe(II), Ni(II) and Cu(II) Ions

“…All reagents were used as received, and solvents for reactions were purified by a PureSolv MD5 solvent purification (Amesbury, MA, USA) system. The 2,9-dicarbaldehyde-1,10-phenanthroline [50,52], 2,9-bis(hydroxymethyl)-1,10-phenanthroline [51], 2,9-bis(chloromethyl)-1,10-phenanthroline [48,49] and Fe(CH 3 CN) 2 (OTf) 2 [65], were prepared in accordance with the literature methods. 1 H, 13 C{ 1 H}, 1 H-1 H COSY, 1 H-1 H-ROESY, 1 H-13 C-HSQC and 1 H- 13 C-HMBC-NMR spectra were recorded on a Bruker 600 AVANCE III FT-NMR spectrometer (Billerica, MA, USA).…”

Carbodicarbene: geminal‐Bimetallic Coordination in Selective Manner

“…Moreover, our group [7] and Lu/Liu [8] have recently expanded the utility of the CDC scaffold as a free organic catalyst for the chemical transformation of CO 2 . Thus, fundamental studies like non‐innocent redox and main group chemistry on the properties of CDCs continue to yield surprising results and may yet usher in new opportunities for enhanced catalyst design [9, 10] …”