The reaction of 1,1,3,3-tetraphenyl-1,3-disiloxandiol (LH2) with n-butyllithium and CrCl2 results in a mononuclear chromium(II) complex (1) that further reacts with O2 at low temperatures to yield a mononuclear chromium(III) superoxide complex [L2CrO2(THF)][Li2(THF)3] (2). The crystal structure revealed that the chromium superoxido entity is stabilized by the coordination to an adjacent lithium cation. Complex 2 thus contains an unprecedented heterobimetallic [Cr(III)(μ-O2)Li(+)] core; beyond this it is the first chromium superoxide for which a temperature-dependent magnetic characterization could be achieved, and the first structurally characterized representative with chromium in an exclusive O-donor environment.

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CAAC–CAAC dimers with alkylene spacers are presented. These compounds are electron-rich and undergo one- and two-electron oxidation.

Syntheses of very electron‐rich dialkylamino‐substituted 2,2':6',2''‐terpyridines (TPYs) were adapted to moderate scale preparation without tedious purification of intermediates. The key 4'‐bromo‐6,6''‐dimethyl‐2,2':6',2''‐terpyridine‐4,4''‐diyl bisnonaflate is now available in gram quantities. Its nucleophilic aromatic substitution with dimethylamine provided mixtures of 4'‐bromo‐substituted 4,4''‐bis(dimethylamino)‐TPY and the tris(dimethylamino)‐TPY. The bromo compound was used in a Buchwald–Hartwig amination to provide the tris(dimethylamino)‐TPY in excellent yield. The 4'‐bromo substituent was reductively removed to furnish the bis(dimethylamino)‐TPY. The same sequence of reactions with pyrrolidine as nucleophile leads to the hitherto unknown pyrrolidino‐TPYs. Calculations at the MP2(FC)/6–31+G(2d,p)//B98/6‐31G(d) level predict very high methyl cation affinities for compounds of this type, with the 4,4',4''‐tri(pyrrolidin‐1‐yl)‐TPY being the most Lewis basic TPY synthesized to date. The efficiently prepared electron‐rich TPYs should be excellent ligands for many applications.

Metal–ligand cooperativity can be used in iridium complexes with an unsymmetrically substituted redox-active diamidobenzene ligand for bond activation reactions.