“…We have previously reported the synthesis of their U III/III and U IV/IV complexes, and others have reported the use of pTP ligands to support catalysis by both partially deprotonated potassium salts [K 2 H 2 (pTP R )], 30 or V V and Mo VI -imido complexes which have shown catalytic reactivity for the ring-opening polymerisation of ε-caprolactone. 26,31 In the case of the potassium complexes, the authors attributed the remarkable stability of the doubly deprotonated salt [K 2 H 2 (pTP R )] to the formation of potassium-arene interactions with the central arene of the platform, and capacity for the remaining protons to bridge the two aryloxide O atoms on each side. 30 In our hands, the tetra-potassium salt 1 R , ([K 4 (pTP R )] 2 (THF) 11 , R = Me), is readily isolated from the reaction between H 4 (pTP Me ) with four equivalents of KN″ (N″ = N(SiMe 3 ) 2 ) in THF at room temperature, Scheme 1, although we note that it is extremely sensitive to hydrolysis.…”