Potassium complexes of the ‘super’ formamidine (2,6-Pr2iC6H3)NC(H)NH(2,6-Pr2iC6H3), HDippForm.: Synthesis and molecular structure of [{K(DippForm)2K(THF)2}n]·nTHF and [K(DippForm)(THF)3]·HDippForm

Ambient temperature treatment of the formamidine (2,6-Pr2iC6H3)NC(H)NH(2,6-Pr2iC6H3), HDippForm, with one equivalent of potassium bis(trimethylsilyl)amide yields the formamidinate species [{K(DippForm)2K(THF)2}n]·nTHF (1), which exhibits a macromolecular structure of alternating η6-arene:η1-amide bound potassium di-amidinate and potassium di-THF units in a one-dimensional polymeric array. Addition of a further equivalent of HDippForm to 1 affords hydrogen bound [K(DippForm)(THF)3]·HDippForm (2). The supramolecular structure of 2 resembles a ‘topochemical’ arrangement of K(DippForm) and HDippForm moieties that, in tandem with 1H-NMR data, corroborate a putative [K(DippForm)(HDippForm)] composition in solution.