From I‐Ligated and I‐Doped to O ‐Ligated Hafnium(IV) Phthalocyaninate(2–) Complexes

Treatment of HfPcI 2 · Pht (Pc = C 32 H 16 N 8 2– ; Pht = phthalonitrile) or bromide analogue HfPcBr 2 · Pht with acetylacetone (acacH) led to the formation of a HfPc(acac) 2 complex that, depending on the crystallization conditions, crystallized with solvent acacH molecules to form mono‐ and disolvate crystals: HfPc(acac) 2 · acacH ( 1 ) and HfPc(acac) 2 · 2acacH ( 2 ). Treatment of the partially oxidized iodine sandwich‐type hafnium(IV) diphthalocyanine HfPc 2 (I 3 ) 2/3 , in which two of three HfPc 2 units are a one‐electron‐oxidized [HfPc 2 ] + unit with a π‐radical character, with benzonitrile (BN) or 4‐methylpyridine (4‐Mepy) under ambient conditions led to the formation of μ 2 (O,OH)(C 6 H 5 COO)(HfPc) 2 ( 3 ), which is bridged by O 2– and OH – and stapled together by deprotonated benzoic acid complex, and μ 2 (O,OH)(C 5 H 4 NCOO)(HfPc) 2 ( 4 ), which is bridged by O 2– and OH – and stapled by deprotonated isonicotinic acid. Complexes 1 – 4 were structurally characterized by X‐ray single‐crystal analysis. In these complexes, the eight or seven coordination number of the closed‐shell (d 0 ) Hf 4+ cation is saturated by four isoindole nitrogen atoms of the phthalocyaninate macrocycle and by four oxygen atoms in 1 and in 2 or three oxygen atoms in 3 and 4 . Interaction of the Hf 4+ cation with the isoindole nitrogen atoms of Pc macrocycle led to the distortion of the aromatic Pc macrocycle to the flattened crown, with the Hf 4+ cation about 1.2 Å out of the N 4 ‐isoindole plane of the Pc macrocycle. The complexes were also characterized by UV/Vis spectroscopy.