Stabilization of a Snub Bisphenoidal Environment of Strontium in Bis[3‐(1‐naphthyl)‐5‐(2‐pyridyl)‐2 H ‐pyrazole]strontium Bis[3‐(1‐naphthyl)‐5‐(2‐pyridyl)pyrazolate] by Strong Hydrogen Bridges

Metalation of 3‐(1‐naphthyl)‐5‐(2‐pyridyl)‐2 H ‐pyrazole ( 1 ) with [(thf) 2 Sr{N(SiMe 3 ) 2 } 2 ] in toluene and recrystallization from tetrahydrofuran and diethyl ether yields ether‐free bis[3‐(1‐naphthyl)‐5‐(2‐pyridyl)‐2 H ‐pyrazole]strontium bis[3‐(1‐naphthyl)‐5‐(2‐pyridyl)pyrazolate] ( 2 ). This complex contains an octa‐coordinate central strontium atom in a snub bisphenoidal coordination sphere. Intramolecular N ··· H ··· N hydrogen bridges between pyrazolyl groups stabilize the large coordination number of the alkaline earth metal. Short N ··· N contacts of 272.5 and 274.5 pm verify the existence of strong hydrogen bridges; the chemical shift of δ = 19.7 for these protons underlines their extremely acidic character.