Cocrystals of 3,5-Dimethyl-1<i>H</i>-pyrazole and Salicylic Acid: Controlled Formation of Trimers via O−H···N Hydrogen Bonds^†

Solid-state reactions of 3,5-dimethyl-1H-pyrazole (dmpz) and salicylic acid (sa) in different stoichiometries afford two different trimers whose structures have been determined by X-ray diffraction and analyzed by 13C and 15N solid-state nuclear magnetic resonance spectroscopy. GIAO absolute shieldings at the B3LYP/6-311++G** level have been calculated and compared with the experimental chemical shifts. Hydrogen-bond interactions between dmpz and sa provide sufficient driving force to direct molecular recognition and crystal packing.