Dynamic properties of molecular tweezers with a bis(2-hydroxyphenyl) pyrimidine backbone
4,6-Bis(2-hydroxyphenyl)-2-alkylpyrimidines with two anthryl or 9-ethylnylanthryl substituents at the positions para to the OH groups prefer a U-shaped conformation supported by two intramolecular OH...N hydrogen bonds in the solid state and in CDCl3