Crystal structure of C-(n-propyl)calix[4]resorcinarene and its complex with caffeine

The crystal structures of the all-cis epimer of C-(n-propyl)calix[4]resorci narene (1) and its caffeine complex are reported. 1 . CH3CN . H2O (2) cryst allizes in the tetragonal space group P (4) over bar, a = 14.3643(9), c = 9 .3344(8) Angstrom, V = 1926(2) Angstrom (3). Refinement led to a final conv entional R-1. value of 0.047 for 3406 reflections and 236 parameters. The c affeine complex 1 . C8H10N4O2. CH3OH .H2O (3) crystallizes in the triclinic space group P (1) over bar, a = 11.2892(4), b = 13.0367(8), c = 16.9700(11 ) Angstrom, alpha = 82.902(2), beta = 79.713(3), gamma = 88.053(2)degrees, V = 2438(2)Angstrom (3). Refinement led to a final conventional R-1 value o f 0.067 for 6393 reflections and 641 parameters. The resorcinarene displays the usual bowl shape in both compounds. The caffeine molecule in 3 is hydr ogen bonded to two resorcinarene and one water molecules and one of its met hyl groups is included in the cavity of a third macrocycle, suggesting CH3. . . pi interactions. Extended hydrogen bonding patterns involving phenolic protons and solvent molecules are also present in both compounds.