The crystal structure of the 2 : 1 cholic acid - Benzophenone clathrate

The 2 : 1 cholic acid - benzophenone clathrate crystallizes in the space gr oup P2(1) with the unit-cell parameters a = 25.498(6), b = 7.942(1), c = 28 .309(6) Angstrom, beta = 101.85(2)degrees. There are four symmetrically ind ependent host molecules in the unit cell: two of them with the steroidal si de chain assuming gauche and the remaining two with the side chain in the t rans conformation. Pairs of the host molecules adopting similar conformatio ns alternate along the [(2) over bar 01] direction of the bilayer. The gues t molecules are accommodated in two crystallographically independent but to pologically similar channels running parallel to [010]. Benzophenone molecu les are disordered and included in each channel in two different conformati ons.