Cholic acid–quinoxaline (2/1)

In the title inclusion compound, 2C(24)H(40)O(5)·C(8)H(6)N(2), the unit cell contains two mol-ecules of cholic acid (3α,7α,12α-trihydr-oxy-5β-cholan-24-oic acid) and one mol-ecule of quinoxaline which implies disorder of the quinoxaline in the space group P2(1). The amphiphilic mol-ecules of cholic acid assemble, in an anti-parallel arrangement, via O-H⋯O hydrogen bonds, into typical corrugated host bilayers which are lipophilic on the outside and lipophobic on the inside. The host framework belongs to the so called α-trans subtype. The quinoxaline mol-ecules are accommodated in lipophilic channels formed between neighboring bilayers with only van der Waals inter-actions between host and guest. There is a crystallographic twofold screw axis directed along an empty channel in the host framework; however, neighboring guests in any one channel are related by a unit-cell translation along the b axis. Thus, the overall structure is a 1:1 superposition of two such channels related by the crystallographic twofold screw axis.