title: (E)-1,1'-Dibutyl-3,3'-biindolinyl-idene-2,2'-dione.
abstract: In the title mol-ecule, C(24)H(26)N(2)O(2), the two indol-2-one units, which are connected by a C=C double bond, are almost coplanar with an inter-planar angle of 6.8 (1)°. On cooling from 293 to 120 K, the space group changes from P2(1)/n to P2(1). Two intra-molecular C-H⋯O hydrogen bonds occur.
authors.forename: Mao-Sen
authors.initials: MS
authors.lastname: Yuan
authors.forename: Qi
authors.initials: Q
authors.lastname: Fang