Crystal structures of bis­[2-(di­phenyl­phosphino­thio­yl)phen­yl] ether and bis­{2-[diphen­yl(selanyl­idene)phosphan­yl]phen­yl} ether

The title compounds, C(36)H(28)OP(2)S(2), (1), and C(36)H(28)OP(2)Se(2), (2), exhibit remarkably similar structures although they are not isomorphous. The whole mol­ecule of compound (2) is generated by twofold symmetry, with the ether O atom located on the twofold axis. Both compounds have intra­molecular π–π inter­actions between terminal phenyl rings with centroid–centroid distances of 3.6214 (16) and 3.8027 (14) Å in (1) and (2), respectively. In the crystal of (1), short C—H⋯S hydrogen bonds link the mol­ecules, forming chains along [001], while in (2) there are no analogous C—H⋯Se inter­actions present.