High symmetry crystal supramolecularity: –XPh3 molecules in cubic latticesElectronic supplementary information (ESI) available: additional figures (Fig. S1–3) described in the text. See http://www.rsc.org/suppdata/nj/b1/b104324m/

Abstract

The majority of molecular crystals in the Cambridge Structural Database involve relatively low symmetry molecules, engaged by intermolecular interactions with restricted symmetry, resulting in the preponderant occurrence of a small number of relatively low symmetry crystallographic space groups as expounded by Brock and Dunitz. We are examining some contrasting crystal structure types that contain higher symmetry molecules involved in high symmetry intermolecular motifs and generating high symmetry space groups. This paper considers molecules containing XPh3 groups, engaged in multiple phenyl embraces with local S6 () symmetry, generating crystal lattices with cubic symmetry. The conceptual framework for these analyses also involves the presence, symmetry, and occupancy of cavities in high symmetry lattices, with extensions to crystal trapping of unusual species such as [Cu2Br5]2− and [Cu8Br15]6−. The compounds included in the analyses of crystal packing and symmetry in this paper are (MePh3P+)2[Cu2Br5]2−, Ph3POGaCl3 , Ph3AsI2 , N(Ph-2-OMe)3 , Ph3SnCl, Ph3PAuCCAuPPh3·(C6H6)2 , Ph3PAu(B6H6)AuPPh3 , (Ph3PH+)2[SnCl6]2−, and (Ph3MeP+)6 [Cu8Br15]6−. Concerts of edge-to-face (EF) and offset-face-to-face (OFF) local interactions between phenyl groups generate bimolecular (EF)6 = 6PE with symmetry S6 , hexamolecular (EF)6 with symmetry S6 , trimolecular (EF)3 , hexamolecular (OFF)6 , and two-dimensional {(OFF)6}∞ . Crystal supramolecular analysis includes description of the asymmetric segments of intermolecular motifs, as well as the conventional asymmetric sector of the molecule.