title: Formation of M4Se4 cuboids (M = As, Sb, Bi) via secondary pnictogen-chalcogen interactions in the co-crystals MX3·Se=P(p-FC6)H4)3 (M = As, X = Br; M = Sb, X = Cl; M = Bi, X = Cl, Br).
abstract: The reactions of the group 15 trihalides, MX(3) (M = As, Sb, Bi; X = Cl, Br), with the phosphine selenide SeP(p-FC(6)H(4))(3) result in the formation of co-crystals of formula MX(3)·SeP(p-FC(6)H(4))(3). No reaction was observed with MI(3) (M = As, Sb, Bi). The structures of MX(3)·SeP(p-FC(6)H(4))(3) (M = As, X = Br 2; M = Sb, X = Cl 3; M = Bi, X = Cl 5; M = Bi, X = Br 6) have been established, and are isomorphous, crystallising in the cubic I23 space group. All the structures feature a primary MX(3) unit, which has three weak secondary MSe interactions to SeP(p-FC(6)H(4))(3) molecules. However, each of these SeP(p-FC(6)H(4))(3) molecules bridges three MX(3) molecules, resulting in the generation of an M(4)Se(4) (M = As, Sb, Bi) distorted cuboid linked by the pnictogen-chalcogen interactions. Four opposing corners of the cuboid are occupied by the M atom (M = As, Sb, Bi) of an MX(3) pyramid, and the other four by the selenium atom of the phosphine selenide.
authors: School of Chemistry, University of Manchester, Manchester, UK.
authors: Fatma B
authors: FB
authors: Alhanash
authors: Nicholas A
authors: NA
authors: Barnes
authors: Alan K
authors: AK
authors: Brisdon
authors: Stephen M
authors: SM
authors: Godfrey
authors: Robin G
authors: RG
authors: Pritchard