The Structure of the “Third‐Generation” Tris(pyrazolyl)borate Caesium Salt p‐BrC6H4TpCs

Abstract

AbstractSlow crystallisation at lowered temperature yielded crystals of the “third‐generation” tris(pyrazolyl)borate transfer agent p‐BrC6H4TpCs (Tp′Cs) 1 (triclinic; P$\bar{1}$; a = 8.540(4), b = 15.045(6), c = 15.879(7) Å; α = 65.853(8), β = 88.457(8), γ = 75.056(8)°; V = 1791.4(13) Å3; Z = 4). The central caesium ion in 1 interacts with three individual p‐BrC6H4Tp ligands in two different chelating fashions.In particular, κ1‐N‐coordination and η5‐π‐coordination of pyrazole moieties as well as η6‐π‐coordination of the p‐BrC6H4 substituent are observed. Further, comparable coordination of neighbouring caesium ions leads to the formation of polymeric structures connected by two bridging modes.