Diaryliodonium Tetrachloroplatinates(II): Recognition of a Trifurcated Metal-Involving μ3-I•••(Cl,Cl,Pt) Halogen Bond

Synthesis and X ray characterization of the four diaryliodonium tetrachloroplatinates(II) [(ArArI)-Ar-1-I-2](2)[PtCl4] (Ar-1/Ar-2 = Ph/Ph (1), 4-Cl-C6H4/2,4,6-(MeO)(3)C6H2 (2), 4-Me-C6H4/2,4,6-(MeO)(3)C6H2 (3), Ph/2,4,6-(MeO)(3)C6H2 (4)) allowed the deterimination of several types of unconventional halogen-bond (HaB) patterns. The first example of a metal-involved trifurcated four-center mu(3)-X center dot center dot center dot(X',X',M) HaB is represented by the metal-involving I center dot center dot center dot Pt HaB (the structure of 4) with iodonium cations acting as HaB donors, which is supported by two weak I center dot center dot center dot Cl HaB contacts. The structures of 1-3 display bifurcated three-center mu(2)-I center dot center dot center dot(Cl,Cl) HaBs with iodonium cations. DFT calculations were used to estimate the energetic features of the two types of HaB contacts. Molecular electrostatic potential (MEP) surfaces and noncovalent interaction plot index (NCIPlot) computational tools were used to evaluate the sigma-holes and characterize the HaBs, respectively, in all structures.

Automated summary

Synthesis and X-ray characterization of four diaryliodonium tetrachloroplatinates(II) allowed the determination of unconventional halogen-bond patterns. The study revealed a metal-involved trifurcated four-center HaB and bifurcated three-center HaBs with iodonium cations, providing insights into the structural and energetic features of these HaB contacts.