Dihalomethanes as Bent Bifunctional XB/XB-Donating Building Blocks for Construction of Metal-involving Halogen Bonded Hexagons

The dihalomethanes CH₂X₂ (X=Cl, Br, I) were co‐crystallized with the isocyanide complexes trans‐[MX^M₂(CNC₆H₄‐4‐X^C)₂] (M=Pd, Pt; X^M=Br, I; X^C=F, Cl, Br) to give an extended series comprising 15 X‐ray structures of isostructural adducts featuring 1D metal‐involving hexagon‐like arrays. In these structures, CH₂X₂ behave as bent bifunctional XB/XB‐donating building blocks, whereas trans‐[MX^M₂(CNC₆H₄‐4‐X^C)₂] act as a linear XB/XB acceptors. Results of DFT calculations indicate that all XCH₂–X⋅⋅⋅X^M–M contacts are typical noncovalent interactions with estimated strengths in the range of 1.3–3.2 kcal mol⁻¹. A CCDC search reveals that hexagon‐like arrays are rather common but previously overlooked structural motives for adducts of trans‐bis(halide) complexes and halomethanes.