Diaryliodonium Tetracyanidometallates Self-Assemble into Halogen-Bonded Square-Like Arrays

• Published in: Crystal growth & design 2022-04, Vol.22 (4), p.2749-2758
• Main Authors: Suslonov, Vitalii V, Soldatova, Natalia S, Postnikov, Pavel S, Resnati, Giuseppe, Kukushkin, Vadim Yu, Ivanov, Daniil M, Bokach, Nadezhda A
• Format: Article
• Language: English
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.2c00175

Two diphenyliodonium tetracyanidometallates, [Ph2I]2[M­(CN)4] (M = Ni and Pd), were prepared through anion metathesis. Their X-ray structural analyses show that the structure-defining contact for both crystals is the charge-assisted I···N halogen bond (HaB) formed between the I atom of the iodonium cations and the N atoms of the CN– ligands. These HaBs assemble the bidentate and 90°-orienting HaB donor Ph2I+ and the tetradentate, square planar, and 90/180°-orienting HaB acceptors [M­(CN)4]2– into supramolecular rectangles, which further assemble into infinite chains by sharing the vertexes occupied by the [M­(CN)4]2– anions. The noncovalent nature of these contacts was confirmed by density functional theory calculations (M06/def2-TZVP) followed by combined topological analysis of the electron density distribution in the quantum theory of the atoms-in-molecules approach and noncovalent interaction analysis. The philicities of the HaB partners were further verified by the analysis of electron localization function projections, electron density/electrostatic potential profiles along the I···N bond paths, natural bond orbital analysis, and the natural population analysis or atoms-in-molecules charge sums in model systems.