Designer Metallic Acceptor-Containing Halogen Bonds: General Strategies.

Being electrostatic interactions in nature, hydrogen bonding (HB) and halogen bonding (XB) are considered to be two parallel worlds. In principle, all the applications that HB have could also be applied to XB. However, there has been no report on an anionic, metallic XB acceptor, but metal anions have been observed to be good HB acceptors. This missing mosaic piece of XB theory is because common metal anions are reactive for XB donors. In view of this, two strategies are proposed for designing metallic acceptor-containing XB using ab initio calculations. The first one is to utilize a metal cluster anion with a high electron detachment energy, such as the superatom, Al₁₃⁻ as the XB acceptor. The second strategy is to design a ligand-passivated/protected metal core that can maintain the negative charge; several exotic clusters, such as PtH₅⁻, PtZnH₅⁻, and PtMgH₅⁻, are used as examples. Based on these two strategies, it is anticipated that more metallic acceptor-containing XBs will be discovered. [ABSTRACT FROM AUTHOR]