Halogen Bonding in Ring‐Substituted Group 10 POCOP Iodido Complexes with Iodine and Its Possible Role in Oxidative Addition

Abstract

Halogen bonding (XB) of an isostructural series of complexes of the type [3,5‐tBu(tBuPOCOPtBu)MI] [3,5‐tBu2(tBuPOCOPtBu) = κ3‐C6H‐3,5‐(tBu)2‐2,6‐(OPtBu2)2; M = Ni, Pd, Pt] with iodine as XB donor was studied in the solid state. Co‐crystallization experiments afforded single crystals for all three XB systems [3,5‐tBu(tBuPOCOPtBu)NiI] (1‐I2), [3,5‐tBu(tBuPOCOPtBu)PdI] (2‐I2), and [3,5‐tBu(tBuPOCOPtBu)PtI] (3‐I2). Whereas in the case of 1‐I2, two molecules of I2 bind to the iodide ligand, complexes 2‐I2 and 3‐I2 are isostructural 1:1 adducts with almost orthogonal binding of I2 to the metal iodido acceptor. All adducts form zig‐zag chain structures where the pincer complexes act as bifunctional XB acceptors, forming XB interactions between metal iodide ligand and I2 as well as between the aryl backbone of the pincer ligand and the I2 XB donor. DFT studies were performed to analyze the electronic structure of the XB adducts. Halogen bonded adducts and related products of I2 coordination were examined as formal intermediates in oxidative addition of I2 to a metal(II) center. Computational data suggest that the herein described complexes do not play a role in this context.