Iodine(I) and Silver(I) Complexes of Benzoimidazole and Pyridylcarbazole Derivatives

Abstract

Abstract The synthesis of iodine(I) complexes with either benzoimidazole or carbazole‐derived sp 2 N ‐containing Lewis bases is described, as well as their corresponding silver(I) complexes. The addition of elemental iodine to the linear two‐coordinate Ag(I) complexes produces iodine(I) complexes with a three‐center four‐electron (3c–4e) [N−I−N] + bond. The 1 H and 1 H‐ 15 N HMBC NMR studies unambiguously confirm the formation of the complexes in all cases via the [N−Ag−N] + →[N−I−N] + cation exchange, with the 15 N NMR chemical shift change between 94 to 111 ppm when compared to the free ligand. The single crystal X‐ray crystallographic studies on eight I + complexes revealed highly symmetrical [N−I−N] + bonds with I−N bond distances of 2.21–2.26 Å and N−I−N angles of 177–180°, whilst some of the corresponding Ag + complexes showed a clear deviation from linearity with N−Ag−N angles of ca. 150° and Ag−N bond distances of 2.09–2.18 Å.