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

The synthesis of iodine(I) complexes with either benzoimidazole or carbazole‐derived sp2N‐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 1H and 1H‐15N 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 15N 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. [ABSTRACT FROM AUTHOR]