A linear homocatenated compound containing six indium Centers

In contrast to carbon and its heavier congeners, group 13 elements are rarely observed to catenate into linear chains. Here, we find that treatment of indium(I) iodide with a protonated N-xylyl ß-diketiminate and a strong potassium base in tetrahydrofuran yields a hexa-indium chain. X-ray crystallography revealed one ß-diketiminate ligand bound to each indium center with no bridging ligands supporting the five indium-indium single bonds. The terminal indium centers were capped with iodine. Electronic spectroscopy and computations on a model compound offer preliminary support for s delocalization along the chain.