Recently, main group elements containing transition metal carbonyl complexes have received much attention due to their novel bonding modes and versatile reactivities. In this article, we will focus on the development of pnictogen (Bi, Sb, and As)‐containing Fe or Cr carbonyl complexes reported in our previous study, in which their rational synthetic methodologies, intriguing reactivities, as well as their special properties will be described and systematically compared. Importantly, a unique zig‐zag Bi‐Fe polymer was synthesized, and several Bi‐Cr complexes were found to exhibit surprising semiconducting behaviors with varied ultra‐low energy gaps via the through‐bond or through‐space electron communication.