[CuCo(CO) 4 ] n —Crystal Structure of a Polymer with a One‐Dimensional, Infinite Copper‐Cobalt Bonding System

CuCo(CO) 4 crystallizes dimorphically. The tetramer with a Cu 4 Co 4 eight‐membered ring (orange‐red crystals) is known: new is the polymer with CuCo zig‐zag chains (strongly distorted yellow platelets or needles that separate into fibers). Interatomic distances and bond angles in the building blocks of the chains are almost the same as in the tetrameric modification.