The Trigonal Prism in Coordination Chemistry

Herein we analyze the accessibility of the trigonal‐prismatic geometry to metal complexes with different electron configurations, as well as the ability of several hexadentate ligands to favor that coordination polyhedron. Our study combines i) a structural database analysis of the occurrence of the prismatic geometry throughout the transition‐metal series, ii) a qualitative molecular orbital analysis of the distortions expected for a trigonal‐prismatic geometry, and iii) a computational study of complexes of several transition‐metal ions with different hexadentate ligands. Also the tendency of specific electron configurations to present a cis bond‐stretch Jahn–Teller distortion is analyzed.