Cyclopentadiene based low-valent group 13 metal compounds: Ligands in coordination chemistry and link between metal rich molecules and intermetallic materials

A study was conducted to demonstrate ligands in coordination chemistry and link between metal rich molecules and intermetallic materials. It was demonstrated that the coordination chemistry of RE ligands initially focused on transition-metal carbonyl substitution reactions yielding stable and kinetically inert complexes that simultaneously contained CO and RE ligands. The coordination chemistry of these ligands was expanded to complexes of s-, p-, and f-block metals, stabilizing electrophilic metal centers, such as Ca, Mg, and lanthanides. The stability, isolability, and ease of handling of the low-coordinated compounds RE provided them with significant potential as ligands toward transition metals. It was essential to analyze the frontier orbitals of the RE compounds, along with their interaction with the corresponding orbitals of the appropriate symmetry at the transition metals for a better understanding.