Group 13 Aminopyridinato Complexes and Co─Al Heterobimetallics: Impact of Ligand Substituent and Metal Exchange on Thermal Behavior

Abstract

A family of monometallic aluminum and gallium complexes supported by simple aminopyridinato ligands was synthesized and fully characterized by NMR spectroscopy and single‐crystal X‐ray diffraction. In addition, two Co─Al heterobimetallic complexes were synthesized and structurally characterized. We investigated how ligand substitution, metal identity, and the corresponding heterobimetallic complexes influence volatility and their thermal behavior as evaluated by thermogravimetry‐differential scanning calorimetry (TG‐DSC). The aluminum complexes exhibit volatility with onset temperatures between 80 and 140 °C, whereas the corresponding gallium analogs bearing the same ligand framework are nonvolatile under comparable conditions, underscoring the critical role of the metal center. TG‐DSC of the heterobimetallic complexes reveals exclusive decomposition without observable sublimation, indicating that heterobimetallic complex formation significantly reduces volatility relative to the monometallic aluminum species.