2,6-Bis(benzimidazol-2-yl)pyridine complexes of group 14 elements

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• The synthesis and characterization of novel metal complexes are crucial for advancing materials science and understanding chemical reactivity.
• Benzimidazole-based ligands offer unique coordination properties, influencing the electronic and structural characteristics of metal complexes.

Purpose of the Study:

• To synthesize and characterize novel germanium (Ge) and tin (Sn) complexes using 2,6-bis(benzimidazol-2-yl)pyridine (G-BZIMPY) ligands.
• To investigate the self-ionization behavior and electronic properties of these newly formed metal complexes.
• To explore the reactivity of these complexes in reduction reactions and analyze their spectral characteristics, including UV-vis absorption and solvatochromism.

Main Methods:

• Treatment of MCl2 (M = Ge or Sn) with various G-BZIMPY ligands.
• Isolation and characterization of self-ionization products [G-BZIMPYMCl][MCl3] (compounds 1-6).
• Investigation of reduction reactions, including the isolation of nickel complexes 8 and 9.
• UV-vis absorption spectroscopy to analyze MLCT bands and solvatochromism.

Main Results:

• High yields (75-98%) of self-ionization products [G-BZIMPYMCl][MCl3] were achieved for both germanium and tin.
• Novel nickel complexes, [(NBn-BZIMPY)2Ni][MCl3]2 (8 and 9), were successfully isolated from reduction reactions.
• [NBn-BZIMPYSnCl][SnCl3] exhibited a stronger MLCT band compared to its germanium analogs.
• Germanium complexes displayed negative solvatochromism, a phenomenon not observed in the tin complexes.

Conclusions:

• The study successfully synthesized novel self-ionized germanium and tin complexes with G-BZIMPY ligands.
• The electronic and spectral properties, particularly MLCT bands and solvatochromism, differ significantly between the germanium and tin complexes.
• These findings contribute to the understanding of organometallic chemistry and the development of new materials with tunable electronic properties.