N-Heterocyclic imine-based bis-gallium(i) carbene analogs featuring a four-membered Ga2N2 ring

Abstract

A combination of Ga(I) centers as important building blocks and scaffolds containing N-heterocyclic imines gives new insights into low-valent Ga chemistry. In this study, a mixture of L^DipNLi (L^Dip = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene), ^tBuOK, and Cp*Ga (Cp* = pentamethylcyclopentadienyl) in toluene afforded [L^DipN-Ga]₂ (1) via salt metathesis. X-ray structure analysis of 1 revealed a four-membered Ga₂N₂ ring, and DFT studies indicated the presence of a lone pair at each Ga center. In addition, compound 1 demonstrated diverse reactivities towards methyl trifluoromethanesulfonate, diphenyl disulfide, 9,10-phenanthrenequinone, and ECl₂ (E = Ge or Sn).