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

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 Dip NLi (L Dip = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene), t BuOK, and Cp*Ga (Cp* = pentamethylcyclopentadienyl) in toluene afforded [L Dip N-Ga] 2 ( 1 ) via salt metathesis. X-ray structure analysis of 1 revealed a four-membered Ga 2 N 2 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 ECl 2 (E = Ge or Sn). A mixture of L Dip NLi, t BuOK, and Cp*Ga gave rise to a dinuclear Ga( i ) complex. X-ray structure analysis revealed its dimeric structure with a four-membered Ga 2 N 2 ring and DFT studies indicated nonbonding lone pairs at each gallium centre.