Synthesis and structural characterization of bis(tropolonatodimethylgallium), [(C7H5O2)Ga(CH3)2]2

Details of the synthesis, physical properties, and solid-state structure of [(C 7 H 5 O 2 )Ga(CH 3 ) 2 ] 2 are reported. Crystals of bis(tropolonatodimethylgallium) are monoclinic, a = 10.2669(9), b = 9.3237(3), c = 10.8671(10) Å, β = 112.896(4)°, Z = 2, space group P2 1 /n (22°C, λ = 0.70930 Å). The structure was solved by conventional heavy-atom techniques and was refined by full-matrix least-squares procedures to R = 0.034 and R w  = 0.037 for 1746 reflections with I ≥ 3σ(I). The centrosymmetric binuclear dimer features five-coordinate gallium atoms having irregular trigonal bipyramidal coordination geometry and a planar four-membered Ga 2 O 2 ring. Important bond lengths (corrected for libration) are Ga—O(equatorial) = 1.972(2), Ga—O(axial) = 2.025(2) and 2.551(2) Å, and Ga—C = 1.951(4) and 1.954(4) Å.