Crystal Structure of a Lithium Complex with 2,2'-(Biphenyl-2,2'-diylbis(oxy))diacetic Acid

The crystal structure of [Li(HL)] (H2L = 2,2′-(biphenyl-2,2′-diylbis(oxy))diacetic acid) was studied by X-ray diffraction methods. This complex crystallized in the monoclinic space group P21/c, with a = 13.970(11), b = 7.098(6), c = 16.097(12)A, β = 103.910(9)°, Z = 4, V = 1549(2)A3, and R = 0.0768. The crystal structure shows that the complex units are linked by classical intermolecular hydrogen bonds between an uncoordinated carboxyl of one complex molecule and an oxygen atom from a coordinated carboxyl of the adjacent complex molecule to form a single-helical chain. Two infinite homochiral helices self-assemble into a dimer through a non-classical C-H…π hydrogen bonding interaction.