Crystal structure analysis and chiral recognition study of Delta-[Ru(bpy)(2)(py)(2)][(+)-O,O '-dibenzoyl-D-tartrate]center dot 12H(2)O and Lambda-[Ru(bpy)(2)(py)(2)][(-)-O,O '-dibenzoyl-L-tartrate]center dot 12H(2)O

The molecular structure and crystal-packing mode of the enantiopure chiral building blocks Delta-[Ru(bpy)(2)(py)(2)][(+)-O,O'-dibenzoyl-D-tartrate]. 1 2H(2)O (I) and Lambda-[Ru(bpy)(2)(py)(2)][(-)-O,O'-dibenzoyl-L-tartarate]. 12H(2)O (II) have been determined by single-crystal X-ray diffraction data. This study proposes a model of how the L- and D-dibenzoyltartrate anions r ecognize the chirality of the hydrophobic [Ru(bpy)(2)(py)(2)](2+) complex. The monoclinic unit cell contains four complex cations, four tartrate anion s, and 48 water molecules. Since there are no possibilities to form hydroge n bonds between the cations and anions, chiral recognition is due to crysta l packing. Two benzoyl rings of two different tartrate anions are gripping the two bpy-planes of the Ru-complex. Further a third benzoyl ring from a t artrate anion is packed between the two pyridine rings, favoring one enanti omeric form to crystallize from aqueous solution. Crystal structure data fo r I at 153 K: a = 15.342(3) Angstrom. b = 19.200(4) Angstrom, c = 18.872(4) Angstrom, beta = 104.841(3)degrees, monoclinic space group C-2, R-1 = 0.02 39 (I > 2 sigma (I). R-2 = 0.0606, Flack parameter = 0.0115 (with esd 0.016 6). For II at 293 K: a = 15.376(4) Angstrom, b = 19.388(11) Angstrom, c = 1 9.085(7) Angstrom, beta = 105.11(2)degrees, monoclinic space group C121, R- 1 = 0.0686 (I > 2 sigma (I), R-2 = 0,1819, Flack parameter = -0.0100 (with esd 0.0521).