Syntheses, Crystal Structures, and CD Spectra of Simple Heterobimetallic Transition Metal Binaphtholates

The first pseudooctahedral tris(binaphtholates) of first-row transition elements, Na3[Fe(S-binaphtholate)3]·3Et2O·H2O (1), Li3[Fe(R-binaphtholate)3]·6THF (2), and Li3[Cr(R-binaphtholate)3]·6THF (3), are heterobimetallic complexes incorporating alkali metal ions. 1 crystallizes in the monoclinic spacegroup P21 with a = 11.3256(10) Å, b = 20.735(3) Å, c = 13.5741(15) Å, β = 91.086(8)°, and Z = 2. 2 and 3 are isomorphous, crystallizing in the hexagonal space group P6322 with a = 14.897(15) Å, b = 19.2849(19) Å, and Z = 2 (2) and a = 14.850(4) Å, b = 19.052(7) Å, and Z = 2 (3). The CD and absorption spectra of the Fe(III) and Cr(III) compounds are discussed and compared with those reported for [Fe(enterobactin)]3- and model compounds and for [Cr(entereobactin)]3-, respectively.