Comparative study of structures, including jahn-teller effects, in the saccharinate complexes, [M(C7H4NO3S)2(H2O)4].2H2O, of chromium and zinc, as well as other divalent metal ions

Abstract

The chromium(II) and zinc(II) complexes of saccharine, [M(C7H4NO3S)2(H2O)4].2H2O, have been prepared and their structures determined by X-ray crystallography. The chromium compound shows clear evidence of Jahn-Teller distortion. When the results for the two new compounds are combined with results in the literature for analogous compounds of MnII, FeII, CoII, NiII, and CuII, a broad picture of structural properties vs. d-orbital population for high-spin divalent ions for the first transition series is provided. For the series Mn, Fe, Co, Ni, and Zn the expected trends are seen in the bond lengths as the high-spin configurations change, with maxima at Mn and Zn and a minimum at Ni. The bond lengths for the Cu compound deviate enormously (one Cu-O distance being greater, the other Cu-0 and the Cu-N distances being less) from the values interpolated between the Ni and Zn data. For the Cr compound, the Jahn-Teller distortions take the same form as those for Cu, but they are only about half as large. The chromium and zinc compounds are isomorphous, crystallizing in space group P21/c with Z = 2. The cell constants for ZnC14H20O12N2S2 are a = 7.934 (1) Å, b = 16.118 (3) Å, c = 7.691 (1) Å, and β = 99.90 (1)° and for CrC14H20O12N2S2 are a = 8.042 (4) Å,b= 16.032 (8) Å, c = 7.804 (4) Å, and β = 100.90 (4)°. © 1984, American Chemical Society. All rights reserved.