TRANSITION-METAL 8-COORDINATION .13. SYNTHESIS, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURE OF THE SCHIFF-BASE CHELATE BIS(N,N'-DISALICYLIDENE-1,2-PHENYLENEDIAMINO)ZIRCONIUM(IV) BENZENE SOLVATE

As part of our program to elucidate eight-coordinate complexes and their polymeric counterparts we have isolated and structurally characterized the model Schiff-base chelate bis(N, N-disalicylidene-l, 2-phenylenediamino)zirconium(IV), Zr(dsp)2, as the benzene solvate Zr(dsp)2-2.5C6H6. The synthesis involves a condensation between tetrakis(salicylaldehydato)-zirconium(IV), Zr(sal)4, and o-phenylenediamine, a method which also allows the synthesis of analogous coordination polymers. The Zr(dsp)2 unit is an eight-coordinate dodecahedral species with nitrogen donors in the dodecahedral A position and oxygen donors in the B positions in accord with theoretical predictions. The chelating ligands span the mam edges. The Zr-O bonds average 2.10 A, which is appreciably shorter than the Zr-N distance of 2.43 A. The donor atoms are in an almost perfect dodecahedral array with the trapezoidal planes intersecting at 89.2°, even though the chelating ligands are quite puckered from these planes. The Zr(dsp)2-2.5C6H6 solvate crystallizes in the space group P1 with Z = 2, a = 13.037 (4) Å, b = 13.669 (6) Å, c = 14.500 (2) Å, α = 98.81 (2)°, β = 116.47 (2)°, and γ = 92.78 (3)°. © 1979, American Chemical Society. All rights reserved.