SYNTHESIS AND COMPLEXATION STUDIES OF MESOCYCLIC AND MACROCYCLIC POLYTHIOETHERS .9. SYNTHESIS AND CRYSTAL-STRUCTURE OF BIS(1,4,7-TRITHIACYCLODECANE)PALLADIUM(II) HEXAFLUOROPHOSPHATE

We wish to report the synthesis and X-ray crystal structure of the crown thioether complex bis(1,4,7-trithiacyclodecane)palladium(II) hexafluorophosphate, [Pd(10S3)2](PF6)2. The two 10S3 ligands are arranged around the palladium in pseudooctahedral fashion to yield the meso stereoisomer. Four of the six sulfur atoms from the 10S3 ligands form a square-planar arrangement around the palladium (mean Pd-S(equatorial) bond distance = 2.27 angstrom). The remaining two sulfurs are coordinated axially at a much greater distance from the Pd (Pd-S(axial) = 3.11 angstrom). Despite this long distance, the axial sulfur atoms do influence the electronic absorption spectrum for the complex resulting in a blue-green solid with a single d-d absorption band at 602 nm. The palladium complex crystallizes with two nitromethane solvent molecules per palladium atom. Crystal data for [Pd(10S3)2](PF6)2.2CH3NO2: C16H34PdS6P2F12N2O4, monoclinic, space group C2/c; a = 22.473 (9) angstrom, b = 12.071 (4) angstrom, c = 11.186 (3) angstrom, beta = 94.14 (3)-degrees, V = 3026.53 angstrom 3, Z = 4, R = 0.046, D = 1.991 g/cm3, 2836 reflections measured. The complex undergoes a chemically reversible one-electron oxidation in nitromethane at +1.03 V vs Ag/AgCl.