Inorganic Chemistry, Vol.33, No.6, 1071-1079, 1994
Synthesis and X-Ray Crystal-Structures of a Calixarene-Related, Tetraamino, Tetraphenolic, Polynucleating Macrocyclic Ligand and Its Zn-II(4) and Co-III(3) Derivatives
Reduction with NaBH4 Of the macrocyclic tetra Schiff base ligand formed by condensation of two molecules of 2,6-diformyl-4-methylphenol with two molecules of 2,6-bis(aminomethyl)-4-methylphenol affords the corresponding tetraamino, tetraphenolic macrocyclic ligand LrH4. Determination of the structure of the hydrochloride salt with the remarkable solvation composition LrH4.4HCl.H2O.CH3OH.C2H5OH, reveals a dome-shaped L(r)H84+ cation with a water molecule and two of the chloride ions H-bonded inside the domed macrocyclic cavity. Crystal data : monoclinic, space group P2(1)/c, a = 16.190(3) angstrom, b = 10.246(3) angstrom, c = 26.756(6) angstrom, beta = 96.88(2)-degrees, Z = 4. Reaction of LrH4-4HCl with zinc acetate in methanol containing tetraethylammonium hydroxide affords crystals of [L4Zn(II)4(OH)(CH3CO2)3(CH3OH)].1.5CH3OH whose structure was determined by X-ray crystallography. Crystal data : monoclinic, space group C2/c, a = 34.213(9) angstrom, b = 16.028(3) angstrom, c = 20.640(3) angstrom, beta = 119.17(2)-degrees, Z = 8. The macrocycle binds the four zincs in a kite-shaped arrangement totally lacking in symmetry. A central hydroxo ligand bridges three of the zincs and is 2.849(5) angstrom from the fourth zinc. Ignoring this weak interaction with the hydroxo, this fourth zinc has an irregular 4-coordinate geometry; two of the remaining zincs are 5-coordinate, and the other is 6-coordinate. Reaction in air of LrH4.4HCl with cobaltous acetate in the presence of OH- and BF4-yields crystals of [LrCO(III)3(OH)(CH3CO2)3]BF4.3.83H2O whose structure was determined by X-ray crystallography. Crystal data : monoclinic, space group P2(1)/n, a = 15.555(3) angstrom, b = 15.141(4) angstrom, c = 21.723(3) angstrom, beta = 98.96(1)-degrees, Z = 4. The macrocycle binds three cobalt(III) centers, the fourth nucleation site being vacant. A central bridging hydroxo ligand and three bridging acetato ligands afford distorted octahedral arrangements for all three cobalts.