Increasing solubility and stability of linear tricobalt(II) chains with depa (diethyldipyridylamide) ligands.
A new and more basic ligand has been used to make two new tricobalt extended metal atom chains (EMACs), namely, Co(3)(depa)(4)Cl(2), 3, and Co(3)(depa)(4)(CN)(2), 4. The depa ligand is di(4-ethyl-2-pyridyl)amide, a useful modification of the well-known di(2-pyridyl)amide, dpa, ligand. The new compounds have been thoroughly characterized, and informative comparisons are made of 3 with Co(3)(dpa)(4)Cl(2), 1, and 4 with Co(3)(dpa)(4)(CN)(2), 2, which were described several years ago. Introduction of the eight ethyl groups into the trimetal compounds improves solubility, makes oxidations easier, and allows for a more complete examination of the magnetic susceptibility as a function of temperature for 3 than was possible for 1. The data clearly indicate that the upper state for 3 has S = (3)/(2) and suggest that this is the case for 1 as well.
Berry
John F
JF
Department of Chemistry, PO Box 30012, Texas A&M University, College Station, Texas 77842-3012, USA.
Cotton
F Albert
FA
Lu
Tongbu
T
Murillo
Carlos A
CA