Exchange interaction in multinuclear transition-metal complexes. 3. Synthesis, x-ray structure, and magnetic properties of Cu2L(CH3COO)2.2CH3OH (L2- = anion of N,N'-bis((2-(o-hydroxybenzhydrylidene)amino)ethyl)-1,2-ethanediamine), a one-dimensional Heisenberg antiferromagnet having through-bond coup