Conformational Isomerism and Weak Molecular and Magnetic Interactions in Ternary Copper(II) Complexes of [Cu(AA)L‘]ClO 4 · n H 2 O, Where AA = l -Phenylalanine and l -Histidine, L‘ = 1,10-Phenanthroline and 2,2-Bipyridine, and n = 1 or 1.5: Synthesis, Single-Crystal X-ray Structures, and Magnetic Resonance Investigations