NMR Investigation of Lipophilic Cage Ligands. Part 2. Structural Assignments and Conformational Properties of the Ligand 12-hexadecyl-7,17,22,27-tetraoxa-1,4,10,14-tetraazatricyclo (12.5.5.54,10) nonacosane and of its Sodium, Potassium & Silver Complexes