The La(III), Ce(III), Pr(III), Nd(III), Sm(III), and Eu(III) complexes of the racemic heterochiral nonaaza macrocyclic amine L have been synthesized and characterized by spectroscopic methods. The X-ray crystal structures of the [PrL][Pr(NO3)(6)] center dot CH3OH and the isomorphic [NdL][Nd(NO3)(6)] center dot CH3OH complexes show that all nine nitrogen atoms of the macrocycle coordinate to the Ln(3+) ion, completing its coordination sphere. The macrocycle wraps tightly around the metal ion in double-helical fashion. The structures reveal the RRRRSS/SSSSRR configuration at the stereogenic carbon atoms of the three cyclohexane rings, confirming the heterochiral nature of the parent 3 + 3 macrocycle obtained in the condensation of racemic trans-1,2-diaminocyclohexane and 2,6-diformylpyridine. The NMR spectra of the isolated complexes indicate the presence of low C-1 symmetry [LnL](3+) complexes. The same symmetry is indicated by the X-ray crystal structures of Pr(III) and Nd(III) complexes, which show that for the RRRRSS enantiomer of the macrocycle L; the helix axis passes through the cyclohexane ring of RR chirality and the opposite pyridine ring. The NMR studies of complex formation in solution by the paramagnetic Pr3+ and Eu3+ ions indicate that the initially formed [LnL](3+) complexes are of C-2 symmetry. For the RRRRSS enantiomer of the macrocycle L in the C-2-symmetric species, the helix axis passes through the cyclohexane ring of SS chirality and the opposite pyridine ring. The C-1-symmetric and C-2-symmetric forms of the [LnL](3+) complexes constitute a new kind of isomers and the conversion of the kinetic complexation product of C-2 symmetry into the thermodynamic product of C-1 symmetry corresponds to an unprecedented switching of the orientation of the helix axis within the macrocycle framework.