Our previous EPR studies dealt with the contrasting behaviour of the lamellar C8OCu, as against the columnar C8Cu/C10Cu. X-ray and EPR studies of C n , Cu(n = 6–12) and CnOCu(n = 6–12) presented here, however, indicate that some members exhibit anomalous behaviour within each series. Thus C6Cu, C8Cu, C10Cu and C12Cu (even members) show a single exchange-narrowed strong asymmetric g⊥ along with a weak g‖ in pure solids. Interestingly, C7Cu and C9Cu (odd members) show hyperfine quartets in g‖, indicating weak or no exchange. C7Cu shows a single g⊥, conforming to the axial symmetry in CnCu. However, C9Cu is rather unique: gives three different mesophases and exhibits non-axial behaviour. Crystal structure for C9Cu and C7Cu reported here for the first time, indicate that the former has a structure similar to that of C7Cu. However, C7Cu, which also has z = 1 and belongs to the same triclinic space group, has a close interaction between two molecules at the opposite corners of the ab plane in the unit cell, through chain – chain intermolecular interaction and possibility π – π interaction among phenyl-rings in adjacent molecules. This is reflected in the ‘c’ parameter, which is 10.066 Å, as compared to 5.863 Å in C6Cu. However, this interaction in C7Cu vanishes in the mesophase, as indicated by the collapse of the quartet. Weak exchange in C7Cu is also reflected in the proton relaxation time T 1 (68.9 msecs), as compared 1.9 msecs for C6Cu. In C n OCu, C7OCu behaves like the dimer C8OCu, with a complex hyperfine structure including quadrupole forbidden transitions after g 1 along with a broad g 2 and a weak g 3. The dimer in C8OCu is strong and the quartet persists in the mesophase. Other members, possibly monomers viz., C6OCu, and C10OCu, give a hyperfine quartet in g 1 (while in C12OCu it is after g 1), followed by a strong single g2 line and a weak g3, conforming to the non-axial symmetry of the lamellar complex. Thus, chain length does play a role but not in a linear fashion, because of the anomalies presented above.