The binuclear Cu complex salts of 1, 4, 7‐trithiacyclononane (9S3) with an inorganic anion (BF4)‐ and with an organic radical anion TCNQ‐ (7, 7′, 8, 8′‐tetracyanoquinodimethanide) were synthesized and their molecular and crystal structures were examined in connection with the magnetic properties. The new complex cation [Cu(9S3)CN(9S3)Cu]+ varies its charges and magnetic properties depending on the counter anions; [Cu(9S3)CN(9S3)Cu](BF4) (1) was obtained as diamagnetic colorless crystals, while [Cu(9S3)CN(9S3)Cu](TCNQ)2 (2) was obtained as dark blue crystals with antiferromagnetic properties. Complex 1 crystallized in the monoclinic space group C2/c with a = 26.863(2), b = 7.0878(5), c = 13.4864(8) Å, β = 116.318(2)°. Complex 2 crystallized in the triclinic space group P1¯ with a = 12.521(1), b = 20.2698(8), c = 8.0205(4) Å, α = 100.688(4), β = 93.846(5), γ = 94.953(4)°. Both complexes are comprised of cyano‐bridged two Cu(9S3) ions with tetrahedral coordination. The X‐ray structural study revealed that 1 has two crystallographically equivalent copper(I) atoms, while 2 has two crystallographically independent CuI/II sites. The two CuI/II sites could not be distinguished from the X‐ray structural study. For 2 the IR spectra show that both crystallographically independent TCNQ species were monoanions and are strongly dimerized due to π‐stacking, which well explains their diamagnetic contribution to the magnetic susceptibility and the highly insulating property of this salt. The temperature‐dependent magnetic susceptibility of 2 showed a deviation from the Curie‐Weiss behaviour around 60 K, which indicates a strong antiferromagnetic intermolecular interaction between the copper complexes and that such intermolecular interaction should partly occur via the TCNQ radical anion dimer.

Ipidacrine (2,3,5,6,7,8-hexa­hydro-1H-cyclo­penta­[b]quinolin-9-amine) was reacted with 4-methoxy­phenyl isocyanate to give the title compound, C28H30N4O4. An intra­molecular N—H⋯O hydrogen bond results in an essentially planar [r.m.s. deviation from the mean plane is 0.126 (1) Å] conformation for the biuret unit. The central ring of the quinoline unit is twisted by 78.2 (1)° with respect to the biuret mean plane, whereas the two 4-methoxy­benzene rings are twisted out of this plane by 24.3 (1)° and 48.5 (1)°, resulting in an overall propeller-like structure. An inter­molecular N—H⋯N hydrogen bond between the biuret NH atom and the quinoline ring nitro­gen defines the crystal packing.