AbstractA number of Ni(II) complexes ofN,N′‐bis(8‐quinolyl)trimethylenediamines are synthesized both as perchlorate salts and neutral amino complexes. Substitutions on the 2 and 6 positions of the quinolyl ligands are introduced for various reasons concerning the structural studies. The structural informations are obtained by studies of the magnetic properties, electronic spectra and NMR spectra. Structural changes effected by acid/base property of the medium are followed by NMR spectro