Elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR), and mass spectra were used to characterize (p-methylphenylazo)quinolin-8-ol (L1) and (p-methoxylphenylazo) quinolin-8-ol (L2). The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also, the important fragments in the ligands and the complexes were determined using mass spectra, and the main peaks corresponded to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and studied by elemental and thermal analyses (TG and DTA) as well as by IR, 1HNMR, magnetic measurements, electronic transitions, and molar conductance. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Ni, Cu, and Zn metal ions with the investigated ligands 1:1 and 1:2 complexes, and all of the formed complexes contain coordinated water molecules and hydrated water. All of the prepared solid complexes behave as non-electrolytes in chloroform.