This work reports isolation of three multinuclear complexes of Dy(III) ion ([DyIII2(L-NO2)2(Ph3PO)2(NO3)2] (1), [DyIII5(L)6(Ph3PO)(NO3)(H2O)2(μ3-OH)2] (2), [DyIII6(L–CH3)6(Ph3PO)2 (μ3-OH)3(NO3)2 (CH3OH)2] (3)]) by controlling substitution on ligand molecule. The reactions of substituted Schiff-base ligands (H2L−R; R=NO2 (1), R=H (2), R=CH3 (3)), triphenylphosphine oxide(Ph3PO) with Dy(NO3)3 ⋅ 6H2O in the presence of triethyl amine afford three multinuclear complexs with varing nuclearity, topologies. This work demonstrates effect of substitution on ligand molecules that leads to the isolation of diffrent complexes in the presence of similar reaction conditions.These complexes have been charaterized by single crystal X-ray diffration (SC-XRD), High resolution mass spectrometry (HR-MS). In order to study magnetic behaviour of complexes 1–3, direct current (dc) magnetic susceptibilities have aslo been measured. The effect of substitution on ligand has also been demonstrated by computational studies. © 2020 Wiley-VCH GmbH