In this paper the spectroscopic and the geometric properties of four ligands with pyrazole unit are studied at both experimental and computational levels. The computational results are perfectly in good agreement with the experimental results especially in terms of the IR, 1H-NMR and 13C-NMR shifts. The spectroscopic features as well as the computed properties help to establish the successful synthesis of ligands bdmpzm and bdmpza. The theoretical and the experimental IR and Raman significantly help in distinguishing the four ligands. The results show that the Raman spectral is better applicable in characterising the CH3 deformation, the C—H, CNN and CCNNout of the ligands but vibrations like N—H in dmpz and O—H, CO in bdmpza are observed to be Raman inactive. A significant variations are observed among the two available *N atoms characterising the bidentate features of bdmpzm, bdmpza and bdcpzm which indicates a possible different affinities for metal coordination. Also the result suggest that bdmpza will be the best starting material for NLO application than other while bdcpzm is predicted to have potential of been a poor coordinating ligand. The computed variations in the properties of *N atoms that are the characteristic features of their power of coordination can be of immense help since these type of ligands have a wide application in transition metal coordination.