Nuclear Magnetic Resonance (NMR) spectroscopy is an effective tool for identifying compounds and investigating their molecular structures. This technique provide information about the number of equivalent and non-equivalent neighbors to an atom under investigation, the types of functional groups each that nucleus is associated with, and dynamic information. Chemical shift, due to the change in the resonance frequency of the nucleus in different electronic environments, is a valuable tool for detecting changes arising from chemical reactions and geometric isomerism. Extensive databases of chemical shifts allow to predict shifts of target molecules [1,2]. In this study, several new compounds were synthesized and fully characterized using IR, 1H-NMR, 13C-NMR, and 31P-NMR spectroscopy. The synthesized compounds are (4-Cl-C6H4O)(4-CH3-C6H4)CH(CH3)NH)2P(O) (I), (4-Cl-C6H4O)((CH3)2CHNH)2P(O) (II), (CHCl2C(O)NH)(2-Cl-C6H4CH2NH)2P(O) (III), and (CHCl2C(O)NH)((C6H5CH2)(CH3CH2)N)2P(O) (IV). The phosphorus chemical shifts in the 31P-NMR spectra were investigated and compared with analogous compounds, and the effects of amine, amide and phenoxy substituents and anisotropic effect caused by arene rings were evaluated. Some topics related to IR and 1H-NMR and 13C-NMR spectra were detailed.

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