Infrared, 1H and 13C NMR spectra, structural charcterization and DFT calculations of novel adenine-cyclodiphosp(V)azane derivatives

Adenine tetrachlorocyclodiphospha(V)zane derivatives (III(a-c)) were prepared by the reaction of hexachlorocyclodiphospha(V)zane derivatives (I(a-c)) and adenine (II) as precursors. The synthesized compound's and their structures (III(a-c)) were firmly characterized (based on the presence of an inversion center) using FT-IR (4000-200 cm(-1)), UV-vis. (190-800 nm), (1)H, (13)C NMR and Mass spectral measurements in addition to C, H, N, P elemental analysis. The compounds (III(a-c)) were found to be a 1:2 molar ratio of (I(a-c)) and adenine (II) adducts, respectively. Confident and complete vibrational assignments are proposed for nearly all fundamental vibrations, along with detailed interpretation for all observed signals in both (1)H and (13)C NMR spectra of the investigated phospha(V)zanes (III(a-c)). In addition, unconstrained geometry optimization of III(a-c) were carried out by means of DFT-B3LYP/3-21G(d) calculations to provide new insight into the structural parameters and molecular geometries of compounds III(a-c). The results are reported herein and compared with similar molecules whenever appropriate.