Affiliations: [a] Department of Chemistry, Tarbiat Modares University, Tehran, Iran | [b] Department of Biology, Islamic Azad University, Garmsar, Iran | [c] Department of Chemistry, Amirkabir University of Technology, Tehran, Iran
Correspondence:
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Correspondence to: Khodayar Gholivand, Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran. Tel.: +98 2182884422; Fax: +98 2182883455; gholi_kh@modares.ac.ir
Abstract: A novel zwitterionic bisphosphoramide compound with formula [4-NH-C5H4C(O)NHP(O)O–]2O•(H3O +)2(H2O)2 was synthesized and characterized by NMR and FT-IR spectroscopy. The 31P{1H} NMR spectrum illustrates a singlet peak at −16.51 ppm that is indicative of the structural symmetry. Also, the crystal structure of the title compound was determined by X-ray crystallography. In this structure there is one bisphosphoramide dianion BS two H3O + cations that are co-crystallized with two H2O molecules. In the bisphosphoramide dianion, the two phosphorus atoms are connected to each other through an oxygen atom with P1-O3-P2 angle of 133.40(13)°. Intermolecular P-O ... H-N, C=O ... H–N and H-O ... H-O hydrogen bonds led to a three dimensional network in the crystalline lattice. DFT computations were performed on the X-ray crystal structure and also on assumed cis and trans conformations of the two P-NR groups using Gaussian 98 software at B3LYP/6-31G * level of theory. The optimizations yielded identical pseudo-trans conformation for the both optimized cis and trans forms.
