Structural diversity in phosphoramidate’s chemistry: Syntheses, spectroscopic and X-ray crystallography studies Khodayar Gholivand a, * , Zahra Shariatinia b,1 , Seyedeh Mahdieh Mashhadi a , Farzaneh Daeepour a , Narjes Farshidnasab a , Hamid Reza Mahzouni a , Nasrin Taheri a , Shadi Amiri a , Sheida Ansar a a Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran b Department of Chemistry, Amirkabir University of Technology, P.O. Box 159163-4311, Tehran, Iran article info Article history: Received 15 September 2008 Accepted 7 October 2008 Available online 4 December 2008 Keywords: Bisphosphoramidates Phosphoramidates NMR X-ray crystallography abstract Novel phosphorus compounds of bisphosphoramidate, phosphoramidate and phosphoric triamide deriv- atives were synthesized using the starting materials PCl 5 and POCl 3 . The products were then character- ized by 1 H, 13 C, 31 P, 19 F NMR, IR spectroscopy and CHN elemental analysis. It is noticeable that the reaction of 4-aminobenzamide with PCl 5 in different molar ratios yields different products, bisphospho- ramides and phosphoric triamides. Moreover, we were taken by surprise that the interaction of POCl 3 with the first-type aromatic amines gave bisphosphoramidates with P–N–P linkages that exhibited 2 J(P,P)  20.0 Hz in the 31 P NMR spectra. In fact, two simple one-pot pathways are presented here for the synthesis of new bisphosphoramidates, and to the best of our knowledge these are the first instances of bisphosphoramidates that have been obtained up until now. The structures of compounds I (4-OCH 3 – C 6 H 4 –CH 2 –C 9 H 13 –NH 2 Cl), 34 and 44 were further determined by X-ray crystallography. All of these struc- tures produced three dimensional polymeric chains through strong- and weak hydrogen bonds. The pres- ence of chiral aminoacidester moieties in the phosphoric triamides lead to chiral molecules that showed two sets of signals for the two groups. Interestingly, in phosphoric triamides containing cyanoacetamide moieties, the existence of aromatic amine substituents on the P atoms created central chiral phosphorus atoms, i.e. the two aromatic groups revealed two sets of peaks in the 1 H and 13 C NMR spectra, while com- pounds with aliphatic moieties did not display this effect. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction Phosphorus chemistry covers a wide area of sciences, including synthesis, coordination, biomedicine and theoretical matters. Phos- phoramidates, bisphosphoramidates and phosphoric triamides are some important instances of phosphorus derivatives whose chem- istry plays a significant role in various parts of science. Among the phosphoramidates, N-phosphorylated aminoacids have revealed high antitumor, antiviral and anti-HIV activities [1–4]. So far the syntheses and coordination chemistry of many bisphosphorami- dates have been reported, containing P–N–P bonds via multi-step reactions [5–9], but here a simple one-pot method is presented to prepare such compounds. These types of compounds are potential bidentate ligands for the coordination to the metal atoms [10,11]. There are some reports on the synthesis of bisphosphoramides con- taining P(O)–(CH 2 ) n –P(O) or P(O)–N(CH 3 )–(binaphthyl)–N(CH 3 )– P(O) moieties [12], as well as the P–(CH 2 ) n –P group [13,14]. In addi- tion, it is expected that due to the presence of the two phosphorus atoms in their structures, they will show more anticancer, antibacterial and enzyme inhibitory properties than phosphorami- dates. Besides, the coordination chemistry of phosphoramidates [15–18], their biological applications [19–22], quantum chemical calculations on their structures [23,24], and their spectroscopic and X-ray crystal structures [25–27] are frequently studied. In the pres- ent work, following on from our previous research, we have synthe- sized and characterized several new phosphorus compounds of phosphoramidates, bisphosphoramidates (including P(O)NHC 6 H 4 - C(O)NHP(O) and P–N–P linkages), and phosphoric triamides. It is noteworthy that two simple one-pot pathways are presented for the synthesis of the new bisphosphoramidates and, as far as we know, these are the first examples of bisphosphoramidates that have been prepared so far. Furthermore, their NMR, IR and mass spectroscopic features as well as X-ray crystal structures are dis- cussed and compared with our previous data. 2. Experimental 2.1. X-ray measurements X-ray data of compound 34 were collected on a Bruker APEX II [28] and Siemens P3/PC [29] and those of compounds I and 44 on a 0277-5387/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.poly.2008.10.057 * Corresponding author. Tel.: +98 2182884422; fax: +98 2182883455. E-mail address: gholi_kh@modares.ac.ir (K. Gholivand). 1 Tel.: +982164543298; fax: +982164543296. Polyhedron 28 (2009) 307–321 Contents lists available at ScienceDirect Polyhedron journal homepage: www.elsevier.com/locate/poly