Polymorphism for a novel phosphoramidate; NMR and X-ray crystallography

Abstract

New phosphoramidates with formula 3-NC 5 H 4 C(O)NHP(O)XY (X=Y=Cl (1), X=Y=NH-C(CH 3 ) 3 (2a,2b), X=Y=N(C 4 H 9 ) 2 (3), X=Cl, Y=N(C 2 H 5 ) 2 (4) were synthesized and characterized by IR, 1 H-, 13 C-, 31 P-NMR spectroscopy and CHN elemental analysis. Surprisingly, the reaction of compound 2a with LaCl 3 , 7H 2 O in 3:1 M ratio leads to a polymorph of this compound (2b). NMR spectra indicate that 2 J(PNH amide ) in 2b (7.0 Hz) is very much greater than in 2a (4.1 Hz), while d( 31 P) values are identical for both of them. In IR spectra, t(P=O) is weaker but t(C=O) is stronger in 2a than in 2b. The structures of 2a, 2b were determined by X-ray crystallography. These compounds form centrosymmetric dimers via two intermolecular P=O……H-N hydrogen bonds. Strong intermolecular N-H…N, N-H…O and weak C-H…O hydrogen bonds lead to a three-dimensional polymeric cluster in the 2a while intermolecular strong N-H……N and weak C-H……O hydrogen bonds form a two-dimensional polymeric chain in 2b.

Different orientations of C=O versus P=O in P(O)NHC(O) skeleton: the first study on an aliphatic diazaphosphorinane with a gauche orientation

“…Some researchers have employed the anionic form [P(O)NC(O)] -to obtain compounds with a non-anti orientation [8] and better donority properties [9]. Despite the numerous structures reported in this series [10][11][12][13][14][15][16][17][18][19], there are a few neutral structures with synclinal orientation [2,5,[13][14][15][16][17]19]. Here, we study on two new compounds with different orientations of C=O versus P=O.…”

Hydrogen-bond directionality and symmetry in [C(O)NH](N)2P(O)-based structures: a comparison between X-ray crystallography data and neutron-normalized values, and evaluation of reliability

“…A summary of the analysis for the intermolecular N-HÁ Á ÁO P and N-HÁ Á ÁO C hydrogen bonds in 2, 3, 6, 8 and 9, and a set of 74 analogous [RC(O)NH]P(O)[NHR 1 ] 2 (R 1 6 ¼ H) structures from the CSD is gathered in Table 3. The structures from the CSD include both intermolecular hydrogen bonds noted, with the exception of some structures, in which the C O group is involved in an intramolecular N P -HÁ Á ÁO C [CSD refcodes DUYZUT01 (Gholivand et al, 2010), POKZAQ (Amirkhanov et al, 1997) and TENPUZ (Pourayoubi, Izadyar et al, 2013)] and a C-HÁ Á ÁO C (XAVNEP; Gholivand & Dorosti, 2011) hydrogen bond. Compound 6 studied in this work is another exception (as noted earlier).…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 21, 2010) and the discipline

“…Gholivand et al [166] synthesized and characterized by IR, 1 H-, 13 C-, 31 3 for which X-ray crystal structure were determined were obtained. These compounds form centrosymmetric dimers via intermolecular hydrogen bonds.…”