Diastereotopic groups in two new single-enanti-omer structures (R2)P(O)[NH-(+)CH(C2H5)(C6H5)] (R = OC6H5 and C6H5).

The crystal structures of two single-enanti-omer compounds, i.e. diphenyl [(R)-(+)-α-ethyl-benzyl-amido]-phosphate, C21H22NO3P or (C6H5O)2P(O)[NH-(R)-(+)CH(C2H5)(C6H5)] (I), and N-[(R)-(+)-α-ethyl-benz-yl]-P,P-di-phenyl-phosphinic amide, C21H22NOP or (C6H5)2P(O)[NH-R-(+)CH(C2H5)(C6H5)] (II), were studied. The different environments at the phospho-rus atoms, (O)2P(O)(N) and (C)2P(O)(N), allow the P=O/P-N bond strengths to be compared, as well as the N-H⋯O=P hydrogen-bond strengths, and P=O/N-H vibrations. The following characteristics related to diastereotopic C6H5O/C6H5 groups in I/II were considered: geometry parameters, contributions to the crystal packing, solution 13C/1H NMR chemical shifts, conformations, and NMR coupling constants. The phospho-rus-carbon coupling constants nJ PC (n = 2 and 3) in I and mJ PC (m = 1, 2, 3 and 4) in II were evaluated. For a comparative study, chiral analogous structures were retrieved from the Cambridge Structural Database (CSD) and their geometries and conformations are discussed.

O,O'-Dimethyl (cyclo-hexyl-amido)-thio-phosphate.

The P atom in the title compound, C(8)H(18)NO(2)PS, is bonded in a distorted tetra-hedral PSO(2)N environment with bond angles in the range of 99.23 (5)-115.17 (4)°. The cyclo-hexane ring is disordered over two sets of sites with refined occupancies of 0.528 (5) and 0.472 (5). The ring in both disorder components adopts a chair conformation with the N-H group oriented equatorially. In the crystal, pairs of P=S⋯H-N hydrogen bonds form inversion dimers.

Diphenyl (methyl-amido)-phosphate.

The N-H bond in the title compound, C(13)H(14)NO(3)P, is syn-oriented relative to the P=O bond. The N atom deviates somewhat from planarity, the sum of the bond angles being 353.3°. The P atom has a distorted tetra-hedral coordination; its bond angles are in the range 93.96 (5)-116.83 (6)°. In the crystal, mol-ecules form centrosymmetric dimers through P=O⋯H-N hydrogen bonds.

Diphenyl (isopropyl-amido)-phosphate.

The P atom in the title compound, C15H18NO3P, is in a distorted tetra-hedral P(O)(O)2N environment; the bond angles at P are in the range 98.16 (6)-115.82 (6)°. In the crystal, adjacent mol-ecules are linked via N-H⋯O=P hydrogen bonds into a chain running parallel to the b axis. The methyl groups are disordered over two sets of sites in a 0.677 (14):0.323 (14) ratio. The crystal studied was a non-merohedral twin with a refined minor component of 22.31 (4)%.

N,N-Dibenzyl-O,O'-dimethyl thio-phosphate.

The P atom in the title compound, C(16)H(20)NO(2)PS, is bonded in a distorted tetra-hedral P(S)(O)(2)N environment with the bond angles at the P atom in the range 99.37 (7) to 115.68 (5)°. The angles at the amido N atom (with bond-angle sum of 357.8°) confirm its sp(2) character. The C-O-P bond angles are 119.78 (11) and 119.39 (12)°.

Diphenyl [(S)-1-phenylpropanamido]-phosphate.

The title compound, C(21)H(22)NO(3)P, was synthesized from the reaction of (C(6)H(5)O)(2)P(O)(Cl) and S-1-phenyl-propyl-amine (1:2 mole ratio) at 273 K, followed by removal of the S-1-phenyl-propyl-amine hydro-chloride by-product by dissolving in H(2)O. The P atom is located in a distorted tetra-hedral environment. The bond angles at the P atom vary from 99.51 (12) to 116.68 (12)°. The sp(2) character of the N atom is reflected by the C-N-P angle [120.9 (2)°]. The P=O group and the N-H unit adopt an anti orientation with respect to one another. In the crystal, adjacent mol-ecules are linked via N-H⋯O(P) hydrogen bonds into a one-dimensional arrangement running parallel to the a axis.

Diphenyl (o-tolyl-amido)-phospho-nate.

The asymmetric unit of the title compound, C(19)H(18)NO(3)P, contains two independent mol-ecules in which the P atoms are found in slightly distorted tetrahedral environments. In the crystal, pairs of inter-molecular N-H⋯O(P) hydrogen bonds form two independent centrosymmetric dimers.

Diphenyl (cyclo-pentyl-amido)-phospho-nate.

In the title mol-ecule, C(17)H(20)NO(3)P, the P atom is bonded in a distorted tetra-hedral environment. The dihedral angle between the two phenyl rings is 23.52 (10)°. The phosphoryl and N-H groups are anti with respect to one another. The -CH(2)-CH(2)-CH(2)-CH(2)- sequence of atoms in the cyclo-pentyl ring is disordered over two sets of sites with refined occupancies of 0.574 (10) and 0.426 (10). In the crystal, mol-ecules are linked via N-H⋯O=P hydrogen bonds to form extended chains along [010].

O-Phenyl (cyclo-hexyl-amido)(p-tolyl-amido)-phosphinate.

In the title mol-ecule, C(19)H(25)N(2)O(2)P, the P atom is bonded in a distorted tetra-hedral environment. The dihedral angle between the two phenyl rings is 89.09 (8)°. The methyl H atoms are disordered over two sets of sites with equal occupancy. The O atom of the P=O group acts as a double hydrogen-bond acceptor of the type (N-H)(2)⋯(O=)P-, forming R(2) (2)(8) rings which are further linked into chains along [010].

N,N'-Dicyclo-hexyl-N'',N''-dimethyl-phospho-ric triamide.

In the title compound, C(14)H(30)N(3)OP, both cyclo-hexyl groups adopt chair conformations with the NH unit in an equatorial position. The P atom adopts a slightly distorted tetra-hedral environment. In the (CH(3))(2)NP(O) unit, the O-P-N-C torsion angles, showing the orientations of the methyl groups with respect to the phosphoryl group, are -166.6 (3) and 34.6 (4)°. The O atom of the P=O group acts as a double hydrogen-bond acceptor and is involved in two different inter-molecular N-H⋯OP hydrogen bonds, building R(2) (2)(8) rings that are further linked into chains running parallel to the b axis.

Conformational analysis of two new organotin(IV) structures completed with a CSD survey.

The conformational flexibilities are studied in two new organotin(IV) complexes, namely, trans-dichloridodimethylbis[N,N',N''-tris(2-chlorobenzyl)phosphoric triamide]tin(IV), [Sn(CH3)2(C21H21Cl3N3OP)2Cl2] or Sn(CH3)2Cl2{OP[NHCH2C6H4(2-Cl)]3}2, (I), and bis(dipropylammonium) tetrachloridodimethylstannate(IV), [(CH3CH2CH2)2NH2]2[Sn(CH3)2Cl4], (II), and their analogous structures from the Cambridge Structural Database (CSD). The conformations are considered based on the N-P=O-Sn torsion angles for (I) and the C-C-C-N, C-C-N-C, C-N-C-C and N-C-C-C torsion angles for the two symmetry-independent [CH3CH2CH2NH2CH2CH2CH3]+ cations in (II), and the ±ac±sp±ac (ac = anticlinal and sp = synperiplanar) and ±ap±ap±ap±ap (ap = antiperiplanar) conformations are observed, respectively. In both structures, the four atoms in the corners of the square-planar segment of the octahedral shape around the Sn atom participate in normal hydrogen-bonding interactions as acceptors, which include two O and two Cl atoms for (I), and four Cl atoms for (II). However, the phosphoric triamide ligands block the environment around the Sn atom and limit the hydrogen-bond pattern to form a supramolecular ribbon assembly, while in the presence of small organic cations in (II), a two-dimensional hydrogen-bonded architecture is achieved. The weak interactions π-π, C-H...π and C-Cl...π in (I), and C-H...Cl in (II) do not change the dimensionality of the hydrogen-bond pattern. The 62 CSD structures analogous to (I), i.e. with an SnOPN3 segment (including 83 entries) fall into four categories of conformations based on the N-P=O-Sn torsion angles. The 132 [(CH3CH2CH2)2NH2]+ cations from 85 CSD structures are classified into seven groups based on the torsion angles noted for (II). Most of the CSD structures adopt the same associated conformations noted for (I) and (II). 15 [Sn(CH3)2Cl4]2- anions extracted from the CSD are compared with the structure of (II).

N,N'-Dicyclo-hexyl-N''-(4-nitro-benzo-yl)phospho-ric triamide.

The P atom in the title compound, C(19)H(29)N(4)O(4)P, exhibits a tetra-hedral coordination and the phosphoryl and carbonyl groups are anti to each other. Adjacent mol-ecules are linked by N-H⋯O hydrogen bonds to form a layer motif.

N,N'-Dicyclo-hexyl-N,N'-dimethyl-N''-(4-nitro-benzo-yl)phospho-ric triamide.

The P atom in the title compound, C(21)H(33)N(4)O(4)P, is in a slightly distorted tetra-hedral coordination environment and the phosphoryl and carbonyl groups are anti to each other. The environment of each N atom is essentially planar (average angles of 119.9 and 118.4°). In the crystal structure, the H atom of the C(=O)NHP(=O) group is involved in an inter-molecular -P=O⋯H-N- hydrogen bond, forming centrosymmetric dimers.

p-Tolyl bis-(o-tolyl-amido)-phosphinate.

In the title compound, C(21)H(23)N(2)O(2)P, the P atom has a distorted tetra-hedral configuration. The O atom of the OC(6)H(4)-4-CH(3) group and the N atoms show sp(2) character. In the crystal, adjacent mol-ecules are linked by N-H⋯O hydrogen bonds into helical chains parallel to the b axis.

Two single-enantiomer amidophosphoesters: a database study on the chirality of (O)2P(O)(N)-based structures.

The crystal structures of two single-enantiomer amidophosphoesters with an (O)2P(O)(N) skeleton, i.e. diphenyl [(R)-(+)-α-methylbenzylamido]phosphate, (I), and diphenyl [(S)-(-)-α-methylbenzylamido]phosphate, (II), both C20H20NO3P, are reported. In both structures, chiral one-dimensional hydrogen-bonded architectures, along [010], are mediated by N-H...OP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P21. As a result of synergistic co-operation from C-H...O interactions, a two-dimensional superstructure is built including a noncentrosymmetric R44(22) hydrogen-bonded motif. A Cambridge Structural Database survey was performed on (O)2P(O)(N)-based structures in order to review the frequency of space groups observed in this family of compounds; the hydrogen-bond motifs in structures with chiral space groups and the types of groups inducing chirality are discussed. The 2,3JX-P (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C6H5O groups are different, which is reflected in the different chemical shifts and some coupling constants.

Cyclo-hexyl-methyl-ammonium N,N'-dicyclo-hexyl-N,N'-dimethyl-N''-(2,2,2-trifluoro-acet-yl)phospho-nic triamide).

In the salt, C(7)H(16)N(+)·C(16)H(28)F(3)N(3)O(2)P(-), the P atom shows tetra-hedral coordination. Two ion pairs are linked by N-H⋯O hydrogen bonds across a center of inversion. The phosphoryl and carbonyl groups are staggered [O-P-N-C = 64.8 (3)°].

A novel tubular hydrogen-bond pattern in a new diazaphosphole oxide: a combination of X-ray crystallography and theoretical study of hydrogen bonds.

In the structure of 2-(4-chloroanilino)-1,3,2λ4-diazaphosphol-2-one, C12H11ClN3OP, each molecule is connected with four neighbouring molecules through (N-H)2...O hydrogen bonds. These hydrogen bonds form a tubular arrangement along the [001] direction built from R33(12) and R43(14) hydrogen-bond ring motifs, combined with a C(4) chain motif. The hole constructed in the tubular architecture includes a 12-atom arrangement (three P, three N, three O and three H atoms) belonging to three adjacent molecules hydrogen bonded to each other. One of the N-H groups of the diazaphosphole ring, not co-operating in classical hydrogen bonding, takes part in an N-H...π interaction. This interaction occurs within the tubular array and does not change the dimension of the hydrogen-bond pattern. The energies of the N-H...O and N-H...π hydrogen bonds were studied by NBO (natural bond orbital) analysis, using the experimental hydrogen-bonded cluster of molecules as the input file for the chemical calculations. In the 1H NMR experiment, the nitrogen-bound proton of the diazaphosphole ring has a high value of 17.2 Hz for the 2JH-P coupling constant.