In N,N'-di-tert-butyl-N'',N''-dimethylphosphoric triamide, C(10)H(26)N(3)OP, (I), and N,N',N'',N'''-tetra-tert-butyl[oxybis(phosphonic diamide), [corrected] C(16)H(40)N(4)O(3)P(2), (II), the extended structures are mediated by P(O)...(H-N)(2) interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H-N)(2) hydrogen bonds, giving R(2)(1)(6) loops and forming two independent chains parallel to the a axis. Of the 12 independent tert-butyl groups, five are disordered over two different positions with occupancies ranging from 1/6 to 5/6. In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H-N)(2) hydrogen bonds give S(6) and R(2)(2)(8) rings, and the molecules form extended chains parallel to the c axis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)(2) and (NH)(2)P(O)(O)P(O)(NH)(2) skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen-bond patterns in these families of phosphoramidates. The strengths of P(O)[...H-N](x) (x = 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)(2)P(O)(NH) and P(O)(NH)(3) fragments.
In the title compound, C14H30N3OP, both cyclohexyl groups adopt chair conformations with the NH unit in an equatorial position. The P atom adopts a slightly distorted tetrahedral environment. In the (CH3)2NP(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 intermolecular N—H⋯OP hydrogen bonds, building R 2 2(8) rings that are further linked into chains running parallel to the b axis.
The mixed-amide phosphinates, rac-phenyl (N-methylcyclohexylamido)(p-tolylamido)phosphinate, C20H27N2O2P, (I), and rac-phenyl (allylamido)(p-tolylamido)phosphinate, C16H19N2O2P, (II), were synthesized from the racemic phosphorus-chlorine compound (R,S)-(Cl)P(O)(OC6H5)(NHC6H4-p-CH3). Furthermore, the phosphorus-chlorine compound ClP(O)(OC6H5)(NH-cyclo-C6H11) was synthesized for the first time and used for the synthesis of rac-phenyl (benzylamido)(cyclohexylamido)phosphinate, C19H25N2O2P, (III). The strategies for the synthesis of racemic mixed-amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N(1))P(=O)(O)(N(2)) environment. In (I) and (II), the p-tolylamido substituent makes a longer P-N bond than those involving the N-methylcyclohexylamido and allylamido substituents. In (III), the differences between the P-N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N-H unit in hydrogen-bonding interactions, viz. an N-H···O=P hydrogen bond for (I) and (N-H)(N-H)···O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).
Novel optical isomers of phosphoramide-methacrylate monomers were synthesized and used for the preparation of corresponding polymers and hydrogels as chiral absorbents. In order to direct enantioseparation, two simple and inexpensive methods were designed: (a) immobilization of the chiral polymers on glass beads as packing material for the separation columns and (b) filling of chiral hydrogels in tea bags to fabricate separation bags. The specific rotations for R-and S-monomers were + 22.0 and − 21.8 , while those for R-and S-polymers were + 20.8 and − 22.1 , respectively. The enantioseparation of (AE)-α-methylbenzylamine, DL-alanine, DL-valine, DL-tartaric acid, DL-phenylalanine, and omeprazole was evaluated. The maximum enantioseparation (optical purity) of 97% was observed for (AE)-α-methylbenzylamine by S-hydrogel. Chiral hydrogels resulted in enantioseparations with higher purities (up to 97%) comparing to the chiral polymers, but in longer times (2-3 days). The desorption process easily occurred from the absorbed columns or bags.Phosphoramides with a P( O)(N) segment are attractive to study owing to their extensive applications in the coordination chemistry, catalysts, and medicine. [32][33][34] From our previous studies on phosphorus-oxygen, phosphorus-nitrogen, and phosphorus-sulfur compounds, 35-37 the P O group was found as the best hydrogen-bond acceptor with respect to the other possible acceptor groups, which usually exist in the molecules, typically C O, S O, N─O, P S, ester and ether oxygen atoms, nitrogen, and π-system, examined with X-ray diffraction study, statistical analysis based on the data deposited in the Cambridge structural database (CSD) 38 and quantum chemical calculations in some cases. The structures investigated include achiral, racemate, and chiral single-enantiomer phosphorus compounds. 36,37,39,40 According to Reaxys web-based tool (licensed by Elsevier) for chiral polymers, there is no report about an enantiomeric pair of phosphoric triamide-based polymers, and such polymers seem to be good chiral selectors, due to relatively strong interaction of P O with OH and NH units, as was observed in small molecules model compounds.In this work, levo-and dextro-rotatory isomers with two chiral centers, P( O)(NH-R-(−)CH(CH 3 )C 6 H 5 ) 2 (Cl) and P( O)(NH-S-(−)CH(CH 3 )C 6 H 5 ) 2 (Cl) (1 and 2), have been synthesized and reacted with 2-aminoethylmethacrylate (AEMA) to prepare phosphoric triamides monomers (3 and 4) as chiral selectors. The methacrylate moiety brought the opportunity for the radical or ionic polymerization reactions of these monomers. Through radical polymerization of these novel monomers, a pair of singleenantiomer phosphoric triamide-based polymers (P1 and P2) and hydrogels (H1 and H2) were prepared. In order to direct Additional Supporting Information may be found in the online version of this article.
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