title: Syntheses and structures of four new mixed-amide phosphoric triamides.
abstract: Phosphoric triamides have extensive applications in biochemistry and are also used as O-donor ligands. Four new mixed-amide phosphoric triamide structures, namely rac-N-tert-butyl-N',N''-dicyclohexyl-N''-methylphosphoric triamide, C17H36N3OP, (I), rac-N,N'-dicyclohexyl-N'-methyl-N''-(p-tolyl)phosphoric triamide, C20H34N3OP, (II), N,N',N''-tricyclohexyl-N''-methylphosphoric triamide, C19H38N3OP, (III), and 2-[cyclohexyl(methyl)amino]-5,5-dimethyl-1,3,2λ(5)-diazaphosphinan-2-one, C12H26N3OP, (IV), have been synthesized and studied by X-ray diffraction and spectroscopic methods. Structures (I) and (II) are the first diffraction studies of acyclic racemic mixed-amide phosphoric triamides. The P-N bonds resulting from the different substituent -N(CH3)(C6H11), (C6H11)NH-, 4-CH3-C6H4NH-, (tert-C4H9)NH- and -NHCH2C(CH3)2CH2NH- groups are compared, along with the different molecular volumes and electron-donor strengths. In all four structures, the molecules form extended chains through N-H...O hydrogen bonds.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 91779, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Keikha
authors.affiliation: Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 91779, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Pourayoubi
authors.affiliation: Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad 91779, Iran.
authors.forename: Atekeh
authors.initials: A
authors.lastname: Tarahhomi
authors.affiliation: Institut Européen des Membranes, Université de Montpellier, 34095 Montpellier, France.
authors.forename: Arie
authors.initials: A
authors.lastname: van der Lee
keywords: NMR experiment; N—H...O hydrogen bond; crystal structure; mixed-amide phosphoric triamide; racemic