Recently, the structures of some racemate mixed-amidophosphinates,with an (N2)P(O)(O)(N1) skeleton, were reported in which two different amido groups are bonded to P atom[1].The systematic studies on such molecules may be useful according to the following reasons: i) to achieve an insight on which amidosegment makes a stronger/weaker P-N bond, ii) preparation of racemate compounds [2], iii) study of the hydrogen-bond patterns,and a try to find some empirical rules benefit in prediction of hydrogen-bond pattern based on the molecular structure [3].The title mixed-amidophosphinates, rac-phenyl (iso-propylamido)(p-tolylamido)phosphinate, (I), rac-phenyl (cyclo-heptylamido)(p-tolylamido)phosphinate, (II), and rac-phenyl (2-chlorobenzylamido)(p-tolylamido) phosphinate, (III), were synthesized from initial phosphorus-chlorine compound (R,S)-(Cl)P(O)(OC6H5)(NHC6H4-p-CH3)[3]. For each of (I) and (II), the asymmetric unit consists of two symmetrically independent molecules, and the asymmetric unit of (III) contains four molecules. The P atom in each molecule is in a distorted tetrahedral environment. The P-N (p-tolylamido) bond is slightly longer than the P-N (iso-propylamido), P-N (cyclo-heptylamido) and P-N (2-chlorobenzylamido) in (I), (II) and (III), respectively. In all structures, the oxygen atom of C6H5O group and the nitrogen atoms bonded to P atom do not take part in hydrogen bonding as an acceptor; whereas, the oxygen atom of phosphoryl acts as a doubleH-bond acceptor to form (N-H)(N-H)...OP grouping. In the crystal structures of (I), (II) and (III), adjacent molecules are hydrogen-bonded into linear arrangements, along [010] for (I) and [010] for both (II) and (III).

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