(3-Aminophenyl)diphenylphosphine oxide–2-propanol (1/1)

The title compound, C18H16NOP·C3H8O, was synthesized by the reduction of (3-nitrophenyl)diphenylphosphine oxide in the presence of 2-propanol as recrystallization solvent. There are two molecules in the asymmetric unit. Each P atom is tetracoordinated by three C and one O atom from two phenyl fragments, one aniline group and one double-bonded O atom in a distorted tetrahedral geometry. C—H⋯π and N—H⋯π interactions are present. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding [of the types of O—H⋯O, N—H⋯O and C—H⋯O, with D⋯A distances ranging from 2.680 (3) to 3.478 (3) Å] and π–π [centroid–centroid distance of 3.7720 (15) Å] stacking interactions connect the various components into a supramolecular structure.

The title compound, C 18 H 16 NOPÁC 3 H 8 O, was synthesized by the reduction of (3-nitrophenyl)diphenylphosphine oxide in the presence of 2-propanol as recrystallization solvent. There are two molecules in the asymmetric unit. Each P atom is tetracoordinated by three C and one O atom from two phenyl fragments, one aniline group and one double-bonded O atom in a distorted tetrahedral geometry. C-HÁ Á Á and N-HÁ Á Á interactions are present. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding [of the types of O-HÁ Á ÁO, N-HÁ Á ÁO and C-HÁ Á ÁO, with DÁ Á ÁA distances ranging from 2.680 (3) to 3.478 (3) Å ] and -[centroid-centroid distance of 3.7720 (15) Å ] stacking interactions connect the various components into a supramolecular structure. 1 restraint H-atom parameters constrained Á max = 1.04 e Å À3 Á min = À0.71 e Å À3 Table 1 Selected geometric parameters (Å , ).

Comment
Polymer supported phosphine reagents have wide application in organic synthesis (Chael & Buchmeiser, 2003). Usually, for preparation of these reagents, mono functional derivatives of phosphine or phosphine oxide compounds are used. But direct mono-functionalization of triphenylphosphine and triphenylphosphine oxide is one of the problematic reactions in organic synthesis and generally higher functionalization is performed and di and/or tri-substituted products are obtained. In this study, the synthesis and characterization of 3-aminophenyldiphenylphosphine oxide is reported for the first time.
The molecular structure of this compound is presented in Fig. 1, while the crystal packing diagram is illustrated in Fig. 2.
Selected bond lengths and bond angles are presented in Table 1. Also hydrogen bond lengths are given separately in Table   2. This complex crystallizes in the triclinic system, space group P1, with four molecules in the unit cell. There are two symmetrically independent parts in the crystal structure. To each phosphorus atom are attached three C and one O atoms from two phenyl fragments, one aniline group and one double-bonded O atom. The phosphorus-oxygen bond distances are 1.4959 (16) and 1.4974 (16) Å, and phosphorus-carbon bond distances range from 1.792 (2) to 1.803 (2) Å, which are within normal ranges (Al-Farhan, 1992). According to the bond lengths and bond angles, arrangement of the four donor atoms around each phosphorus atom is distorted tetrahedral. N1A and N1B atoms are disordered, and occupancies of positions of atoms N1A and N1B are 0.75 and 1/4, respectively.
Experimental 3-aminophenyldiphenylphosphine oxide (APDPPO) was prepared from triphenylphosphine oxide according to our previous paper (Mahdavi & Amani, 2008). In this procedure, the solid product was recrystallized from 2-propanol, and 3aminophenyldiphenylphosphine oxide was obtained as white crystals. Yield was 87% with m.p. = 166 °C.
supplementary materials sup-2 Refinement Hydrogen atoms on oxygen and nitrogen atoms were found from difference Fourier maps and on carbon atoms were placed in geometrically calculated positions. All hydrogen atoms were refined in isotropic approximation in riding model with the U iso (H) parameters equal to 1.5Ueq(O), 1.5Ueq(C) for methyl groups and to 1.2Ueq(N) and 1.2Ueq(C) for other carbon atoms where U eq (O), U eq (N) and U eq (C) are the equivalent thermal parameters of the atoms to which corresponding H atoms are bonded. Fig. 1. The molecular structure of the title compound, showing the atom-numbering scheme and displacements. Ellipsoids are drawn at 50% probability level. 2-propanol groups are removed for clarity. N1A and N1B atoms are disordered and occupancies of positions of atoms N1A and N1B are 0.75 and 1/4, respectively.       Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.