organic compounds
Tetraphenyl piperazine-1,4-diyldiphosphonate
aDepartment of Chemistry, Ferdowsi University of Mashhad, Mashhad, 91779, Iran
*Correspondence e-mail: mehrdad_pourayoubi@yahoo.com
The molecule of the title compound, C28H28N2O6P2, is organized around an inversion center located at the centre of the piperazine ring. Both piperazine N atoms are substituted by P(O)(OC6H5)2 phosphoester groups. The P atoms display a slightly distorted tetrahedral environment; the N atoms show some deviation from planarity. The O atoms of the P=O groups are involved in intermolecular C—H⋯O hydrogen bonds, building R22(22) rings, in extended chains parallel to the a axis. C—H⋯π interactions involving the phenyl rings further stabilize the packing.
Related literature
For the physical properties of bisphosphoramidates, see: Nguyen & Kim (2008). For related structures, see: Chen et al. (2007); Balakrishna et al. (2003, 2006); Rodriguez i Zubiri et al. (2002). For hydrogen-bond motifs, see: Etter et al. (1990); Bernstein et al. (1995).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2005); cell SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536810047860/dn2623sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810047860/dn2623Isup2.hkl
To a solution of (C6H5O)2P(O)Cl in chloroform, a solution of piperazine and triethylamine (2:1:2 mole ratio) in chloroform was added at 273 K. After 4 h stirring, the solvent was removed and product was washed with distilled water and recrystallized from chloroform/n-heptane at room temperature. IR (KBr, cm-1): 3051.2, 2913.8, 2866.3, 1592.5, 1490.4, 1383.3, 1334.6, 1261.7, 1198.5, 1135.3, 1067.1, 1013.7, 969.8, 931.6, 776.8, 686.8. Raman (cm-1): 3066.5, 2526.4, 1593.0, 1469.5, 1452.2, 1265.1, 1218.8, 1168.7, 1157.1, 1024.0, 1006.6, 939.2, 771.4, 705.8, 617.1, 414.6, 262.2. 31P{1H} NMR (202.45 MHz, DMSO-d6, 300.0 K, H3PO4 external): -1.45 p.p.m. (s). 1H NMR (500.13 MHz, DMSO-d6, 300.0 K, TMS): 3.01 (s, 8H, CH2), 7.15–7.27 (m, 12H, Ar—H), 7.38–7.40 p.p.m. (m, 8H, Ar—H). 13C NMR (125.75 MHz, DMSO-d6, 300.0 K, TMS): 43.98 (d, 2(&3)J(P,C) = 3.5 Hz, 4 C), 119.94 (d, 3J(P,C) = 4.7 Hz, 8 C, Cortho), 125.11 (s), 129.90 (s), 150.07 p.p.m. (d, 2J(P,C) = 6.4 Hz, 4 C, Cipso).
H atoms were placed in calculated positions and included in the
in a riding-model approximation with C–H = 0.93–0.97 Å, and Uiso(H) = 1.2Ueq(C).The thermal behavior and flame retardancies of some bisphosphoramidates, with a P(O)XP(O) skeleton, such as the title compound have been investigated by Nguyen & Kim (2008). Here, we report the
of the title compound.The molecule of the title compound is organized around inversion center located in the middle of the piperazine ring. Both the nitrogen atoms of the piperazine are substituted by the P(O)(OC6H5)2 phosphoester moieties (Fig. 1). The phosphorus atom has a distorted tetrahedral configuration with the bond angles in the range of 99.04 (4)° [O(2)–P(1)–O(3)] to 115.93 (5)° [O(1)–P(1)–O(2)]. As observed in related compounds containing piperazine ring substituted by phosphorus (Chen et al., 2007; Balakrishna et al., 2003, 2006; Rodriguez i Zubiri et al., 2002), the N atom shows some deviation from planarity, indeed it is 0.25 (1)Å above the C1, C2, P1 plane.
The oxygen atom of P═O group are involved in a C–H···O hydrogen bond building a R22(22) ring (Etter et al., 1990; Bernstein et al., 1995) (Table 1, Fig. 2). Furthermore, these rings are interconnected building infinite chains parallel to the a axis. C–H···π interactions involving the phenyl rings stabilize the packing (Table 1).
For the physical properties of bisphosphoramidates, see: Nguyen & Kim (2008). For related structures, see: Chen et al. (2007); Balakrishna et al. (2003, 2006); Rodriguez i Zubiri et al. (2002). For hydrogen-bond motifs, see: Etter et al. (1990); Bernstein et al. (1995).
Data collection: APEX2 (Bruker, 2005); cell
SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C28H28N2O6P2 | F(000) = 576 |
Mr = 550.46 | Dx = 1.425 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 2258 reflections |
a = 6.3117 (4) Å | θ = 3–29° |
b = 8.9530 (5) Å | µ = 0.22 mm−1 |
c = 22.8630 (13) Å | T = 100 K |
β = 96.756 (1)° | Plate, colourless |
V = 1282.99 (13) Å3 | 0.55 × 0.40 × 0.20 mm |
Z = 2 |
Bruker APEXII CCD area-detector diffractometer | 3405 independent reflections |
Radiation source: fine-focus sealed tube | 3071 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
ω scans | θmax = 29.0°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −8→8 |
Tmin = 0.890, Tmax = 0.958 | k = −12→12 |
14864 measured reflections | l = −30→31 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0496P)2 + 0.567P] where P = (Fo2 + 2Fc2)/3 |
3405 reflections | (Δ/σ)max = 0.002 |
172 parameters | Δρmax = 0.51 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C28H28N2O6P2 | V = 1282.99 (13) Å3 |
Mr = 550.46 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.3117 (4) Å | µ = 0.22 mm−1 |
b = 8.9530 (5) Å | T = 100 K |
c = 22.8630 (13) Å | 0.55 × 0.40 × 0.20 mm |
β = 96.756 (1)° |
Bruker APEXII CCD area-detector diffractometer | 3405 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 3071 reflections with I > 2σ(I) |
Tmin = 0.890, Tmax = 0.958 | Rint = 0.025 |
14864 measured reflections |
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.51 e Å−3 |
3405 reflections | Δρmin = −0.27 e Å−3 |
172 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
P1 | 0.29408 (4) | 0.70141 (3) | 0.584588 (12) | 0.01226 (9) | |
O1 | 0.08499 (13) | 0.65211 (10) | 0.59873 (4) | 0.01722 (18) | |
O2 | 0.30060 (14) | 0.86102 (9) | 0.55434 (4) | 0.01595 (17) | |
O3 | 0.46851 (13) | 0.72855 (9) | 0.63989 (3) | 0.01431 (17) | |
N1 | 0.40456 (15) | 0.59125 (11) | 0.54033 (4) | 0.01435 (19) | |
C1 | 0.27230 (18) | 0.49056 (13) | 0.50046 (5) | 0.0154 (2) | |
H1A | 0.2168 | 0.5452 | 0.4642 | 0.019* | |
H1B | 0.1490 | 0.4557 | 0.5198 | 0.019* | |
C2 | 0.59794 (18) | 0.64262 (13) | 0.51554 (5) | 0.0159 (2) | |
H2A | 0.6852 | 0.7054 | 0.5448 | 0.019* | |
H2B | 0.5564 | 0.7039 | 0.4800 | 0.019* | |
C3 | 0.24646 (19) | 0.99346 (12) | 0.58193 (5) | 0.0141 (2) | |
C4 | 0.03688 (19) | 1.04226 (13) | 0.57405 (5) | 0.0174 (2) | |
H4A | −0.0717 | 0.9831 | 0.5531 | 0.021* | |
C5 | −0.0111 (2) | 1.18012 (14) | 0.59758 (6) | 0.0213 (2) | |
H5A | −0.1538 | 1.2157 | 0.5925 | 0.026* | |
C6 | 0.1478 (2) | 1.26566 (14) | 0.62831 (6) | 0.0224 (3) | |
H6A | 0.1142 | 1.3603 | 0.6436 | 0.027* | |
C7 | 0.3561 (2) | 1.21302 (14) | 0.63680 (6) | 0.0221 (3) | |
H7A | 0.4642 | 1.2709 | 0.6586 | 0.026* | |
C8 | 0.40715 (19) | 1.07579 (14) | 0.61346 (5) | 0.0181 (2) | |
H8A | 0.5494 | 1.0393 | 0.6191 | 0.022* | |
C9 | 0.51165 (18) | 0.61794 (12) | 0.68335 (5) | 0.0136 (2) | |
C10 | 0.36396 (19) | 0.58904 (13) | 0.72215 (5) | 0.0160 (2) | |
H10A | 0.2295 | 0.6380 | 0.7181 | 0.019* | |
C11 | 0.4174 (2) | 0.48638 (14) | 0.76736 (5) | 0.0190 (2) | |
H11A | 0.3176 | 0.4638 | 0.7941 | 0.023* | |
C12 | 0.6154 (2) | 0.41695 (14) | 0.77356 (5) | 0.0203 (2) | |
H12A | 0.6518 | 0.3486 | 0.8049 | 0.024* | |
C13 | 0.7607 (2) | 0.44750 (14) | 0.73384 (6) | 0.0204 (2) | |
H13A | 0.8957 | 0.3993 | 0.7380 | 0.025* | |
C14 | 0.70950 (18) | 0.54823 (13) | 0.68798 (5) | 0.0168 (2) | |
H14A | 0.8075 | 0.5688 | 0.6605 | 0.020* |
U11 | U22 | U33 | U12 | U13 | U23 | |
P1 | 0.01325 (14) | 0.01125 (14) | 0.01239 (14) | 0.00080 (10) | 0.00199 (10) | −0.00088 (9) |
O1 | 0.0147 (4) | 0.0193 (4) | 0.0182 (4) | 0.0001 (3) | 0.0038 (3) | −0.0014 (3) |
O2 | 0.0226 (4) | 0.0125 (4) | 0.0133 (4) | 0.0031 (3) | 0.0041 (3) | −0.0003 (3) |
O3 | 0.0169 (4) | 0.0121 (4) | 0.0136 (4) | −0.0012 (3) | −0.0001 (3) | 0.0006 (3) |
N1 | 0.0137 (4) | 0.0127 (4) | 0.0170 (5) | −0.0015 (3) | 0.0031 (3) | −0.0035 (3) |
C1 | 0.0135 (5) | 0.0158 (5) | 0.0170 (5) | −0.0008 (4) | 0.0017 (4) | −0.0036 (4) |
C2 | 0.0165 (5) | 0.0133 (5) | 0.0187 (5) | −0.0013 (4) | 0.0054 (4) | −0.0029 (4) |
C3 | 0.0207 (5) | 0.0103 (5) | 0.0116 (5) | 0.0014 (4) | 0.0039 (4) | 0.0008 (4) |
C4 | 0.0195 (5) | 0.0157 (5) | 0.0166 (5) | 0.0005 (4) | 0.0005 (4) | 0.0003 (4) |
C5 | 0.0238 (6) | 0.0170 (6) | 0.0240 (6) | 0.0060 (5) | 0.0065 (5) | 0.0036 (5) |
C6 | 0.0344 (7) | 0.0118 (5) | 0.0229 (6) | 0.0006 (5) | 0.0112 (5) | −0.0009 (4) |
C7 | 0.0290 (6) | 0.0170 (6) | 0.0206 (6) | −0.0073 (5) | 0.0049 (5) | −0.0026 (4) |
C8 | 0.0191 (5) | 0.0177 (6) | 0.0179 (5) | −0.0020 (4) | 0.0033 (4) | 0.0012 (4) |
C9 | 0.0165 (5) | 0.0107 (5) | 0.0130 (5) | −0.0004 (4) | −0.0004 (4) | −0.0008 (4) |
C10 | 0.0174 (5) | 0.0157 (5) | 0.0150 (5) | 0.0024 (4) | 0.0027 (4) | −0.0012 (4) |
C11 | 0.0249 (6) | 0.0178 (5) | 0.0148 (5) | 0.0005 (5) | 0.0045 (4) | 0.0005 (4) |
C12 | 0.0268 (6) | 0.0166 (6) | 0.0167 (5) | 0.0024 (5) | −0.0011 (5) | 0.0019 (4) |
C13 | 0.0181 (5) | 0.0180 (6) | 0.0245 (6) | 0.0037 (4) | −0.0006 (5) | −0.0001 (5) |
C14 | 0.0154 (5) | 0.0157 (5) | 0.0195 (5) | 0.0000 (4) | 0.0021 (4) | −0.0016 (4) |
P1—O1 | 1.4633 (9) | C5—C6 | 1.3855 (19) |
P1—O2 | 1.5901 (9) | C5—H5A | 0.9500 |
P1—O3 | 1.5944 (8) | C6—C7 | 1.3885 (19) |
P1—N1 | 1.6275 (10) | C6—H6A | 0.9500 |
O2—C3 | 1.4040 (13) | C7—C8 | 1.3923 (17) |
O3—C9 | 1.4066 (13) | C7—H7A | 0.9500 |
N1—C1 | 1.4702 (14) | C8—H8A | 0.9500 |
N1—C2 | 1.4783 (14) | C9—C10 | 1.3847 (16) |
C1—C2i | 1.5155 (16) | C9—C14 | 1.3889 (16) |
C1—H1A | 0.9900 | C10—C11 | 1.3946 (16) |
C1—H1B | 0.9900 | C10—H10A | 0.9500 |
C2—C1i | 1.5155 (16) | C11—C12 | 1.3880 (18) |
C2—H2A | 0.9900 | C11—H11A | 0.9500 |
C2—H2B | 0.9900 | C12—C13 | 1.3913 (18) |
C3—C4 | 1.3846 (16) | C12—H12A | 0.9500 |
C3—C8 | 1.3855 (17) | C13—C14 | 1.3919 (17) |
C4—C5 | 1.3937 (17) | C13—H13A | 0.9500 |
C4—H4A | 0.9500 | C14—H14A | 0.9500 |
O1—P1—O2 | 115.93 (5) | C6—C5—H5A | 119.7 |
O1—P1—O3 | 115.30 (5) | C4—C5—H5A | 119.7 |
O2—P1—O3 | 99.04 (4) | C5—C6—C7 | 120.00 (11) |
O1—P1—N1 | 114.71 (5) | C5—C6—H6A | 120.0 |
O2—P1—N1 | 103.85 (5) | C7—C6—H6A | 120.0 |
O3—P1—N1 | 106.20 (5) | C6—C7—C8 | 120.27 (12) |
C3—O2—P1 | 122.92 (7) | C6—C7—H7A | 119.9 |
C9—O3—P1 | 120.74 (7) | C8—C7—H7A | 119.9 |
C1—N1—C2 | 112.78 (9) | C3—C8—C7 | 118.71 (11) |
C1—N1—P1 | 120.23 (8) | C3—C8—H8A | 120.6 |
C2—N1—P1 | 118.91 (7) | C7—C8—H8A | 120.6 |
N1—C1—C2i | 110.39 (9) | C10—C9—C14 | 122.29 (11) |
N1—C1—H1A | 109.6 | C10—C9—O3 | 119.68 (10) |
C2i—C1—H1A | 109.6 | C14—C9—O3 | 117.89 (10) |
N1—C1—H1B | 109.6 | C9—C10—C11 | 118.39 (11) |
C2i—C1—H1B | 109.6 | C9—C10—H10A | 120.8 |
H1A—C1—H1B | 108.1 | C11—C10—H10A | 120.8 |
N1—C2—C1i | 109.99 (9) | C12—C11—C10 | 120.49 (11) |
N1—C2—H2A | 109.7 | C12—C11—H11A | 119.8 |
C1i—C2—H2A | 109.7 | C10—C11—H11A | 119.8 |
N1—C2—H2B | 109.7 | C11—C12—C13 | 119.99 (11) |
C1i—C2—H2B | 109.7 | C11—C12—H12A | 120.0 |
H2A—C2—H2B | 108.2 | C13—C12—H12A | 120.0 |
C4—C3—C8 | 121.97 (11) | C12—C13—C14 | 120.44 (11) |
C4—C3—O2 | 119.17 (10) | C12—C13—H13A | 119.8 |
C8—C3—O2 | 118.76 (10) | C14—C13—H13A | 119.8 |
C3—C4—C5 | 118.47 (11) | C9—C14—C13 | 118.39 (11) |
C3—C4—H4A | 120.8 | C9—C14—H14A | 120.8 |
C5—C4—H4A | 120.8 | C13—C14—H14A | 120.8 |
C6—C5—C4 | 120.55 (12) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Cg1 and Cg2 are the centroids of the C3–C8 and C11–C14 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O1ii | 0.95 | 2.49 | 3.4327 (15) | 172 |
C11—H11A···Cg1iii | 0.95 | 2.74 | 3.3324 (12) | 121 |
C7—H7A···Cg2iv | 0.95 | 2.59 | 3.4099 (13) | 145 |
Symmetry codes: (ii) x+1, y, z; (iii) −x+1/2, y−1/2, −z+3/2; (iv) x, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | C28H28N2O6P2 |
Mr | 550.46 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 100 |
a, b, c (Å) | 6.3117 (4), 8.9530 (5), 22.8630 (13) |
β (°) | 96.756 (1) |
V (Å3) | 1282.99 (13) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.22 |
Crystal size (mm) | 0.55 × 0.40 × 0.20 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.890, 0.958 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14864, 3405, 3071 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.682 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.089, 1.03 |
No. of reflections | 3405 |
No. of parameters | 172 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.51, −0.27 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009).
Cg1 and Cg2 are the centroids of the C3–C8 and C11–C14 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O1i | 0.95 | 2.49 | 3.4327 (15) | 171.6 |
C11—H11A···Cg1ii | 0.95 | 2.74 | 3.3324 (12) | 121.1 |
C7—H7A···Cg2iii | 0.95 | 2.59 | 3.4099 (13) | 144.8 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1/2, y−1/2, −z+3/2; (iii) x, y+1, z. |
Acknowledgements
Support of this investigation by Ferdowsi University of Mashhad is gratefully acknowledged.
References
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The thermal behavior and flame retardancies of some bisphosphoramidates, with a P(O)XP(O) skeleton, such as the title compound have been investigated by Nguyen & Kim (2008). Here, we report the crystal structure of the title compound.
The molecule of the title compound is organized around inversion center located in the middle of the piperazine ring. Both the nitrogen atoms of the piperazine are substituted by the P(O)(OC6H5)2 phosphoester moieties (Fig. 1). The phosphorus atom has a distorted tetrahedral configuration with the bond angles in the range of 99.04 (4)° [O(2)–P(1)–O(3)] to 115.93 (5)° [O(1)–P(1)–O(2)]. As observed in related compounds containing piperazine ring substituted by phosphorus (Chen et al., 2007; Balakrishna et al., 2003, 2006; Rodriguez i Zubiri et al., 2002), the N atom shows some deviation from planarity, indeed it is 0.25 (1)Å above the C1, C2, P1 plane.
The oxygen atom of P═O group are involved in a C–H···O hydrogen bond building a R22(22) ring (Etter et al., 1990; Bernstein et al., 1995) (Table 1, Fig. 2). Furthermore, these rings are interconnected building infinite chains parallel to the a axis. C–H···π interactions involving the phenyl rings stabilize the packing (Table 1).