The title compound, [Na(C
12H
8N
2O
8P)], consists of one Na
+ cation and one bis(
p-nitrophenyl)phosphate anion with a considerable distortion of the phosphate tetrahedron due to the presence of two P—O ester bonds. The anion bridges five Na
+ cations whereby each cation is chelated by the nitro O atoms of one anion and bonded
via a nitro O atom and phosphate O atoms to four other anions. This bridging arrangement leads to the formation of double layers parallel to (001). Adjacent layers are linked through weak C—H

O hydrogen bonds.
Supporting information
CCDC reference: 961952
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean
(C-C) = 0.001 Å
- R factor = 0.030
- wR factor = 0.090
- Data-to-parameter ratio = 31.1
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) ..... 3
Alert level G
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension . 2
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in the CIF ? Do !
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal .......... 0.03000 Deg.
PLAT793_ALERT_4_G The Model has Chirality at P1 (Verify) .... S
PLAT804_ALERT_5_G ARU-Pack Problem in PLATON Analysis ............ 15 Times
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L= 0.600 290
0 ALERT level A = Most likely a serious problem - resolve or explain
0 ALERT level B = A potentially serious problem, consider carefully
1 ALERT level C = Check. Ensure it is not caused by an omission or oversight
6 ALERT level G = General information/check it is not something unexpected
1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
2 ALERT type 4 Improvement, methodology, query or suggestion
3 ALERT type 5 Informative message, check
The bis(p-nitrophenyl)phosphate sodium salt was purchased from
Sigma-Aldrich. Yellow crystals were obtained after several days by slow
evaporation of an aqueous solution.
All H atoms were introduced in geometrically calculated positions, with
C—H = 0.95 A ° and Uiso(H) = 1.2Ueq(C).
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).
Poly[[µ-bis(4-nitrophenyl) phosphato-
κ2O,
O']sodium]
top
Crystal data top
[Na(C12H8N2O8P)] | Z = 2 |
Mr = 362.16 | F(000) = 368 |
Triclinic, P1 | Dx = 1.806 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.963 (2) Å | Cell parameters from 8925 reflections |
b = 9.844 (3) Å | θ = 3.2–37.5° |
c = 11.213 (3) Å | µ = 0.29 mm−1 |
α = 103.93 (3)° | T = 100 K |
β = 105.83 (3)° | Block, yellow |
γ = 106.38 (3)° | 0.30 × 0.27 × 0.25 mm |
V = 666.1 (3) Å3 | |
Data collection top
Agilent Xcalibur (Onyx with CCD camera) diffractometer | 6748 independent reflections |
Radiation source: fine-focus sealed tube | 5542 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.014 |
ω and π scans | θmax = 37.6°, θmin = 3.2° |
Absorption correction: analytical (CrysAlis PRO; Agilent, 2011) | h = −11→10 |
Tmin = 0.918, Tmax = 0.931 | k = −16→15 |
13418 measured reflections | l = −19→15 |
Refinement top
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)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.090 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0486P)2 + 0.1337P] where P = (Fo2 + 2Fc2)/3 |
6748 reflections | (Δ/σ)max = 0.001 |
217 parameters | Δρmax = 0.66 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
Crystal data top
[Na(C12H8N2O8P)] | γ = 106.38 (3)° |
Mr = 362.16 | V = 666.1 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.963 (2) Å | Mo Kα radiation |
b = 9.844 (3) Å | µ = 0.29 mm−1 |
c = 11.213 (3) Å | T = 100 K |
α = 103.93 (3)° | 0.30 × 0.27 × 0.25 mm |
β = 105.83 (3)° | |
Data collection top
Agilent Xcalibur (Onyx with CCD camera) diffractometer | 6748 independent reflections |
Absorption correction: analytical (CrysAlis PRO; Agilent, 2011) | 5542 reflections with I > 2σ(I) |
Tmin = 0.918, Tmax = 0.931 | Rint = 0.014 |
13418 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.090 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.66 e Å−3 |
6748 reflections | Δρmin = −0.33 e Å−3 |
217 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
P1 | 0.19163 (3) | 0.36887 (2) | 0.291283 (19) | 0.00783 (4) | |
O1 | 0.52988 (11) | 1.11256 (7) | 0.18582 (7) | 0.01642 (12) | |
O2 | 0.66594 (11) | 1.15233 (7) | 0.39510 (6) | 0.01488 (11) | |
O3 | −0.28509 (13) | −0.46498 (7) | 0.15506 (8) | 0.02195 (14) | |
O4 | −0.14079 (12) | −0.34783 (8) | 0.36644 (7) | 0.01817 (13) | |
O11 | 0.18884 (10) | 0.45097 (6) | 0.18143 (6) | 0.01210 (10) | |
O21 | 0.02554 (10) | 0.20680 (6) | 0.18007 (6) | 0.01107 (10) | |
O31 | 0.40483 (10) | 0.36277 (7) | 0.34892 (6) | 0.01340 (11) | |
O41 | 0.08681 (9) | 0.42769 (7) | 0.37940 (6) | 0.01131 (10) | |
N1 | 0.55665 (11) | 1.06716 (8) | 0.27967 (7) | 0.01084 (11) | |
N2 | −0.18533 (12) | −0.34891 (8) | 0.25185 (8) | 0.01290 (12) | |
C1 | 0.28334 (12) | 0.60309 (8) | 0.21207 (7) | 0.00932 (12) | |
C2 | 0.24915 (13) | 0.65553 (9) | 0.10570 (8) | 0.01132 (12) | |
H2 | 0.1654 | 0.5862 | 0.0187 | 0.014* | |
C3 | 0.33698 (13) | 0.80825 (9) | 0.12681 (8) | 0.01110 (12) | |
H3 | 0.3144 | 0.8448 | 0.0551 | 0.013* | |
C4 | 0.45900 (12) | 0.90670 (8) | 0.25538 (8) | 0.00970 (12) | |
C5 | 0.49639 (13) | 0.85587 (9) | 0.36171 (8) | 0.01053 (12) | |
H5 | 0.5815 | 0.9255 | 0.4484 | 0.013* | |
C6 | 0.40903 (13) | 0.70311 (9) | 0.34079 (8) | 0.01043 (12) | |
H6 | 0.4341 | 0.6669 | 0.4126 | 0.013* | |
C11 | −0.01420 (12) | 0.07325 (8) | 0.20306 (8) | 0.00914 (11) | |
C21 | −0.14071 (13) | −0.05705 (9) | 0.09256 (8) | 0.01090 (12) | |
H21 | −0.1902 | −0.0492 | 0.0077 | 0.013* | |
C31 | −0.19405 (13) | −0.19754 (9) | 0.10643 (8) | 0.01187 (13) | |
H31 | −0.2790 | −0.2867 | 0.0320 | 0.014* | |
C41 | −0.11984 (13) | −0.20435 (9) | 0.23230 (8) | 0.01057 (12) | |
C51 | 0.00777 (13) | −0.07667 (9) | 0.34263 (8) | 0.01163 (13) | |
H51 | 0.0579 | −0.0854 | 0.4271 | 0.014* | |
C61 | 0.06168 (13) | 0.06395 (9) | 0.32862 (8) | 0.01120 (12) | |
H61 | 0.1489 | 0.1526 | 0.4033 | 0.013* | |
Na | 0.75570 (5) | 1.41177 (4) | 0.39243 (3) | 0.01082 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
P1 | 0.00772 (8) | 0.00661 (8) | 0.00894 (8) | 0.00226 (6) | 0.00311 (6) | 0.00274 (6) |
O1 | 0.0212 (3) | 0.0124 (3) | 0.0172 (3) | 0.0056 (2) | 0.0065 (2) | 0.0091 (2) |
O2 | 0.0167 (3) | 0.0091 (2) | 0.0144 (3) | 0.0027 (2) | 0.0032 (2) | 0.0020 (2) |
O3 | 0.0321 (4) | 0.0079 (3) | 0.0231 (3) | 0.0030 (3) | 0.0129 (3) | 0.0025 (2) |
O4 | 0.0225 (3) | 0.0154 (3) | 0.0206 (3) | 0.0075 (2) | 0.0087 (3) | 0.0116 (2) |
O11 | 0.0172 (3) | 0.0066 (2) | 0.0100 (2) | 0.00113 (19) | 0.0046 (2) | 0.00292 (18) |
O21 | 0.0137 (2) | 0.0062 (2) | 0.0103 (2) | 0.00136 (19) | 0.00201 (19) | 0.00335 (18) |
O31 | 0.0084 (2) | 0.0132 (3) | 0.0176 (3) | 0.0045 (2) | 0.0038 (2) | 0.0042 (2) |
O41 | 0.0108 (2) | 0.0121 (2) | 0.0121 (2) | 0.00466 (19) | 0.00572 (19) | 0.00352 (19) |
N1 | 0.0107 (3) | 0.0084 (3) | 0.0147 (3) | 0.0041 (2) | 0.0052 (2) | 0.0049 (2) |
N2 | 0.0142 (3) | 0.0093 (3) | 0.0190 (3) | 0.0054 (2) | 0.0094 (2) | 0.0063 (2) |
C1 | 0.0102 (3) | 0.0068 (3) | 0.0107 (3) | 0.0024 (2) | 0.0041 (2) | 0.0031 (2) |
C2 | 0.0127 (3) | 0.0092 (3) | 0.0100 (3) | 0.0020 (2) | 0.0031 (2) | 0.0035 (2) |
C3 | 0.0123 (3) | 0.0092 (3) | 0.0111 (3) | 0.0031 (2) | 0.0036 (2) | 0.0044 (2) |
C4 | 0.0101 (3) | 0.0072 (3) | 0.0122 (3) | 0.0031 (2) | 0.0044 (2) | 0.0038 (2) |
C5 | 0.0119 (3) | 0.0078 (3) | 0.0106 (3) | 0.0031 (2) | 0.0035 (2) | 0.0025 (2) |
C6 | 0.0123 (3) | 0.0086 (3) | 0.0097 (3) | 0.0031 (2) | 0.0037 (2) | 0.0035 (2) |
C11 | 0.0094 (3) | 0.0073 (3) | 0.0110 (3) | 0.0029 (2) | 0.0039 (2) | 0.0036 (2) |
C21 | 0.0126 (3) | 0.0084 (3) | 0.0101 (3) | 0.0025 (2) | 0.0036 (2) | 0.0028 (2) |
C31 | 0.0136 (3) | 0.0082 (3) | 0.0124 (3) | 0.0025 (2) | 0.0054 (3) | 0.0024 (2) |
C41 | 0.0121 (3) | 0.0074 (3) | 0.0142 (3) | 0.0040 (2) | 0.0068 (2) | 0.0046 (2) |
C51 | 0.0130 (3) | 0.0104 (3) | 0.0118 (3) | 0.0040 (2) | 0.0040 (2) | 0.0053 (2) |
C61 | 0.0130 (3) | 0.0086 (3) | 0.0099 (3) | 0.0024 (2) | 0.0027 (2) | 0.0031 (2) |
Na | 0.00911 (14) | 0.00915 (14) | 0.01433 (15) | 0.00301 (11) | 0.00447 (12) | 0.00451 (12) |
Geometric parameters (Å, º) top
P1—O31 | 1.4733 (8) | C2—C3 | 1.3861 (12) |
P1—O41 | 1.4834 (7) | C2—H2 | 0.9500 |
P1—O11 | 1.6266 (8) | C3—C4 | 1.3908 (14) |
P1—O21 | 1.6287 (12) | C3—H3 | 0.9500 |
O1—N1 | 1.2282 (10) | C4—C5 | 1.3895 (12) |
O1—Na | 2.9377 (18) | C5—C6 | 1.3867 (12) |
O2—N1 | 1.2399 (12) | C5—H5 | 0.9500 |
O2—Na | 2.4618 (11) | C6—H6 | 0.9500 |
O3—N2 | 1.2288 (12) | C11—C61 | 1.3976 (12) |
O4—N2 | 1.2335 (11) | C11—C21 | 1.3995 (14) |
O4—Nai | 2.3853 (11) | C21—C31 | 1.3857 (12) |
O11—C1 | 1.3663 (11) | C21—H21 | 0.9500 |
O21—C11 | 1.3668 (10) | C31—C41 | 1.3894 (12) |
O31—Naii | 2.2386 (10) | C31—H31 | 0.9500 |
O41—Naiii | 2.3135 (9) | C41—C51 | 1.3862 (14) |
O41—Naiv | 2.4065 (14) | C51—C61 | 1.3877 (12) |
N1—C4 | 1.4552 (12) | C51—H51 | 0.9500 |
N2—C41 | 1.4560 (12) | C61—H61 | 0.9500 |
C1—C2 | 1.3987 (12) | Na—Nav | 3.253 (2) |
C1—C6 | 1.3998 (14) | | |
| | | |
O31—P1—O41 | 119.67 (5) | C1—C6—H6 | 120.6 |
O31—P1—O11 | 110.86 (4) | O21—C11—C61 | 123.21 (8) |
O41—P1—O11 | 110.02 (4) | O21—C11—C21 | 116.04 (7) |
O31—P1—O21 | 110.48 (5) | C61—C11—C21 | 120.74 (8) |
O41—P1—O21 | 110.21 (4) | C31—C21—C11 | 120.28 (8) |
O11—P1—O21 | 92.20 (4) | C31—C21—H21 | 119.9 |
N1—O1—Na | 83.76 (6) | C11—C21—H21 | 119.9 |
N1—O2—Na | 106.72 (6) | C21—C31—C41 | 118.15 (8) |
N2—O4—Nai | 116.10 (7) | C21—C31—H31 | 120.9 |
C1—O11—P1 | 123.69 (6) | C41—C31—H31 | 120.9 |
C11—O21—P1 | 123.67 (6) | C51—C41—C31 | 122.37 (8) |
P1—O31—Naii | 157.93 (4) | C51—C41—N2 | 117.95 (8) |
P1—O41—Naiii | 143.20 (5) | C31—C41—N2 | 119.61 (8) |
P1—O41—Naiv | 129.49 (4) | C41—C51—C61 | 119.45 (8) |
Naiii—O41—Naiv | 87.11 (4) | C41—C51—H51 | 120.3 |
O1—N1—O2 | 122.74 (7) | C61—C51—H51 | 120.3 |
O1—N1—C4 | 119.12 (8) | C51—C61—C11 | 119.01 (8) |
O2—N1—C4 | 118.13 (8) | C51—C61—H61 | 120.5 |
O1—N1—Na | 72.71 (6) | C11—C61—H61 | 120.5 |
O2—N1—Na | 50.43 (5) | O31vi—Na—O41vii | 165.08 (3) |
C4—N1—Na | 167.00 (5) | O31vi—Na—O4viii | 99.55 (4) |
O3—N2—O4 | 123.14 (8) | O41vii—Na—O4viii | 81.55 (4) |
O3—N2—C41 | 119.25 (8) | O31vi—Na—O41iv | 101.98 (5) |
O4—N2—C41 | 117.59 (8) | O41vii—Na—O41iv | 92.89 (4) |
O11—C1—C2 | 115.91 (8) | O4viii—Na—O41iv | 80.28 (4) |
O11—C1—C6 | 123.34 (8) | O31vi—Na—O2 | 84.38 (4) |
C2—C1—C6 | 120.75 (7) | O41vii—Na—O2 | 92.94 (4) |
C3—C2—C1 | 120.25 (8) | O4viii—Na—O2 | 172.26 (3) |
C3—C2—H2 | 119.9 | O41iv—Na—O2 | 105.55 (4) |
C1—C2—H2 | 119.9 | O31vi—Na—O1 | 74.29 (5) |
C2—C3—C4 | 118.44 (8) | O41vii—Na—O1 | 93.25 (4) |
C2—C3—H3 | 120.8 | O4viii—Na—O1 | 128.23 (3) |
C4—C3—H3 | 120.8 | O41iv—Na—O1 | 151.44 (3) |
C5—C4—C3 | 121.88 (8) | O2—Na—O1 | 46.28 (3) |
C5—C4—N1 | 118.65 (8) | O31vi—Na—N1 | 76.99 (4) |
C3—C4—N1 | 119.43 (8) | O41vii—Na—N1 | 94.92 (4) |
C6—C5—C4 | 119.77 (8) | O4viii—Na—N1 | 151.70 (3) |
C6—C5—H5 | 120.1 | O41iv—Na—N1 | 128.02 (4) |
C4—C5—H5 | 120.1 | O2—Na—N1 | 22.85 (2) |
C5—C6—C1 | 118.90 (8) | O1—Na—N1 | 23.53 (2) |
C5—C6—H6 | 120.6 | | |
| | | |
O31—P1—O11—C1 | −74.91 (8) | C4—C5—C6—C1 | −0.33 (12) |
O41—P1—O11—C1 | 59.73 (8) | O11—C1—C6—C5 | −179.42 (7) |
O21—P1—O11—C1 | 172.18 (6) | C2—C1—C6—C5 | 1.12 (12) |
O31—P1—O21—C11 | 53.96 (7) | P1—O21—C11—C61 | 8.66 (11) |
O41—P1—O21—C11 | −80.51 (7) | P1—O21—C11—C21 | −172.40 (6) |
O11—P1—O21—C11 | 167.21 (6) | O21—C11—C21—C31 | −178.45 (7) |
P1—O11—C1—C2 | −174.63 (6) | C61—C11—C21—C31 | 0.52 (12) |
P1—O11—C1—C6 | 5.90 (11) | C11—C21—C31—C41 | 0.45 (12) |
O11—C1—C2—C3 | 179.50 (7) | C21—C31—C41—C51 | −1.26 (12) |
C6—C1—C2—C3 | −1.01 (12) | C21—C31—C41—N2 | 175.67 (7) |
C1—C2—C3—C4 | 0.09 (12) | O3—N2—C41—C51 | −174.72 (8) |
C2—C3—C4—C5 | 0.72 (12) | O4—N2—C41—C51 | 6.77 (11) |
C2—C3—C4—N1 | 178.70 (7) | O3—N2—C41—C31 | 8.22 (12) |
O1—N1—C4—C5 | 177.82 (7) | O4—N2—C41—C31 | −170.30 (8) |
O2—N1—C4—C5 | −1.43 (11) | C31—C41—C51—C61 | 1.08 (12) |
O1—N1—C4—C3 | −0.23 (11) | N2—C41—C51—C61 | −175.90 (7) |
O2—N1—C4—C3 | −179.48 (7) | C41—C51—C61—C11 | −0.07 (12) |
C3—C4—C5—C6 | −0.60 (12) | O21—C11—C61—C51 | 178.18 (7) |
N1—C4—C5—C6 | −178.60 (7) | C21—C11—C61—C51 | −0.71 (12) |
Symmetry codes: (i) x−1, y−2, z; (ii) x, y−1, z; (iii) x−1, y−1, z; (iv) −x+1, −y+2, −z+1; (v) −x+2, −y+3, −z+1; (vi) x, y+1, z; (vii) x+1, y+1, z; (viii) x+1, y+2, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O3ix | 0.95 | 2.50 | 3.1865 (15) | 129 |
C21—H21···O1x | 0.95 | 2.53 | 3.3337 (18) | 142 |
Symmetry codes: (ix) −x, −y, −z; (x) −x, −y+1, −z. |
Selected geometric parameters (Å, º) topP1—O31 | 1.4733 (8) | O2—Na | 2.4618 (11) |
P1—O41 | 1.4834 (7) | O4—Nai | 2.3853 (11) |
P1—O11 | 1.6266 (8) | O31—Naii | 2.2386 (10) |
P1—O21 | 1.6287 (12) | O41—Naiii | 2.3135 (9) |
O1—Na | 2.9377 (18) | O41—Naiv | 2.4065 (14) |
| | | |
O31—P1—O41 | 119.67 (5) | O31—P1—O21 | 110.48 (5) |
O31—P1—O11 | 110.86 (4) | O41—P1—O21 | 110.21 (4) |
O41—P1—O11 | 110.02 (4) | O11—P1—O21 | 92.20 (4) |
Symmetry codes: (i) x−1, y−2, z; (ii) x, y−1, z; (iii) x−1, y−1, z; (iv) −x+1, −y+2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O3v | 0.95 | 2.50 | 3.1865 (15) | 129.4 |
C21—H21···O1vi | 0.95 | 2.53 | 3.3337 (18) | 142.3 |
Symmetry codes: (v) −x, −y, −z; (vi) −x, −y+1, −z. |
Phosphate diester hydrolysis is a reaction of continuing interest since such process is of fundamental biological importance. Currently, there is much interest in developing artificial nucleases that hydrolyze the phosphate diester bonds in RNA and DNA (Sredhera & Cowan, 2001; Belousoff et al., 2009; Branum et al., 2001). Thus, there have been numerous model studies devoted to understanding how metalloenzymes hydrolyze phosphate diesters (Mancin et al., 2005; Liu et al., 2004). In most cases the substrate of choice is the "activated" phosphate diester bis(p-nitrophenyl)phosphate (BNPP). It is considered as an activated phosphate diester because the p-nitro groups draw electron density away from the phosphorus atom as well as help to stabilize the negatively charged leaving group (Jurek & Martell, 1999). For this reason the bis(p-nitrophenyl)phosphate anion is a popular model substrate for kinetic studies of the hydrolytic cleavage of the phosphodiester bond similar to DNA (Chang et al., 2009; Oh et al., 1996).
BNPP is commercially available as a sodium salt. There are many references concerning solid state studies of BNPP acting as a ligand in complexes or as an anion in salts. The first publications referring to BNPP describe salts of local anesthetics (Sax et al., 1970, 1971; Pletcher et al., 1972; Yoo et al., 1975). The structure of BNPP has been observed also in many macrocyclic complexes (Král et al., 2006; Bazzicalupi et al., 2004; Fry et al., 2003; Warden et al., 2005). Here we report the structure of BNPP as a sodium salt, [Na(C12H8N2O8P)], (I).
Compound (I) crystallizes with one bis(p-nitrophenyl)phosphate anion (Fig. 1) and one sodium cation in the asymmetric unit. The phenyl rings are almost coplanar. The interplanar angle between two phenyl rings amounts to 2.36 (3)°. The nitro group O1—N1—O2 is rotated 2.00 (4)° from the phenyl ring C1—C6 and the second nitro group O3—N2—O4 is rotated 9.01 (4)° from the phenyl ring C11—C61. The phosphate group is highly distorted from the ideal tetrahedral geometry (Table 1). In the anion there are two shorter P—O bonds of 1.4733 (8) Å and 1.4834 (7) Å, and two longer P—O ester bonds lengths of 1.6266 (8) Å and 1.6287 (12) Å. The shortest bond is P–O31. A little longer than the P–O31 bond is the P–O41 bond, bridging Na+ ions. Both O11 and O21 atoms involved in longer ester bonds are attached to aryl rings. The average P—O distance is 1.55 Å, but individual P—O bonds in the structure of compound (I) show how much the phosphate group is deformed. In previous reports containing BNPP anions the most similar deviations for P—O ester bond length in the phosphate group has been observed for these four examples (Sax et al., 1970, 1971; Pletcher et al., 1972; Yoo et al., 1975).
The bond angles in the phosphate group distinctly deviate from the ideal value of 109.5°. The average value for the O–P–O angle is 108.9°, however, individual angles show considerable deviations. The smallest angle is 92.20 (4)° for O11—P1—O21, that is ArO—P—OAr. This deviation can be correlated with the corresponding bond lengths. Such a small angle has not been observed in any previous report of a BNPP structure. The most comparabler value of an O—P—O angle is 95.3 (2)° (Bond et al., 1985). The largest angle is 119.67 (5)° for O31—P—O41, and the four remaining angles are about 110°.
In (I), the coordination geometry of Na+ ion is irregular, with an overall coordination number of six [5 + 1] . The Na+ ion is coordinated by five symmetry-related BNPP anions via oxygen atoms. It is chelated by one anion in a bidentate mode (via O1 and O2), and coordinated by four anions in a monodentate manner (via O31iv, O4iii, O41v and O41vi) (Fig. 2). The Na—O distances are in the range 2.2386 (10) to 2.9377 (18) Å (Table 2). In the structure there is also a short Na···Na distance of 3.253 (2) Å, and two sodium cations are bridged by two O atoms (denoted as O41 in Fig. 2), forming a dimeric sub-structure with a four-membered ring (Figs. 2 and 4). The cations and anions are arranged in double layers parallel to (001) (Figs. 3 and 4). Adjacent layers are linked through weak C—H···O hydrogen bonds existing between H atoms of the aromatic rings and nitro O atoms (Fig. 3, Table 2).