Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801016993/na6096sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801016993/na6096Isup2.hkl |
CCDC reference: 176024
The title compound was crystallized from an aqueous solution of DL-phenylalanine and orthophosphoric acid (1:1) by slow evaporation.
The hydrogen atoms H1B and H2B of the carboxyl group of both phenylalaninium residues (A and B) were located and refined isotropically (since these suggest a strong nearly symmetric hydrogen bond), while all other H atoms of both phenylalaninium residues and phosphate anions were fixed by HFIX and allowed to ride on the atoms to which they are attached.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.
C9H12NO2+·H2PO4− | F(000) = 552 |
Mr = 263.18 | Dx = 1.474 Mg m−3 Dm = 1.469 Mg m−3 Dm measured by flotation in a mixture of carbon tetrachloride and xylene |
Monoclinic, Pc | Mo Kα radiation, λ = 0.71073 Å |
a = 13.899 (7) Å | Cell parameters from 25 reflections |
b = 9.956 (8) Å | θ = 11.3–13.9° |
c = 9.051 (2) Å | µ = 0.25 mm−1 |
β = 108.726 (8)° | T = 293 K |
V = 1186.1 (12) Å3 | Needle, colorless |
Z = 4 | 0.6 × 0.33 × 0.13 mm |
Enraf-Nonius CAD-4 diffractometer | 2078 reflections with I > 2σ |
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 25.0°, θmin = 1.6° |
ω–2θ scans | h = −16→15 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→11 |
Tmin = 0.918, Tmax = 0.967 | l = 0→10 |
2235 measured reflections | 3 standard reflections every 60 min |
2235 independent reflections | intensity decay: none |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.028 | w = 1/[σ2(Fo2) + (0.0491P)2 + 0.1839P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.074 | (Δ/σ)max < 0.001 |
S = 1.07 | Δρmax = 0.21 e Å−3 |
2235 reflections | Δρmin = −0.29 e Å−3 |
317 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
2 restraints | Extinction coefficient: 0.0238 (18) |
Primary atom site location: structure-invariant direct methods | Absolute structure: [Flack, 1983] |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.03 (10) |
C9H12NO2+·H2PO4− | V = 1186.1 (12) Å3 |
Mr = 263.18 | Z = 4 |
Monoclinic, Pc | Mo Kα radiation |
a = 13.899 (7) Å | µ = 0.25 mm−1 |
b = 9.956 (8) Å | T = 293 K |
c = 9.051 (2) Å | 0.6 × 0.33 × 0.13 mm |
β = 108.726 (8)° |
Enraf-Nonius CAD-4 diffractometer | 2078 reflections with I > 2σ |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.000 |
Tmin = 0.918, Tmax = 0.967 | 3 standard reflections every 60 min |
2235 measured reflections | intensity decay: none |
2235 independent reflections |
R[F2 > 2σ(F2)] = 0.028 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.074 | Δρmax = 0.21 e Å−3 |
S = 1.07 | Δρmin = −0.29 e Å−3 |
2235 reflections | Absolute structure: [Flack, 1983] |
317 parameters | Absolute structure parameter: −0.03 (10) |
2 restraints |
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 | 0.15371 (6) | 0.54460 (7) | 0.41704 (8) | 0.0278 (2) | |
O11 | 0.10420 (19) | 0.4143 (2) | 0.3594 (3) | 0.0396 (6) | |
O12 | 0.20465 (19) | 0.6095 (2) | 0.3097 (3) | 0.0356 (6) | |
O13 | 0.07248 (19) | 0.6420 (2) | 0.4400 (3) | 0.0392 (6) | |
H13 | 0.0930 | 0.7195 | 0.4434 | 0.059* | |
O14 | 0.23888 (18) | 0.5305 (2) | 0.5782 (3) | 0.0404 (6) | |
H14 | 0.2268 | 0.4654 | 0.6249 | 0.061* | |
P2 | 0.88507 (6) | −0.02763 (8) | 0.13941 (8) | 0.0295 (2) | |
O21 | 0.93679 (19) | 0.0995 (2) | 0.2073 (3) | 0.0392 (6) | |
O22 | 0.8397 (2) | −0.1064 (2) | 0.2453 (3) | 0.0367 (6) | |
O23 | 0.96464 (19) | −0.1190 (2) | 0.0969 (3) | 0.0410 (6) | |
H23 | 0.9463 | −0.1976 | 0.0923 | 0.061* | |
O24 | 0.79616 (17) | −0.0018 (3) | −0.0140 (3) | 0.0437 (6) | |
H24 | 0.8192 | 0.0215 | −0.0829 | 0.066* | |
O1A | 0.1404 (2) | −0.1116 (2) | 0.4569 (3) | 0.0389 (6) | |
O1B | 0.21052 (19) | −0.1453 (2) | 0.2699 (3) | 0.0365 (6) | |
H1B | 0.202 (5) | −0.264 (7) | 0.296 (8) | 0.12 (2)* | |
C11 | 0.1743 (3) | −0.0704 (3) | 0.3562 (4) | 0.0285 (7) | |
C12 | 0.1726 (2) | 0.0786 (3) | 0.3202 (4) | 0.0292 (7) | |
H12 | 0.1255 | 0.0909 | 0.2142 | 0.035* | |
N11 | 0.1282 (2) | 0.1489 (3) | 0.4269 (3) | 0.0317 (6) | |
H11A | 0.1258 | 0.2367 | 0.4075 | 0.048* | |
H11B | 0.1664 | 0.1340 | 0.5252 | 0.048* | |
H11C | 0.0656 | 0.1183 | 0.4122 | 0.048* | |
C13 | 0.2747 (3) | 0.1381 (3) | 0.3228 (4) | 0.0382 (7) | |
H13A | 0.2966 | 0.0921 | 0.2446 | 0.046* | |
H13B | 0.2641 | 0.2316 | 0.2920 | 0.046* | |
C14 | 0.3596 (3) | 0.1310 (3) | 0.4755 (4) | 0.0364 (7) | |
C15 | 0.3791 (3) | 0.2374 (4) | 0.5789 (5) | 0.0545 (10) | |
H15 | 0.3356 | 0.3110 | 0.5580 | 0.065* | |
C16 | 0.4620 (5) | 0.2360 (7) | 0.7124 (6) | 0.0870 (17) | |
H16 | 0.4740 | 0.3078 | 0.7817 | 0.104* | |
C17 | 0.5268 (5) | 0.1278 (9) | 0.7427 (7) | 0.103 (3) | |
H17 | 0.5839 | 0.1270 | 0.8314 | 0.124* | |
C18 | 0.5072 (4) | 0.0215 (7) | 0.6422 (9) | 0.094 (2) | |
H18 | 0.5505 | −0.0523 | 0.6634 | 0.112* | |
C19 | 0.4244 (3) | 0.0228 (4) | 0.5110 (6) | 0.0628 (11) | |
H19 | 0.4115 | −0.0509 | 0.4443 | 0.075* | |
O2A | 0.90648 (19) | 0.6226 (2) | 0.0761 (3) | 0.0365 (6) | |
O2B | 0.82341 (19) | 0.6439 (2) | 0.2493 (3) | 0.0380 (6) | |
H2B | 0.830 (5) | 0.765 (6) | 0.243 (8) | 0.103 (19)* | |
C21 | 0.8626 (2) | 0.5756 (3) | 0.1621 (4) | 0.0286 (7) | |
C22 | 0.8505 (2) | 0.4243 (3) | 0.1712 (4) | 0.0292 (7) | |
H22 | 0.8623 | 0.3989 | 0.2802 | 0.035* | |
N21 | 0.9282 (2) | 0.3595 (3) | 0.1158 (3) | 0.0329 (6) | |
H21A | 0.9227 | 0.2707 | 0.1208 | 0.049* | |
H21B | 0.9897 | 0.3850 | 0.1757 | 0.049* | |
H21C | 0.9189 | 0.3838 | 0.0176 | 0.049* | |
C23 | 0.7446 (3) | 0.3759 (3) | 0.0726 (4) | 0.0375 (7) | |
H23A | 0.7176 | 0.4382 | −0.0131 | 0.045* | |
H23B | 0.7516 | 0.2893 | 0.0280 | 0.045* | |
C24 | 0.6682 (2) | 0.3623 (3) | 0.1593 (4) | 0.0326 (7) | |
C25 | 0.6898 (3) | 0.2830 (3) | 0.2909 (4) | 0.0505 (9) | |
H25 | 0.7535 | 0.2430 | 0.3299 | 0.061* | |
C26 | 0.6198 (3) | 0.2618 (3) | 0.3653 (4) | 0.0745 (15) | |
H26 | 0.6366 | 0.2098 | 0.4553 | 0.089* | |
C27 | 0.5265 (5) | 0.3161 (6) | 0.3085 (8) | 0.089 (2) | |
H27 | 0.4787 | 0.2998 | 0.3584 | 0.107* | |
C28 | 0.5011 (3) | 0.3956 (6) | 0.1773 (9) | 0.087 (2) | |
H28 | 0.4365 | 0.4328 | 0.1386 | 0.105* | |
C29 | 0.5739 (3) | 0.4204 (4) | 0.1013 (6) | 0.0576 (10) | |
H29 | 0.5581 | 0.4752 | 0.0135 | 0.069* |
U11 | U22 | U33 | U12 | U13 | U23 | |
P1 | 0.0372 (4) | 0.0215 (3) | 0.0274 (4) | −0.0028 (3) | 0.0140 (3) | 0.0003 (3) |
O11 | 0.0556 (15) | 0.0228 (11) | 0.0404 (14) | −0.0039 (11) | 0.0154 (12) | 0.0007 (10) |
O12 | 0.0554 (16) | 0.0258 (11) | 0.0343 (13) | −0.0016 (10) | 0.0265 (12) | −0.0004 (9) |
O13 | 0.0440 (13) | 0.0299 (12) | 0.0507 (15) | −0.0007 (10) | 0.0248 (12) | −0.0011 (11) |
O14 | 0.0421 (13) | 0.0456 (15) | 0.0319 (13) | −0.0092 (10) | 0.0095 (11) | 0.0077 (10) |
P2 | 0.0402 (4) | 0.0247 (4) | 0.0253 (4) | −0.0039 (3) | 0.0129 (3) | −0.0006 (3) |
O21 | 0.0527 (15) | 0.0283 (11) | 0.0341 (13) | −0.0074 (10) | 0.0104 (11) | 0.0000 (10) |
O22 | 0.0608 (15) | 0.0270 (11) | 0.0312 (12) | −0.0059 (11) | 0.0272 (12) | −0.0036 (10) |
O23 | 0.0516 (15) | 0.0323 (11) | 0.0473 (15) | −0.0060 (11) | 0.0274 (12) | −0.0024 (11) |
O24 | 0.0432 (13) | 0.0555 (14) | 0.0308 (13) | −0.0069 (12) | 0.0096 (11) | 0.0036 (12) |
O1A | 0.0721 (17) | 0.0246 (11) | 0.0285 (13) | −0.0016 (11) | 0.0282 (12) | −0.0007 (10) |
O1B | 0.0587 (15) | 0.0282 (11) | 0.0306 (12) | 0.0011 (10) | 0.0257 (11) | 0.0009 (9) |
C11 | 0.0388 (18) | 0.0254 (15) | 0.0218 (15) | −0.0051 (13) | 0.0105 (13) | 0.0003 (13) |
C12 | 0.0392 (16) | 0.0261 (15) | 0.0239 (15) | −0.0029 (13) | 0.0124 (13) | −0.0003 (13) |
N11 | 0.0429 (16) | 0.0226 (12) | 0.0300 (15) | −0.0022 (11) | 0.0124 (12) | 0.0015 (11) |
C13 | 0.0528 (19) | 0.0318 (16) | 0.0333 (17) | −0.0051 (14) | 0.0182 (15) | 0.0016 (13) |
C14 | 0.0407 (17) | 0.0363 (16) | 0.0372 (18) | −0.0033 (14) | 0.0194 (15) | 0.0024 (14) |
C15 | 0.060 (2) | 0.055 (2) | 0.048 (2) | −0.0107 (18) | 0.0160 (19) | −0.0118 (18) |
C16 | 0.092 (4) | 0.103 (4) | 0.055 (3) | −0.039 (4) | 0.009 (3) | −0.014 (3) |
C17 | 0.071 (3) | 0.150 (7) | 0.066 (4) | −0.037 (4) | −0.010 (3) | 0.040 (4) |
C18 | 0.060 (3) | 0.098 (4) | 0.114 (5) | 0.019 (3) | 0.015 (3) | 0.053 (4) |
C19 | 0.060 (2) | 0.056 (3) | 0.073 (3) | 0.012 (2) | 0.022 (2) | 0.012 (2) |
O2A | 0.0545 (14) | 0.0277 (12) | 0.0356 (14) | −0.0014 (10) | 0.0260 (12) | −0.0002 (10) |
O2B | 0.0548 (14) | 0.0293 (12) | 0.0403 (13) | 0.0005 (10) | 0.0296 (12) | −0.0039 (10) |
C21 | 0.0316 (16) | 0.0280 (15) | 0.0256 (16) | 0.0026 (13) | 0.0083 (13) | 0.0009 (13) |
C22 | 0.0371 (16) | 0.0268 (16) | 0.0259 (16) | 0.0004 (13) | 0.0132 (14) | 0.0009 (13) |
N21 | 0.0418 (15) | 0.0240 (13) | 0.0383 (15) | −0.0015 (11) | 0.0207 (13) | 0.0013 (11) |
C23 | 0.0405 (17) | 0.0426 (18) | 0.0298 (17) | −0.0071 (14) | 0.0119 (14) | −0.0048 (14) |
C24 | 0.0352 (15) | 0.0305 (14) | 0.0327 (16) | −0.0052 (12) | 0.0117 (13) | −0.0054 (13) |
C25 | 0.055 (2) | 0.051 (2) | 0.045 (2) | −0.0188 (17) | 0.0148 (17) | 0.0059 (17) |
C26 | 0.099 (4) | 0.082 (3) | 0.056 (3) | −0.047 (3) | 0.045 (3) | −0.010 (2) |
C27 | 0.100 (4) | 0.084 (4) | 0.119 (5) | −0.045 (3) | 0.086 (4) | −0.037 (4) |
C28 | 0.042 (2) | 0.071 (3) | 0.158 (6) | −0.002 (2) | 0.045 (3) | −0.029 (4) |
C29 | 0.046 (2) | 0.052 (2) | 0.075 (3) | 0.0061 (18) | 0.020 (2) | 0.003 (2) |
P1—O11 | 1.483 (3) | C16—H16 | 0.9300 |
P1—O12 | 1.518 (2) | C17—C18 | 1.365 (11) |
P1—O13 | 1.552 (3) | C17—H17 | 0.9300 |
P1—O14 | 1.562 (3) | C18—C19 | 1.362 (7) |
O13—H13 | 0.8200 | C18—H18 | 0.9300 |
O14—H14 | 0.8200 | C19—H19 | 0.9300 |
P2—O21 | 1.488 (3) | O2A—C21 | 1.226 (4) |
P2—O22 | 1.523 (2) | O2B—C21 | 1.287 (4) |
P2—O24 | 1.556 (3) | O2B—H2B | 1.21 (6) |
P2—O23 | 1.572 (3) | C21—C22 | 1.521 (4) |
O23—H23 | 0.8200 | C22—N21 | 1.477 (4) |
O24—H24 | 0.8200 | C22—C23 | 1.533 (4) |
O1A—C11 | 1.224 (4) | C22—H22 | 0.9800 |
O1B—C11 | 1.293 (4) | N21—H21A | 0.8900 |
O1B—H1B | 1.22 (7) | N21—H21B | 0.8900 |
C11—C12 | 1.518 (4) | N21—H21C | 0.8900 |
C12—N11 | 1.479 (4) | C23—C24 | 1.515 (4) |
C12—C13 | 1.531 (5) | C23—H23A | 0.9700 |
C12—H12 | 0.9800 | C23—H23B | 0.9700 |
N11—H11A | 0.8900 | C24—C29 | 1.374 (5) |
N11—H11B | 0.8900 | C24—C25 | 1.379 (5) |
N11—H11C | 0.8900 | C25—C26 | 1.3659 |
C13—C14 | 1.503 (5) | C25—H25 | 0.9300 |
C13—H13A | 0.9700 | C26—C27 | 1.346 (8) |
C13—H13B | 0.9700 | C26—H26 | 0.9300 |
C14—C19 | 1.374 (5) | C27—C28 | 1.375 (9) |
C14—C15 | 1.382 (5) | C27—H27 | 0.9300 |
C15—C16 | 1.376 (7) | C28—C29 | 1.415 (7) |
C15—H15 | 0.9300 | C28—H28 | 0.9300 |
C16—C17 | 1.375 (10) | C29—H29 | 0.9300 |
O11—P1—O12 | 113.98 (14) | C18—C17—H17 | 120.1 |
O11—P1—O13 | 108.57 (15) | C16—C17—H17 | 120.1 |
O12—P1—O13 | 109.17 (14) | C19—C18—C17 | 120.4 (5) |
O11—P1—O14 | 112.17 (14) | C19—C18—H18 | 119.8 |
O12—P1—O14 | 105.44 (15) | C17—C18—H18 | 119.8 |
O13—P1—O14 | 107.27 (15) | C18—C19—C14 | 121.2 (5) |
P1—O13—H13 | 109.5 | C18—C19—H19 | 119.4 |
P1—O14—H14 | 109.5 | C14—C19—H19 | 119.4 |
O21—P2—O22 | 114.90 (15) | C21—O2B—H2B | 117 (3) |
O21—P2—O24 | 111.58 (15) | O2A—C21—O2B | 125.6 (3) |
O22—P2—O24 | 106.03 (15) | O2A—C21—C22 | 119.9 (3) |
O21—P2—O23 | 107.99 (15) | O2B—C21—C22 | 114.4 (3) |
O22—P2—O23 | 108.78 (14) | N21—C22—C21 | 108.0 (3) |
O24—P2—O23 | 107.28 (16) | N21—C22—C23 | 109.6 (3) |
P2—O23—H23 | 109.5 | C21—C22—C23 | 112.5 (3) |
P2—O24—H24 | 109.5 | N21—C22—H22 | 108.9 |
C11—O1B—H1B | 111 (3) | C21—C22—H22 | 108.9 |
O1A—C11—O1B | 125.1 (3) | C23—C22—H22 | 108.9 |
O1A—C11—C12 | 120.3 (3) | C22—N21—H21A | 109.5 |
O1B—C11—C12 | 114.6 (3) | C22—N21—H21B | 109.5 |
N11—C12—C11 | 107.7 (2) | H21A—N21—H21B | 109.5 |
N11—C12—C13 | 112.7 (3) | C22—N21—H21C | 109.5 |
C11—C12—C13 | 115.1 (3) | H21A—N21—H21C | 109.5 |
N11—C12—H12 | 107.0 | H21B—N21—H21C | 109.5 |
C11—C12—H12 | 107.0 | C24—C23—C22 | 115.3 (3) |
C13—C12—H12 | 107.0 | C24—C23—H23A | 108.4 |
C12—N11—H11A | 109.5 | C22—C23—H23A | 108.4 |
C12—N11—H11B | 109.5 | C24—C23—H23B | 108.4 |
H11A—N11—H11B | 109.5 | C22—C23—H23B | 108.4 |
C12—N11—H11C | 109.5 | H23A—C23—H23B | 107.5 |
H11A—N11—H11C | 109.5 | C29—C24—C25 | 119.2 (3) |
H11B—N11—H11C | 109.5 | C29—C24—C23 | 120.4 (3) |
C14—C13—C12 | 116.5 (3) | C25—C24—C23 | 120.2 (3) |
C14—C13—H13A | 108.2 | C26—C25—C24 | 121.4 (2) |
C12—C13—H13A | 108.2 | C26—C25—H25 | 119.3 |
C14—C13—H13B | 108.2 | C24—C25—H25 | 119.3 |
C12—C13—H13B | 108.2 | C27—C26—C25 | 120.1 (3) |
H13A—C13—H13B | 107.3 | C27—C26—H26 | 119.9 |
C19—C14—C15 | 118.2 (4) | C25—C26—H26 | 119.9 |
C19—C14—C13 | 120.9 (3) | C26—C27—C28 | 120.6 (4) |
C15—C14—C13 | 120.8 (3) | C26—C27—H27 | 119.7 |
C16—C15—C14 | 120.9 (5) | C28—C27—H27 | 119.7 |
C16—C15—H15 | 119.5 | C27—C28—C29 | 119.7 (4) |
C14—C15—H15 | 119.5 | C27—C28—H28 | 120.2 |
C17—C16—C15 | 119.6 (6) | C29—C28—H28 | 120.2 |
C17—C16—H16 | 120.2 | C24—C29—C28 | 118.9 (5) |
C15—C16—H16 | 120.2 | C24—C29—H29 | 120.5 |
C18—C17—C16 | 119.8 (5) | C28—C29—H29 | 120.5 |
O1A—C11—C12—N11 | 1.3 (4) | O2A—C21—C22—N21 | 21.0 (4) |
O1B—C11—C12—N11 | 179.2 (3) | O2B—C21—C22—N21 | −159.4 (3) |
O1A—C11—C12—C13 | 128.0 (3) | O2A—C21—C22—C23 | −100.0 (4) |
O1B—C11—C12—C13 | −54.1 (4) | O2B—C21—C22—C23 | 79.6 (4) |
N11—C12—C13—C14 | 62.5 (4) | N21—C22—C23—C24 | 145.7 (3) |
C11—C12—C13—C14 | −61.5 (4) | C21—C22—C23—C24 | −94.2 (3) |
C12—C13—C14—C19 | 90.4 (4) | C22—C23—C24—C29 | 129.3 (3) |
C12—C13—C14—C15 | −94.3 (4) | C22—C23—C24—C25 | −55.7 (4) |
C19—C14—C15—C16 | 1.1 (6) | C29—C24—C25—C26 | −0.5 (4) |
C13—C14—C15—C16 | −174.4 (4) | C23—C24—C25—C26 | −175.60 (19) |
C14—C15—C16—C17 | 0.6 (8) | C24—C25—C26—C27 | 1.6 (3) |
C15—C16—C17—C18 | −1.5 (9) | C25—C26—C27—C28 | −1.4 (6) |
C16—C17—C18—C19 | 0.8 (9) | C26—C27—C28—C29 | 0.0 (8) |
C17—C18—C19—C14 | 0.8 (8) | C25—C24—C29—C28 | −0.9 (6) |
C15—C14—C19—C18 | −1.8 (6) | C23—C24—C29—C28 | 174.2 (4) |
C13—C14—C19—C18 | 173.6 (4) | C27—C28—C29—C24 | 1.1 (7) |
D—H···A | D—H | H···A | D···A | D—H···A |
O13—H13···O1Ai | 0.82 | 1.80 | 2.615 (4) | 178 |
O14—H14···O12ii | 0.82 | 1.94 | 2.684 (3) | 150 |
O23—H23···O2Aiii | 0.82 | 1.86 | 2.684 (4) | 178 |
O24—H24···O22iv | 0.82 | 1.87 | 2.668 (4) | 164 |
O1B—H1B···O12iii | 1.22 (7) | 1.27 (7) | 2.473 (4) | 170 (6) |
N11—H11A···O11 | 0.89 | 1.82 | 2.709 (4) | 173 |
N11—H11B···O1Bv | 0.89 | 2.10 | 2.944 (4) | 157 |
N11—H11C···O21vi | 0.89 | 2.13 | 2.806 (4) | 132 |
N11—H11C···O23vii | 0.89 | 2.50 | 3.142 (4) | 129 |
O2B—H2B···O22i | 1.21 (6) | 1.28 (6) | 2.497 (4) | 177 (6) |
N21—H21A···O21 | 0.89 | 1.86 | 2.708 (4) | 159 |
N21—H21B···O11viii | 0.89 | 1.92 | 2.771 (4) | 160 |
N21—H21C···O2Bix | 0.89 | 2.38 | 3.167 (4) | 147 |
N21—H21C···O13x | 0.89 | 2.47 | 2.934 (4) | 113 |
Symmetry codes: (i) x, y+1, z; (ii) x, −y+1, z+1/2; (iii) x, y−1, z; (iv) x, −y, z−1/2; (v) x, −y, z+1/2; (vi) x−1, y, z; (vii) x−1, −y, z+1/2; (viii) x+1, y, z; (ix) x, −y+1, z−1/2; (x) x+1, −y+1, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C9H12NO2+·H2PO4− |
Mr | 263.18 |
Crystal system, space group | Monoclinic, Pc |
Temperature (K) | 293 |
a, b, c (Å) | 13.899 (7), 9.956 (8), 9.051 (2) |
β (°) | 108.726 (8) |
V (Å3) | 1186.1 (12) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.25 |
Crystal size (mm) | 0.6 × 0.33 × 0.13 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.918, 0.967 |
No. of measured, independent and observed (I > 2σ) reflections | 2235, 2235, 2078 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.074, 1.07 |
No. of reflections | 2235 |
No. of parameters | 317 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.29 |
Absolute structure | [Flack, 1983] |
Absolute structure parameter | −0.03 (10) |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 1999), SHELXL97.
P1—O11 | 1.483 (3) | P2—O24 | 1.556 (3) |
P1—O12 | 1.518 (2) | P2—O23 | 1.572 (3) |
P1—O13 | 1.552 (3) | O1A—C11 | 1.224 (4) |
P1—O14 | 1.562 (3) | O1B—C11 | 1.293 (4) |
P2—O21 | 1.488 (3) | O2A—C21 | 1.226 (4) |
P2—O22 | 1.523 (2) | O2B—C21 | 1.287 (4) |
O1A—C11—C12—N11 | 1.3 (4) | O2A—C21—C22—N21 | 21.0 (4) |
N11—C12—C13—C14 | 62.5 (4) | N21—C22—C23—C24 | 145.7 (3) |
C12—C13—C14—C19 | 90.4 (4) | C22—C23—C24—C29 | 129.3 (3) |
C12—C13—C14—C15 | −94.3 (4) | C22—C23—C24—C25 | −55.7 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
O13—H13···O1Ai | 0.82 | 1.80 | 2.615 (4) | 178 |
O14—H14···O12ii | 0.82 | 1.94 | 2.684 (3) | 150 |
O23—H23···O2Aiii | 0.82 | 1.86 | 2.684 (4) | 178 |
O24—H24···O22iv | 0.82 | 1.87 | 2.668 (4) | 164 |
O1B—H1B···O12iii | 1.22 (7) | 1.27 (7) | 2.473 (4) | 170 (6) |
N11—H11A···O11 | 0.89 | 1.82 | 2.709 (4) | 173 |
N11—H11B···O1Bv | 0.89 | 2.10 | 2.944 (4) | 157 |
N11—H11C···O21vi | 0.89 | 2.13 | 2.806 (4) | 132 |
N11—H11C···O23vii | 0.89 | 2.50 | 3.142 (4) | 129 |
O2B—H2B···O22i | 1.21 (6) | 1.28 (6) | 2.497 (4) | 177 (6) |
N21—H21A···O21 | 0.89 | 1.86 | 2.708 (4) | 159 |
N21—H21B···O11viii | 0.89 | 1.92 | 2.771 (4) | 160 |
N21—H21C···O2Bix | 0.89 | 2.38 | 3.167 (4) | 147 |
N21—H21C···O13x | 0.89 | 2.47 | 2.934 (4) | 113 |
Symmetry codes: (i) x, y+1, z; (ii) x, −y+1, z+1/2; (iii) x, y−1, z; (iv) x, −y, z−1/2; (v) x, −y, z+1/2; (vi) x−1, y, z; (vii) x−1, −y, z+1/2; (viii) x+1, y, z; (ix) x, −y+1, z−1/2; (x) x+1, −y+1, z−1/2. |
The crystal structures of L-phenylalanine hydrochloride (Gurskaya & Vainshtein, 1963; Al-Karaghouli & Koetzle, 1975), L-phenylalanine L-phenylalaninium formate (Gorbitz & Etter, 1992), bis(L-phenylalanine) sulfate monohydrate (Nagashima et al., 1992), L-phenylalanine L-phenylalaninium perchlorate (Srinivasan & Rajaram, 1997), bis(DL-phenylalaninium)sulfate monohydrate (Srinivasan et al., 2001b) and L-Phenylalanine–nitric acid (2/1) (Srinivasan et al., 2001c) have been reported. In the present study, the conformation and hydrogen bonding of DL-phenylalanine in the presence of orthophosphoric acid was undertaken.
The title compound (I) crystallized in an unusual, but not uncommon, non-centrosymmetric space group, Pc. However, racemates with more than one molecule in the asymmetric unit are found to grow in non-centrosymmetric, non-polar space groups (Dalhus & Gorbitz, 2000). The asymmetric unit contains two crystallographically independent phenylalaninium residues (A and B) and dihydrogen phosphate anions (I and II). The two phenylalaninium and phosphate residues are related by a pseudo-inversion centre at about (1/2, 1/4, 1/4). The deviation from the pseudo-inversion centre is less for the phosphate anions and the backbone of the amino-acid, but more for the branched side chain. An attempt to look for higher symmetry using LEPAGE (Spek, 1999) yielded a C-centred orthorhombic lattice, possibly in the space group Cmm2, with a = 9.051, b = 26.327 and c = 9.956 Å with a transformation a' = -c; b' = -(2 a + c) and c' = b. However Rint was 0.61 and hence no attempt was made to solve the structure in the orthorhombic system.
The conformation angles ψ1 for residues A and B are 1.3 (4) and 21.0 (4)°, respectively, (see Table 1). The branched-side-chain conformation angle χ1 is in gauche I form [62.5 (4)°] for residue A, while for residue B, it is in nearly trans form [145.7 (3)°]. The torsion angles χ21 and χ22 for residue A [90.4 (4) and -94.3 (4)°], indicating a folded conformation, while those for residue B [129.3 (4)° and -55.7 (4)°] indicate a distorted folded conformation. The difference in the conformation angle for the two residues and the unusual less favoured χ1 conformation for residue B may be due to the large deviation from the pseudo-inversion centre.
The phosphate anions have similar geometry. However the distances of the H atom from the oxygen atoms in each ion [H1B—O12 1.27 (7) and H2B—O22 1.28 (6) Å] are longer than the expected O—H distance, and the P—O distances [P1—O12 1.518 (2) and P2—O22 1.523 (3) Å] are in between expected single- and double-bonded P—O distances [1.55 and 1.49 Å; Blessing et al., 1988].
Both phosphate anions play a vital role in forming hydrogen bonds with both phenylalaninium residues and stabilizing the structure (Table 2). Each phosphate anion forms a strong hydrogen bond with a phenylalaninium residue (O1B—H1B···O12 and O2B—H2B···O22). The O—H and H···O distances [1.22 (7) and 1.27 (7) Å for A, 1.21 (6) and 1.28 (6) Å for B] are nearly the same. Precise neutron diffraction measurements at various temperatures have revealed two inversion-related maleate residues connected by a short hydrogen bond with disordered H atoms about a pseudo-centrosymmetric site in potassium hydrogen dichloromaleate (Olovsson et al., 2001). The C—O distances are also very similar to those in the title compound. Hence, in the title compound, these hydrogen bonds may be termed symmetric hydrogen bonds or asymmetric hydrogen bonds with flip-flop disorder (Jeffrey & Saenger, 1991). For both phosphate anions, a strong O—H···O intermolecular hydrogen bond connects two symmetry-related phosphate anions. Besides these, the O atoms (O13 and O23) of the phosphate anions form strong hydrogen bonds with the carboxyl-O atoms O1A and O2A of the two phenylalaninium residues. A bifurcated hydrogen bond is observed in the phenylalaninium residue A [amino-N atom with O atoms O21 and O23 of phosphate anion (II)], while a similar bifurcated hydrogen bond occurs in phenylalaninium residue B [amino-N atom with O atom of carboxyl group (zigzag Z2 glide-related head-to-tail sequence] and oxygen atom O13 of phosphate anion (I)]. In the phenylalaninium residue A, a head-to-tail Z2 sequence is engaged, since N11—H11B···O1B connects two glide-related amino acids (Vijayan, 1988). The packing arrangement leads to the formation of a hydrophilic zone along x = 0. The aggregation of the hydrophilic zone is in a layer parallel to (010) and the hydrophobic zone at x = 1/2 is sandwiched between two such layers at x = 0 and x = 1 (Fig. 2), as in bis(D-phenylglycinium) sulfate monohydrate (Srinivasan et al., 2001a) and L-phenylalanine–nitric acid (2/1) (Srinivasan et al., 2001c).