DL-Valinium di­hydrogen phosphate

In the title compound, C₅H₁₂O₂N⁺·H₂PO₄⁻, the valinium and phosphate ions are held together by a strong O—H...O hydrogen bond. The valinium residue has gauche II conform­ation. The phosphate anion links the amino acids, extending as a chain running along the b axis.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.028
• wR factor = 0.079
• Data-to-parameter ratio = 12.6

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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Computing details

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.

DL-valinium dihydrogen phosphate

Crystal data

C5H12NO2^+·H2PO4^−	F(000) = 456
Mr = 215.14	Dx = 1.515 Mg m^−3 Dm = 1.516 Mg m^−3 Dm measured by flotation in a mixture of carbon tetrachloride and xylene
Monoclinic, P21/a	Mo Kα radiation, λ = 0.71073 Å
a = 9.201 (1) Å	Cell parameters from 25 reflections
b = 10.0035 (6) Å	θ = 11.5–14.0°
c = 11.195 (2) Å	µ = 0.29 mm^−1
β = 113.73 (1)°	T = 293 K
V = 943.3 (2) Å^3	Needles, colorless
Z = 4	0.5 × 0.2 × 0.2 mm

Data collection

Enraf-Nonius sealed tube diffractometer	1359 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.008
Graphite monochromator	θmax = 25.0°, θmin = 2.0°
ω–2θ scans	h = 0→10
Absorption correction: ψ scan (North et al., 1968)	k = 0→11
Tmin = 0.905, Tmax = 0.939	l = −13→12
1766 measured reflections	3 standard reflections every 60 min
1652 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.028	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.079	w = 1/[σ^2(Fo^2) + (0.0408P)^2 + 0.3465P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1652 reflections	Δρmax = 0.23 e Å^−3
131 parameters	Δρmin = −0.28 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0108 (16)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
P1	0.50142 (6)	0.21693 (5)	−0.15572 (4)	0.02454 (17)
O1	0.50143 (16)	0.34340 (13)	−0.08673 (13)	0.0334 (3)
O2	0.34035 (15)	0.14883 (13)	−0.21665 (13)	0.0314 (3)
H1	0.603 (3)	0.035 (3)	−0.087 (3)	0.067 (9)*
O3	0.5538 (2)	0.23870 (16)	−0.27073 (14)	0.0384 (4)
H2	0.638 (4)	0.264 (3)	−0.247 (3)	0.068 (10)*
O4	0.62407 (16)	0.11788 (15)	−0.05733 (14)	0.0358 (4)
O1A	0.44063 (15)	0.13241 (13)	0.14947 (14)	0.0359 (4)
O1B	0.70155 (15)	0.09357 (13)	0.24357 (14)	0.0332 (3)
H1B	0.673 (4)	−0.021 (4)	0.235 (3)	0.108 (12)*
C11	0.5786 (2)	0.17016 (19)	0.20103 (17)	0.0261 (4)
C12	0.6187 (2)	0.31798 (18)	0.22195 (18)	0.0261 (4)
H12	0.6960	0.3378	0.1845	0.039*
N11	0.47164 (19)	0.39498 (15)	0.14681 (15)	0.0289 (4)
H11A	0.4953	0.4813	0.1478	0.043*
H11B	0.4022	0.3838	0.1830	0.043*
H11C	0.4295	0.3658	0.0648	0.043*
C13	0.6953 (2)	0.3539 (2)	0.36759 (18)	0.0298 (4)
H13	0.7869	0.2944	0.4075	0.045*
C14	0.7595 (3)	0.4956 (2)	0.3899 (2)	0.0544 (7)
H14A	0.8241	0.5097	0.3417	0.082*
H14B	0.8224	0.5089	0.4812	0.082*
H14C	0.6727	0.5577	0.3608	0.082*
C15	0.5870 (3)	0.3282 (3)	0.4374 (2)	0.0468 (6)
H15A	0.5500	0.2375	0.4227	0.070*
H15B	0.4979	0.3879	0.4044	0.070*
H15C	0.6445	0.3430	0.5293	0.070*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0274 (3)	0.0183 (3)	0.0289 (3)	−0.0012 (2)	0.0125 (2)	−0.00231 (19)
O1	0.0471 (8)	0.0199 (7)	0.0368 (7)	−0.0016 (6)	0.0207 (6)	−0.0033 (6)
O2	0.0256 (7)	0.0220 (7)	0.0454 (8)	0.0004 (5)	0.0131 (6)	−0.0023 (6)
O3	0.0363 (9)	0.0467 (9)	0.0367 (8)	−0.0046 (7)	0.0194 (7)	−0.0037 (7)
O4	0.0340 (8)	0.0253 (8)	0.0390 (8)	0.0006 (6)	0.0053 (6)	−0.0020 (6)
O1A	0.0262 (7)	0.0216 (7)	0.0587 (9)	−0.0013 (6)	0.0157 (7)	−0.0049 (6)
O1B	0.0252 (7)	0.0222 (7)	0.0477 (8)	0.0003 (6)	0.0101 (6)	−0.0015 (6)
C11	0.0276 (10)	0.0229 (10)	0.0301 (9)	−0.0021 (8)	0.0138 (8)	−0.0021 (8)
C12	0.0267 (9)	0.0206 (9)	0.0340 (10)	−0.0009 (7)	0.0152 (8)	0.0001 (7)
N11	0.0359 (9)	0.0194 (8)	0.0298 (8)	−0.0026 (7)	0.0116 (7)	−0.0005 (6)
C13	0.0263 (10)	0.0258 (10)	0.0328 (10)	0.0002 (8)	0.0071 (8)	−0.0010 (8)
C14	0.0654 (16)	0.0359 (13)	0.0500 (13)	−0.0166 (12)	0.0109 (12)	−0.0104 (11)
C15	0.0424 (13)	0.0650 (16)	0.0325 (11)	−0.0008 (11)	0.0145 (10)	−0.0001 (11)

Geometric parameters (Å, º)

P1—O1	1.4822 (14)	N11—H11A	0.8900
P1—O2	1.5205 (13)	N11—H11B	0.8900
P1—O3	1.5612 (15)	N11—H11C	0.8900
P1—O4	1.5710 (14)	C13—C15	1.515 (3)
O3—H2	0.75 (3)	C13—C14	1.517 (3)
O4—H1	0.88 (3)	C13—H13	0.9800
O1A—C11	1.224 (2)	C14—H14A	0.9600
O1B—C11	1.289 (2)	C14—H14B	0.9600
O1B—H1B	1.17 (4)	C14—H14C	0.9600
C11—C12	1.519 (3)	C15—H15A	0.9600
C12—N11	1.488 (2)	C15—H15B	0.9600
C12—C13	1.536 (3)	C15—H15C	0.9600
C12—H12	0.9800
O1—P1—O2	114.32 (8)	C12—N11—H11C	109.5
O1—P1—O3	112.04 (8)	H11A—N11—H11C	109.5
O2—P1—O3	105.14 (8)	H11B—N11—H11C	109.5
O1—P1—O4	108.88 (8)	C15—C13—C14	111.51 (19)
O2—P1—O4	109.11 (8)	C15—C13—C12	113.05 (16)
O3—P1—O4	107.05 (9)	C14—C13—C12	112.04 (17)
P1—O3—H2	111 (2)	C15—C13—H13	106.6
P1—O4—H1	109.7 (18)	C14—C13—H13	106.6
C11—O1B—H1B	114.7 (17)	C12—C13—H13	106.6
O1A—C11—O1B	125.50 (17)	C13—C14—H14A	109.5
O1A—C11—C12	120.97 (16)	C13—C14—H14B	109.5
O1B—C11—C12	113.52 (15)	H14A—C14—H14B	109.5
N11—C12—C11	107.90 (14)	C13—C14—H14C	109.5
N11—C12—C13	113.80 (15)	H14A—C14—H14C	109.5
C11—C12—C13	111.75 (15)	H14B—C14—H14C	109.5
N11—C12—H12	107.7	C13—C15—H15A	109.5
C11—C12—H12	107.7	C13—C15—H15B	109.5
C13—C12—H12	107.7	H15A—C15—H15B	109.5
C12—N11—H11A	109.5	C13—C15—H15C	109.5
C12—N11—H11B	109.5	H15A—C15—H15C	109.5
H11A—N11—H11B	109.5	H15B—C15—H15C	109.5
O1A—C11—C12—N11	−11.5 (2)	N11—C12—C13—C15	60.4 (2)
O1B—C11—C12—N11	169.24 (14)	C11—C12—C13—C15	−62.1 (2)
O1A—C11—C12—C13	114.34 (19)	N11—C12—C13—C14	−66.6 (2)
O1B—C11—C12—C13	−64.9 (2)	C11—C12—C13—C14	170.86 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H1···O1A^i	0.88 (3)	1.80 (3)	2.6820 (19)	180 (3)
O3—H2···O2^ii	0.75 (3)	1.96 (3)	2.702 (2)	168 (3)
O1B—H1B···O2^i	1.17 (4)	1.29 (4)	2.4548 (18)	170 (3)
N11—H11A···O1^iii	0.89	1.89	2.738 (2)	160
N11—H11B···O1B^iv	0.89	2.22	3.087 (2)	164
N11—H11C···O1	0.89	2.07	2.785 (2)	137
N11—H11C···O4^iv	0.89	2.59	3.096 (2)	117

Symmetry codes: (i) −x+1, −y, −z; (ii) x+1/2, −y+1/2, z; (iii) −x+1, −y+1, −z; (iv) x−1/2, −y+1/2, z.