L-Valinium hydrogenphosphite

The crystal structure of the title compound, C₅H₁₂NO₂⁺·H₂PO₃^-, can be described as a stacking of L-val­in­ium and ­hydrogenphosphite ions. The stability of such an arrangement results from a network of hydrogen bonds, which maintain the cohesion of the organic-inorganic layers in the crystal. The asymmetric unit contains two valinium residues and two ­hydrogenphosphite ions, one of which is disordered.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• Disorder in solvent or counterion
• R factor = 0.038
• wR factor = 0.100
• Data-to-parameter ratio = 10.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           26.36
         From the CIF: _reflns_number_total               3629
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         3839
         Completeness (_total/calc)             94.53%
          Alert C: < 95% complete

PLAT_302  Alert C Anion/Solvent Disorder .......................       4.00 Perc.

PLAT_420  Alert C D-H Without Acceptor       P(1B)  -  >H(5C)             ?

PLAT_420  Alert C D-H Without Acceptor       P(1A)  -   H(13A)            ?

PLAT_707  Alert C D...A   Calc  2.6285(19), Rep    2.626(2), Dev.      1.32 Sigma
                     O5A  -O2A     1.555   1.555


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 5 Alert Level C = Please check

---

S1. Comment

In recent years, organic–inorganic hybrid materials have attracted considerable attention as preferable materials in non-linear optics (NLO), such as second harmonic generation (SHG) and optical bistability, owing to their large optical non-linearities (Masse & Zyss, 1991; Zaccaro et al., 1998; Mosset et al., 1996). The very high SGH and NLO properties make these hybrid materials highly attractive for application to frequency doubling of the light produced by semiconductor lasers (Kondo et al., 1988). Bis(L-valinium) monohydrogenphosphite is a result of our systematic investigation on organic–inorganic hybrid materials resulting from interaction between various phosphoric acids and amino acids. The structure can be described as mixed layers built with organic cations (C₅H₁₂NO₂⁺) and phosphite anions (H₂PO₃⁻), both layers developing parallel to the [ac] plane. The main feature of this stacking is the presence of strong hydrogen bonds, similar to those observed in other ionic compounds (Pecaut & Bagieu-Beucher, 1993; Averbuch-Pouchot, 1993). In a layer, the distance between the H₂PO₃⁻ groups is significantly longer [P—P = 4.904 (3) A°] because the (HPO₃H)_n chain is more stretched. These entities form through strong hydrogen bonds infinite chains of (HPO₃H)_n parallel to the b axis. Phosphite groups are hydrogen bonded to the organic cation in two ways, first via the carboxylic acid group [O5A—H4A···O2A = 2.628 (2) Å] and second via the ammonium groups [N1A—H10A···O3B = 2.783 (2) Å, N1A—H11A···O4B = 2.837 (2) Å and N1A—H12A···O3B = 2.802 (2) Å; N1B—H10B···O3A = 2.845 (2) Å, N1B—H11B···O3A =2.724 (2) Å, and N1B—H12B···O4A = 2.852 (2) Å]. We did not observe any hydrogen bonds either between organic entities or between inorganic anions. The valinium residues adopt a gauche II conformation and their mean backbone conformation angles Ψ₁(O2—C1—C2—N1) and Ψ₂(O1—C1—C2—N1) [−11.7 (2)/168.8 (1) and −12.1 (2)/167.9 (1)° for cations A and B respectively] (Table 1)] are similar to those observed in DL-valinium dihydrogenphosphate (Ravikumar et al., 2002).

S2. Experimental

Crystals of bis L-valinium monohydrogenphosphite were prepared by slow evaporation at room temperature of an aqueous solution of L-valine and phosphorous acid in a stoichiometric ratio. After six months, crystals appeared as colourless prisms.

S3. Refinement

One of the monohydrogenphosphite anions is disordered. The disorder can be described as a rotation of this anion around the axis which bisects the O4B—P1B—O3B angle. The refined model corresponds to a disordered distribution between OH and H, with occupation factors of 0.85 and 0.15. Some of the H atoms were found in difference Fourier maps and were refined with isotropic displacement parameters. The hydroxyl H atoms were constrained using an AFIX 147 instruction. The H atoms of the disordered phosphite group were constrained.

Computing details

Data collection: KappaCCD Reference Manual (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELX97 (Sheldrick, 1998); program(s) used to refine structure: SHELX97; molecular graphics: ORTEP2 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. An ORTEP-3 (Farrugia, 1997) view with the atomic labelling scheme showing the asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

(I)

Crystal data

2C5H12NO2^+·2H2PO3^−	F(000) = 848
Mr = 398.29	Dx = 1.408 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 12190 reflections
a = 16.3590 (3) Å	θ = 1.4–26.4°
b = 6.2540 (2) Å	µ = 0.28 mm^−1
c = 19.4560 (3) Å	T = 293 K
β = 109.238 (1)°	Prism, colorless
V = 1879.37 (8) Å^3	0.60 × 0.40 × 0.35 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	3205 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.065
Graphite monochromator	θmax = 26.4°, θmin = 1.4°
ϕ scans	h = −20→20
12190 measured reflections	k = −7→7
3629 independent reflections	l = −23→23

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.100	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0425P)^2 + 0.5313P] where P = (Fo^2 + 2Fc^2)/3
3629 reflections	(Δ/σ)max = 0.034
335 parameters	Δρmax = 0.25 e Å^−3
6 restraints	Δρmin = −0.24 e Å^−3

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	Occ. (<1)
N1B	0.94569 (9)	0.7688 (2)	0.94100 (8)	0.0334 (3)
O2A	1.11810 (8)	0.56334 (19)	0.75490 (7)	0.0431 (3)
O1A	1.00386 (8)	0.7676 (2)	0.74927 (7)	0.0454 (3)
C1A	1.07410 (10)	0.7242 (2)	0.73555 (8)	0.0317 (3)
N1A	1.18909 (8)	0.8476 (2)	0.69167 (7)	0.0309 (3)
C2A	1.09959 (10)	0.8950 (2)	0.69071 (8)	0.0312 (3)
C3A	1.03663 (11)	0.9128 (3)	0.61199 (9)	0.0430 (4)
C4A	1.01512 (19)	0.6983 (5)	0.57475 (13)	0.0702 (7)
C5A	0.95530 (16)	1.0358 (5)	0.60860 (15)	0.0726 (7)
O4A	0.96181 (8)	0.50055 (19)	0.82765 (6)	0.0411 (3)
O4B	0.72263 (8)	1.39736 (19)	1.08334 (6)	0.0410 (3)
O3A	0.98837 (8)	0.16535 (19)	0.90586 (6)	0.0419 (3)
O3B	0.73116 (8)	1.06769 (19)	1.16091 (6)	0.0448 (3)
O5A	1.08408 (9)	0.2533 (2)	0.83260 (9)	0.0556 (4)
H14A	1.0949	0.3619	0.8136	0.083*
P1B	0.74461 (3)	1.16508 (7)	1.09540 (2)	0.03368 (14)
P1A	0.99145 (2)	0.27053 (6)	0.83830 (2)	0.03187 (14)
O1B	0.76483 (8)	0.6622 (2)	1.00204 (7)	0.0446 (3)
O2B	0.87394 (8)	0.4572 (2)	0.99502 (8)	0.0510 (3)
C2B	0.85797 (9)	0.8103 (2)	0.94514 (8)	0.0308 (3)
C1B	0.83356 (10)	0.6222 (3)	0.98358 (8)	0.0336 (3)
C4B	0.75966 (15)	0.6568 (5)	0.82464 (12)	0.0634 (6)
C3B	0.79278 (11)	0.8582 (3)	0.86876 (9)	0.0432 (4)
C5B	0.71834 (15)	0.9975 (4)	0.87349 (14)	0.0641 (6)
O5B	0.83698 (11)	1.1263 (3)	1.09437 (11)	0.0635 (5)	0.85
H14B	0.8521	1.2276	1.0746	0.095*	0.85
O13B	0.7050 (7)	1.0432 (19)	1.0270 (4)	0.051 (3)	0.15
H13B	0.7339	0.9358	1.0273	0.076*	0.15
H13C	0.8265 (14)	1.18 (2)	1.124 (6)	0.030*	0.15
H5C	0.6973 (16)	1.060 (5)	1.0410 (13)	0.030*	0.85
H2A	1.1035 (11)	1.020 (3)	0.7162 (10)	0.035 (4)*
H2B	0.8663 (10)	0.936 (3)	0.9752 (10)	0.032 (4)*
H12A	1.1954 (12)	0.720 (4)	0.6803 (10)	0.041 (5)*
H12B	0.9469 (13)	0.656 (4)	0.9113 (12)	0.048 (5)*
H10A	1.2256 (12)	0.862 (3)	0.7356 (11)	0.038 (5)*
H11B	0.9650 (12)	0.890 (4)	0.9284 (11)	0.048 (5)*
H3A	1.0678 (14)	0.999 (3)	0.5870 (12)	0.058 (6)*
H11A	1.2041 (12)	0.934 (3)	0.6633 (11)	0.041 (5)*
H9B	0.6776 (17)	0.920 (5)	0.8938 (15)	0.084 (8)*
H10B	0.9826 (13)	0.741 (3)	0.9845 (12)	0.047 (5)*
H3B	0.8266 (13)	0.942 (4)	0.8457 (12)	0.057 (6)*
H7A	0.9212 (18)	0.946 (5)	0.6325 (16)	0.090 (9)*
H5A	1.0689 (19)	0.633 (5)	0.5752 (15)	0.087 (9)*
H6A	0.9782 (16)	0.718 (4)	0.5227 (15)	0.076 (7)*
H8A	0.9165 (19)	1.059 (5)	0.5602 (18)	0.098 (9)*
H7B	0.6794 (19)	1.049 (5)	0.8248 (18)	0.104 (10)*
H8B	0.7389 (17)	1.139 (5)	0.8987 (15)	0.083 (8)*
H4A	0.986 (2)	0.614 (6)	0.598 (2)	0.111 (12)*
H6B	0.8068 (17)	0.560 (4)	0.8229 (14)	0.077 (8)*
H1B	0.7575 (17)	0.571 (4)	1.0233 (15)	0.071 (8)*
H5B	0.7236 (17)	0.679 (5)	0.7726 (16)	0.081 (8)*
H4B	0.722 (2)	0.583 (5)	0.8469 (17)	0.097 (9)*
H1A	0.9971 (17)	0.670 (5)	0.7759 (15)	0.086 (9)*
H9A	0.9753 (19)	1.195 (6)	0.6354 (17)	0.102 (10)*
H13A	0.9486 (8)	0.163 (2)	0.7816 (7)	0.014 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1B	0.0359 (7)	0.0342 (7)	0.0326 (7)	−0.0042 (5)	0.0145 (6)	0.0037 (5)
O2A	0.0483 (6)	0.0390 (7)	0.0524 (7)	0.0071 (5)	0.0306 (5)	0.0152 (5)
O1A	0.0489 (7)	0.0456 (7)	0.0541 (7)	0.0097 (5)	0.0339 (6)	0.0164 (6)
C1A	0.0383 (8)	0.0311 (8)	0.0293 (7)	−0.0005 (6)	0.0162 (6)	0.0016 (5)
N1A	0.0375 (7)	0.0275 (7)	0.0305 (7)	−0.0019 (5)	0.0150 (6)	0.0022 (5)
C2A	0.0380 (8)	0.0278 (8)	0.0328 (7)	−0.0006 (6)	0.0184 (6)	0.0024 (6)
C3A	0.0393 (8)	0.0548 (11)	0.0367 (8)	0.0016 (7)	0.0150 (7)	0.0122 (7)
C4A	0.0668 (15)	0.0852 (18)	0.0446 (12)	−0.0021 (13)	−0.0005 (11)	−0.0144 (11)
C5A	0.0557 (12)	0.092 (2)	0.0697 (15)	0.0274 (13)	0.0204 (11)	0.0304 (14)
O4A	0.0490 (6)	0.0375 (6)	0.0487 (6)	0.0093 (5)	0.0319 (5)	0.0098 (5)
O4B	0.0554 (7)	0.0346 (6)	0.0457 (6)	0.0059 (5)	0.0339 (5)	0.0053 (5)
O3A	0.0547 (7)	0.0383 (7)	0.0379 (6)	−0.0057 (5)	0.0224 (5)	0.0072 (5)
O3B	0.0631 (7)	0.0380 (6)	0.0356 (6)	−0.0061 (5)	0.0193 (5)	0.0026 (5)
O5A	0.0533 (8)	0.0433 (8)	0.0846 (10)	0.0144 (6)	0.0424 (7)	0.0235 (7)
P1B	0.0430 (2)	0.0306 (2)	0.0323 (2)	0.00354 (15)	0.01885 (17)	−0.00120 (14)
P1A	0.0378 (2)	0.0308 (2)	0.0311 (2)	−0.00076 (15)	0.01700 (16)	0.00251 (14)
O1B	0.0504 (7)	0.0431 (7)	0.0516 (7)	0.0042 (5)	0.0324 (6)	0.0152 (5)
O2B	0.0539 (7)	0.0369 (7)	0.0719 (9)	0.0045 (6)	0.0340 (6)	0.0142 (6)
C2B	0.0355 (7)	0.0310 (8)	0.0290 (7)	−0.0025 (6)	0.0147 (6)	0.0015 (6)
C1B	0.0380 (8)	0.0338 (8)	0.0310 (7)	−0.0033 (6)	0.0142 (6)	0.0025 (6)
C4B	0.0445 (11)	0.0944 (18)	0.0460 (11)	0.0004 (11)	0.0078 (9)	−0.0207 (11)
C3B	0.0388 (8)	0.0588 (11)	0.0327 (8)	0.0000 (8)	0.0129 (6)	0.0126 (7)
C5B	0.0583 (12)	0.0656 (15)	0.0650 (13)	0.0185 (11)	0.0156 (10)	0.0215 (11)
O5B	0.0532 (10)	0.0722 (13)	0.0755 (12)	0.0187 (9)	0.0351 (8)	0.0009 (9)
O13B	0.083 (7)	0.046 (5)	0.025 (4)	0.014 (4)	0.021 (4)	−0.012 (3)

Geometric parameters (Å, º)

N1B—C2B	1.4863 (19)	O3B—P1B	1.4930 (12)
O2A—C1A	1.2218 (19)	O5A—P1A	1.5591 (12)
O1A—C1A	1.2913 (18)	P1B—O13B	1.484 (6)
C1A—C2A	1.522 (2)	P1B—O5B	1.5369 (16)
N1A—C2A	1.4879 (19)	O1B—C1B	1.3121 (19)
C2A—C3A	1.542 (2)	O2B—C1B	1.206 (2)
C3A—C4A	1.510 (3)	C2B—C1B	1.517 (2)
C3A—C5A	1.519 (3)	C2B—C3B	1.546 (2)
O4A—P1A	1.5104 (12)	C4B—C3B	1.520 (3)
O4B—P1B	1.4964 (12)	C3B—C5B	1.525 (3)
O3A—P1A	1.4855 (11)
O2A—C1A—O1A	125.70 (14)	O4B—P1B—O5B	109.73 (10)
O2A—C1A—C2A	120.64 (13)	O3A—P1A—O4A	116.11 (7)
O1A—C1A—C2A	113.66 (13)	O3A—P1A—O5A	110.45 (7)
N1A—C2A—C1A	107.89 (12)	O4A—P1A—O5A	109.37 (7)
N1A—C2A—C3A	111.05 (12)	N1B—C2B—C1B	107.88 (13)
C1A—C2A—C3A	113.60 (13)	N1B—C2B—C3B	110.75 (12)
C4A—C3A—C5A	111.5 (2)	C1B—C2B—C3B	114.44 (13)
C4A—C3A—C2A	112.72 (16)	O2B—C1B—O1B	125.42 (14)
C5A—C3A—C2A	111.60 (16)	O2B—C1B—C2B	122.52 (13)
O13B—P1B—O3B	114.3 (5)	O1B—C1B—C2B	112.07 (14)
O13B—P1B—O4B	110.3 (5)	C4B—C3B—C5B	111.37 (18)
O3B—P1B—O4B	115.76 (7)	C4B—C3B—C2B	112.77 (17)
O13B—P1B—O5B	92.8 (4)	C5B—C3B—C2B	111.37 (16)
O3B—P1B—O5B	111.65 (10)
O2A—C1A—C2A—N1A	−11.7 (2)	N1B—C2B—C1B—O2B	−12.1 (2)
O1A—C1A—C2A—N1A	168.78 (13)	N1B—C2B—C1B—O1B	167.89 (13)
N1A—C2A—C3A—C4A	74.0 (2)	N1B—C2B—C3B—C4B	80.56 (19)
N1A—C2A—C3A—C5A	−159.58 (18)	N1B—C2B—C3B—C5B	−153.39 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1A—H1A···O4A	0.83 (3)	1.69 (3)	2.506 (2)	167 (3)
O1B—H1B···O4B^i	0.74 (3)	1.82 (3)	2.538 (2)	165 (3)
N1A—H10A···O3B^ii	0.87 (2)	1.95 (2)	2.783 (2)	159 (2)
N1B—H11B···O3A^iii	0.89 (2)	1.85 (2)	2.724 (2)	170 (2)
N1A—H11A···O4B^iv	0.87 (2)	1.98 (2)	2.837 (2)	169 (2)
N1B—H10B···O3A^v	0.88 (2)	2.11 (2)	2.845 (2)	141 (2)
N1A—H12A···O3B^vi	0.84 (2)	1.97 (2)	2.802 (2)	170 (2)
N1B—H12B···O4A	0.91 (2)	1.98 (2)	2.852 (2)	159 (2)
O5A—H14A···O2A	0.82	1.82	2.626 (2)	167
O5B—H14B···O2B^iii	0.82	2.23	3.026 (2)	165
O13B—H13B···O1B	0.82	1.90	2.681 (11)	160

Symmetry codes: (i) x, y−1, z; (ii) −x+2, −y+2, −z+2; (iii) x, y+1, z; (iv) x+1/2, −y+5/2, z−1/2; (v) −x+2, −y+1, −z+2; (vi) x+1/2, −y+3/2, z−1/2.