Charge-density distribution in hydrogen methylphosphonates of calcium and lithium

Two new crystal structures, calcium bis(hydrogen methylphos­phonate), Ca(CH₃PO₃H)₂, and lithium hydrogen methylphos­phonate, Li(CH₃PO₃H), have been obtained, and the experimental and theoretical charge densities, as well as their topological properties, are reported. Both compounds display layered structures. Each hydrogen methylphosphonate anion coordinates three metal cations in the calcium compound and four in the lithium one. Weak polarization of oxygen lone pairs is observed, with lithium showing somewhat stronger polarization strength than calcium. The reported topological properties from the density functional theory (DFT) and X-ray approach are consistent with each other. In both structures the P-O bonds have a significant share of ionic character. The hyperconjugation effects within the phosphonate group are quenched upon coordination of the metal cations.

Computing details

For both compounds, data collection: CrysAlis CCD, Oxford Diffraction Ltd., Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET) (compiled Jan 5 2010,16:28:46); cell refinement: CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET) (compiled Jan 5 2010,16:28:46); data reduction: CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET) (compiled Jan 5 2010,16:28:46); program(s) used to refine structure: Volkov et al., (2006); molecular graphics: Volkov et al., (2006); software used to prepare material for publication: Volkov et al., (2006).

Figures

(merca1)

Crystal data

C2H8CaO6P2	F(000) = 472
Mr = 230.10	Dx = 1.939 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.7107 Å
a = 20.403 (13) Å	Cell parameters from 23644 reflections
b = 5.601 (2) Å	θ = 4.7–75.7°
c = 7.274 (6) Å	µ = 1.18 mm^−1
β = 108.48 (8)°	T = 85 K
V = 788.4 (9) Å^3	Plate, colourless
Z = 4	0.48 × 0.35 × 0.06 mm

Data collection

Xcalibur, Onyx diffractometer	8103 independent reflections
Radiation source: fine-focus sealed tube	7052 reflections with > 3σ(I)
Graphite monochromator	Rint = 0.034
Detector resolution: 8.1956 pixels mm^-1	θmax = 75.7°, θmin = 4.7°
ω and π scans	h = −42→55
Absorption correction: analytical CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.33.32 (release 27-01-2009 CrysAlis171 .NET) (compiled Jan 27 2009,14:17:37) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −14→15
Tmin = 0.667, Tmax = 0.941	l = −19→12
86583 measured reflections

Refinement

Refinement on F	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)] = 0.012	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.013	H-atom parameters constrained
S = 1.46	w1 = 1/[s^2(Fo)]
4683 reflections	(Δ/σ)max < 0.001
174 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
CA	0.5	0.63148 (2)	0.75	0.007
P	0.398714 (3)	0.175982 (9)	0.552366 (7)	0.006
O(1)	0.384805 (14)	0.28858 (4)	0.73543 (3)	0.012
O(2)	0.454444 (9)	0.32516 (3)	0.51219 (3)	0.009
O(3)	0.415304 (9)	−0.08814 (3)	0.57913 (2)	0.008
C	0.317876 (11)	0.22111 (4)	0.36616 (3)	0.011
H(1)	0.401222	0.207098	0.86594	0.027
H(2)	0.302093	0.406229	0.371456	0.034
H(3)	0.323745	0.175292	0.226578	0.033
H(4)	0.278267	0.109237	0.393638	0.037
DUM1	0.5000	0.0400	0.7500	0	0

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
CA	0.00965 (2)	0.00515 (4)	0.00528 (5)	0	0.00257 (3)	0
P	0.007951 (17)	0.004638 (16)	0.005466 (18)	−0.000073 (10)	0.002267 (13)	0.000044 (10)
O(1)	0.01999 (9)	0.00950 (6)	0.00723 (6)	0.00456 (6)	0.00590 (6)	0.00029 (5)
O(2)	0.00976 (5)	0.00752 (4)	0.00922 (5)	−0.00205 (4)	0.00357 (4)	−0.00002 (4)
O(3)	0.01210 (5)	0.00522 (4)	0.00847 (5)	0.00084 (3)	0.00372 (4)	0.00043 (3)
C	0.00920 (6)	0.01209 (7)	0.00988 (7)	0.00078 (5)	0.00158 (5)	0.00007 (5)
H(1)	0.043056	0.024709	0.013725	0.009418	0.010645	0.00424
H(2)	0.034585	0.023067	0.037739	0.012466	0.002198	−0.00127
H(3)	0.032644	0.046922	0.016207	0.005089	0.005196	−0.005527
H(4)	0.020456	0.044803	0.043048	−0.009785	0.007733	0.009548

Geometric parameters (Å, º)

CA—O(2)^i	2.3841 (2)	P—C	1.7896 (2)
CA—O(3)^ii	2.3740 (2)	O(1)—H(1)	1.0100
P—O(1)	1.5783 (2)	C—H(2)	1.0900
P—O(2)	1.5123 (2)	C—H(3)	1.0900
P—O(3)	1.5163 (2)	C—H(4)	1.0900
O(2)^i—CA—O(2)^iii	168.305 (10)	P—O(1)—H(1)	121.179
O(2)^i—CA—O(3)^ii	85.265 (6)	CA^i—O(2)—P	135.933 (10)
O(2)^i—CA—O(3)^iv	87.005 (6)	CA^v—O(3)—P	143.946 (10)
O(3)^ii—CA—O(3)^iv	97.166 (9)	P—C—H(2)	108.622
O(1)—P—O(2)	106.831 (12)	P—C—H(3)	108.950
O(1)—P—O(3)	111.964 (11)	P—C—H(4)	109.817
O(1)—P—C	102.303 (13)	H(2)—C—H(3)	112.20
O(2)—P—O(3)	114.388 (10)	H(2)—C—H(4)	107.207
O(2)—P—C	110.165 (11)	H(3)—C—H(4)	110.012
O(3)—P—C	110.467 (10)
O(2)—P—O(1)—H(1)	−106.73	CA^i—O(2)—P—O(1)	−166.064 (18)
O(3)—P—O(1)—H(1)	19.23	CA^i—O(2)—P—O(3)	69.450 (14)
C—P—O(1)—H(1)	137.51	CA^i—O(2)—P—C	−55.684 (14)
O(1)—P—C—H(2)	48.615	CA^vi—O(2)—P—O(1)	−166.064 (18)
O(1)—P—C—H(3)	171.110	CA^vi—O(2)—P—O(3)	69.450 (14)
O(1)—P—C—H(4)	−68.338	CA^vi—O(2)—P—C	−55.684 (14)
O(2)—P—C—H(2)	−64.701	CA^v—O(3)—P—O(1)	−70.292 (18)
O(2)—P—C—H(3)	57.794	CA^v—O(3)—P—O(2)	51.420 (16)
O(2)—P—C—H(4)	178.346	CA^v—O(3)—P—C	176.39 (2)
O(3)—P—C—H(2)	167.956	CA^vii—O(3)—P—O(1)	−70.292 (18)
O(3)—P—C—H(3)	−69.548	CA^vii—O(3)—P—O(2)	51.420 (16)
O(3)—P—C—H(4)	51.004)	CA^vii—O(3)—P—C	176.39 (2)

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

(mpli)

Crystal data

CH4LiO3P	F(000) = 208
Mr = 101.95	Dx = 1.701 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.7107 Å
a = 9.267 (5) Å	Cell parameters from 20862 reflections
b = 4.604 (2) Å	θ = 4.9–75.8°
c = 9.384 (3) Å	µ = 0.53 mm^−1
β = 96.12 (4)°	T = 85 K
V = 398.1 (3) Å^3	Plate, colourless
Z = 4	0.46 × 0.34 × 0.06 mm

Data collection

Xcalibur, Onyx diffractometer	8219 independent reflections
Radiation source: fine-focus sealed tube	6325 reflections with > 3σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 8.1956 pixels mm^-1	θmax = 75.8°, θmin = 4.9°
ω and π scans	h = −22→24
Absorption correction: analytical CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET) (compiled Jan 5 2010,16:28:46) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −8→12
Tmin = 0.832, Tmax = 0.970	l = −25→20
30520 measured reflections

Refinement

Refinement on F	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)] = 0.015	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.015	H-atom parameters constrained
S = 1.47	w1 = 1/[s^2(Fo)]
4610 reflections	(Δ/σ)max = 0.037
169 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
P	0.702565 (6)	0.100820 (11)	0.925332 (5)	0.006
O(1)	0.75694 (3)	−0.11478 (5)	1.05052 (2)	0.011
O(3)	0.640403 (19)	0.36966 (3)	0.990615 (18)	0.009
O(2)	0.596249 (19)	−0.05190 (4)	0.817823 (18)	0.009
C	0.86195 (3)	0.20363 (6)	0.84614 (3)	0.014
LI	0.50745 (6)	0.10053 (10)	0.64061 (5)	0.011
H(2)	0.908304	0.016652	0.796195	0.04
H(3)	0.827395	0.364978	0.764563	0.036
H(4)	0.942114	0.282895	0.930629	0.037
H(1)	0.723309	−0.3097	1.010264	0.024

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P	0.007178 (17)	0.005580 (16)	0.006224 (16)	0.000047 (11)	−0.000020 (11)	0.000142 (12)
O(1)	0.01440 (7)	0.00730 (5)	0.00980 (6)	−0.00054 (5)	−0.00388 (5)	0.00160 (5)
O(3)	0.01101 (5)	0.00643 (4)	0.00896 (5)	0.00075 (4)	0.00099 (4)	−0.00068 (4)
O(2)	0.01048 (5)	0.00781 (4)	0.00739 (4)	−0.00103 (4)	−0.00151 (4)	0.00004 (4)
C	0.00988 (7)	0.01817 (9)	0.01472 (8)	−0.00118 (6)	0.00338 (6)	0.00179 (7)
LI	0.01262 (17)	0.01022 (16)	0.00910 (15)	0.00056 (13)	−0.00011 (13)	0.00009 (12)
H(2)	0.034295	0.038506	0.05078	0.005678	0.020632	−0.01019
H(3)	0.031855	0.043255	0.034146	−0.000435	0.006529	0.019282
H(4)	0.022728	0.053814	0.033546	−0.012673	−0.00312	−0.002958
H(1)	0.033559	0.012588	0.024381	−0.001819	−0.006757	0.000199

Geometric parameters (Å, º)

P—O(1)	1.5789 (2)	O(1)—H(1)	1.0100
P—O(3)	1.5213 (2)	C—H(2)	1.0900
P—O(2)	1.5070 (2)	C—H(3)	1.0900
P—C	1.7866 (2)	C—H(4)	1.0900
O(1)—P—O(3)	108.443 (11)	P—C—H(2)	110.535
O(1)—P—O(2)	109.804 (11)	P—C—H(3)	106.180
O(1)—P—C	105.286 (13)	P—C—H(4)	108.401
O(3)—P—O(2)	113.615 (10)	H(2)—C—H(3)	109.64
O(3)—P—C	108.499 (12)	H(2)—C—H(4)	107.93
O(2)—P—C	110.831 (12)	H(3)—C—H(4)	114.15
P—O(1)—H(1)	102.652
O(3)—P—O(1)—H(1)	138.129	O(3)—P—C—H(2)	−178.82
O(2)—P—O(1)—H(1)	13.455	O(3)—P—C—H(3)	−59.983
O(1)—P—C—H(2)	65.25	O(3)—P—C—H(4)	63.071
O(1)—P—C—H(3)	−175.91	O(2)—P—C—H(2)	−53.421
O(1)—P—C—H(4)	−52.860	O(2)—P—C—H(3)	65.416
C—P—O(1)—H(1)	−105.902	O(2)—P—C—H(4)	−171.53