Synthesis and crystal structure of calcium hydrogen phosphite, CaHPO₃

The title compound is built up from CaO₇ polyhedra and HPO₃ pseudo tetra­hedra sharing corners and edges to generate a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](P-O) = 0.001 Å
• R factor = 0.014
• wR factor = 0.037
• Data-to-parameter ratio = 13.1

checkCIF/PLATON results

No syntax errors found



Datablock: I


Alert level B
PLAT417_ALERT_2_B Short Inter D-H..H-D       H1       ..H1       .       2.08 Ang.
                                              1-y,1-x,1/2-z  =      8_665 Check

Author Response: this is a typical H...H contact distance.

Alert level C
PLAT430_ALERT_2_C Short Inter D...A Contact  O1       ..O2       .       2.89 Ang.
                                          1/2+x,1/2-y,1/4-z  =      6_555 Check

Author Response: this is a normal "touching contact" distance for nominal oxide anions in an inorgaic structure

PLAT430_ALERT_2_C Short Inter D...A Contact  O2       ..O3       .       2.88 Ang.
                                                  -1+y,x,-z  =      7_455 Check

Author Response: this is a normal "touching contact" distance for nominal oxide anions in an inorgaic structure

Alert level G
PLAT913_ALERT_3_G Missing # of Very Strong Reflections in FCF ....          1 Note
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......     Please Check

   0 ALERT level A = Most likely a serious problem - resolve or explain
   1 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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Computing details

Data collection: CrysAlis PRO (Rigaku, 2017); cell refinement: CrysAlis PRO (Rigaku, 2017); data reduction: CrysAlis PRO (Rigaku, 2017); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

Calcium hydrogen phosphite

Crystal data

CaHPO3	Dx = 2.763 Mg m^−3
Mr = 120.06	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P43212	Cell parameters from 6820 reflections
a = 6.67496 (6) Å	θ = 3.0–27.5°
c = 12.9542 (2) Å	µ = 2.49 mm^−1
V = 577.18 (1) Å^3	T = 100 K
Z = 8	Prism, colourless
F(000) = 480	0.20 × 0.11 × 0.10 mm

Data collection

Rigaku AFC12 CCD diffractometer	668 independent reflections
Confocal mirrors, HF Varimax monochromator	667 reflections with I > 2σ(I)
Detector resolution: 28.5714 pixels mm^-1	Rint = 0.030
ω scans	θmax = 27.5°, θmin = 3.4°
Absorption correction: multi-scan (CrysAlis PRO; Rigaku, 2017)	h = −8→8
Tmin = 0.811, Tmax = 1.000	k = −8→8
7615 measured reflections	l = −16→16

Refinement

Refinement on F^2	All H-atom parameters refined
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0206P)^2 + 0.1946P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.014	(Δ/σ)max < 0.001
wR(F^2) = 0.037	Δρmax = 0.28 e Å^−3
S = 1.26	Δρmin = −0.38 e Å^−3
668 reflections	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
51 parameters	Extinction coefficient: 0.056 (4)
0 restraints	Absolute structure: Flack x determined using 230 quotients [(I^+)-(I^-)]/[(I^+)+(I^-)] (Parsons et al., 2013)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.006 (16)
Hydrogen site location: difference Fourier map

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq
Ca1	0.31831 (5)	0.10351 (5)	0.11917 (3)	0.00616 (14)
P1	0.29735 (7)	0.57084 (7)	0.10542 (3)	0.00575 (15)
H1	0.220 (4)	0.625 (4)	0.1928 (19)	0.013 (6)*
O1	0.4785 (2)	0.43959 (19)	0.12612 (11)	0.0080 (3)
O2	0.1356 (2)	0.4401 (2)	0.05361 (10)	0.0078 (3)
O3	0.3393 (2)	0.76729 (19)	0.05029 (9)	0.0081 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ca1	0.0058 (2)	0.00652 (19)	0.0061 (2)	−0.00010 (12)	0.00026 (13)	0.00022 (12)
P1	0.0057 (2)	0.0056 (2)	0.0059 (2)	−0.00049 (15)	−0.00009 (17)	0.00001 (15)
O1	0.0070 (6)	0.0078 (5)	0.0092 (5)	0.0004 (5)	−0.0005 (5)	0.0000 (5)
O2	0.0070 (6)	0.0086 (6)	0.0079 (5)	−0.0012 (5)	−0.0002 (5)	−0.0001 (5)
O3	0.0100 (6)	0.0067 (6)	0.0076 (6)	−0.0003 (5)	−0.0002 (5)	0.0005 (5)

Geometric parameters (Å, º)

Ca1—O1^i	2.2870 (13)	P1—O3	1.5192 (13)
Ca1—O2^ii	2.3600 (14)	P1—O2	1.5423 (13)
Ca1—O2^iii	2.3907 (13)	P1—H1	1.30 (2)
Ca1—O3^iv	2.4014 (12)	O1—Ca1^ii	2.2869 (13)
Ca1—O3^v	2.4192 (13)	O2—Ca1^i	2.3600 (14)
Ca1—O1	2.4869 (14)	O2—Ca1^iii	2.3907 (13)
Ca1—O2	2.6938 (14)	O3—Ca1^vi	2.4014 (12)
P1—O1	1.5173 (13)	O3—Ca1^vii	2.4192 (13)
O1^i—Ca1—O2^ii	149.66 (5)	O1—Ca1—O2	56.90 (4)
O1^i—Ca1—O2^iii	111.93 (5)	O1—P1—O3	115.75 (8)
O2^ii—Ca1—O2^iii	95.90 (4)	O1—P1—O2	107.96 (8)
O1^i—Ca1—O3^iv	81.56 (5)	O3—P1—O2	114.40 (8)
O2^ii—Ca1—O3^iv	74.49 (4)	O1—P1—H1	109.0 (12)
O2^iii—Ca1—O3^iv	161.56 (5)	O3—P1—H1	104.1 (11)
O1^i—Ca1—O3^v	87.17 (5)	O2—P1—H1	104.9 (11)
O2^ii—Ca1—O3^v	89.43 (5)	P1—O1—Ca1^ii	150.21 (8)
O2^iii—Ca1—O3^v	73.62 (4)	P1—O1—Ca1	99.88 (7)
O3^iv—Ca1—O3^v	121.07 (5)	Ca1^ii—O1—Ca1	108.30 (5)
O1^i—Ca1—O1	122.62 (4)	P1—O2—Ca1^i	120.90 (7)
O2^ii—Ca1—O1	73.14 (4)	P1—O2—Ca1^iii	131.49 (8)
O2^iii—Ca1—O1	78.87 (4)	Ca1^i—O2—Ca1^iii	105.94 (5)
O3^iv—Ca1—O1	83.24 (5)	P1—O2—Ca1	91.01 (6)
O3^v—Ca1—O1	145.62 (5)	Ca1^i—O2—Ca1	99.78 (5)
O1^i—Ca1—O2	70.38 (4)	Ca1^iii—O2—Ca1	92.99 (5)
O2^ii—Ca1—O2	130.00 (4)	P1—O3—Ca1^vi	127.66 (7)
O2^iii—Ca1—O2	77.54 (5)	P1—O3—Ca1^vii	128.07 (7)
O3^iv—Ca1—O2	96.39 (4)	Ca1^vi—O3—Ca1^vii	103.77 (5)
O3^v—Ca1—O2	133.13 (5)
O3—P1—O1—Ca1^ii	11.3 (2)	O3—P1—O2—Ca1^iii	53.71 (12)
O2—P1—O1—Ca1^ii	140.99 (16)	O1—P1—O2—Ca1	18.17 (8)
O3—P1—O1—Ca1	−149.73 (6)	O3—P1—O2—Ca1	148.60 (6)
O2—P1—O1—Ca1	−20.05 (8)	O1—P1—O3—Ca1^vi	78.88 (11)
O1—P1—O2—Ca1^i	120.21 (8)	O2—P1—O3—Ca1^vi	−47.62 (13)
O3—P1—O2—Ca1^i	−109.36 (9)	O1—P1—O3—Ca1^vii	−110.53 (10)
O1—P1—O2—Ca1^iii	−76.72 (11)	O2—P1—O3—Ca1^vii	122.98 (9)

Symmetry codes: (i) x−1/2, −y+1/2, −z+1/4; (ii) x+1/2, −y+1/2, −z+1/4; (iii) y, x, −z; (iv) y−1/2, −x+1/2, z+1/4; (v) x, y−1, z; (vi) −y+1/2, x+1/2, z−1/4; (vii) x, y+1, z.