Dipotassium hydrogencarbonate fluoride monohydrate.

Single crystals of the title compound, K2(HCO3)F·H2O, were obtained as a secondary product after performing flux synthesis experiments aimed at the preparation of potassium rare earth silicates. The basic building unit of the structure is an [(HCO3)(H2O)F](2-) zigzag chain running parallel to [001]. Both types of anions as well as the water mol-ecules reside on mirror planes perpendicular to [010] at y = 0.25 and y = 0.75, respectively. Linkage between the different constituents of the chains is provided by O-H⋯O and O-H⋯F hydrogen bonding. The K(+) cations are located between the chains and are coordinated by two F and five O atoms in form of a distorted monocapped trigonal prism.

Related literature

For phase equilibria in the system (Na,K)–(CO3,HCO3,F)–H2O, see: Soliev & Nizimov (2009 ▶, 2011 ▶, 2012 ▶). For structure determinations of phases in the system K–(CO3,HCO3,F)–H2O, see: Arlt & Jansen (1990 ▶); Beurskens & Jeffrey (1964 ▶); Broch et al. (1929 ▶); Cirpus & Adam (1995 ▶); Hill & Miller (1927 ▶); Preisinger et al. (1994 ▶); Skakle et al. (2001 ▶); Thomas et al. (1974 ▶). For phases related to the title compound, see: Dinnebier & Jansen (2008 ▶); Margraf et al. (2003 ▶); Pritchard & Islam (2003 ▶). For bond-valence parameters, see: Brown & Altermatt (1985 ▶). For details of the synthetic procedure, see: Vidican et al. (2003 ▶).

Experimental

Crystal data

K2(HCO3)F·H2O

M = 176.24

Monoclinic,

a = 5.4228 (4) Å

b = 7.1572 (6) Å

c = 7.4539 (7) Å

β = 105.121 (9)°

V = 279.28 (4) Å3

Z = 2

Mo Kα radiation

μ = 1.64 mm−1

T = 173 K

0.18 × 0.18 × 0.06 mm

Data collection

Agilent Xcalibur (Ruby, Gemini ultra) diffractometer

Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T min = 0.946, T max = 1

1008 measured reflections

551 independent reflections

475 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.028

wR(F 2) = 0.075

S = 1.05

551 reflections

52 parameters

4 restraints

All H-atom parameters refined

Δρmax = 0.31 e Å−3

Δρmin = −0.31 e Å−3

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS for Windows (Dowty, 2011 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶);.

Click here for additional data file.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813006041/wm2728sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813006041/wm2728Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

K2(HCO3)F·H2O	F(000) = 176
Mr = 176.24	standard setting
Monoclinic, P21/m	Dx = 2.096 Mg m−3
Hall symbol: -P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 5.4228 (4) Å	Cell parameters from 538 reflections
b = 7.1572 (6) Å	θ = 2.8–28.5°
c = 7.4539 (7) Å	µ = 1.64 mm−1
β = 105.121 (9)°	T = 173 K
V = 279.28 (4) Å3	Plate, colourless
Z = 2	0.18 × 0.18 × 0.06 mm

Agilent Xcalibur (Ruby, Gemini ultra) diffractometer	551 independent reflections
Radiation source: Enhance (Mo) X-ray Source	475 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 10.3575 pixels mm-1	θmax = 25.3°, θmin = 2.8°
ω scans	h = −5→6
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −8→7
Tmin = 0.946, Tmax = 1	l = −8→7
1008 measured reflections

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.075	All H-atom parameters refined
S = 1.05	w = 1/[σ2(Fo2) + (0.0329P)2] where P = (Fo2 + 2Fc2)/3
551 reflections	(Δ/σ)max < 0.001
52 parameters	Δρmax = 0.31 e Å−3
4 restraints	Δρmin = −0.31 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
K	0.79241 (9)	0.50302 (5)	0.23529 (7)	0.0170 (2)
F	0.4966 (3)	0.75	−0.0096 (2)	0.0164 (5)
O4	1.1731 (4)	0.25	0.2263 (3)	0.0231 (6)
H41	1.265 (6)	0.25	0.336 (2)	0.028*
H42	1.280 (5)	0.25	0.163 (4)	0.028*
O1	0.4539 (4)	0.25	0.5871 (3)	0.0212 (6)
O2	0.8344 (4)	0.25	0.5210 (3)	0.0186 (5)
O3	0.8172 (4)	0.25	0.8112 (3)	0.0182 (5)
H3	0.708 (5)	0.25	0.868 (4)	0.022*
C	0.6926 (6)	0.25	0.6289 (4)	0.0150 (7)

	U11	U22	U33	U12	U13	U23
K	0.0181 (3)	0.0121 (3)	0.0193 (4)	−0.00008 (16)	0.0021 (3)	−0.00045 (18)
F	0.0177 (10)	0.0170 (10)	0.0140 (10)	0	0.0034 (8)	0
O4	0.0165 (12)	0.0340 (14)	0.0198 (13)	0	0.0065 (9)	0
O1	0.0168 (12)	0.0290 (12)	0.0179 (12)	0	0.0046 (9)	0
O2	0.0198 (11)	0.0205 (11)	0.0171 (12)	0	0.0079 (9)	0
O3	0.0153 (11)	0.0262 (12)	0.0136 (12)	0	0.0049 (9)	0
C	0.0195 (17)	0.0082 (14)	0.0168 (17)	0	0.0037 (14)	0

K—Fi	2.6816 (11)	O4—H42	0.838 (17)
K—F	2.7389 (11)	O1—C	1.250 (3)
K—O1ii	2.7541 (17)	O1—Kvii	2.7541 (17)
K—O2	2.7590 (17)	O1—Kii	2.7541 (17)
K—O4	2.7599 (17)	O2—C	1.250 (4)
K—O3iii	2.8477 (18)	O2—Kvi	2.7590 (17)
K—O2iii	2.9330 (16)	O2—Kiii	2.9330 (16)
F—Ki	2.6816 (11)	O2—Kviii	2.9330 (16)
F—Kiv	2.6816 (11)	O3—C	1.350 (4)
F—Kv	2.7389 (11)	O3—Kiii	2.8477 (17)
O4—Kvi	2.7599 (17)	O3—Kviii	2.8477 (17)
O4—H41	0.838 (17)	O3—H3	0.814 (18)
Fi—K—F	82.698 (16)	Kvi—O4—H41	103.7 (16)
Fi—K—O1ii	117.24 (5)	K—O4—H41	103.7 (16)
F—K—O1ii	68.47 (5)	Kvi—O4—H42	130.3 (11)
Fi—K—O2	87.60 (4)	K—O4—H42	130.3 (11)
F—K—O2	148.65 (6)	H41—O4—H42	103 (2)
O1ii—K—O2	90.17 (5)	C—O1—Kvii	118.72 (13)
Fi—K—O4	81.96 (5)	C—O1—Kii	118.72 (13)
F—K—O4	135.97 (6)	Kvii—O1—Kii	79.86 (6)
O1ii—K—O4	153.18 (6)	C—O2—Kvi	123.79 (11)
O2—K—O4	71.12 (6)	C—O2—K	123.79 (11)
Fi—K—O3iii	132.40 (6)	Kvi—O2—K	82.05 (6)
F—K—O3iii	80.97 (4)	C—O2—Kiii	92.42 (14)
O1ii—K—O3iii	97.43 (4)	Kvi—O2—Kiii	141.11 (8)
O2—K—O3iii	125.94 (6)	K—O2—Kiii	89.27 (3)
O4—K—O3iii	79.62 (5)	C—O2—Kviii	92.42 (14)
Fi—K—O2iii	172.55 (4)	Kvi—O2—Kviii	89.27 (3)
F—K—O2iii	102.32 (3)	K—O2—Kviii	141.11 (8)
O1ii—K—O2iii	70.01 (5)	Kiii—O2—Kviii	74.13 (5)
O2—K—O2iii	90.73 (3)	C—O3—Kiii	94.04 (14)
O4—K—O2iii	90.63 (5)	C—O3—Kviii	94.04 (14)
O3iii—K—O2iii	44.48 (6)	Kiii—O3—Kviii	76.74 (6)
Ki—F—Kiv	84.96 (4)	C—O3—H3	106 (2)
Ki—F—Kv	177.20 (5)	Kiii—O3—H3	136.9 (10)
Kiv—F—Kv	97.302 (16)	Kviii—O3—H3	136.9 (10)
Ki—F—K	97.302 (16)	O1—C—O2	127.6 (3)
Kiv—F—K	177.20 (5)	O1—C—O3	117.7 (3)
Kv—F—K	80.39 (4)	O2—C—O3	114.7 (2)
Kvi—O4—K	82.01 (6)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H41···O1ix	0.84 (2)	1.89 (2)	2.723 (3)	176 (3)
O4—H42···Fx	0.84 (2)	1.87 (2)	2.707 (3)	177 (3)
O3—H3···Fii	0.81 (2)	1.72 (2)	2.529 (3)	174 (4)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H41⋯O1i	0.84 (2)	1.89 (2)	2.723 (3)	176 (3)
O4—H42⋯Fii	0.84 (2)	1.87 (2)	2.707 (3)	177 (3)
O3—H3⋯Fiii	0.81 (2)	1.72 (2)	2.529 (3)	174 (4)

Symmetry codes: (i) ; (ii) ; (iii) .