Potassium (4-methyl-2-oxo-2H-chromen-7-yl­oxy)sulfate

In the title compound, K⁺·C₁₀H₇O₆S⁻, the sulfate S atom is located in the plane defined by the rest of the anion. This uncommon geometry is accompanied by the existence of a bifurcated three-centered intra­molecular C—H...O inter­action involving two of the sulfate O atoms. The combination of intra- and inter­molecular contacts gives rise to R₄⁵(24) rings and folded layers parallel to (010), in which one of the sulfate O atoms and the carbonyl O atom act as acceptors. The stabilization of the crystal structure along the b axis comes from the coordination of the anions to the potassium cations and is assisted by π–π stacking inter­actions between layers.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.056
• wR factor = 0.105
• Data-to-parameter ratio = 12.2

checkCIF/PLATON results

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Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.12 Ratio

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell refinement: CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXL97.

Potassium (4-methyl-2-oxo-2H-chromen-7-yloxy)sulfate

Crystal data

K^+·C10H7O6S^−	F(000) = 1200
Mr = 294.32	Dx = 1.814 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 12730 reflections
a = 14.230 (3) Å	θ = 4.5–28.1°
b = 6.945 (2) Å	µ = 0.70 mm^−1
c = 21.808 (9) Å	T = 100 K
V = 2155 (2) Å^3	Needle, colourless
Z = 8	0.54 × 0.05 × 0.05 mm

Data collection

Oxford Diffraction Xcalibur diffractometer	1995 independent reflections
Radiation source: fine-focus sealed tube	1831 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.065
ω and φ scans	θmax = 25.5°, θmin = 4.5°
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2003)	h = −17→17
Tmin = 0.775, Tmax = 0.968	k = −8→8
26394 measured reflections	l = −26→21

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.105	H-atom parameters constrained
S = 1.24	w = 1/[σ^2(Fo^2) + (0.0439P)^2 + 1.5833P] where P = (Fo^2 + 2Fc^2)/3
1995 reflections	(Δ/σ)max < 0.001
164 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.40 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
K	0.10343 (5)	0.98449 (10)	0.22853 (3)	0.0159 (2)
S	0.14720 (5)	0.52461 (11)	0.27773 (3)	0.0124 (2)
O1	0.33150 (14)	0.2518 (3)	0.52120 (9)	0.0135 (5)
O2	0.39052 (16)	0.1537 (3)	0.60928 (9)	0.0187 (5)
O7	0.22491 (14)	0.4603 (3)	0.32862 (9)	0.0152 (5)
O8	0.20804 (15)	0.5960 (3)	0.23011 (9)	0.0162 (5)
O9	0.09486 (15)	0.3538 (3)	0.26236 (9)	0.0185 (5)
O10	0.08913 (15)	0.6714 (3)	0.30568 (9)	0.0172 (5)
C2	0.3198 (2)	0.1860 (4)	0.58064 (13)	0.0132 (7)
C3	0.2252 (2)	0.1589 (4)	0.60227 (14)	0.0154 (7)
C4	0.1489 (2)	0.1936 (4)	0.56704 (14)	0.0142 (7)
C5	0.0905 (2)	0.3016 (5)	0.46400 (14)	0.0160 (7)
C6	0.1075 (2)	0.3641 (4)	0.40512 (14)	0.0153 (7)
C7	0.2000 (2)	0.3922 (4)	0.38676 (13)	0.0141 (7)
C8	0.2748 (2)	0.3551 (4)	0.42546 (13)	0.0127 (7)
C9	0.2545 (2)	0.2898 (4)	0.48407 (13)	0.0128 (6)
C10	0.1632 (2)	0.2613 (4)	0.50518 (13)	0.0128 (7)
C11	0.0518 (2)	0.1572 (5)	0.59033 (14)	0.0178 (7)
H3	0.2160	0.1148	0.6431	0.019*
H5	0.0273	0.2853	0.4771	0.019*
H6	0.0570	0.3876	0.3776	0.018*
H8	0.3379	0.3737	0.4124	0.015*
H11A	0.0547	0.1197	0.6336	0.027*
H11B	0.0228	0.0533	0.5665	0.027*
H11C	0.0141	0.2746	0.5862	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
K	0.0157 (4)	0.0158 (4)	0.0161 (4)	−0.0009 (3)	0.0004 (3)	−0.0010 (3)
S	0.0118 (4)	0.0141 (4)	0.0113 (4)	0.0011 (3)	−0.0010 (3)	0.0004 (3)
O1	0.0097 (11)	0.0175 (11)	0.0132 (10)	0.0014 (9)	−0.0012 (9)	0.0026 (9)
O2	0.0169 (12)	0.0245 (13)	0.0148 (11)	0.0008 (10)	−0.0024 (10)	0.0031 (10)
O7	0.0131 (11)	0.0199 (12)	0.0125 (10)	0.0010 (9)	−0.0006 (9)	0.0017 (9)
O8	0.0142 (11)	0.0204 (12)	0.0139 (11)	0.0016 (10)	0.0012 (9)	0.0004 (9)
O9	0.0165 (13)	0.0187 (13)	0.0202 (12)	−0.0015 (10)	−0.0018 (10)	−0.0013 (9)
O10	0.0173 (12)	0.0177 (12)	0.0165 (11)	0.0021 (10)	0.0000 (9)	0.0010 (9)
C2	0.0158 (17)	0.0119 (16)	0.0119 (15)	−0.0002 (13)	−0.0021 (14)	0.0001 (13)
C3	0.0180 (18)	0.0161 (16)	0.0122 (15)	0.0003 (14)	0.0037 (13)	0.0019 (13)
C4	0.0162 (17)	0.0101 (15)	0.0163 (16)	0.0005 (13)	0.0031 (14)	−0.0034 (12)
C5	0.0137 (17)	0.0156 (16)	0.0188 (17)	0.0013 (13)	0.0030 (13)	−0.0028 (13)
C6	0.0130 (16)	0.0154 (17)	0.0176 (16)	0.0004 (14)	−0.0034 (13)	0.0014 (13)
C7	0.0205 (18)	0.0120 (15)	0.0099 (14)	0.0011 (13)	0.0024 (13)	−0.0015 (13)
C8	0.0112 (16)	0.0112 (15)	0.0158 (15)	−0.0001 (12)	0.0024 (13)	−0.0008 (13)
C9	0.0149 (15)	0.0107 (15)	0.0128 (14)	0.0014 (13)	−0.0032 (13)	−0.0040 (13)
C10	0.0142 (17)	0.0085 (15)	0.0158 (16)	0.0014 (13)	0.0006 (13)	−0.0034 (12)
C11	0.0167 (17)	0.0197 (18)	0.0170 (16)	0.0003 (14)	0.0020 (14)	0.0006 (14)

Geometric parameters (Å, º)

K—O8	3.082 (2)	C2—C3	1.439 (4)
K—O10	2.757 (2)	C3—C4	1.351 (4)
K—O2^i	2.773 (2)	C3—H3	0.95
K—O7^ii	3.280 (2)	C4—C10	1.443 (4)
K—O8^ii	2.792 (2)	C4—C11	1.494 (4)
K—O9^iii	2.672 (2)	C5—C6	1.377 (4)
K—O9^iv	2.971 (2)	C5—C10	1.398 (4)
K—O10^iv	3.122 (2)	C5—H5	0.95
K—K^v	4.6477 (12)	C6—C7	1.390 (4)
S—O7	1.629 (2)	C6—H6	0.95
S—O8	1.440 (2)	C7—C8	1.383 (4)
S—O9	1.440 (2)	C8—C9	1.387 (4)
S—O10	1.447 (2)	C8—H8	0.95
O1—C2	1.385 (3)	C9—C10	1.392 (4)
O1—C9	1.388 (4)	C11—H11A	0.98
O2—C2	1.206 (4)	C11—H11B	0.98
O7—C7	1.399 (3)	C11—H11C	0.98
O7—S—O8	100.23 (12)	C7—O7—K^vii	144.00 (17)
O7—S—O9	106.49 (12)	S—O7—K^vii	92.18 (9)
O7—S—O10	107.08 (12)	S—O8—K^vii	119.41 (11)
O8—S—O9	115.26 (13)	S—O8—K	91.09 (10)
O8—S—O10	113.86 (13)	K^vii—O8—K	134.97 (8)
O9—S—O10	112.52 (13)	S—O9—K^viii	146.24 (13)
C7—O7—S	122.6 (2)	S—O9—K^v	102.95 (11)
O9^iii—K—O10	125.83 (7)	K^viii—O9—K^v	110.80 (7)
O9^iii—K—O2^i	126.34 (7)	S—O10—K	104.86 (11)
O10—K—O2^i	107.56 (7)	S—O10—K^v	96.18 (10)
O9^iii—K—O8^ii	76.95 (7)	K—O10—K^v	104.29 (7)
O10—K—O8^ii	106.38 (7)	O2—C2—O1	116.5 (3)
O2^i—K—O8^ii	94.46 (6)	O2—C2—C3	125.9 (3)
O9^iii—K—O9^iv	103.38 (5)	O1—C2—C3	117.6 (3)
O10—K—O9^iv	69.39 (6)	C4—C3—C2	122.8 (3)
O2^i—K—O9^iv	89.23 (6)	C4—C3—H3	118.6
O8^ii—K—O9^iv	175.14 (6)	C2—C3—H3	118.6
O9^iii—K—O8	149.26 (6)	C3—C4—C10	118.4 (3)
O10—K—O8	48.57 (6)	C3—C4—C11	121.3 (3)
O2^i—K—O8	72.10 (6)	C10—C4—C11	120.2 (3)
O8^ii—K—O8	77.21 (4)	C6—C5—C10	122.1 (3)
O9^iv—K—O8	100.99 (6)	C6—C5—H5	118.9
O9^iii—K—O10^iv	68.09 (6)	C10—C5—H5	118.9
O10—K—O10^iv	114.13 (5)	C5—C6—C7	118.6 (3)
O2^i—K—O10^iv	86.96 (6)	C5—C6—H6	120.7
O8^ii—K—O10^iv	136.95 (7)	C7—C6—H6	120.7
O9^iv—K—O10^iv	46.33 (6)	C8—C7—C6	121.8 (3)
O8—K—O10^iv	142.23 (6)	C8—C7—O7	114.9 (3)
O9^iii—K—O7^ii	84.22 (6)	C6—C7—O7	123.3 (3)
O10—K—O7^ii	66.95 (6)	C7—C8—C9	117.6 (3)
O2^i—K—O7^ii	125.68 (6)	C7—C8—H8	121.2
O8^ii—K—O7^ii	44.81 (6)	C9—C8—H8	121.2
O9^iv—K—O7^ii	130.33 (6)	C8—C9—O1	115.8 (3)
O8—K—O7^ii	65.67 (6)	C8—C9—C10	123.1 (3)
O10^iv—K—O7^ii	146.48 (6)	O1—C9—C10	121.1 (3)
O9^iii—K—K^v	129.25 (5)	C9—C10—C5	116.7 (3)
O10—K—K^v	40.62 (4)	C9—C10—C4	119.2 (3)
O2^i—K—K^v	87.14 (5)	C5—C10—C4	124.1 (3)
O8^ii—K—K^v	144.41 (5)	C4—C11—H11A	109.5
O9^iv—K—K^v	32.50 (4)	C4—C11—H11B	109.5
O8—K—K^v	69.48 (4)	H11A—C11—H11B	109.5
O10^iv—K—K^v	78.63 (5)	C4—C11—H11C	109.5
O7^ii—K—K^v	107.42 (4)	H11A—C11—H11C	109.5
C2—O1—C9	120.9 (2)	H11B—C11—H11C	109.5
C2—O2—K^vi	125.18 (19)
O8—S—O7—C7	175.4 (2)	O7—C7—C8—C9	179.1 (3)
O9—S—O7—C7	−64.2 (2)	C7—C8—C9—O1	179.2 (3)
O10—S—O7—C7	56.4 (2)	C7—C8—C9—C10	−0.2 (4)
S—O7—C7—C6	3.4 (4)	C2—O1—C9—C8	180.0 (3)
S—O7—C7—C8	−176.3 (2)	C2—O1—C9—C10	−0.6 (4)
C9—O1—C2—O2	178.8 (3)	C8—C9—C10—C5	0.1 (4)
C9—O1—C2—C3	0.0 (4)	O1—C9—C10—C5	−179.2 (3)
O2—C2—C3—C4	−178.3 (3)	C8—C9—C10—C4	−179.8 (3)
O1—C2—C3—C4	0.5 (4)	O1—C9—C10—C4	0.9 (4)
C2—C3—C4—C10	−0.2 (5)	C6—C5—C10—C9	0.8 (4)
C2—C3—C4—C11	177.8 (3)	C6—C5—C10—C4	−179.3 (3)
C10—C5—C6—C7	−1.6 (5)	C3—C4—C10—C9	−0.5 (4)
C5—C6—C7—C8	1.4 (5)	C11—C4—C10—C9	−178.5 (3)
C5—C6—C7—O7	−178.2 (3)	C3—C4—C10—C5	179.7 (3)
C6—C7—C8—C9	−0.6 (4)	C11—C4—C10—C5	1.6 (5)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O8^ix	0.95	2.40	3.312 (4)	161
C6—H6···O2^x	0.95	2.40	3.106 (4)	131
C6—H6···O9	0.95	2.58	3.119 (4)	116
C6—H6···O10	0.95	2.56	3.054 (4)	113

Symmetry codes: (ix) x, −y+1/2, z+1/2; (x) x−1/2, −y+1/2, −z+1.