Poly[diaquatris(μ6-4,6-dioxo-1,4,5,6-tetra-hydro-1,3,5-triazine-2-carboxylato)tripotassium].

The asymmetric unit of the title compound, [K3(C4H2N3O4)3(H2O)2] n , contains two potassium cations (one in general position, one located on a twofold rotation axis), one and a half oxonate anions (the other half generated by twofold symmetry) and one water mol-ecule. As a result of the twofold symmetry, one H atom of the symmetric anion is statistically occupied. Both potassium cations are surrounded by eight oxygen atoms in the form of distorted polyhedra. Adjacent cations are inter-connected by oxygen bridges, generating layers parallel to (100). The aromatic ring system of the oxonate anions link these layers into a network structure. The crystal packing is stabilized by N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, three of which are bifurcated. In addition, inter-molecular π-π stacking inter-actions exist between neighboring aromatic rings with a centroid-centroid distance of 3.241 (2) Å.

Related literature

For applications of metal-organic coordination materials, see: Yaghi et al. (2003 ▶); Janiak (2003 ▶); Lalart et al. (1981 ▶); Mori et al. (2005 ▶, 2006 ▶); Dybtsev et al. (2004 ▶). For studies and properties of oxonic acid, see: Lalart et al. (1981 ▶); Pancheva (1977 ▶); Cihak et al. (1968 ▶). For comparable inter­atomic distances in related structures, see: Sheldrick & Poonia (1986 ▶); Cuesta et al. (2003 ▶); Pike (1976 ▶). For π–π stacking inter­actions, see: Janiak (2000 ▶). For a multipolar atom model transfered from the ELMAM2 electron density database, see: Domagała et al. (2012 ▶). For fractal analysis of the residual electron density, see: Meindl & Henn (2008 ▶).

Experimental

Crystal data

[K3(C4H2N3O4)3(H2O)2]

M = 621.55

Monoclinic,

a = 7.0284 (2) Å

b = 7.6736 (2) Å

c = 19.2668 (4) Å

β = 99.355 (2)°

V = 1025.30 (5) Å3

Z = 2

Mo Kα radiation

μ = 0.77 mm−1

T = 110 K

0.16 × 0.13 × 0.07 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2012 ▶) T min = 0.887, T max = 0.948

34196 measured reflections

2953 independent reflections

2637 reflections with > 2.0σ(I)

R int = 0.038

Refinement

R[F 2 > 2σ(F 2)] = 0.027

wR(F 2) = 0.067

S = 0.93

2953 reflections

190 parameters

14 restraints

Only H-atom coordinates refined

Δρmax = 0.50 e Å−3

Δρmin = −0.36 e Å−3

Data collection: APEX2 (Bruker, 2012 ▶); cell refinement: SAINT (Bruker, 2012 ▶); data reduction: SAINT; program(s) used to solve structure: MoPro (Jelsch et al., 2005 ▶); program(s) used to refine structure: MoPro; molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: MoPro.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814007569/wm5013sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814007569/wm5013Isup2.hkl

CCDC reference: 995461

Additional supporting information: crystallographic information; 3D view; checkCIF report

[K3(C4H2N3O4)3(H2O)2]	Z = 4
Mr = 310.77	F(000) = 628
Monoclinic, P2/c	Dx = 2.013 Mg m−3
Hall symbol: -P 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 7.0284 (2) Å	θ = 2.7–31.0°
b = 7.6736 (2) Å	µ = 0.77 mm−1
c = 19.2668 (4) Å	T = 110 K
β = 99.355 (2)°	Prism, colourless
V = 1025.30 (5) Å3	0.16 × 0.13 × 0.07 mm

Bruker APEXII CCD diffractometer	2953 independent reflections
Radiation source: fine-focus sealed tube	2637 reflections with > 2.0σ(I)
Mirror monochromator	Rint = 0.038
ω scans	θmax = 30.4°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −9→9
Tmin = 0.887, Tmax = 0.948	k = 0→10
34196 measured reflections	l = 0→27

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)] = 0.027	Hydrogen site location: difference Fourier map
wR(F2) = 0.067	Only H-atom coordinates refined
S = 0.93	w = 1/[σ2(Fo2) + (0.04P)2 + 0.5P] where P = (Fo2 + 2Fc2)/3
2953 reflections	(Δ/σ)max = 0.005
190 parameters	Δρmax = 0.50 e Å−3
14 restraints	Δρmin = −0.36 e Å−3

Refinement. Refinement of F2 against reflections. The threshold expression of F2 > σ(F2) is used for calculating R-factors(gt) 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	Occ. (<1)
K1_1	1.08353 (4)	0.48766 (4)	0.412084 (14)	0.01245 (4)
K2_2	1	0.11136 (5)	0.25000	0.01989 (6)
O8_3	1.45467 (13)	−0.43420 (12)	0.40758 (5)	0.01477 (13)
O9_3	1.76362 (13)	−0.39318 (12)	0.45621 (5)	0.01479 (13)
O10_3	1.88936 (13)	0.20722 (12)	0.47622 (5)	0.01638 (13)
O11_3	1.25768 (13)	0.18741 (12)	0.37279 (5)	0.01419 (13)
N1_3	1.41234 (15)	−0.07072 (14)	0.40074 (5)	0.00943 (13)
N3_3	1.73874 (15)	−0.05408 (13)	0.45147 (5)	0.00987 (14)
N5_3	1.57096 (15)	0.20278 (14)	0.42495 (5)	0.00984 (14)
C2_3	1.57561 (17)	−0.14319 (16)	0.42608 (6)	0.00913 (16)
C4_3	1.74401 (17)	0.12642 (15)	0.45228 (6)	0.01027 (16)
C6_3	1.40543 (17)	0.11050 (16)	0.39764 (6)	0.00935 (15)
C7_3	1.59851 (17)	−0.34380 (16)	0.43032 (6)	0.00942 (16)
H3_3	1.8583 (19)	−0.121 (2)	0.4729 (8)	0.01180*
H5_3	1.559 (3)	0.3346 (13)	0.4231 (9)	0.01177*
N12_4	0.66429 (16)	0.65016 (15)	0.27330 (6)	0.01528 (15)
N14_4	0.50000	0.3866 (2)	0.25000	0.0163 (2)
C13_4	0.50000	0.7302 (2)	0.25000	0.0151 (3)
C15_4	0.6706 (2)	0.46992 (18)	0.27535 (7)	0.01688 (19)
C5_4	0.50000	0.9310 (3)	0.25000	0.0207 (3)
O16_4	0.34766 (19)	1.00230 (15)	0.22125 (6)	0.0303 (2)
O17_4	0.81757 (16)	0.38998 (15)	0.29846 (6)	0.03083 (18)
H14_4	0.50000	0.253 (2)	0.25000	0.01920*
H12_4	0.7874 (15)	0.7204 (7)	0.287 (2)	0.01819*	0.50
O18_5	1.05599 (15)	0.78304 (15)	0.32766 (6)	0.02606 (16)
H18A_5	1.173 (2)	0.828 (3)	0.3556 (10)	0.03898*
H18B_5	0.953 (2)	0.845 (3)	0.3439 (10)	0.03898*

	U11	U22	U33	U12	U13	U23
K1_1	0.00912 (12)	0.01238 (13)	0.01537 (13)	0.00076 (9)	0.00058 (9)	0.00085 (9)
K2_2	0.0193 (2)	0.01123 (18)	0.0248 (2)	0	−0.00922 (16)	0
O8_3	0.0112 (4)	0.0094 (4)	0.0229 (5)	−0.0023 (3)	0.0001 (3)	−0.0009 (4)
O9_3	0.0117 (4)	0.0102 (4)	0.0209 (4)	0.0021 (3)	−0.0020 (3)	0.0011 (3)
O10_3	0.0091 (4)	0.0102 (4)	0.0273 (5)	−0.0019 (3)	−0.0046 (3)	0.0019 (4)
O11_3	0.0112 (4)	0.0110 (4)	0.0184 (4)	0.0029 (3)	−0.0034 (3)	−0.0010 (3)
N1_3	0.0074 (4)	0.0077 (4)	0.0124 (4)	0.0005 (4)	−0.0009 (3)	0.0000 (4)
N3_3	0.0073 (4)	0.0069 (4)	0.0145 (5)	−0.0002 (3)	−0.0012 (4)	0.0007 (4)
N5_3	0.0078 (4)	0.0076 (5)	0.0131 (4)	0.0005 (4)	−0.0014 (4)	0.0007 (4)
C2_3	0.0076 (5)	0.0069 (5)	0.0122 (5)	−0.0010 (4)	−0.0004 (4)	−0.0007 (4)
C4_3	0.0079 (5)	0.0065 (5)	0.0155 (5)	0.0002 (4)	−0.0008 (4)	0.0008 (4)
C6_3	0.0078 (5)	0.0087 (5)	0.0109 (5)	−0.0001 (4)	−0.0005 (4)	−0.0006 (4)
C7_3	0.0086 (5)	0.0062 (5)	0.0132 (5)	−0.0002 (4)	0.0013 (4)	−0.0002 (4)
N12_4	0.0117 (5)	0.0110 (5)	0.0231 (5)	−0.0020 (4)	0.0024 (4)	−0.0021 (4)
N14_4	0.0195 (8)	0.0079 (7)	0.0186 (7)	0	−0.0051 (6)	0
C13_4	0.0180 (9)	0.0093 (8)	0.0198 (8)	0	0.0090 (7)	0
C15_4	0.0156 (6)	0.0120 (6)	0.0200 (6)	0.0032 (5)	−0.0062 (5)	−0.0028 (5)
C5_4	0.0336 (11)	0.0083 (8)	0.0244 (9)	0	0.0178 (8)	0
O16_4	0.0455 (7)	0.0169 (5)	0.0337 (6)	0.0130 (5)	0.0218 (5)	0.0081 (4)
O17_4	0.0267 (6)	0.0269 (6)	0.0325 (6)	0.0161 (5)	−0.0144 (5)	−0.0108 (5)
O18_5	0.0161 (5)	0.0236 (5)	0.0345 (6)	−0.0058 (4)	−0.0076 (4)	0.0098 (4)

K1_1—K1_1i	3.7662 (3)	N1_3—C2_3	1.297 (2)
K1_1—K2_2ii	4.2236 (3)	N3_3—C4_3	1.386 (2)
K1_1—O17_4	2.7419 (9)	N3_3—C2_3	1.356 (2)
K1_1—O11_3	2.7714 (7)	N3_3—H3_3	1.015 (19)
K1_1—O18_5	2.7782 (9)	N5_3—C4_3	1.375 (2)
K1_1—O10_3iii	2.9272 (7)	N5_3—C6_3	1.390 (2)
K1_1—O10_3iv	3.1649 (6)	N5_3—H5_3	1.015 (19)
K1_1—O9_3v	2.6893 (6)	C2_3—C7_3	1.549 (2)
K1_1—O9_3vi	2.6893 (6)	N12_4—C15_4	1.384 (2)
K2_2—O17_4	2.7342 (9)	N12_4—C13_4	1.320 (2)
K2_2—O11_3	2.7972 (7)	N12_4—H12_4	1.016 (18)
K2_2—O16_4vii	2.7236 (9)	N14_4—C15_4	1.376 (2)
K1_1—O8_3viii	2.6916 (6)	N14_4—C15_4xii	1.376 (2)
K2_2—O18_5ix	2.9240 (6)	N14_4—H14_4	1.03 (3)
K2_2—O18_5x	2.9240 (6)	C13_4—N12_4xii	1.320 (2)
K2_2—O17_4ii	2.7342 (9)	C13_4—C5_4	1.541 (3)
K2_2—O11_3ii	2.7972 (6)	C15_4—O17_4	1.222 (3)
O8_3—C7_3	1.246 (2)	C5_4—O16_4	1.249 (2)
O9_3—C7_3	1.245 (2)	C5_4—O16_4xii	1.249 (2)
O10_3—K1_1xi	2.9272 (7)	O16_4—K2_2xiii	2.7236 (9)
O10_3—C4_3	1.220 (2)	O17_4—K1_1	2.7419 (9)
O11_3—K1_1	2.7714 (7)	O17_4—K2_2	2.7342 (9)
O11_3—K2_2	2.7972 (7)	O18_5—K1_1	2.7782 (9)
O11_3—C6_3	1.222 (2)	O18_5—H18B_5	0.96 (3)
N1_3—C6_3	1.392 (2)	O18_5—H18A_5	0.97 (3)
O17_4—K1_1—O11_3	80.13 (3)	C6_3—N5_3—H5_3	116 (4)
O17_4—K1_1—O18_5	77.41 (3)	C15_4—N12_4—C13_4	119.8 (2)
O17_4—K1_1—O10_3iii	80.33 (3)	C15_4—N12_4—H12_4	120 (1)
O11_3—K1_1—O18_5	120.67 (3)	C13_4—N12_4—H12_4	120 (1)
O11_3—K1_1—O10_3iii	76.18 (4)	C15_4—N14_4—C15_4xii	124.6 (5)
O18_5—K1_1—O10_3iii	148.7 (2)	C15_4—N14_4—H14_4	117.7 (2)
O17_4—K2_2—O11_3	79.81 (4)	C15_4xii—N14_4—H14_4	117.7 (2)
O17_4—K2_2—O16_4vii	71.63 (4)	N12_4xii—C13_4—C5_4	117.7 (4)
O11_3—K2_2—O16_4vii	111.78 (4)	O17_4—C15_4—N14_4	122.2 (5)
K1_1xi—O10_3—C4_3	129.30 (5)	O17_4—C15_4—N12_4	122.2 (5)
C6_3—N1_3—C2_3	117.8 (4)	O16_4—C5_4—O16_4xii	128.0 (6)
C4_3—N3_3—C2_3	121.8 (4)	O16_4—C5_4—C13_4	115.98 (11)
C4_3—N3_3—H3_3	118.9 (9)	O16_4xii—C5_4—C13_4	116.0 (5)
C2_3—N3_3—H3_3	119.2 (9)	K2_2xiii—O16_4—C5_4	141.0 (2)
C4_3—N5_3—C6_3	124.2 (4)	H18B_5—O18_5—H18A_5	105 (5)
C4_3—N5_3—H5_3	120 (4)
K1_1—O17_4—K2_2—O11_3	5.20 (14)	N1_3—C6_3—N5_3—C4_3	2.8 (3)
K1_1—O17_4—C15_4—N14_4	−141.9 (5)	N1_3—C6_3—N5_3—H5_3	−178.2 (7)
K1_1—O17_4—C15_4—N12_4	37.7 (3)	N1_3—C2_3—N3_3—C4_3	−0.1 (3)
K1_1—O11_3—K2_2—O17_4	−5.11 (14)	N1_3—C2_3—N3_3—H3_3	177 (2)
K1_1—O11_3—C6_3—N5_3	−38.9 (3)	N3_3—C4_3—N5_3—C6_3	−1.1 (3)
K1_1—O11_3—C6_3—N1_3	139.8 (5)	N3_3—C4_3—N5_3—H5_3	180 (2)
K2_2—O17_4—K1_1—O11_3	−5.25 (14)	N3_3—C2_3—N1_3—C6_3	1.8 (3)
K2_2—O17_4—K1_1—O18_5	119.46 (17)	N5_3—C4_3—N3_3—C2_3	−0.3 (3)
K2_2—O17_4—C15_4—N14_4	47.3 (3)	N5_3—C4_3—N3_3—H3_3	−177 (2)
K2_2—O17_4—C15_4—N12_4	−133.1 (5)	N5_3—C6_3—N1_3—C2_3	−3.1 (3)
K2_2—O11_3—K1_1—O17_4	5.09 (14)	C4_3—N3_3—C2_3—C7_3	−179.5 (3)
K2_2—O11_3—K1_1—O18_5	−63.78 (12)	C6_3—O11_3—K1_1—O17_4	−177.7 (3)
K2_2—O11_3—C6_3—N5_3	137.5 (4)	C6_3—O11_3—K1_1—O18_5	113.4 (4)
K2_2—O11_3—C6_3—N1_3	−43.7 (3)	C6_3—O11_3—K2_2—O17_4	177.5 (3)
O8_3—C7_3—C2_3—N3_3	−179.6 (2)	C6_3—N1_3—C2_3—C7_3	−178.8 (2)
O8_3—C7_3—C2_3—N1_3	0.9 (3)	C7_3—C2_3—N3_3—H3_3	−3 (4)
O9_3—C7_3—C2_3—N3_3	−0.2 (4)	N12_4—C15_4—N14_4—H14_4	179.05 (3)
O9_3—C7_3—C2_3—N1_3	−179.7 (4)	N12_4—C13_4—C5_4—O16_4	173.1 (3)
O10_3—C4_3—N5_3—C6_3	179.966 (4)	N14_4—C15_4—N12_4—C13_4	1.9 (4)
O10_3—C4_3—N5_3—H5_3	1 (4)	N14_4—C15_4—N12_4—H12_4	−174 (3)
O10_3—C4_3—N3_3—C2_3	178.64 (8)	C13_4—N12_4—C15_4—O17_4	−177.7 (3)
O10_3—C4_3—N3_3—H3_3	2 (4)	C15_4—O17_4—K1_1—O18_5	−53.7 (5)
O11_3—K1_1—O17_4—C15_4	−178.4 (3)	C15_4—N12_4—C13_4—C5_4	178.97 (10)
O11_3—K1_1—O18_5—H18B_5	159.5 (3)	C5_4—C13_4—N12_4—H12_4	−5.2 (7)
O11_3—K1_1—O18_5—H18A_5	−95 (4)	O17_4—K1_1—O18_5—H18B_5	89 (3)
O11_3—K2_2—O17_4—C15_4	177.5 (3)	O17_4—K1_1—O18_5—H18A_5	−166 (2)
O11_3—C6_3—N5_3—C4_3	−178.4 (2)	O17_4—C15_4—N14_4—H14_4	−1.3 (3)
O11_3—C6_3—N5_3—H5_3	1 (4)	O17_4—C15_4—N12_4—H12_4	6.4 (8)
O11_3—C6_3—N1_3—C2_3	178.2 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N3_3—H3_3···O9_3	1.02 (1)	2.20 (1)	2.6086 (7)	102 (1)
N5_3—H5_3···O8_3viii	1.02 (1)	1.93 (1)	2.9070 (7)	162 (1)
N5_3—H5_3···O9_3viii	1.02 (1)	2.56 (1)	3.3977 (6)	140 (1)
N12_4—H12_4···O18_5	1.016 (5)	1.984 (8)	2.9628 (7)	160.9 (4)
N12_4—H12_4···O18_5ii	1.016 (5)	2.659 (9)	3.1515 (8)	110 (2)
N14_4—H14_4···O16_4ix	1.03 (1)	2.23 (1)	3.1553 (6)	150 (2)
N14_4—H14_4···O16_4vii	1.03 (1)	2.23 (1)	3.1553 (7)	150 (2)
O18_5—H18B_5···O16_4xii	0.96 (1)	2.58 (1)	3.3013 (8)	133 (2)
O18_5—H18A_5···N1_3viii	0.97 (1)	1.93 (1)	2.8927 (9)	173 (1)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3_3—H3_3⋯O9_3	1.02 (1)	2.20 (1)	2.6086 (7)	102 (1)
N5_3—H5_3⋯O8_3i	1.02 (1)	1.93 (1)	2.9070 (7)	162 (1)
N5_3—H5_3⋯O9_3i	1.02 (1)	2.56 (1)	3.3977 (6)	140 (1)
N12_4—H12_4⋯O18_5	1.016 (5)	1.984 (8)	2.9628 (7)	160.9 (4)
N12_4—H12_4⋯O18_5ii	1.016 (5)	2.659 (9)	3.1515 (8)	110 (2)
N14_4—H14_4⋯O16_4iii	1.03 (1)	2.23 (1)	3.1553 (6)	150 (2)
N14_4—H14_4⋯O16_4iv	1.03 (1)	2.23 (1)	3.1553 (7)	150 (2)
O18_5—H18B_5⋯O16_4v	0.96 (1)	2.58 (1)	3.3013 (8)	133 (2)
O18_5—H18A_5⋯N1_3i	0.97 (1)	1.93 (1)	2.8927 (9)	173 (1)

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