In the title compound, K
+·C
9H
10N
5O
6−·C
9H
11N
5O
6·4.88H
2O, the cations are eight-coordinate. There is a one-dimensional coordination-polymer substructure, built from K and O atoms only, in the form of chains of distorted confacial octahedra, and these are linked into sheets by the neutral organic ligand. The sheets are linked into a single framework by a combination of N—H
O and O—H
O hydrogen bonds.
Supporting information
CCDC reference: 219550
The title compound was obtained by adding 6-amino-3,4-dihydro-3-methyl-2-methoxy-5-nitroso-4-oxopyrimidine (3.5 mmol) to a solution of potassium (S)-aspartate (3.5 mmol) in methanol (40 cm3). The mixture was stirred at 315 K for 2 d, and a pink solid was removed by filtration. The filtrate was evaporated to dryness, the residue was dissolved in water, and the pH of the resulting solution was adjusted to 2.15 by dropwise addition of aqueous HCl. After two weeks at room temperature, red crystals of the product were collected by filtration and washed with ethanol. Analysis found: C 31.3, H 4.9, N 20.3%; C18H30.76KN10O16.88 requires: C 31.0, H 4.5, N 20.1%. Crystals suitable for single-crystal X-ray diffraction were selected directly from the prepared sample.
Crystals of (I) are orthorhombic and the space group P212121 was uniquely assigned from the systematic absences. H atoms bonded to C or N atoms were treated as riding atoms, with C—H distances of 0.98 (CH3), 0.99 (CH2) and 1.00 Å (CH), and N—H distances of 0.88 Å. Water H atoms were located from difference maps and were initially constrained, with O—H distances in each molecule set to the average distance found for that molecule from the difference maps, and finally treated as riding atoms using AFIX 3, giving O—H distances of 0.90–0.98 Å. Carboxyl H atoms were treated as riding atoms, the C—H distances of 0.99–1.12 Å being deduced from difference maps. At a late stage in the refinement, it became apparent that there was a partially occupied water O-atom site, denoted O6, whose distances from the sites denoted O4 and O5 meant that site O6 could not be occupied at the same time as either O4 and O5; sites O4 and O5 could themselves be concurrently occupied, provided that site O6 was unoccupied. This situation was modelled by assigning a common site occupancy to sites O4 and O5 while tying the occupancy of site O6 to this common occupancy. The resulting occupancy factors are 0.883 (5) for O4 and O5, and 0.117 (5) for O6, and these occupancy values are associated with satisfactory displacement parameters.
Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO–SMN (Otwinowski & Minor, 1997); data reduction: DENZO–SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Potassium
N-(6-amino-3,4-dihydro-3-methyl-5-nitroso- 4-oxopyrimidin-2-yl)-(S)-aspartate
N-(6-amino-3,4-dihydro-3-methyl- 5-nitroso-4-oxopyrimidin-2-yl)-(S)-aspartic acid 4.88(hydrate)
top
Crystal data top
K+·C9H10N5O6−·C9H11N5O6·4.88H2O | F(000) = 1451.32 |
Mr = 696.52 | Dx = 1.591 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 6543 reflections |
a = 7.4986 (1) Å | θ = 3.1–27.5° |
b = 13.0997 (2) Å | µ = 0.28 mm−1 |
c = 29.5866 (6) Å | T = 120 K |
V = 2906.27 (8) Å3 | Needle, red |
Z = 4 | 0.35 × 0.10 × 0.06 mm |
Data collection top
NONIUS KappaCCD diffractometer | 6543 independent reflections |
Radiation source: rotating anode | 5256 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.071 |
ϕ scans, and ω scans with κ offsets | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (DENZO–SMN; Otwinowski & Minor, 1997) | h = −9→9 |
Tmin = 0.941, Tmax = 0.986 | k = −17→14 |
21931 measured reflections | l = −37→38 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.114 | w = 1/[σ2(Fo2) + (0.0292P)2 + 1.9469P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max = 0.001 |
6543 reflections | Δρmax = 0.66 e Å−3 |
422 parameters | Δρmin = −0.58 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 2893 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.00 (5) |
Crystal data top
K+·C9H10N5O6−·C9H11N5O6·4.88H2O | V = 2906.27 (8) Å3 |
Mr = 696.52 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.4986 (1) Å | µ = 0.28 mm−1 |
b = 13.0997 (2) Å | T = 120 K |
c = 29.5866 (6) Å | 0.35 × 0.10 × 0.06 mm |
Data collection top
NONIUS KappaCCD diffractometer | 6543 independent reflections |
Absorption correction: multi-scan (DENZO–SMN; Otwinowski & Minor, 1997) | 5256 reflections with I > 2σ(I) |
Tmin = 0.941, Tmax = 0.986 | Rint = 0.071 |
21931 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.114 | Δρmax = 0.66 e Å−3 |
S = 1.04 | Δρmin = −0.58 e Å−3 |
6543 reflections | Absolute structure: Flack (1983), 2893 Friedel pairs |
422 parameters | Absolute structure parameter: 0.00 (5) |
0 restraints | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
K1 | 0.14017 (9) | 0.69196 (5) | 0.49688 (2) | 0.02062 (16) | |
N11 | 0.3778 (3) | 0.65195 (19) | 0.30134 (8) | 0.0143 (5) | |
C12 | 0.4557 (4) | 0.7391 (2) | 0.31210 (10) | 0.0145 (6) | |
N12 | 0.5311 (3) | 0.79242 (19) | 0.27860 (8) | 0.0150 (5) | |
C122 | 0.3275 (4) | 0.7430 (2) | 0.21636 (10) | 0.0171 (7) | |
C121 | 0.5214 (4) | 0.7566 (2) | 0.23173 (10) | 0.0151 (6) | |
O121 | 0.2171 (3) | 0.81012 (17) | 0.23024 (7) | 0.0192 (5) | |
O122 | 0.2938 (3) | 0.67396 (17) | 0.18868 (7) | 0.0210 (5) | |
C123 | 0.6364 (4) | 0.6633 (2) | 0.22258 (10) | 0.0165 (6) | |
C124 | 0.8327 (4) | 0.6805 (2) | 0.22802 (9) | 0.0171 (6) | |
O123 | 0.9349 (3) | 0.61502 (19) | 0.24087 (8) | 0.0262 (6) | |
O124 | 0.8846 (3) | 0.77407 (18) | 0.21657 (8) | 0.0252 (5) | |
N13 | 0.4647 (4) | 0.77896 (19) | 0.35544 (8) | 0.0171 (6) | |
C13 | 0.5460 (5) | 0.8791 (2) | 0.36356 (11) | 0.0239 (8) | |
C14 | 0.3952 (4) | 0.7251 (2) | 0.39206 (10) | 0.0167 (7) | |
O14 | 0.4085 (3) | 0.75943 (17) | 0.43065 (7) | 0.0225 (5) | |
C15 | 0.3107 (4) | 0.6273 (2) | 0.38114 (10) | 0.0163 (7) | |
O15 | 0.1630 (3) | 0.49228 (16) | 0.40951 (7) | 0.0222 (5) | |
N15 | 0.2417 (4) | 0.5793 (2) | 0.41642 (8) | 0.0187 (6) | |
C16 | 0.3076 (4) | 0.5941 (2) | 0.33406 (10) | 0.0163 (7) | |
N16 | 0.2360 (4) | 0.5066 (2) | 0.32266 (9) | 0.0198 (6) | |
N21 | 0.1753 (4) | 1.08915 (19) | 0.62104 (8) | 0.0183 (6) | |
C22 | 0.1359 (4) | 1.0934 (2) | 0.57742 (10) | 0.0169 (6) | |
N22 | 0.0645 (4) | 1.1782 (2) | 0.56070 (8) | 0.0201 (6) | |
C221 | 0.0660 (5) | 1.2746 (2) | 0.58422 (11) | 0.0244 (8) | |
C222 | −0.1177 (5) | 1.3121 (3) | 0.59578 (10) | 0.0257 (8) | |
O221 | −0.2291 (4) | 1.2415 (2) | 0.60677 (10) | 0.0453 (8) | |
O222 | −0.1500 (4) | 1.40394 (18) | 0.59728 (9) | 0.0371 (7) | |
C223 | 0.1699 (5) | 1.3538 (3) | 0.55727 (11) | 0.0267 (8) | |
C224 | 0.0916 (5) | 1.3735 (3) | 0.51116 (11) | 0.0234 (8) | |
O223 | −0.0138 (3) | 1.31679 (18) | 0.49232 (7) | 0.0296 (6) | |
O224 | 0.1570 (3) | 1.45686 (17) | 0.49261 (7) | 0.0283 (6) | |
N23 | 0.1665 (4) | 1.0155 (2) | 0.54696 (8) | 0.0179 (6) | |
C23 | 0.1254 (5) | 1.0283 (2) | 0.49871 (10) | 0.0236 (7) | |
C24 | 0.2493 (4) | 0.9257 (2) | 0.56066 (10) | 0.0189 (7) | |
O24 | 0.2923 (3) | 0.86121 (17) | 0.53267 (7) | 0.0229 (5) | |
C25 | 0.2813 (4) | 0.9159 (2) | 0.60906 (10) | 0.0184 (7) | |
N25 | 0.3485 (4) | 0.8254 (2) | 0.62120 (9) | 0.0205 (6) | |
O25 | 0.3798 (3) | 0.81102 (18) | 0.66367 (7) | 0.0240 (5) | |
C26 | 0.2463 (4) | 1.0029 (2) | 0.63769 (10) | 0.0167 (7) | |
N26 | 0.2848 (4) | 1.0009 (2) | 0.68087 (8) | 0.0201 (6) | |
O1 | 0.4270 (3) | 0.66524 (18) | 0.55405 (8) | 0.0297 (6) | |
O2 | 0.7524 (3) | 0.96926 (16) | 0.27425 (7) | 0.0206 (5) | |
O3 | 1.0547 (3) | 0.86206 (17) | 0.31114 (7) | 0.0252 (5) | |
O4 | 0.5677 (4) | 0.5247 (2) | 0.61381 (9) | 0.0295 (8) | 0.883 (5) |
O5 | 0.4768 (3) | 0.3244 (2) | 0.62752 (8) | 0.0282 (8) | 0.883 (5) |
O6 | 0.482 (3) | 0.4608 (15) | 0.6348 (7) | 0.025 (6)* | 0.117 (5) |
H12 | 0.5872 | 0.8498 | 0.2848 | 0.018* | |
H121 | 0.5719 | 0.8128 | 0.2127 | 0.018* | |
H12A | 0.5993 | 0.6080 | 0.2433 | 0.020* | |
H12B | 0.6133 | 0.6397 | 0.1913 | 0.020* | |
H124 | 1.0325 | 0.7855 | 0.2202 | 0.038* | |
H13A | 0.6747 | 0.8750 | 0.3581 | 0.036* | |
H13B | 0.5244 | 0.8997 | 0.3949 | 0.036* | |
H13C | 0.4932 | 0.9295 | 0.3431 | 0.036* | |
H16A | 0.2350 | 0.4874 | 0.2942 | 0.024* | |
H16B | 0.1889 | 0.4670 | 0.3435 | 0.024* | |
H22 | 0.0138 | 1.1754 | 0.5339 | 0.024* | |
H221 | 0.1310 | 1.2640 | 0.6133 | 0.029* | |
H21E | −0.3430 | 1.2771 | 0.6131 | 0.054* | |
H22A | 0.1724 | 1.4186 | 0.5745 | 0.032* | |
H22B | 0.2945 | 1.3301 | 0.5537 | 0.032* | |
H224 | 0.1427 | 1.4760 | 0.4574 | 0.034* | |
H23A | 0.1708 | 0.9695 | 0.4818 | 0.035* | |
H23B | 0.1821 | 1.0908 | 0.4875 | 0.035* | |
H23C | −0.0040 | 1.0333 | 0.4947 | 0.035* | |
H26A | 0.2638 | 1.0548 | 0.6978 | 0.024* | |
H26B | 0.3315 | 0.9456 | 0.6929 | 0.024* | |
H1A | 0.3933 | 0.7158 | 0.5728 | 0.036* | |
H1B | 0.4535 | 0.6115 | 0.5718 | 0.036* | |
H2A | 0.8628 | 0.9476 | 0.2813 | 0.025* | |
H2B | 0.7449 | 1.0340 | 0.2842 | 0.025* | |
H3A | 1.1437 | 0.8425 | 0.2885 | 0.030* | |
H3B | 1.0059 | 0.7971 | 0.3220 | 0.030* | |
H4A | 0.6697 | 0.4900 | 0.6093 | 0.035* | 0.883 (5) |
H4B | 0.5861 | 0.5639 | 0.6384 | 0.035* | 0.883 (5) |
H5A | 0.4013 | 0.3083 | 0.6536 | 0.034* | 0.883 (5) |
H5B | 0.4671 | 0.3987 | 0.6242 | 0.034* | 0.883 (5) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
K1 | 0.0223 (4) | 0.0216 (3) | 0.0180 (3) | −0.0003 (3) | 0.0002 (3) | −0.0044 (3) |
N11 | 0.0151 (14) | 0.0150 (12) | 0.0128 (12) | −0.0032 (11) | 0.0019 (10) | 0.0003 (10) |
C12 | 0.0130 (16) | 0.0182 (15) | 0.0124 (14) | 0.0049 (13) | 0.0006 (12) | 0.0006 (12) |
N12 | 0.0151 (13) | 0.0156 (13) | 0.0144 (12) | −0.0028 (11) | −0.0003 (10) | 0.0002 (10) |
C122 | 0.0190 (17) | 0.0183 (15) | 0.0140 (14) | −0.0021 (13) | 0.0002 (13) | 0.0076 (12) |
C121 | 0.0155 (16) | 0.0165 (15) | 0.0134 (15) | −0.0018 (13) | 0.0012 (12) | 0.0018 (12) |
O121 | 0.0160 (11) | 0.0184 (11) | 0.0231 (11) | 0.0023 (10) | 0.0029 (9) | 0.0045 (10) |
O122 | 0.0217 (12) | 0.0251 (12) | 0.0160 (11) | −0.0013 (10) | −0.0011 (9) | 0.0012 (10) |
C123 | 0.0182 (16) | 0.0199 (16) | 0.0115 (14) | 0.0016 (13) | 0.0011 (13) | 0.0004 (11) |
C124 | 0.0145 (16) | 0.0242 (16) | 0.0127 (14) | 0.0027 (14) | 0.0050 (12) | 0.0022 (13) |
O123 | 0.0185 (13) | 0.0309 (14) | 0.0291 (13) | 0.0073 (11) | 0.0052 (10) | 0.0114 (11) |
O124 | 0.0181 (13) | 0.0239 (12) | 0.0336 (13) | −0.0009 (10) | −0.0003 (11) | 0.0046 (10) |
N13 | 0.0210 (15) | 0.0164 (13) | 0.0139 (13) | −0.0020 (11) | 0.0009 (11) | −0.0009 (10) |
C13 | 0.033 (2) | 0.0173 (17) | 0.0212 (17) | −0.0100 (15) | 0.0040 (15) | −0.0040 (13) |
C14 | 0.0148 (17) | 0.0201 (16) | 0.0152 (15) | 0.0021 (13) | 0.0021 (13) | 0.0027 (12) |
O14 | 0.0283 (14) | 0.0258 (13) | 0.0134 (11) | −0.0026 (10) | 0.0002 (9) | −0.0030 (9) |
C15 | 0.0194 (18) | 0.0174 (15) | 0.0122 (14) | 0.0025 (13) | −0.0011 (12) | −0.0003 (12) |
O15 | 0.0287 (13) | 0.0188 (11) | 0.0190 (11) | −0.0055 (10) | 0.0037 (10) | 0.0003 (9) |
N15 | 0.0214 (15) | 0.0163 (13) | 0.0186 (13) | 0.0012 (12) | 0.0027 (12) | 0.0030 (11) |
C16 | 0.0166 (17) | 0.0173 (15) | 0.0148 (15) | 0.0019 (13) | −0.0013 (12) | 0.0009 (12) |
N16 | 0.0259 (16) | 0.0194 (14) | 0.0141 (13) | −0.0057 (12) | 0.0033 (12) | −0.0015 (11) |
N21 | 0.0244 (16) | 0.0162 (13) | 0.0141 (13) | 0.0020 (12) | 0.0003 (11) | −0.0008 (10) |
C22 | 0.0174 (17) | 0.0163 (15) | 0.0170 (15) | −0.0041 (13) | 0.0031 (13) | −0.0005 (12) |
N22 | 0.0319 (16) | 0.0163 (14) | 0.0122 (12) | −0.0012 (13) | −0.0036 (11) | −0.0006 (11) |
C221 | 0.046 (2) | 0.0145 (16) | 0.0124 (15) | 0.0007 (15) | −0.0020 (15) | 0.0017 (13) |
C222 | 0.043 (2) | 0.0199 (16) | 0.0144 (15) | 0.0063 (16) | 0.0046 (15) | 0.0051 (13) |
O221 | 0.0403 (18) | 0.0273 (15) | 0.068 (2) | 0.0030 (13) | 0.0226 (15) | 0.0006 (14) |
O222 | 0.0456 (17) | 0.0220 (13) | 0.0436 (16) | 0.0090 (12) | −0.0072 (14) | −0.0034 (11) |
C223 | 0.037 (2) | 0.0231 (17) | 0.0203 (17) | −0.0030 (16) | −0.0030 (15) | 0.0028 (14) |
C224 | 0.0235 (19) | 0.0244 (17) | 0.0222 (17) | 0.0001 (14) | 0.0044 (14) | 0.0009 (14) |
O223 | 0.0373 (14) | 0.0290 (13) | 0.0224 (12) | −0.0109 (12) | −0.0083 (11) | 0.0051 (11) |
O224 | 0.0414 (15) | 0.0254 (12) | 0.0180 (11) | −0.0124 (11) | −0.0013 (11) | 0.0078 (10) |
N23 | 0.0193 (15) | 0.0185 (14) | 0.0160 (13) | 0.0005 (11) | 0.0009 (11) | −0.0044 (10) |
C23 | 0.031 (2) | 0.0244 (16) | 0.0151 (15) | 0.0016 (15) | −0.0033 (15) | −0.0027 (13) |
C24 | 0.0187 (18) | 0.0203 (16) | 0.0177 (15) | −0.0059 (14) | 0.0022 (13) | −0.0035 (13) |
O24 | 0.0283 (14) | 0.0202 (12) | 0.0203 (12) | 0.0010 (10) | 0.0016 (10) | −0.0070 (10) |
C25 | 0.0208 (18) | 0.0162 (16) | 0.0184 (15) | −0.0031 (14) | 0.0009 (13) | −0.0028 (13) |
N25 | 0.0231 (15) | 0.0180 (13) | 0.0204 (13) | −0.0017 (12) | −0.0014 (12) | −0.0012 (11) |
O25 | 0.0332 (14) | 0.0201 (11) | 0.0187 (11) | 0.0043 (11) | −0.0016 (10) | −0.0009 (10) |
C26 | 0.0163 (17) | 0.0155 (15) | 0.0183 (15) | −0.0034 (13) | 0.0007 (13) | 0.0006 (12) |
N26 | 0.0308 (17) | 0.0142 (13) | 0.0153 (13) | 0.0060 (12) | −0.0001 (12) | −0.0018 (11) |
O1 | 0.0371 (15) | 0.0257 (13) | 0.0261 (13) | 0.0121 (12) | −0.0029 (11) | −0.0066 (10) |
O2 | 0.0202 (12) | 0.0177 (11) | 0.0240 (12) | 0.0010 (10) | −0.0004 (10) | 0.0012 (9) |
O3 | 0.0285 (14) | 0.0225 (12) | 0.0245 (12) | −0.0007 (11) | 0.0042 (10) | 0.0001 (10) |
O4 | 0.0360 (18) | 0.0270 (16) | 0.0254 (15) | 0.0130 (13) | 0.0018 (12) | −0.0008 (12) |
O5 | 0.0247 (16) | 0.0342 (17) | 0.0256 (15) | 0.0034 (13) | 0.0062 (11) | 0.0033 (12) |
Geometric parameters (Å, º) top
K1—O1 | 2.758 (2) | N12—C121 | 1.466 (4) |
K1—O14 | 2.944 (2) | N12—H12 | 0.88 |
K1—O24 | 2.709 (2) | C122—C121 | 1.534 (4) |
K1—N15 | 2.902 (3) | C121—C123 | 1.519 (4) |
N11—C12 | 1.321 (4) | C121—H121 | 1.00 |
C12—N13 | 1.386 (4) | C123—C124 | 1.498 (4) |
N13—C14 | 1.394 (4) | C123—H12A | 0.99 |
C14—C15 | 1.466 (4) | C123—H12B | 0.99 |
C15—C16 | 1.459 (4) | O124—H124 | 1.12 |
C16—N11 | 1.338 (4) | C13—H13A | 0.98 |
C12—N12 | 1.338 (4) | C13—H13B | 0.98 |
N13—C13 | 1.466 (4) | C13—H13C | 0.98 |
C14—O14 | 1.231 (4) | N16—H16A | 0.88 |
C15—N15 | 1.324 (4) | N16—H16B | 0.88 |
O15—N15 | 1.300 (3) | N22—C221 | 1.442 (4) |
C16—N16 | 1.309 (4) | N22—H22 | 0.88 |
C122—O121 | 1.275 (4) | C221—C222 | 1.502 (5) |
C122—O122 | 1.246 (4) | C221—C223 | 1.523 (5) |
C124—O123 | 1.211 (4) | C221—H221 | 1.00 |
C124—O124 | 1.330 (4) | O221—H21E | 0.99 |
K1—O1i | 2.885 (3) | C223—C224 | 1.507 (5) |
K1—O14i | 2.832 (2) | C223—H22A | 0.99 |
K1—O24i | 2.838 (2) | C223—H22B | 0.99 |
K1—O224ii | 3.085 (2) | O224—H224 | 1.08 |
N21—C22 | 1.325 (4) | C23—H23A | 0.98 |
C22—N23 | 1.381 (4) | C23—H23B | 0.98 |
N23—C24 | 1.390 (4) | C23—H23C | 0.98 |
C24—C25 | 1.458 (4) | N26—H26A | 0.88 |
C25—C26 | 1.445 (4) | N26—H26B | 0.88 |
C26—N21 | 1.342 (4) | O1—H1A | 0.90 |
C22—N22 | 1.329 (4) | O1—H1B | 0.90 |
N23—C23 | 1.470 (4) | O2—H2A | 0.90 |
C24—O24 | 1.226 (4) | O2—H2B | 0.90 |
C25—N25 | 1.337 (4) | O3—H3A | 0.98 |
N25—O25 | 1.292 (3) | O3—H3B | 0.98 |
C26—N26 | 1.310 (4) | O4—H4A | 0.90 |
C222—O221 | 1.287 (4) | O4—H4B | 0.90 |
C222—O222 | 1.228 (4) | O5—H5A | 0.98 |
C224—O223 | 1.220 (4) | O5—H5B | 0.98 |
C224—O224 | 1.316 (4) | | |
| | | |
O24—K1—O1 | 62.35 (7) | O15—N15—K1 | 117.13 (17) |
O24—K1—O14i | 77.19 (7) | C15—N15—K1 | 120.5 (2) |
O1—K1—O14i | 92.44 (7) | N16—C16—N11 | 118.1 (3) |
O24—K1—O24i | 135.10 (7) | N16—C16—C15 | 120.9 (3) |
O1—K1—O24i | 150.98 (8) | N11—C16—C15 | 121.0 (3) |
O14i—K1—O24i | 74.02 (7) | C16—N16—H16A | 120.0 |
O24—K1—O1i | 84.65 (7) | C16—N16—H16B | 120.0 |
O1—K1—O1i | 146.56 (5) | H16A—N16—H16B | 120.0 |
O14i—K1—O1i | 84.82 (7) | C22—N21—C26 | 118.8 (3) |
O24i—K1—O1i | 59.27 (7) | N21—C22—N22 | 119.2 (3) |
O24—K1—N15 | 128.78 (7) | N21—C22—N23 | 124.6 (3) |
O1—K1—N15 | 103.53 (7) | N22—C22—N23 | 116.2 (3) |
O14i—K1—N15 | 153.65 (8) | C22—N22—C221 | 123.4 (3) |
O24i—K1—N15 | 82.16 (7) | C22—N22—H22 | 118.3 |
O1i—K1—N15 | 92.67 (7) | C221—N22—H22 | 118.3 |
O24—K1—O14 | 74.14 (6) | N22—C221—C222 | 112.9 (3) |
O1—K1—O14 | 85.03 (7) | N22—C221—C223 | 110.4 (3) |
O14i—K1—O14 | 148.82 (3) | C222—C221—C223 | 111.5 (3) |
O24i—K1—O14 | 119.78 (7) | N22—C221—H221 | 107.3 |
O1i—K1—O14 | 80.58 (7) | C222—C221—H221 | 107.3 |
N15—K1—O14 | 55.08 (7) | C223—C221—H221 | 107.3 |
O24—K1—O224ii | 144.68 (7) | O222—C222—O221 | 124.5 (4) |
O1—K1—O224ii | 82.33 (7) | O222—C222—C221 | 120.6 (3) |
O14i—K1—O224ii | 106.30 (7) | O221—C222—C221 | 114.7 (3) |
O24i—K1—O224ii | 77.29 (7) | C222—O221—H21E | 105.6 |
O1i—K1—O224ii | 130.43 (7) | C224—C223—C221 | 113.1 (3) |
N15—K1—O224ii | 56.50 (7) | C224—C223—H22A | 109.0 |
O14—K1—O224ii | 104.15 (7) | C221—C223—H22A | 109.0 |
C12—N11—C16 | 119.3 (3) | C224—C223—H22B | 109.0 |
N11—C12—N12 | 117.3 (3) | C221—C223—H22B | 109.0 |
N11—C12—N13 | 124.8 (3) | H22A—C223—H22B | 107.8 |
N12—C12—N13 | 117.9 (3) | O223—C224—O224 | 123.8 (3) |
C12—N12—C121 | 120.8 (3) | O223—C224—C223 | 124.1 (3) |
C12—N12—H12 | 119.6 | O224—C224—C223 | 112.0 (3) |
C121—N12—H12 | 119.6 | C224—O224—K1iv | 142.7 (2) |
O122—C122—O121 | 125.5 (3) | C224—O224—H224 | 124.0 |
O122—C122—C121 | 118.1 (3) | K1iv—O224—H224 | 78.6 |
O121—C122—C121 | 116.1 (3) | C22—N23—C24 | 120.6 (3) |
N12—C121—C123 | 113.5 (2) | C22—N23—C23 | 121.0 (3) |
N12—C121—C122 | 111.4 (2) | C24—N23—C23 | 118.3 (2) |
C123—C121—C122 | 113.1 (3) | N23—C23—H23A | 109.5 |
N12—C121—H121 | 106.1 | N23—C23—H23B | 109.5 |
C123—C121—H121 | 106.1 | H23A—C23—H23B | 109.5 |
C122—C121—H121 | 106.1 | N23—C23—H23C | 109.5 |
C124—C123—C121 | 114.7 (3) | H23A—C23—H23C | 109.5 |
C124—C123—H12A | 108.6 | H23B—C23—H23C | 109.5 |
C121—C123—H12A | 108.6 | O24—C24—N23 | 120.2 (3) |
C124—C123—H12B | 108.6 | O24—C24—C25 | 124.0 (3) |
C121—C123—H12B | 108.6 | N23—C24—C25 | 115.8 (3) |
H12A—C123—H12B | 107.6 | C24—O24—K1 | 135.8 (2) |
O123—C124—O124 | 123.2 (3) | C24—O24—K1iii | 128.2 (2) |
O123—C124—C123 | 123.4 (3) | K1—O24—K1iii | 93.77 (7) |
O124—C124—C123 | 113.5 (3) | N25—C25—C26 | 127.6 (3) |
C124—O124—H124 | 112.7 | N25—C25—C24 | 113.8 (3) |
C12—N13—C14 | 120.7 (3) | C26—C25—C24 | 118.4 (3) |
C12—N13—C13 | 120.6 (3) | O25—N25—C25 | 117.3 (3) |
C14—N13—C13 | 118.7 (3) | N26—C26—N21 | 117.6 (3) |
N13—C13—H13A | 109.5 | N26—C26—C25 | 121.0 (3) |
N13—C13—H13B | 109.5 | N21—C26—C25 | 121.4 (3) |
H13A—C13—H13B | 109.5 | C26—N26—H26A | 120.0 |
N13—C13—H13C | 109.5 | C26—N26—H26B | 120.0 |
H13A—C13—H13C | 109.5 | H26A—N26—H26B | 120.0 |
H13B—C13—H13C | 109.5 | K1—O1—K1iii | 91.69 (7) |
O14—C14—N13 | 120.4 (3) | K1—O1—H1A | 93.7 |
O14—C14—C15 | 124.0 (3) | K1iii—O1—H1A | 90.0 |
N13—C14—C15 | 115.6 (3) | K1—O1—H1B | 129.0 |
C14—O14—K1iii | 146.5 (2) | K1iii—O1—H1B | 133.5 |
C14—O14—K1 | 116.9 (2) | H1A—O1—H1B | 106.2 |
K1iii—O14—K1 | 89.02 (6) | H2A—O2—H2B | 106.2 |
N15—C15—C16 | 127.2 (3) | H3A—O3—H3B | 104.5 |
N15—C15—C14 | 114.2 (3) | H4A—O4—H4B | 106.1 |
C16—C15—C14 | 118.6 (3) | H5A—O5—H5B | 104.5 |
O15—N15—C15 | 118.0 (3) | | |
| | | |
N11—C12—N12—C121 | 2.0 (4) | C14—C15—C16—N16 | 179.0 (3) |
C12—N12—C121—C122 | 57.6 (4) | N15—C15—C16—N11 | 177.8 (3) |
C12—N12—C121—C123 | −71.3 (4) | C14—C15—C16—N11 | −1.0 (4) |
N12—C121—C122—O121 | 38.6 (4) | C26—N21—C22—N22 | 179.6 (3) |
N12—C121—C123—C124 | −64.1 (3) | C26—N21—C22—N23 | −1.6 (5) |
C121—C123—C124—O123 | 147.8 (3) | N21—C22—N22—C221 | 15.5 (5) |
C16—N11—C12—N12 | 177.1 (3) | C22—N22—C221—C222 | −116.6 (3) |
C16—N11—C12—N13 | −2.9 (5) | C22—N22—C221—C223 | 117.9 (3) |
N13—C12—N12—C121 | −177.9 (3) | N22—C221—C222—O221 | 36.3 (4) |
O122—C122—C121—N12 | −147.5 (3) | N22—C221—C223—C224 | 60.5 (4) |
O122—C122—C121—C123 | −18.3 (4) | C221—C223—C224—O223 | −17.3 (5) |
O121—C122—C121—C123 | 167.7 (2) | N23—C22—N22—C221 | −163.4 (3) |
C122—C121—C123—C124 | 167.9 (2) | N22—C221—C222—O222 | −148.5 (3) |
C121—C123—C124—O124 | −33.3 (3) | C223—C221—C222—O222 | −23.6 (4) |
N11—C12—N13—C14 | 2.7 (5) | C223—C221—C222—O221 | 161.2 (3) |
N12—C12—N13—C14 | −177.4 (3) | C222—C221—C223—C224 | −65.9 (4) |
N11—C12—N13—C13 | −176.7 (3) | C221—C223—C224—O224 | 165.7 (3) |
N12—C12—N13—C13 | 3.3 (4) | O223—C224—O224—K1iv | 108.3 (4) |
C12—N13—C14—O14 | 177.7 (3) | C223—C224—O224—K1iv | −74.7 (4) |
C13—N13—C14—O14 | −2.9 (5) | N21—C22—N23—C24 | −2.2 (5) |
C12—N13—C14—C15 | −1.4 (4) | N22—C22—N23—C24 | 176.6 (3) |
C13—N13—C14—C15 | 178.0 (3) | N21—C22—N23—C23 | −177.4 (3) |
N13—C14—O14—K1iii | −68.2 (5) | N22—C22—N23—C23 | 1.5 (4) |
C15—C14—O14—K1iii | 110.9 (4) | C22—N23—C24—O24 | −172.6 (3) |
N13—C14—O14—K1 | 154.8 (2) | C23—N23—C24—O24 | 2.7 (5) |
C15—C14—O14—K1 | −26.2 (4) | C22—N23—C24—C25 | 6.6 (4) |
O24—K1—O14—C14 | −162.7 (2) | C23—N23—C24—C25 | −178.0 (3) |
O1—K1—O14—C14 | 134.7 (2) | N23—C24—O24—K1 | −92.8 (4) |
O14i—K1—O14—C14 | −138.8 (2) | C25—C24—O24—K1 | 88.0 (4) |
O24i—K1—O14—C14 | −29.4 (2) | N23—C24—O24—K1iii | 108.6 (3) |
O1i—K1—O14—C14 | −75.6 (2) | C25—C24—O24—K1iii | −70.6 (4) |
N15—K1—O14—C14 | 24.4 (2) | O1—K1—O24—C24 | −110.0 (3) |
O224ii—K1—O14—C14 | 53.9 (2) | O14i—K1—O24—C24 | −10.3 (3) |
O24—K1—O14—K1iii | 39.42 (6) | O24i—K1—O24—C24 | 40.8 (3) |
O1—K1—O14—K1iii | −23.22 (7) | O1i—K1—O24—C24 | 75.6 (3) |
O14i—K1—O14—K1iii | 63.28 (16) | N15—K1—O24—C24 | 164.7 (3) |
O24i—K1—O14—K1iii | 172.72 (7) | O14—K1—O24—C24 | 157.3 (3) |
O1i—K1—O14—K1iii | 126.49 (7) | O224ii—K1—O24—C24 | −110.5 (3) |
N15—K1—O14—K1iii | −133.53 (10) | O1—K1—O24—K1iii | 53.29 (7) |
O224ii—K1—O14—K1iii | −104.00 (7) | O14i—K1—O24—K1iii | 152.99 (8) |
O14—C14—C15—N15 | 2.6 (5) | O24i—K1—O24—K1iii | −155.93 (9) |
N13—C14—C15—N15 | −178.3 (3) | O1i—K1—O24—K1iii | −121.12 (7) |
O14—C14—C15—C16 | −178.4 (3) | N15—K1—O24—K1iii | −31.99 (11) |
N13—C14—C15—C16 | 0.7 (4) | O14—K1—O24—K1iii | −39.42 (6) |
C16—C15—N15—O15 | 0.7 (5) | O224ii—K1—O24—K1iii | 52.80 (13) |
C14—C15—N15—O15 | 179.5 (3) | O24—C24—C25—N25 | −5.6 (5) |
C16—C15—N15—K1 | −155.3 (2) | N23—C24—C25—N25 | 175.2 (3) |
C14—C15—N15—K1 | 23.5 (4) | O24—C24—C25—C26 | 171.7 (3) |
O24—K1—N15—O15 | 170.80 (18) | N23—C24—C25—C26 | −7.5 (4) |
O1—K1—N15—O15 | 105.6 (2) | C26—C25—N25—O25 | 3.2 (5) |
O14i—K1—N15—O15 | −20.2 (3) | C24—C25—N25—O25 | −179.8 (3) |
O24i—K1—N15—O15 | −45.4 (2) | C22—N21—C26—N26 | 179.7 (3) |
O1i—K1—N15—O15 | −103.9 (2) | C22—N21—C26—C25 | 0.4 (5) |
O14—K1—N15—O15 | 179.5 (2) | N25—C25—C26—N26 | 1.9 (5) |
O224ii—K1—N15—O15 | 34.47 (18) | C24—C25—C26—N26 | −175.0 (3) |
O24—K1—N15—C15 | −33.0 (3) | N25—C25—C26—N21 | −178.9 (3) |
O1—K1—N15—C15 | −98.3 (2) | C24—C25—C26—N21 | 4.2 (5) |
O14i—K1—N15—C15 | 136.0 (2) | O24—K1—O1—K1iii | −51.92 (7) |
O24i—K1—N15—C15 | 110.7 (2) | O14i—K1—O1—K1iii | −126.08 (7) |
O1i—K1—N15—C15 | 52.2 (2) | O24i—K1—O1—K1iii | 173.34 (11) |
O14—K1—N15—C15 | −24.3 (2) | O1i—K1—O1—K1iii | −41.78 (13) |
O224ii—K1—N15—C15 | −169.4 (3) | N15—K1—O1—K1iii | 75.04 (7) |
C12—N11—C16—N16 | −178.0 (3) | O14—K1—O1—K1iii | 22.77 (6) |
C12—N11—C16—C15 | 2.1 (4) | O224ii—K1—O1—K1iii | 127.80 (7) |
N15—C15—C16—N16 | −2.2 (5) | | |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) x, y−1, z; (iii) x+1/2, −y+3/2, −z+1; (iv) x, y+1, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N12—H12···O2 | 0.88 | 2.02 | 2.852 (3) | 157 |
O124—H124···O121v | 1.12 | 1.45 | 2.570 (3) | 172 |
N16—H16A···O2vi | 0.88 | 2.04 | 2.910 (3) | 170 |
N16—H16B···O15 | 0.88 | 1.99 | 2.634 (3) | 129 |
N22—H22···O223 | 0.88 | 2.23 | 2.781 (3) | 120 |
O221—H21E···O5vii | 0.99 | 1.55 | 2.534 (4) | 174 |
O224—H224···O15iv | 1.08 | 1.44 | 2.502 (3) | 167 |
N26—H26A···O121viii | 0.88 | 2.02 | 2.875 (3) | 164 |
N26—H26B···O25 | 0.88 | 2.00 | 2.637 (3) | 129 |
N26—H26B···O123i | 0.88 | 2.25 | 2.989 (3) | 141 |
O1—H1A···N25 | 0.90 | 2.06 | 2.949 (3) | 172 |
O1—H1B···O4 | 0.90 | 1.89 | 2.762 (3) | 163 |
O2—H2A···O3 | 0.90 | 2.03 | 2.881 (3) | 158 |
O2—H2B···O122ix | 0.90 | 2.02 | 2.918 (3) | 174 |
O3—H3A···O121v | 0.98 | 1.86 | 2.771 (3) | 154 |
O3—H3B···O25iii | 0.98 | 1.76 | 2.723 (3) | 169 |
O4—H4A···O222x | 0.90 | 1.80 | 2.687 (4) | 171 |
O4—H4B···O3i | 0.90 | 1.80 | 2.672 (3) | 164 |
O5—H5A···O122xi | 0.98 | 1.81 | 2.719 (3) | 153 |
O5—H5B···O4 | 0.98 | 1.84 | 2.741 (4) | 151 |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (iii) x+1/2, −y+3/2, −z+1; (iv) x, y+1, z; (v) x+1, y, z; (vi) −x+1, y−1/2, −z+1/2; (vii) x−1, y+1, z; (viii) −x+1/2, −y+2, z+1/2; (ix) −x+1, y+1/2, −z+1/2; (x) x+1, y−1, z; (xi) −x+1/2, −y+1, z+1/2. |
Experimental details
Crystal data |
Chemical formula | K+·C9H10N5O6−·C9H11N5O6·4.88H2O |
Mr | 696.52 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 120 |
a, b, c (Å) | 7.4986 (1), 13.0997 (2), 29.5866 (6) |
V (Å3) | 2906.27 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.28 |
Crystal size (mm) | 0.35 × 0.10 × 0.06 |
|
Data collection |
Diffractometer | NONIUS KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO–SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.941, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 21931, 6543, 5256 |
Rint | 0.071 |
(sin θ/λ)max (Å−1) | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.114, 1.04 |
No. of reflections | 6543 |
No. of parameters | 422 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.66, −0.58 |
Absolute structure | Flack (1983), 2893 Friedel pairs |
Absolute structure parameter | 0.00 (5) |
Selected geometric parameters (Å, º) topK1—O1 | 2.758 (2) | K1—O1i | 2.885 (3) |
K1—O14 | 2.944 (2) | K1—O14i | 2.832 (2) |
K1—O24 | 2.709 (2) | K1—O24i | 2.838 (2) |
K1—N15 | 2.902 (3) | K1—O224ii | 3.085 (2) |
N11—C12 | 1.321 (4) | N21—C22 | 1.325 (4) |
C12—N13 | 1.386 (4) | C22—N23 | 1.381 (4) |
N13—C14 | 1.394 (4) | N23—C24 | 1.390 (4) |
C14—C15 | 1.466 (4) | C24—C25 | 1.458 (4) |
C15—C16 | 1.459 (4) | C25—C26 | 1.445 (4) |
C16—N11 | 1.338 (4) | C26—N21 | 1.342 (4) |
C12—N12 | 1.338 (4) | C22—N22 | 1.329 (4) |
N13—C13 | 1.466 (4) | N23—C23 | 1.470 (4) |
C14—O14 | 1.231 (4) | C24—O24 | 1.226 (4) |
C15—N15 | 1.324 (4) | C25—N25 | 1.337 (4) |
O15—N15 | 1.300 (3) | N25—O25 | 1.292 (3) |
C16—N16 | 1.309 (4) | C26—N26 | 1.310 (4) |
C122—O121 | 1.275 (4) | C222—O221 | 1.287 (4) |
C122—O122 | 1.246 (4) | C222—O222 | 1.228 (4) |
C124—O123 | 1.211 (4) | C224—O223 | 1.220 (4) |
C124—O124 | 1.330 (4) | C224—O224 | 1.316 (4) |
| | | |
N11—C12—N12—C121 | 2.0 (4) | N21—C22—N22—C221 | 15.5 (5) |
C12—N12—C121—C122 | 57.6 (4) | C22—N22—C221—C222 | −116.6 (3) |
C12—N12—C121—C123 | −71.3 (4) | C22—N22—C221—C223 | 117.9 (3) |
N12—C121—C122—O121 | 38.6 (4) | N22—C221—C222—O221 | 36.3 (4) |
N12—C121—C123—C124 | −64.1 (3) | N22—C221—C223—C224 | 60.5 (4) |
C121—C123—C124—O123 | 147.8 (3) | C221—C223—C224—O223 | −17.3 (5) |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) x, y−1, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N12—H12···O2 | 0.88 | 2.02 | 2.852 (3) | 157 |
O124—H124···O121iii | 1.12 | 1.45 | 2.570 (3) | 172 |
N16—H16A···O2iv | 0.88 | 2.04 | 2.910 (3) | 170 |
N16—H16B···O15 | 0.88 | 1.99 | 2.634 (3) | 129 |
N22—H22···O223 | 0.88 | 2.23 | 2.781 (3) | 120 |
O221—H21E···O5v | 0.99 | 1.55 | 2.534 (4) | 174 |
O224—H224···O15vi | 1.08 | 1.44 | 2.502 (3) | 167 |
N26—H26A···O121vii | 0.88 | 2.02 | 2.875 (3) | 164 |
N26—H26B···O25 | 0.88 | 2.00 | 2.637 (3) | 129 |
N26—H26B···O123i | 0.88 | 2.25 | 2.989 (3) | 141 |
O1—H1A···N25 | 0.90 | 2.06 | 2.949 (3) | 172 |
O1—H1B···O4 | 0.90 | 1.89 | 2.762 (3) | 163 |
O2—H2A···O3 | 0.90 | 2.03 | 2.881 (3) | 158 |
O2—H2B···O122viii | 0.90 | 2.02 | 2.918 (3) | 174 |
O3—H3A···O121iii | 0.98 | 1.86 | 2.771 (3) | 154 |
O3—H3B···O25ix | 0.98 | 1.76 | 2.723 (3) | 169 |
O4—H4A···O222x | 0.90 | 1.80 | 2.687 (4) | 171 |
O4—H4B···O3i | 0.90 | 1.80 | 2.672 (3) | 164 |
O5—H5A···O122xi | 0.98 | 1.81 | 2.719 (3) | 153 |
O5—H5B···O4 | 0.98 | 1.84 | 2.741 (4) | 151 |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (iii) x+1, y, z; (iv) −x+1, y−1/2, −z+1/2; (v) x−1, y+1, z; (vi) x, y+1, z; (vii) −x+1/2, −y+2, z+1/2; (viii) −x+1, y+1/2, −z+1/2; (ix) x+1/2, −y+3/2, −z+1; (x) x+1, y−1, z; (xi) −x+1/2, −y+1, z+1/2. |
We have reported recently the molecular and supramolecular structures of the hydrated potassium complexes derived from the anionic ligands L1 and L2 (Scheme). In [K(L1)H2O], chains of spiro-fused K2O2 rings are linked into sheets by means of the unusual η2 coordination of the nitroso substituent, and the coordination-polymer sheets are linked into a three-dimensional framework by hydrogen bonds (Low et al., 2001b). In [K(L2)H2O], by contrast, the coordination polymer is three-dimensional: K2O2 rings are again present, but they are isolated from one another and the nitroso substituent adopts the more usual η1 coordination mode (Low et al., 2001a).
Continuing this investigation, we have now turned to an analogous ligand, L3, containing a dicarboxylic acid side chain, and we report here the structure of the hydrated potassium complex, (I). The constitution of (I) is that of an acid salt, [K(L3)(HL3)(H2O)4.88], in which the carboxyl group of the HL3 unit is not ionized. There are three fully occupied water sites (viz. those containing atoms O1–O3, including one molecule that is directly coordinated to the cation) and three partially occupied sites (viz. those containing atoms O4–O6 (Fig. 1). The anionic ligand (containing atoms N11, C12 etc.) is coordinated to the K+ cation via both atom O14 and atom N15, while atom O14 is also coordinated to the cation at (0.5 + x, 1.5 − y, 1 − z). The neutral organic HL3 ligand is directly coordinated to the cation only via atom O24, which also coordinates to the K+ cation at (0.5 + x, 1.5 − y, 1 − z); likewise water atom O1 at (x, y, z) is coordinated to cations at both (x, y, z) and (0.5 + x, 1.5 − y, 1 − z). The eight-coordination of the cation is completed by carboxyl atom O224 at (x, −1 + y, z), and a hydrogen bond formed between atoms O1 and N25 effectively prevents this N atom from coordinating to the cation (Fig. 1), so that the coordination behaviour of the neutral HL3 ligand differs from that of the anionic (L3)− ligand. The remaining water molecules are linked to the coordination complex by means of hydrogen bonds, primarily of O—H···O type but including one of N—H···O type (Fig. 1 and Table 2).
In both organic ligands, the ring dimensions (Table 1) display to an extreme degree the electronic polarization that is now a familiar feature of compounds containing this type of substituted oxopyrimidinyl ring (Low et al., 2000; Low et al., 2001a; Low et al., 2001b). In particular, the exocyclic Cn6—Nn6 bonds (n = 1 or 2) are both shorter than those typically found in metal complexes of ligands of this general type (Low et al., 2001b). Overall, the ring dimensions point to the importance of the polarized form (A) at the expense of the classically localized form of L3 (see Scheme).
The C—O distances in the carboxyl groups are consistent with the H-atom locations deduced from difference map. Thus, at both atom C124 and atom C224, the C—O distances are typical of those in unionized carboxyl groups (Allen et al., 1987), while the two distances at atom C122 are very similar and are consistent with the presence of a fully ionized carboxylate unit. At atom C222, on the other hand, the difference between the two C—O distances is less than that typically found in unionized carboxyl groups [mean value 0.122 Å; Allen et al., 1987). Although, in both organic ligands, there is complete synclinal staggering about the Cn21—Cn23 bonds (n = 1 or 2), the skeletal conformations about the Nn1—Cn21 bonds are quite different, being synclinal in the anionic ligand and anticlinal in the neutral ligand; this latter conformation may be influenced by the intramolecular N22—H22···O223 hydrogen bond.
Since atoms O1, O14 and O24 at (x, y, z) all bridge the pair of cations at (x, y, z) and (0.5 + x, 1.5 − y, 1 − z), these interactions give rise to a one-dimensional coordination polymer, which takes the form of a chain of distorted confacial octahedra (Fig. 2) that runs parallel to the [100] direction and is generated by the 21 screw axis along (x, 3/4, 1/2). There is a second such chain passing through the unit cell, this time generated by the 21 screw axis along (x, 1/4, 0). Within each domain of z, the [100] chains are linked into (001) sheets. The final coordination site of the cation at (x, y, z) is occupied by carboxyl atom O224 from the neutral organic ligand at (x, −1 + y, z), so forming by translation a C12(10) motif (Starbuck et al., 1999) running parallel to the [010] direction (Fig. 3). The combination of the [100] and [010] chains generates a (001) sheet, two of which pass through each unit cell.
In addition to three intramolecular N—H···O hydrogen bonds, each of which forms an S(6) motif (Bernstein et al., 1995), there are intermolecular O—H···O, O—H···N and N—H···O hydrogen bonds in the asymmetric unit (Fig. 1 and Table 2). There are also a substantial number of hydrogen bonds linking these molecular aggregates together, and we discuss here just three points concerning these which are of structural significance. First, the three O—H···O hydrogen bonds having carboxyl donors are characterized by short O···O distances, in every case less than 2.60 Å. In particular, the hydrogen bond having anionic nitroso atom O15 as acceptor has an O···O distance of only 2.502 (3) Å, which is comparable with those observed for such hydrogen bonds in neutral N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)amino acids; moreover the C15—N15 and N15—O15 distances associated with this hydrogen bond fit well with the correlation established previously between such distances and the O···O hydrogen bond distances (Low et al., 2000). Secondly, despite the number of unionized carboxyl groups present in the structure, these generate neither of the two hydrogen-bonded motifs [C(4) and R22(8)] that are so characteristic of simple carboxylic acids; indeed, there is no hydrogen bond present in which both donor and acceptor are components of neutral carboxyl groups. There is, however, a single example, namely O124—H124···O121(1 + x, y, z), in which the ionized carboxylate unit provides the acceptor. Thirdly, a number of the hydrogen bonds serve to link the (001) sheets into a single continuous framework, and just two examples suffice to demonstrate this behaviour. Atom N16 at (x, y, z) lies in the (001) sheet containing the 21 screw axes at z = 0.5 and acts as a hydrogen-bond donor, via atom H16A, to water atom O2 at (1 − x, −0.5 + y, 0.5 − z), which lies in the sheet containing the 21 axes at z = 0. A t the same time, atom N26 at (x, y, z) acts as a hydrogen-bond donor, via H26A, to carboxylate atom O121 at (0.5 − x, 2 − y, 0.5 + z), which lies in the sheet containing the 21 axes at z = 1.0. Two O—H···O hydrogen bonds, involving water atoms O2 and O5 as donors, reinforce the linking of the (001) sheets (Table 2).