Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101002670/na1505sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101002670/na1505Isup2.hkl |
CCDC reference: 164630
For related literature, see: Bauer & Andreassen (1972); Bernstein et al. (1995); Davis et al. (1965); Etter (1990); Gregson et al. (2000); Low et al. (2000, 2001); Motherwell et al. (2000); Schlemper et al. (1986); Starbuck et al. (1999); Talberg (1977).
A solution of glycylglycine (16 mmol) in aqueous KOH (16 ml, 1 mol dm-3) was added to a suspension of 6-amino-3,4-dihydro-3-methyl-2-methoxy-5-nitroso-4-oxopyrimidine (16 mmol) in acetonitrile (50 ml). The mixture was heated under reflux for 1.5 h, producing a violet solid, which was filtered off and washed with ethanol and diethyl ether. Crystals suitable for single-crystal X-ray diffraction study were grown from water. Analysis, found: C 31.4, H 3.9, N 24.7%; C9H13KN6O6 requires: C 31.8, H 3.8, N 24.7%.
Compound (1) crystallized in the triclinic system; space group P1 was assumed and confirmed by the analysis. It was apparent from an early stage that, in addition to C3 bonded to N3, there was a small population of a C atom, C41, bonded to O4; the site-occupation factors of C3 and C41 were subsequently constrained to sum to unity, and C41 was refined isotropically. H atoms were located from difference maps and those in the organic fragment were treated as riding atoms with C—H distances of 0.98 (CH3) or 0.99 Å (CH2), and an N—H distance of 0.88 Å. H atoms in the water molecule were initially handled using a DFIX command with an O—H distance of 0.82 Å, and latterly using AFIX.
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, 2000); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
K+·C9H11N6O5−·H2O | Z = 2 |
Mr = 340.35 | F(000) = 352 |
Triclinic, P1 | Dx = 1.672 Mg m−3 |
a = 7.4440 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.4642 (4) Å | Cell parameters from 3476 reflections |
c = 13.5136 (6) Å | θ = 2.9–28.8° |
α = 80.3701 (17)° | µ = 0.44 mm−1 |
β = 76.0568 (18)° | T = 150 K |
γ = 68.6413 (14)° | Lath, pink |
V = 676.06 (6) Å3 | 0.25 × 0.10 × 0.10 mm |
KappaCCD diffractometer | 3476 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 2696 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
ϕ scans, and ω scans with κoffsets | θmax = 28.8°, θmin = 2.9° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −10→10 |
Tmin = 0.926, Tmax = 0.959 | k = −9→9 |
7466 measured reflections | l = −18→18 |
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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0408P)2 + 0.2155P] where P = (Fo2 + 2Fc2)/3 |
3476 reflections | (Δ/σ)max < 0.001 |
205 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.52 e Å−3 |
K+·C9H11N6O5−·H2O | γ = 68.6413 (14)° |
Mr = 340.35 | V = 676.06 (6) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.4440 (4) Å | Mo Kα radiation |
b = 7.4642 (4) Å | µ = 0.44 mm−1 |
c = 13.5136 (6) Å | T = 150 K |
α = 80.3701 (17)° | 0.25 × 0.10 × 0.10 mm |
β = 76.0568 (18)° |
KappaCCD diffractometer | 3476 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 2696 reflections with I > 2σ(I) |
Tmin = 0.926, Tmax = 0.959 | Rint = 0.033 |
7466 measured reflections |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.33 e Å−3 |
3476 reflections | Δρmin = −0.52 e Å−3 |
205 parameters |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
K1 | 1.35730 (6) | 0.24999 (6) | −0.06058 (3) | 0.02045 (13) | |
N1 | 0.2457 (2) | 0.3359 (2) | 0.43876 (11) | 0.0168 (3) | |
C2 | 0.2319 (2) | 0.5041 (3) | 0.38451 (13) | 0.0157 (4) | |
N21 | 0.2248 (2) | 0.5183 (2) | 0.28576 (11) | 0.0175 (3) | |
C21 | 0.2386 (3) | 0.3550 (3) | 0.23481 (14) | 0.0196 (4) | |
C22 | 0.4473 (3) | 0.2264 (3) | 0.19265 (13) | 0.0183 (4) | |
O21 | 0.4700 (2) | 0.1091 (2) | 0.13264 (10) | 0.0250 (3) | |
N22 | 0.5940 (2) | 0.2448 (2) | 0.22522 (12) | 0.0218 (4) | |
C23 | 0.7993 (3) | 0.1396 (3) | 0.18559 (14) | 0.0219 (4) | |
C24 | 0.8891 (3) | 0.2311 (3) | 0.08511 (15) | 0.0212 (4) | |
O22 | 0.7807 (2) | 0.3765 (2) | 0.04093 (10) | 0.0280 (3) | |
O23 | 1.0686 (2) | 0.1468 (2) | 0.05549 (12) | 0.0360 (4) | |
N3 | 0.2248 (2) | 0.6676 (2) | 0.42268 (11) | 0.0156 (3) | |
C3 | 0.2013 (3) | 0.8505 (3) | 0.35773 (14) | 0.0196 (5) | 0.954 (4) |
C4 | 0.2459 (3) | 0.6609 (3) | 0.52374 (13) | 0.0169 (4) | |
O4 | 0.2436 (2) | 0.8059 (2) | 0.55578 (10) | 0.0259 (3) | |
C5 | 0.2701 (3) | 0.4767 (3) | 0.58298 (13) | 0.0162 (4) | |
N5 | 0.2991 (2) | 0.4732 (2) | 0.67826 (11) | 0.0218 (4) | |
O5 | 0.3161 (2) | 0.3169 (2) | 0.73694 (10) | 0.0275 (3) | |
C6 | 0.2661 (3) | 0.3187 (3) | 0.53642 (13) | 0.0159 (4) | |
N6 | 0.2870 (2) | 0.1496 (2) | 0.58922 (12) | 0.0225 (4) | |
O1 | 1.7493 (2) | 0.2210 (2) | −0.12149 (10) | 0.0260 (3) | |
C41 | 0.260 (6) | 0.950 (6) | 0.476 (3) | 0.020* | 0.046 (4) |
H21 | 0.2114 | 0.6306 | 0.2499 | 0.021* | |
H21A | 0.1668 | 0.4052 | 0.1776 | 0.024* | |
H21B | 0.1711 | 0.2746 | 0.2840 | 0.024* | |
H22 | 0.5657 | 0.3238 | 0.2727 | 0.026* | |
H23A | 0.8114 | 0.0073 | 0.1750 | 0.026* | |
H23B | 0.8768 | 0.1284 | 0.2379 | 0.026* | |
H3A | 0.3179 | 0.8359 | 0.3031 | 0.029* | 0.954 (4) |
H3B | 0.1857 | 0.9529 | 0.3993 | 0.029* | 0.954 (4) |
H3C | 0.0846 | 0.8847 | 0.3275 | 0.029* | 0.954 (4) |
H6A | 0.2873 | 0.0521 | 0.5604 | 0.027* | |
H6B | 0.3007 | 0.1341 | 0.6533 | 0.027* | |
H1A | 1.7660 | 0.2752 | −0.0782 | 0.031* | |
H1B | 1.7957 | 0.1035 | −0.1101 | 0.031* | |
H41A | 0.1654 | 1.0757 | 0.4962 | 0.030* | 0.046 (4) |
H41B | 0.2319 | 0.9205 | 0.4143 | 0.030* | 0.046 (4) |
H41C | 0.3936 | 0.9553 | 0.4610 | 0.030* | 0.046 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
K1 | 0.0261 (2) | 0.0163 (2) | 0.0163 (2) | −0.00537 (17) | −0.00243 (17) | −0.00119 (15) |
N1 | 0.0208 (8) | 0.0132 (8) | 0.0159 (7) | −0.0056 (6) | −0.0034 (6) | −0.0008 (6) |
C2 | 0.0135 (8) | 0.0155 (9) | 0.0168 (9) | −0.0038 (7) | −0.0009 (7) | −0.0035 (7) |
N21 | 0.0223 (8) | 0.0150 (8) | 0.0139 (7) | −0.0048 (6) | −0.0036 (6) | −0.0014 (6) |
C21 | 0.0233 (10) | 0.0203 (10) | 0.0170 (9) | −0.0070 (8) | −0.0058 (8) | −0.0045 (7) |
C22 | 0.0259 (10) | 0.0152 (9) | 0.0138 (8) | −0.0067 (8) | −0.0050 (8) | 0.0002 (7) |
O21 | 0.0318 (8) | 0.0200 (7) | 0.0245 (7) | −0.0055 (6) | −0.0090 (6) | −0.0082 (6) |
N22 | 0.0211 (8) | 0.0248 (9) | 0.0192 (8) | −0.0059 (7) | −0.0024 (7) | −0.0081 (7) |
C23 | 0.0217 (10) | 0.0196 (10) | 0.0221 (10) | −0.0040 (8) | −0.0058 (8) | −0.0007 (8) |
C24 | 0.0239 (10) | 0.0152 (10) | 0.0250 (10) | −0.0065 (8) | −0.0061 (8) | −0.0013 (7) |
O22 | 0.0379 (8) | 0.0153 (7) | 0.0256 (7) | −0.0030 (6) | −0.0087 (6) | 0.0018 (6) |
O23 | 0.0233 (8) | 0.0301 (9) | 0.0443 (9) | −0.0067 (7) | 0.0013 (7) | 0.0076 (7) |
N3 | 0.0194 (8) | 0.0121 (8) | 0.0141 (7) | −0.0051 (6) | −0.0020 (6) | −0.0007 (6) |
C3 | 0.0294 (11) | 0.0105 (10) | 0.0169 (9) | −0.0050 (8) | −0.0055 (8) | 0.0013 (7) |
C4 | 0.0170 (9) | 0.0155 (9) | 0.0179 (9) | −0.0062 (7) | −0.0004 (7) | −0.0040 (7) |
O4 | 0.0425 (9) | 0.0172 (7) | 0.0222 (7) | −0.0139 (6) | −0.0076 (6) | −0.0027 (5) |
C5 | 0.0190 (9) | 0.0145 (9) | 0.0158 (8) | −0.0061 (7) | −0.0037 (7) | −0.0013 (7) |
N5 | 0.0296 (9) | 0.0180 (9) | 0.0182 (8) | −0.0085 (7) | −0.0058 (7) | 0.0004 (6) |
O5 | 0.0442 (9) | 0.0211 (8) | 0.0195 (7) | −0.0129 (7) | −0.0112 (6) | 0.0035 (6) |
C6 | 0.0167 (9) | 0.0145 (9) | 0.0168 (8) | −0.0065 (7) | −0.0017 (7) | −0.0013 (7) |
N6 | 0.0373 (10) | 0.0157 (8) | 0.0185 (8) | −0.0127 (7) | −0.0089 (7) | 0.0012 (6) |
O1 | 0.0340 (8) | 0.0218 (8) | 0.0203 (7) | −0.0072 (7) | −0.0083 (6) | 0.0025 (6) |
K1—O23 | 2.617 (2) | N22—C23 | 1.453 (2) |
K1—O22i | 2.632 (2) | C23—C24 | 1.531 (3) |
K1—O21ii | 2.747 (2) | C24—O22 | 1.250 (2) |
K1—O5iii | 2.769 (2) | C24—O23 | 1.247 (2) |
K1—O1 | 2.772 (2) | O4—C41 | 1.41 (4) |
K1—O21iv | 2.850 (2) | N21—H21 | 0.8800 |
N1—C2 | 1.327 (2) | C21—H21A | 0.9900 |
C2—N3 | 1.381 (2) | C21—H21B | 0.9900 |
N3—C4 | 1.403 (2) | N22—H22 | 0.8800 |
C4—C5 | 1.444 (3) | C23—H23A | 0.9900 |
C5—C6 | 1.439 (3) | C23—H23B | 0.9900 |
C6—N1 | 1.344 (2) | C3—H3A | 0.9800 |
C2—N21 | 1.333 (2) | C3—H3B | 0.9800 |
N3—C3 | 1.471 (2) | C3—H3C | 0.9800 |
C4—O4 | 1.224 (2) | N6—H6A | 0.8800 |
C5—N5 | 1.351 (2) | N6—H6B | 0.8800 |
N5—O5 | 1.280 (2) | O1—H1A | 0.820 |
C6—N6 | 1.317 (2) | O1—H1B | 0.820 |
N21—C21 | 1.458 (2) | C41—H41A | 0.9800 |
C21—C22 | 1.527 (3) | C41—H41B | 0.9800 |
C22—O21 | 1.232 (2) | C41—H41C | 0.9800 |
C22—N22 | 1.329 (2) | ||
O23—K1—O5iii | 110.50 (5) | C24—C23—H23A | 108.6 |
O23—K1—O21iv | 74.09 (5) | N22—C23—H23B | 108.6 |
O23—K1—O21ii | 90.62 (5) | C24—C23—H23B | 108.6 |
O23—K1—O22i | 100.40 (5) | H23A—C23—H23B | 107.5 |
O21ii—K1—O5iii | 76.04 (4) | O23—C24—O22 | 126.76 (19) |
O22i—K1—O5iii | 90.89 (4) | O23—C24—C23 | 114.19 (17) |
O21iv—K1—O21ii | 92.51 (4) | O22—C24—C23 | 119.04 (17) |
O21iv—K1—O22i | 99.81 (4) | C24—O22—K1i | 135.26 (13) |
O5iii—K1—O1 | 90.22 (4) | C24—O23—K1 | 134.77 (13) |
O21iv—K1—O1 | 82.27 (4) | C2—N3—C4 | 120.47 (15) |
O21ii—K1—O1 | 77.49 (4) | C2—N3—C3 | 121.00 (15) |
O22i—K1—O1 | 96.14 (5) | C4—N3—C3 | 118.50 (15) |
O23—K1—O1 | 153.06 (5) | N3—C3—H3A | 109.5 |
O5iii—K1—O21iv | 167.50 (4) | N3—C3—H3B | 109.5 |
O22i—K1—O21ii | 165.30 (4) | N3—C3—H3C | 109.5 |
K1v—O21—K1ii | 87.49 (4) | O4—C4—N3 | 119.71 (17) |
C2—N1—C6 | 117.97 (16) | O4—C4—C5 | 124.62 (17) |
N1—C2—N21 | 118.25 (16) | N3—C4—C5 | 115.68 (15) |
N1—C2—N3 | 124.78 (16) | C4—O4—C41 | 111.7 (17) |
N21—C2—N3 | 116.97 (16) | N5—C5—C6 | 127.10 (17) |
C2—N21—C21 | 122.63 (16) | N5—C5—C4 | 113.99 (16) |
C2—N21—H21 | 118.7 | C6—C5—C4 | 118.89 (16) |
C21—N21—H21 | 118.7 | O5—N5—C5 | 117.98 (16) |
N21—C21—C22 | 115.29 (16) | N5—O5—K1vi | 127.96 (11) |
N21—C21—H21A | 108.5 | N6—C6—N1 | 118.02 (16) |
C22—C21—H21A | 108.5 | N6—C6—C5 | 119.90 (16) |
N21—C21—H21B | 108.5 | N1—C6—C5 | 122.06 (16) |
C22—C21—H21B | 108.5 | C6—N6—H6A | 120.0 |
H21A—C21—H21B | 107.5 | C6—N6—H6B | 120.0 |
O21—C22—N22 | 123.83 (17) | H6A—N6—H6B | 120.0 |
O21—C22—C21 | 118.51 (17) | K1—O1—H1A | 103.0 |
N22—C22—C21 | 117.64 (15) | K1—O1—H1B | 97.0 |
C22—O21—K1ii | 152.27 (13) | H1A—O1—H1B | 110.0 |
C22—O21—K1v | 118.67 (12) | O4—C41—H41A | 109.5 |
C22—N22—C23 | 122.60 (16) | O4—C41—H41B | 109.5 |
C22—N22—H22 | 118.7 | H41A—C41—H41B | 109.5 |
C23—N22—H22 | 118.7 | O4—C41—H41C | 109.5 |
N22—C23—C24 | 114.80 (16) | H41A—C41—H41C | 109.5 |
N22—C23—H23A | 108.6 | H41B—C41—H41C | 109.5 |
C6—N1—C2—N21 | 175.58 (16) | K1vii—K1—O23—C24 | 168.0 (2) |
C6—N1—C2—N3 | −4.2 (3) | N1—C2—N3—C4 | 4.5 (3) |
N1—C2—N21—C21 | −2.2 (3) | N21—C2—N3—C4 | −175.33 (15) |
N3—C2—N21—C21 | 177.61 (15) | N1—C2—N3—C3 | −177.47 (17) |
C2—N21—C21—C22 | −86.2 (2) | N21—C2—N3—C3 | 2.7 (2) |
N21—C21—C22—O21 | −166.52 (16) | C2—N3—C4—O4 | 178.40 (17) |
N21—C21—C22—N22 | 15.1 (2) | C3—N3—C4—O4 | 0.3 (3) |
N22—C22—O21—K1ii | 41.0 (4) | C2—N3—C4—C5 | −1.3 (2) |
C21—C22—O21—K1ii | −137.2 (2) | C3—N3—C4—C5 | −179.45 (15) |
N22—C22—O21—K1v | −117.89 (17) | N3—C4—O4—C41 | −12.3 (18) |
C21—C22—O21—K1v | 63.88 (19) | C5—C4—O4—C41 | 167.4 (18) |
O21—C22—N22—C23 | 5.9 (3) | O4—C4—C5—N5 | −2.7 (3) |
C21—C22—N22—C23 | −175.9 (2) | N3—C4—C5—N5 | 177.07 (15) |
C22—N22—C23—C24 | 82.8 (2) | O4—C4—C5—C6 | 178.78 (18) |
N22—C23—C24—O22 | −5.3 (3) | N3—C4—C5—C6 | −1.5 (2) |
N22—C23—C24—O23 | 175.4 (2) | C6—C5—N5—O5 | −3.6 (3) |
O23—C24—O22—K1i | −98.6 (2) | C4—C5—N5—O5 | 177.94 (15) |
C23—C24—O22—K1i | 82.3 (2) | C5—N5—O5—K1vi | −176.56 (12) |
O22—C24—O23—K1 | 25.9 (3) | C2—N1—C6—N6 | −177.56 (16) |
C23—C24—O23—K1 | −154.94 (14) | C2—N1—C6—C5 | 1.0 (3) |
O22i—K1—O23—C24 | 24.3 (2) | N5—C5—C6—N6 | 2.0 (3) |
O21ii—K1—O23—C24 | −145.9 (2) | C4—C5—C6—N6 | −179.69 (16) |
O5iii—K1—O23—C24 | −70.6 (2) | N5—C5—C6—N1 | −176.60 (17) |
O1—K1—O23—C24 | 151.31 (17) | C4—C5—C6—N1 | 1.8 (3) |
O21iv—K1—O23—C24 | 121.7 (2) |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+2, −y, −z; (iii) x+1, y, z−1; (iv) x+1, y, z; (v) x−1, y, z; (vi) x−1, y, z+1; (vii) −x+3, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O22iv | 0.82 | 1.93 | 2.742 (2) | 170 |
O1—H1B···O23vii | 0.82 | 1.89 | 2.687 (2) | 164 |
N6—H6A···O4viii | 0.88 | 1.99 | 2.820 (2) | 156 |
N6—H6B···O5 | 0.88 | 1.96 | 2.614 (2) | 130 |
N21—H21···O1i | 0.88 | 1.92 | 2.715 (2) | 150 |
Symmetry codes: (i) −x+2, −y+1, −z; (iv) x+1, y, z; (vii) −x+3, −y, −z; (viii) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | K+·C9H11N6O5−·H2O |
Mr | 340.35 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 150 |
a, b, c (Å) | 7.4440 (4), 7.4642 (4), 13.5136 (6) |
α, β, γ (°) | 80.3701 (17), 76.0568 (18), 68.6413 (14) |
V (Å3) | 676.06 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.44 |
Crystal size (mm) | 0.25 × 0.10 × 0.10 |
Data collection | |
Diffractometer | KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.926, 0.959 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7466, 3476, 2696 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.678 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.113, 1.07 |
No. of reflections | 3476 |
No. of parameters | 205 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.52 |
Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), DENZO-SMN, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2000), SHELXL97 and PRPKAPPA (Ferguson, 1999).
K1—O23 | 2.617 (2) | C4—O4 | 1.224 (2) |
K1—O22i | 2.632 (2) | C5—N5 | 1.351 (2) |
K1—O21ii | 2.747 (2) | N5—O5 | 1.280 (2) |
K1—O5iii | 2.769 (2) | C6—N6 | 1.317 (2) |
K1—O1 | 2.772 (2) | N21—C21 | 1.458 (2) |
K1—O21iv | 2.850 (2) | C21—C22 | 1.527 (3) |
N1—C2 | 1.327 (2) | C22—O21 | 1.232 (2) |
C2—N3 | 1.381 (2) | C22—N22 | 1.329 (2) |
N3—C4 | 1.403 (2) | N22—C23 | 1.453 (2) |
C4—C5 | 1.444 (3) | C23—C24 | 1.531 (3) |
C5—C6 | 1.439 (3) | C24—O22 | 1.250 (2) |
C6—N1 | 1.344 (2) | C24—O23 | 1.247 (2) |
C2—N21 | 1.333 (2) | O4—C41 | 1.41 (4) |
N3—C3 | 1.471 (2) | ||
O23—K1—O5iii | 110.50 (5) | O5iii—K1—O1 | 90.22 (4) |
O23—K1—O21iv | 74.09 (5) | O21iv—K1—O1 | 82.27 (4) |
O23—K1—O21ii | 90.62 (5) | O21ii—K1—O1 | 77.49 (4) |
O23—K1—O22i | 100.40 (5) | O22i—K1—O1 | 96.14 (5) |
O21ii—K1—O5iii | 76.04 (4) | O23—K1—O1 | 153.06 (5) |
O22i—K1—O5iii | 90.89 (4) | O5iii—K1—O21iv | 167.50 (4) |
O21iv—K1—O21ii | 92.51 (4) | O22i—K1—O21ii | 165.30 (4) |
O21iv—K1—O22i | 99.81 (4) | K1v—O21—K1ii | 87.49 (4) |
C2—N21—C21—C22 | −86.2 (2) | C22—N22—C23—C24 | 82.8 (2) |
N21—C21—C22—N22 | 15.1 (2) | N22—C23—C24—O22 | −5.3 (3) |
C21—C22—N22—C23 | −175.9 (2) | N22—C23—C24—O23 | 175.4 (2) |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+2, −y, −z; (iii) x+1, y, z−1; (iv) x+1, y, z; (v) x−1, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O22iv | 0.82 | 1.93 | 2.742 (2) | 170 |
O1—H1B···O23vi | 0.82 | 1.89 | 2.687 (2) | 164 |
N6—H6A···O4vii | 0.88 | 1.99 | 2.820 (2) | 156 |
N6—H6B···O5 | 0.88 | 1.96 | 2.614 (2) | 130 |
N21—H21···O1i | 0.88 | 1.92 | 2.715 (2) | 150 |
Symmetry codes: (i) −x+2, −y+1, −z; (iv) x+1, y, z; (vi) −x+3, −y, −z; (vii) x, y−1, z. |
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In this paper, we report the structure of a hydrated potassium salt, (I), of the pyrimidylglycylglycinate ligand L- [where LH = (1)]; we have recently reported the structure of the analogous hydrated K salt derived from the simpler pyrimidylglycine (2) in which the cations and anions form organic–inorganic hybrid sheets, which are linked by hydrogen bonds into a three-dimensional framework (Low et al., 2001). The L- anion contains further ligating sites in the form of the amidic O atom of the glycylglycinate fragment, and the resulting K salt takes the form of a three-dimensional coordination polymer.
The potassium in (I) is coordinated by six O atoms, one of which is the water O1 atom within the asymmetric unit, while the other five are components of five different anions. The K—O distances in (I) are typical of their type and the range of these distances is fairly small (Table 1). The coordination geometry at K is approximately octahedral with the cis-O—K—O angles ranging from 74.09 (5) to 110.50 (5)°, with a mean of 90.08°. It is notable that although the nitroso O5 atom participates in the K coordination, there is no evidence for η2-coordination of the nitroso group as observed in the K salt of (2) (Low et al., 2001). In addition to O1 and O5, the three O atoms in the glycylglycinate unit all act as ligating atoms, and the amidic O21 atom acts as a bridging site between pairs of K centres. The structure which results from the octahedral coordination of K is the three-dimensional framework constructed from the K and the anions: the water O1 atom occupies one coordination site but does not directly contribute to the formation of the framework. The framework is reinforced, although its character is not altered, by hydrogen bonds primarily involving the coordinated water molecules.
Adopting the sub-structure approach (Gregson et al., 2000), the framework structure can most readily be analysed in terms of two-dimensional sheets generated by translations only, with each sheet formed from two one-dimensional motifs, again generated by translation only. These sheets are linked by means of the bridging action of the amidic O atoms.
Within the asymmetric unit, the array O1–K1–O23 is approximately linear (Fig. 1 and Table 1) and atoms O21 at (1 + x, y, z) and O5 at (1 + x, y, -1 + z) complete an approximately square-planar KO4 subset of the KO6 coordination polyhedron. This KO4 unit forms the basis of a two-dimensional net. Atom O21 in the anion at (x, y, z) is coordinated to K1 at (-1 + x, y, z), so producing by translation a chain motif running parallel to the [100] direction; adopting for coordination polymers (Starbuck et al., 1999) the graph-set approach developed for hydrogen-bonded supramolecular aggregation (Etter, 1990; Bernstein et al., 1995; Motherwell et al., 2000), this chain is of the C(7) type. In the same anion at (x, y, z), O5 is coordinated to K1 at (-1 + x, y, 1 + z), so producing a C(14) chain parallel to [101]. The combination of the [100] and [101] chain generates a continuous sheet parallel to (010) and built from a single type of R36(32) ring (Fig. 2); in this descriptor, the number of donors defines the number of O atoms coordinated to K within the ring and the number of acceptors defines the number of K centres within the ring. There are two such sheets running through each unit cell, related to one another by the action of the centres of inversion; the linking of these sheets into a continuous framework is most readily analysed in terms of a chain of fused rings running parallel to [010].
Two of the O atoms coordinated to K1 at (x, y, z) are the amidic atoms O21 in the two anions at (1 + x, y, z) and (2 - x, -y, -z); this pair of O atoms also coordinate to K1 at (3 - x, -y, -z), so generating a centrosymmetric K2O2 parallelogram centred at (3/2,0,0). In such a K2O2 ring, the K atoms are components of different (010) nets. A stack of K2O2 rings centred at (3/2,n,0) (n = zero or integer) are linked by the anions acting as bidentate ligands. The reference K2O2 ring centred at (3/2,0,0) contains O atoms which are components of the anions at (1 + x, y, z) and (2 - x, -y, -z); the carboxylate O22 atom in the anion at (1 + x, y, z) is coordinated to K1 at (3 - x, 1 - y, -z), which is a component of the K2O2 ring centred at (3/2,1,0), while O22 in the anion at (2 - x, -y, -z) is coordinated to K1 at (x, -1 + y, z), a component of the K2O2 unit centred at (3/2,-1,0). In this manner, adjacent K2O2 units along the [010] direction, centred at (3/2,n,0) (n = zero or integer), are linked by pairs of anions forming 14-membered rings centred at (3/2,n + 1/2,0) (n = zero or integer) producing a chain of fused rings (Fig. 3). The combination of the (010) sheets and the [010] chains then generates the overall framework, built solely from K—O interactions.
The K2O2 ring motif is also a characteristic feature of the hydrated K salt derived from the simpler pyrimidylglycine derivative (2) (Low et al., 2001). However, in this latter compound, the structure is based upon continuous ribbons of K2O2 rings, fused in a spiro fashion at the K sites; the metal–oxygen ribbons are linked into sheets by the anions, so that the sheets are thus organic–inorganic hybrids consisting of alternating strips of inorganic metal–oxygen ribbons and organic heterocyclic linkers.
Although the water molecules play no direct role in the construction of the three-dimensional coordination polymer framework, the hydrogen bonds formed by the water molecules serve to reinforce this framework (Table 2). Thus water O1 at (x, y, z) acts as a hydrogen-bond donor, via H1A, to carboxylate O22 at (1 + x, y, z), so reinforcing the (010 sheet (cf. Fig. 2), and the same water acts as donor, via H1B, to carboxylate O23 at (3 - x, -y, -z) so reinforcing the [010] chain (cf. Fig. 3).
The dimensions of the pyrimidyl ring (Table 1) show the marked polarization noted in previous studies of amino acid derivatives containing this heterocycle (Low et al., 2000, 2001). In particular, the bond N1—C2 is similar in length to the C2–N21 and C6—N6 bonds, and it is not possible to assign the one as a double bond and the remainder as single bonds; secondly, the dimensions of the C-nitroso fragment provide evidence of significant electronic delocalization since in simple neutral compounds where there is no possibility of such delocalization these distances normally differ by at least 0.20 Å (Talberg, 1977; Schlemper et al., 1986) and the N—O distance rarely exceeds 1.25 Å (Davis et al., 1965; Bauer & Andreassen, 1972; Talberg, 1977; Schlemper et al., 1986). Consequently, the charge-separated form (1a) is a more realistic representation of the electronic structure of the anion in (I). The conformation of the glycyl side chain shows some unexpected features: in addition to the usual trans planar –C(O)—N(H)– fragment, the torsion angles in the chain from C2 to C24 follow the sequence sc, sp, ap, sc. The synthesis of (1) involves a methylation step to introduce the methyl group at N3; in addition to (1), the X-ray analysis revealed the presence of 4.6 (4)% of the isomeric form (1 b), in which methylation had occurred at O4 rather than at N3. This small quantity cannot readily be detected spectroscopically, nor readily removed. However, since O4 is not involved in the coordination to K, the presence of a small quantity of (1 b) does not affect the resulting structure in any way.