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The title complex, [Sr
2(C
5H
5N
4O
3)
4(H
2O)
6], forms centrosymmetric dimers in which one water ligand bridges two Sr centres and in which one of the anionic ligands is bidentate and bonded to just one Sr atom, and the other is tridentate and bridges the two Sr centres within the dimer. The dimeric units are linked by an extensive series of O-H
O, O-H
N and N-H
O hydrogen bonds to form a complex three-dimensional framework.
Supporting information
CCDC reference: 204030
Potassium 6-amino-3-methyl-5-nitrosopyrimidine-2,4(1H,3H)-dionate was prepared by the addition of water (20 mmol) to a suspension of 6-amino-3,4-dihydro-3-methyl-2-methoxy-5-nitroso-4-oxopyrimidine (20 mmol) and potassium hydroxide (20 mmol) in methanol (50 ml). The product was filtered off and recrystallized once from water. Analysis, found: C 28.6, H 2.5, N 26.6%; C5H5KN4O3 requires: C 28.8, H 2.4, N 26.9%. The title strontium complex, (III), was obtained by adding strontium chloride hexahydrate (1 mmol) to a solution of the potassium salt (2 mmol) in water (40 ml). The orange product was filtered off, and washed with cold water and then ethanol. Analysis, found: C 24.3, H 3.4, N 21.9%; C20H32N16O18Sr2 requires: C 25.0, H 3.4, N 23.4%. Crystals of (III) suitable for single-crystal X-ray diffraction were grown by slow evaporation of a dilute solution in water.
Compound (III) is triclinic; space group P1 was assumed and confirmed by the analysis. H atoms were treated as riding atoms, with C—H distances of 0.98 Å, N—H distances of 0.88 Å and O—H distances in the range 0.84–0.88 Å.
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, 2002); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Di-µ-aqua-bis[µ-6-amino-3-methyl-5-nitrosopyrimidine-2,4(1
H,3H)-dionato-
κ3O4,
N5:
O5]bis{diaqua[6-amino-3-methyl-5-nitrosopyrimidine-2,4(1
H,3H)- dionato-
κ2N1,
O2]strontium(II)}
top
Crystal data top
[Sr2(C5H5N4O3)4(H2O)6] | Z = 1 |
Mr = 959.86 | F(000) = 484 |
Triclinic, P1 | Dx = 1.843 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.9388 (2) Å | Cell parameters from 3883 reflections |
b = 9.8852 (2) Å | θ = 3.1–27.5° |
c = 14.1962 (4) Å | µ = 3.19 mm−1 |
α = 69.965 (2)° | T = 120 K |
β = 77.518 (2)° | Block, orange |
γ = 72.361 (2)° | 0.30 × 0.28 × 0.25 mm |
V = 864.91 (4) Å3 | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3883 independent reflections |
Radiation source: rotating anode | 3540 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ϕ scans, and ω scans with κ offsets | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −8→8 |
Tmin = 0.391, Tmax = 0.449 | k = −12→12 |
12233 measured reflections | l = −17→18 |
Refinement top
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) = 0.068 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0297P)2 + 0.7547P] where P = (Fo2 + 2Fc2)/3 |
3883 reflections | (Δ/σ)max = 0.001 |
255 parameters | Δρmax = 0.55 e Å−3 |
0 restraints | Δρmin = −0.68 e Å−3 |
Crystal data top
[Sr2(C5H5N4O3)4(H2O)6] | γ = 72.361 (2)° |
Mr = 959.86 | V = 864.91 (4) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.9388 (2) Å | Mo Kα radiation |
b = 9.8852 (2) Å | µ = 3.19 mm−1 |
c = 14.1962 (4) Å | T = 120 K |
α = 69.965 (2)° | 0.30 × 0.28 × 0.25 mm |
β = 77.518 (2)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3883 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 3540 reflections with I > 2σ(I) |
Tmin = 0.391, Tmax = 0.449 | Rint = 0.031 |
12233 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.028 | 0 restraints |
wR(F2) = 0.068 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.55 e Å−3 |
3883 reflections | Δρmin = −0.68 e Å−3 |
255 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Sr1 | 0.43236 (3) | 0.49004 (2) | 0.653983 (13) | 0.01341 (7) | |
N11 | 0.2042 (3) | 1.15434 (19) | 0.46487 (13) | 0.0156 (4) | |
C12 | 0.1240 (3) | 1.1452 (2) | 0.56136 (16) | 0.0140 (4) | |
O12 | 0.0509 (2) | 1.26071 (16) | 0.58784 (11) | 0.0180 (3) | |
C13 | 0.0286 (4) | 1.0049 (3) | 0.73956 (16) | 0.0207 (5) | |
N13 | 0.1185 (3) | 1.00806 (19) | 0.63491 (13) | 0.0139 (4) | |
C14 | 0.2039 (3) | 0.8740 (2) | 0.61425 (16) | 0.0139 (4) | |
O14 | 0.2000 (2) | 0.75540 (16) | 0.68092 (11) | 0.0179 (3) | |
C15 | 0.2947 (3) | 0.8840 (2) | 0.51022 (15) | 0.0137 (4) | |
N15 | 0.3788 (3) | 0.7529 (2) | 0.49340 (13) | 0.0154 (4) | |
O15 | 0.4562 (2) | 0.75189 (17) | 0.40238 (11) | 0.0188 (3) | |
C16 | 0.2895 (3) | 1.0292 (2) | 0.43806 (16) | 0.0138 (4) | |
N16 | 0.3733 (3) | 1.0400 (2) | 0.34377 (13) | 0.0196 (4) | |
N21 | 0.3883 (3) | 0.4442 (2) | 0.85286 (13) | 0.0160 (4) | |
C22 | 0.5225 (3) | 0.3079 (2) | 0.87216 (16) | 0.0156 (4) | |
O22 | 0.6188 (2) | 0.25973 (17) | 0.80200 (11) | 0.0205 (3) | |
N23 | 0.5503 (3) | 0.2212 (2) | 0.97231 (13) | 0.0176 (4) | |
C23 | 0.7056 (4) | 0.0792 (3) | 0.98704 (19) | 0.0288 (6) | |
C24 | 0.4477 (3) | 0.2668 (3) | 1.05545 (16) | 0.0183 (4) | |
O24 | 0.4756 (3) | 0.18474 (19) | 1.14169 (12) | 0.0267 (4) | |
C25 | 0.3096 (3) | 0.4159 (2) | 1.03339 (15) | 0.0160 (4) | |
N25 | 0.2204 (3) | 0.4634 (2) | 1.11311 (14) | 0.0194 (4) | |
O25 | 0.0970 (2) | 0.59502 (18) | 1.09777 (12) | 0.0227 (4) | |
C26 | 0.2885 (3) | 0.4987 (2) | 0.92849 (16) | 0.0141 (4) | |
N26 | 0.1678 (3) | 0.6350 (2) | 0.90426 (14) | 0.0181 (4) | |
O1 | 0.2560 (2) | 0.50204 (16) | 0.49907 (11) | 0.0166 (3) | |
O2 | 0.1462 (3) | 0.3612 (2) | 0.73356 (12) | 0.0259 (4) | |
O3 | 0.6852 (3) | 0.60167 (19) | 0.68631 (12) | 0.0256 (4) | |
H13A | −0.0481 | 0.9283 | 0.7676 | 0.031* | |
H13B | −0.0634 | 1.1021 | 0.7398 | 0.031* | |
H13C | 0.1375 | 0.9822 | 0.7807 | 0.031* | |
H16A | 0.3726 | 1.1281 | 0.2997 | 0.024* | |
H16B | 0.4298 | 0.9592 | 0.3250 | 0.024* | |
H23A | 0.6917 | 0.0267 | 0.9425 | 0.043* | |
H23B | 0.6871 | 0.0181 | 1.0575 | 0.043* | |
H23C | 0.8415 | 0.0980 | 0.9709 | 0.043* | |
H26A | 0.1564 | 0.6854 | 0.8404 | 0.022* | |
H26B | 0.0992 | 0.6751 | 0.9521 | 0.022* | |
H1A | 0.1606 | 0.5754 | 0.4768 | 0.020* | |
H1B | 0.2039 | 0.4292 | 0.5177 | 0.020* | |
H2A | 0.0812 | 0.3341 | 0.6991 | 0.031* | |
H2B | 0.0593 | 0.3733 | 0.7870 | 0.031* | |
H3A | 0.7298 | 0.5945 | 0.7418 | 0.031* | |
H3B | 0.7591 | 0.6549 | 0.6379 | 0.031* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Sr1 | 0.01849 (11) | 0.01170 (11) | 0.00886 (11) | −0.00230 (7) | −0.00038 (7) | −0.00369 (7) |
N11 | 0.0197 (9) | 0.0122 (9) | 0.0135 (9) | −0.0037 (7) | −0.0005 (7) | −0.0030 (7) |
C12 | 0.0155 (10) | 0.0115 (10) | 0.0148 (10) | −0.0017 (8) | −0.0044 (8) | −0.0036 (8) |
O12 | 0.0236 (8) | 0.0126 (7) | 0.0171 (8) | −0.0011 (6) | −0.0027 (6) | −0.0065 (6) |
C13 | 0.0270 (12) | 0.0199 (11) | 0.0118 (10) | −0.0014 (9) | 0.0027 (9) | −0.0075 (8) |
N13 | 0.0175 (9) | 0.0101 (8) | 0.0117 (8) | −0.0005 (7) | −0.0005 (7) | −0.0039 (7) |
C14 | 0.0148 (10) | 0.0122 (10) | 0.0148 (10) | −0.0012 (8) | −0.0034 (8) | −0.0050 (8) |
O14 | 0.0262 (8) | 0.0118 (7) | 0.0118 (7) | −0.0024 (6) | 0.0000 (6) | −0.0022 (6) |
C15 | 0.0165 (10) | 0.0123 (10) | 0.0115 (10) | −0.0028 (8) | −0.0020 (8) | −0.0032 (8) |
N15 | 0.0186 (9) | 0.0153 (9) | 0.0115 (9) | −0.0029 (7) | −0.0002 (7) | −0.0052 (7) |
O15 | 0.0265 (8) | 0.0159 (8) | 0.0116 (7) | −0.0024 (6) | 0.0016 (6) | −0.0060 (6) |
C16 | 0.0139 (9) | 0.0129 (10) | 0.0142 (10) | −0.0035 (8) | −0.0017 (8) | −0.0035 (8) |
N16 | 0.0284 (10) | 0.0124 (9) | 0.0131 (9) | −0.0029 (8) | 0.0017 (8) | −0.0023 (7) |
N21 | 0.0194 (9) | 0.0150 (9) | 0.0128 (9) | −0.0032 (7) | −0.0023 (7) | −0.0042 (7) |
C22 | 0.0178 (10) | 0.0158 (10) | 0.0127 (10) | −0.0043 (8) | −0.0023 (8) | −0.0033 (8) |
O22 | 0.0234 (8) | 0.0205 (8) | 0.0139 (8) | 0.0010 (6) | −0.0006 (6) | −0.0071 (6) |
N23 | 0.0213 (9) | 0.0156 (9) | 0.0112 (9) | −0.0010 (7) | −0.0034 (7) | −0.0005 (7) |
C23 | 0.0315 (13) | 0.0209 (12) | 0.0242 (13) | 0.0039 (10) | −0.0064 (11) | −0.0021 (10) |
C24 | 0.0216 (11) | 0.0208 (11) | 0.0129 (10) | −0.0087 (9) | −0.0018 (9) | −0.0029 (8) |
O24 | 0.0351 (10) | 0.0264 (9) | 0.0121 (8) | −0.0062 (8) | −0.0029 (7) | 0.0009 (7) |
C25 | 0.0174 (10) | 0.0203 (11) | 0.0099 (10) | −0.0083 (9) | 0.0010 (8) | −0.0027 (8) |
N25 | 0.0224 (9) | 0.0231 (10) | 0.0148 (9) | −0.0104 (8) | 0.0015 (8) | −0.0066 (8) |
O25 | 0.0259 (8) | 0.0259 (9) | 0.0176 (8) | −0.0078 (7) | 0.0029 (7) | −0.0102 (7) |
C26 | 0.0114 (9) | 0.0174 (10) | 0.0176 (10) | −0.0073 (8) | 0.0012 (8) | −0.0087 (8) |
N26 | 0.0236 (9) | 0.0174 (9) | 0.0110 (9) | −0.0016 (8) | −0.0004 (7) | −0.0056 (7) |
O1 | 0.0189 (7) | 0.0130 (7) | 0.0163 (8) | −0.0024 (6) | −0.0028 (6) | −0.0033 (6) |
O2 | 0.0284 (9) | 0.0418 (11) | 0.0172 (8) | −0.0193 (8) | 0.0081 (7) | −0.0181 (7) |
O3 | 0.0384 (10) | 0.0300 (9) | 0.0131 (8) | −0.0210 (8) | −0.0033 (7) | −0.0012 (7) |
Geometric parameters (Å, º) top
N11—C12 | 1.345 (3) | C24—C25 | 1.465 (3) |
C12—N13 | 1.405 (3) | C25—C26 | 1.447 (3) |
N13—C14 | 1.382 (3) | C26—N21 | 1.331 (3) |
C14—C15 | 1.457 (3) | C22—O22 | 1.229 (3) |
C15—C16 | 1.445 (3) | N23—C23 | 1.468 (3) |
C16—N11 | 1.344 (3) | C24—O24 | 1.233 (3) |
C12—O12 | 1.250 (2) | C25—N25 | 1.330 (3) |
C13—N13 | 1.475 (3) | N25—O25 | 1.298 (2) |
C14—O14 | 1.232 (3) | C26—N26 | 1.326 (3) |
C15—N15 | 1.330 (3) | C23—H23A | 0.98 |
N15—O15 | 1.290 (2) | C23—H23B | 0.98 |
C16—N16 | 1.321 (3) | C23—H23C | 0.98 |
C13—H13A | 0.98 | N26—H26A | 0.88 |
C13—H13B | 0.98 | N26—H26B | 0.88 |
C13—H13C | 0.98 | Sr1—O1 | 2.6916 (15) |
N16—H16A | 0.88 | Sr1—O1i | 2.7127 (15) |
N16—H16B | 0.88 | Sr1—O2 | 2.5331 (16) |
Sr1—O14 | 2.7357 (15) | Sr1—O3 | 2.5250 (16) |
Sr1—N15 | 2.7946 (18) | Sr1—Sr1i | 4.2169 (4) |
Sr1—O15i | 2.6231 (15) | O1—H1A | 0.84 |
Sr1—N21 | 2.6654 (17) | O1—H1B | 0.84 |
Sr1—O22 | 2.7175 (15) | O2—H2A | 0.88 |
N21—C22 | 1.362 (3) | O2—H2B | 0.88 |
C22—N23 | 1.406 (3) | O3—H3A | 0.88 |
N23—C24 | 1.382 (3) | O3—H3B | 0.88 |
| | | |
O3—Sr1—O2 | 145.21 (5) | N15—C15—C16 | 127.06 (19) |
O3—Sr1—O15i | 122.60 (5) | N15—C15—C14 | 114.06 (18) |
O2—Sr1—O15i | 75.15 (5) | C16—C15—C14 | 118.87 (18) |
O3—Sr1—N21 | 73.13 (5) | O15—N15—C15 | 118.02 (17) |
O2—Sr1—N21 | 72.14 (5) | O15—N15—Sr1 | 120.69 (12) |
O15i—Sr1—N21 | 115.05 (5) | C15—N15—Sr1 | 120.79 (13) |
O3—Sr1—O1 | 139.14 (5) | N15—O15—Sr1i | 122.83 (12) |
O2—Sr1—O1 | 74.30 (5) | O15i—Sr1—N15 | 113.82 (5) |
O15i—Sr1—O1 | 64.33 (5) | O1—Sr1—O1i | 77.43 (5) |
N21—Sr1—O1 | 145.00 (5) | N16—C16—N11 | 118.87 (19) |
O3—Sr1—O1i | 71.00 (5) | N16—C16—C15 | 119.54 (19) |
O2—Sr1—O1i | 140.35 (5) | N11—C16—C15 | 121.58 (19) |
O15i—Sr1—O1i | 67.74 (5) | C16—N16—H16A | 120.0 |
N21—Sr1—O1i | 136.66 (5) | C16—N16—H16B | 120.0 |
O3—Sr1—O22 | 79.02 (5) | H16A—N16—H16B | 120.0 |
O2—Sr1—O22 | 80.04 (5) | C26—N21—C22 | 120.20 (18) |
O15i—Sr1—O22 | 70.98 (5) | C26—N21—Sr1 | 144.98 (14) |
N21—Sr1—O22 | 49.29 (5) | C22—N21—Sr1 | 94.75 (12) |
O1—Sr1—O22 | 132.63 (5) | O22—C22—N21 | 120.05 (19) |
O1i—Sr1—O22 | 100.01 (4) | O22—C22—N23 | 119.72 (19) |
O3—Sr1—O14 | 76.27 (5) | N21—C22—N23 | 120.22 (18) |
O2—Sr1—O14 | 93.09 (5) | O22—C22—Sr1 | 60.99 (11) |
O15i—Sr1—O14 | 159.75 (5) | N21—C22—Sr1 | 59.21 (10) |
N21—Sr1—O14 | 75.46 (5) | N23—C22—Sr1 | 175.70 (15) |
O1—Sr1—O14 | 96.89 (4) | C22—O22—Sr1 | 95.72 (13) |
O1i—Sr1—O14 | 117.60 (4) | C24—N23—C22 | 123.39 (18) |
O22—Sr1—O14 | 123.92 (4) | C24—N23—C23 | 119.40 (18) |
O3—Sr1—N15 | 81.26 (5) | C22—N23—C23 | 117.12 (18) |
O2—Sr1—N15 | 121.31 (6) | N23—C23—H23A | 109.5 |
N21—Sr1—N15 | 131.12 (5) | N23—C23—H23B | 109.5 |
O1—Sr1—N15 | 62.02 (5) | H23A—C23—H23B | 109.5 |
O1i—Sr1—N15 | 65.36 (5) | N23—C23—H23C | 109.5 |
O22—Sr1—N15 | 158.57 (5) | H23A—C23—H23C | 109.5 |
O14—Sr1—N15 | 58.15 (5) | H23B—C23—H23C | 109.5 |
O3—Sr1—Sr1i | 105.86 (4) | O24—C24—N23 | 120.5 (2) |
O2—Sr1—Sr1i | 108.82 (4) | O24—C24—C25 | 123.8 (2) |
O15i—Sr1—Sr1i | 58.65 (3) | N23—C24—C25 | 115.75 (18) |
N21—Sr1—Sr1i | 172.21 (4) | N25—C25—C26 | 126.5 (2) |
O1—Sr1—Sr1i | 38.89 (3) | N25—C25—C24 | 115.74 (18) |
O1i—Sr1—Sr1i | 38.53 (3) | C26—C25—C24 | 117.76 (18) |
O22—Sr1—Sr1i | 122.96 (3) | O25—N25—C25 | 118.26 (18) |
O14—Sr1—Sr1i | 112.00 (3) | N26—C26—N21 | 117.18 (19) |
N15—Sr1—Sr1i | 55.42 (4) | N26—C26—C25 | 120.22 (19) |
C16—N11—C12 | 119.65 (18) | N21—C26—C25 | 122.59 (19) |
O12—C12—N11 | 120.14 (19) | C26—N26—H26A | 120.0 |
O12—C12—N13 | 118.00 (18) | C26—N26—H26B | 120.0 |
N11—C12—N13 | 121.86 (18) | H26A—N26—H26B | 120.0 |
N13—C13—H13A | 109.5 | Sr1—O1—Sr1i | 102.57 (5) |
N13—C13—H13B | 109.5 | Sr1—O1—H1A | 120.2 |
H13A—C13—H13B | 109.5 | Sr1i—O1—H1A | 105.6 |
N13—C13—H13C | 109.5 | Sr1—O1—H1B | 107.7 |
H13A—C13—H13C | 109.5 | Sr1i—O1—H1B | 117.6 |
H13B—C13—H13C | 109.5 | H1A—O1—H1B | 104.0 |
C14—N13—C12 | 122.33 (17) | Sr1—O2—H2A | 123.5 |
C14—N13—C13 | 118.11 (17) | Sr1—O2—H2B | 125.9 |
C12—N13—C13 | 119.48 (17) | H2A—O2—H2B | 104.8 |
O14—C14—N13 | 120.77 (19) | Sr1—O3—H3A | 132.7 |
O14—C14—C15 | 123.58 (19) | Sr1—O3—H3B | 123.6 |
N13—C14—C15 | 115.64 (18) | H3A—O3—H3B | 103.5 |
C14—O14—Sr1 | 121.33 (13) | | |
| | | |
C16—N11—C12—O12 | 177.46 (19) | O15i—Sr1—N21—C22 | 26.43 (14) |
C16—N11—C12—N13 | −2.9 (3) | O1—Sr1—N21—C22 | 106.88 (14) |
O12—C12—N13—C14 | −176.89 (18) | O1i—Sr1—N21—C22 | −57.02 (15) |
N11—C12—N13—C14 | 3.4 (3) | O22—Sr1—N21—C22 | −2.32 (11) |
O12—C12—N13—C13 | −0.3 (3) | O14—Sr1—N21—C22 | −172.00 (13) |
N11—C12—N13—C13 | −179.96 (19) | N15—Sr1—N21—C22 | −153.85 (12) |
C12—N13—C14—O14 | 178.57 (19) | C26—N21—C22—O22 | −177.85 (19) |
C13—N13—C14—O14 | 1.9 (3) | Sr1—N21—C22—O22 | 4.5 (2) |
C12—N13—C14—C15 | −1.9 (3) | C26—N21—C22—N23 | 2.6 (3) |
C13—N13—C14—C15 | −178.56 (18) | Sr1—N21—C22—N23 | −175.05 (17) |
N13—C14—O14—Sr1 | −167.30 (14) | C26—N21—C22—Sr1 | 177.6 (2) |
C15—C14—O14—Sr1 | 13.2 (3) | O3—Sr1—C22—O22 | −95.09 (13) |
O3—Sr1—O14—C14 | 75.99 (16) | O2—Sr1—C22—O22 | 102.35 (14) |
O2—Sr1—O14—C14 | −137.55 (16) | O15i—Sr1—C22—O22 | 28.24 (13) |
O15i—Sr1—O14—C14 | −84.1 (2) | N21—Sr1—C22—O22 | −175.5 (2) |
N21—Sr1—O14—C14 | 151.80 (17) | O1—Sr1—C22—O22 | 73.52 (16) |
O1—Sr1—O14—C14 | −63.00 (16) | O1i—Sr1—C22—O22 | −36.86 (15) |
O1i—Sr1—O14—C14 | 16.38 (17) | O14—Sr1—C22—O22 | −167.66 (13) |
O22—Sr1—O14—C14 | 142.38 (15) | N15—Sr1—C22—O22 | −129.39 (14) |
N15—Sr1—O14—C14 | −12.16 (15) | Sr1i—Sr1—C22—O22 | 2.39 (17) |
C22—Sr1—O14—C14 | 148.23 (16) | O3—Sr1—C22—N21 | 80.45 (13) |
Sr1i—Sr1—O14—C14 | −25.82 (16) | O2—Sr1—C22—N21 | −82.10 (13) |
O14—C14—C15—N15 | −1.6 (3) | O15i—Sr1—C22—N21 | −156.21 (13) |
N13—C14—C15—N15 | 178.84 (17) | O1—Sr1—C22—N21 | −110.94 (13) |
O14—C14—C15—C16 | 179.61 (19) | O1i—Sr1—C22—N21 | 138.68 (12) |
N13—C14—C15—C16 | 0.1 (3) | O22—Sr1—C22—N21 | 175.5 (2) |
C16—C15—N15—O15 | −3.8 (3) | O14—Sr1—C22—N21 | 7.89 (13) |
C14—C15—N15—O15 | 177.59 (17) | N15—Sr1—C22—N21 | 46.16 (19) |
C16—C15—N15—Sr1 | 168.21 (16) | Sr1i—Sr1—C22—N21 | 177.93 (9) |
C14—C15—N15—Sr1 | −10.4 (2) | N21—C22—O22—Sr1 | −4.4 (2) |
O3—Sr1—N15—O15 | 103.93 (15) | N23—C22—O22—Sr1 | 175.13 (17) |
O2—Sr1—N15—O15 | −104.54 (14) | O3—Sr1—O22—C22 | 79.69 (13) |
O15i—Sr1—N15—O15 | −17.94 (18) | O2—Sr1—O22—C22 | −72.37 (13) |
N21—Sr1—N15—O15 | 162.34 (13) | O15i—Sr1—O22—C22 | −149.98 (14) |
O1—Sr1—N15—O15 | −57.52 (14) | N21—Sr1—O22—C22 | 2.58 (12) |
O1i—Sr1—N15—O15 | 30.90 (13) | O1—Sr1—O22—C22 | −130.02 (13) |
O22—Sr1—N15—O15 | 80.7 (2) | O1i—Sr1—O22—C22 | 147.91 (13) |
O14—Sr1—N15—O15 | −176.86 (16) | O14—Sr1—O22—C22 | 14.63 (15) |
C22—Sr1—N15—O15 | 137.49 (14) | N15—Sr1—O22—C22 | 103.08 (17) |
Sr1i—Sr1—N15—O15 | −12.29 (12) | Sr1i—Sr1—O22—C22 | −178.42 (12) |
O3—Sr1—N15—C15 | −67.86 (15) | O22—C22—N23—C24 | −179.8 (2) |
O2—Sr1—N15—C15 | 83.68 (16) | N21—C22—N23—C24 | −0.3 (3) |
O15i—Sr1—N15—C15 | 170.28 (14) | O22—C22—N23—C23 | 3.7 (3) |
N21—Sr1—N15—C15 | −9.45 (18) | N21—C22—N23—C23 | −176.7 (2) |
O1—Sr1—N15—C15 | 130.69 (16) | C22—N23—C24—O24 | 178.6 (2) |
O1i—Sr1—N15—C15 | −140.89 (17) | C23—N23—C24—O24 | −5.0 (3) |
O22—Sr1—N15—C15 | −91.08 (19) | C22—N23—C24—C25 | −1.9 (3) |
O14—Sr1—N15—C15 | 11.35 (14) | C23—N23—C24—C25 | 174.4 (2) |
C22—Sr1—N15—C15 | −34.3 (2) | O24—C24—C25—N25 | 3.4 (3) |
Sr1i—Sr1—N15—C15 | 175.92 (17) | N23—C24—C25—N25 | −176.05 (19) |
C15—N15—O15—Sr1i | −168.40 (14) | O24—C24—C25—C26 | −178.7 (2) |
Sr1—N15—O15—Sr1i | 19.59 (19) | N23—C24—C25—C26 | 1.9 (3) |
C12—N11—C16—N16 | −177.85 (19) | C26—C25—N25—O25 | 2.1 (3) |
C12—N11—C16—C15 | 1.0 (3) | C24—C25—N25—O25 | 179.80 (18) |
N15—C15—C16—N16 | 0.6 (3) | C22—N21—C26—N26 | 176.74 (19) |
C14—C15—C16—N16 | 179.21 (19) | Sr1—N21—C26—N26 | −7.4 (3) |
N15—C15—C16—N11 | −178.2 (2) | C22—N21—C26—C25 | −2.6 (3) |
C14—C15—C16—N11 | 0.4 (3) | Sr1—N21—C26—C25 | 173.33 (17) |
O3—Sr1—N21—C26 | 91.3 (2) | N25—C25—C26—N26 | −1.3 (3) |
O2—Sr1—N21—C26 | −86.6 (2) | C24—C25—C26—N26 | −179.02 (19) |
O15i—Sr1—N21—C26 | −150.0 (2) | N25—C25—C26—N21 | 178.0 (2) |
O1—Sr1—N21—C26 | −69.6 (3) | C24—C25—C26—N21 | 0.3 (3) |
O1i—Sr1—N21—C26 | 126.5 (2) | O3—Sr1—O1—Sr1i | 39.85 (9) |
O22—Sr1—N21—C26 | −178.8 (3) | O2—Sr1—O1—Sr1i | −151.90 (6) |
O14—Sr1—N21—C26 | 11.5 (2) | O15i—Sr1—O1—Sr1i | −71.12 (5) |
N15—Sr1—N21—C26 | 29.7 (3) | N21—Sr1—O1—Sr1i | −168.75 (7) |
C22—Sr1—N21—C26 | −176.5 (3) | O22—Sr1—O1—Sr1i | −92.10 (7) |
O3—Sr1—N21—C22 | −92.23 (13) | O14—Sr1—O1—Sr1i | 116.81 (5) |
O2—Sr1—N21—C22 | 89.83 (13) | N15—Sr1—O1—Sr1i | 68.58 (5) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N16—H16A···O24ii | 0.88 | 2.13 | 2.776 (3) | 129 |
N16—H16B···O15 | 0.88 | 1.94 | 2.594 (3) | 130 |
N26—H26A···O14 | 0.88 | 2.11 | 2.964 (3) | 164 |
N26—H26B···O25 | 0.88 | 1.94 | 2.595 (3) | 130 |
O1—H1A···O12iii | 0.84 | 1.94 | 2.772 (2) | 174 |
O1—H1B···O12iv | 0.84 | 2.09 | 2.920 (2) | 169 |
O2—H2A···O12iv | 0.88 | 2.02 | 2.846 (2) | 156 |
O2—H2B···O25v | 0.88 | 1.82 | 2.700 (2) | 173 |
O3—H3A···N25vi | 0.88 | 2.02 | 2.871 (3) | 163 |
O3—H3B···N11vii | 0.88 | 2.00 | 2.806 (3) | 152 |
Symmetry codes: (ii) x, y+1, z−1; (iii) −x, −y+2, −z+1; (iv) x, y−1, z; (v) −x, −y+1, −z+2; (vi) −x+1, −y+1, −z+2; (vii) −x+1, −y+2, −z+1. |
Experimental details
Crystal data |
Chemical formula | [Sr2(C5H5N4O3)4(H2O)6] |
Mr | 959.86 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 120 |
a, b, c (Å) | 6.9388 (2), 9.8852 (2), 14.1962 (4) |
α, β, γ (°) | 69.965 (2), 77.518 (2), 72.361 (2) |
V (Å3) | 864.91 (4) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 3.19 |
Crystal size (mm) | 0.30 × 0.28 × 0.25 |
|
Data collection |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.391, 0.449 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12233, 3883, 3540 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.068, 1.00 |
No. of reflections | 3883 |
No. of parameters | 255 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.55, −0.68 |
Selected geometric parameters (Å, º) topN11—C12 | 1.345 (3) | N21—C22 | 1.362 (3) |
C12—N13 | 1.405 (3) | C22—N23 | 1.406 (3) |
N13—C14 | 1.382 (3) | N23—C24 | 1.382 (3) |
C14—C15 | 1.457 (3) | C24—C25 | 1.465 (3) |
C15—C16 | 1.445 (3) | C25—C26 | 1.447 (3) |
C16—N11 | 1.344 (3) | C26—N21 | 1.331 (3) |
C12—O12 | 1.250 (2) | C22—O22 | 1.229 (3) |
C13—N13 | 1.475 (3) | N23—C23 | 1.468 (3) |
C14—O14 | 1.232 (3) | C24—O24 | 1.233 (3) |
C15—N15 | 1.330 (3) | C25—N25 | 1.330 (3) |
N15—O15 | 1.290 (2) | N25—O25 | 1.298 (2) |
C16—N16 | 1.321 (3) | C26—N26 | 1.326 (3) |
Sr1—O14 | 2.7357 (15) | Sr1—O1 | 2.6916 (15) |
Sr1—N15 | 2.7946 (18) | Sr1—O1i | 2.7127 (15) |
Sr1—O15i | 2.6231 (15) | Sr1—O2 | 2.5331 (16) |
Sr1—N21 | 2.6654 (17) | Sr1—O3 | 2.5250 (16) |
Sr1—O22 | 2.7175 (15) | Sr1—Sr1i | 4.2169 (4) |
| | | |
O15—N15—Sr1 | 120.69 (12) | O1—Sr1—O1i | 77.43 (5) |
N15—O15—Sr1i | 122.83 (12) | Sr1—O1—Sr1i | 102.57 (5) |
O15i—Sr1—N15 | 113.82 (5) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N16—H16A···O24ii | 0.88 | 2.13 | 2.776 (3) | 129 |
N16—H16B···O15 | 0.88 | 1.94 | 2.594 (3) | 130 |
N26—H26A···O14 | 0.88 | 2.11 | 2.964 (3) | 164 |
N26—H26B···O25 | 0.88 | 1.94 | 2.595 (3) | 130 |
O1—H1A···O12iii | 0.84 | 1.94 | 2.772 (2) | 174 |
O1—H1B···O12iv | 0.84 | 2.09 | 2.920 (2) | 169 |
O2—H2A···O12iv | 0.88 | 2.02 | 2.846 (2) | 156 |
O2—H2B···O25v | 0.88 | 1.82 | 2.700 (2) | 173 |
O3—H3A···N25vi | 0.88 | 2.02 | 2.871 (3) | 163 |
O3—H3B···N11vii | 0.88 | 2.00 | 2.806 (3) | 152 |
Symmetry codes: (ii) x, y+1, z−1; (iii) −x, −y+2, −z+1; (iv) x, y−1, z; (v) −x, −y+1, −z+2; (vi) −x+1, −y+1, −z+2; (vii) −x+1, −y+2, −z+1. |
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We recently reported the structure, at 150 K, of the dihydrated sodium salt derived from 6-amino-3-methyl-5-nitrosopyrimidine, (I) (Cuesta et al., 2001). In that salt, the Na cations and (C5H4N4O3)− anions, L, (II), form a one-dimensional coordination polymer in the form of a molecular ladder, and the ladders are linked into a continuous three-dimensional framework by a combination of O—H···O and O—H···N hydrogen bonds. Within the ladder, the anion utilizes one amidic O atom and the nitroso N atom to coordinate to a single Na atom, while the other amidic O atom bridges a pair of cations, forming a centrosymmetric Na2O2 ring. \sch
Extending our earlier study to a salt of a dication, we have now investigated the title strontium salt, (III). While the stoichiometry of (III) is apparently simple, Sr(L)2·3H2O, the two anionic ligands adopt entirely different coordination modes and, while one water molecule acts as a bridging ligand between two metal centres, the other two are bonded simply to one metal.
The structures of the two anionic components in (III) are similar, but not identical. Each adopts the usual planar conformation, with the nitroso group trans to the amidic atoms On4 (n = 1 or 2 throughout), and each forms an intramolecular N—H···O hydrogen bond with the nitroso On5 atom as acceptor (Fig. 1). The bond distances (Table 1) show a number of metrical features characteristic of 5-nitrosopyrimidines. In particular, the Cn4—Cn5 and Cn5—Cn6 distances are similar, the difference between the Cn5—Nn5 and Nn5—On5 distances does not exceed 0.05 Å, and the Cn6—Nn6 bonds are very short for a single C—N bond between triply connected atoms of these types (Allen et al., 1987). The C—O distances are all typical of those in neutral amides (Allen et al., 1987) and these observations, taken all together, indicate that the delocalized polarized form (IIa) is a significantly better representation of the anions than the localized form, (II).
The coordination complex of (III) (Fig. 1) takes the form of a centrosymmetric dimer, located for the sake of convenience across the inversion centre at (1/2,1/2,1/2). The anion of type 1 (with n = 1 in the atom labels) at (x, y, z) forms a bridge between the two Sr centres at (x, y, z) and (1 − x, 1 − y, 1 − z), with the amidic O14 and nitroso N15 atoms coordinated to the Sr atom at (x, y, z) and the nitroso O15 atom bonded to the Sr atom at (1 − x, 1 − y, 1 − z). By contrast, the type 2 anion (with n = 2 in the atom labels) is bonded to a single Sr atom, via the amidic O22 and N21 atoms of the pyrimidine ring.
Effectively orthogonal to the (SrNO)2 ring is an Sr2O2 ring, in which water atom O1 acts as a bridging ligand between two Sr centres. The irregular nine-coordination around the Sr is completed by two water molecules, each bonded to just one Sr atom. We have previously observed examples of metal complexes of substituted 5-nitrosopyrimidines in which the nitroso group acts as an η1 ligand, via O, to Na (Low, Moreno Sánchez et al., 2001), K (Low, Arranz et al., 2001) and Sr (Glidewell et al., 2002), as an η1 ligand, via N, to Na (Cuesta et al., 2001), and as an η2 ligand binding to a single K centre via both N and O (Low, Moreno Sánchez et al., 2001), but no previous examples of this ligand adopting a µ bridging action have been observed. In contrast to the metal-bridging action of the nitroso group of the type 1 ligand, the nitroso group in the type 2 ligand plays no role in the metal-ligand bonding, although both atoms N25 and O25 act as acceptors of hydrogen bonds (Table 2).
In addition to the N—H···O hydrogen bonds within each anionic ligand of (III), there is a third N—H···O hydrogen bond within the dimeric complex (Fig. 1, Table 2). Amino atom N26 in the type 2 anion acts as a hydrogen-bond donor, via atom H26A, to amidic atom O14 in the type 1 anion. This then leaves within the dimer one amino N—H bond and six distinct water O—H bonds, each duplicated by inversion, all of which act as hydrogen-bond donors to acceptors in other dimer units, so linking these units into a single three-dimensional framework. The number of distinct hydrogen bonds leads to some complexity in the framework structure, but the formation of the framework is readily described in terms of a small number of one-dimensional substructures, each in the form of a chain of rings, such that the combination of these substructures necessarily leads to a single framework structure.
The simplest of the hydrogen-bonded substructures in (III) is that running parallel to the [001] direction. Water atom O3 at (x, y, z), which forms part of the complex centred at (1/2,1/2,1/2), acts as a hydrogen-bond donor, via atom H3A, to nitroso atom N25 at (1 − x, 1 − y, 2 − z), which lies in the dimer centred at (1/2,1/2, 3/2), so forming an R22(14) ring centred at (1/2,1/2,1) (Fig. 2). Propagation of this hydrogen bond by inversion thus generates a chain of spiro-fused rings along [001].
Three hydrogen bonds are involved in chain formation along [010]. Water atoms O1 and O2 at (x, y, z) both act as hydrogen-bond donors, via atoms H1B and H2A, respectively, to amidic atom O12 at (x, y − 1, z), which lies in the dimer centred at (1/2,-1/2,1/2). At the same time, the water atom O3 at (x, y, z) acts as a hydrogen-bond donor, via atom H3A, to pyrimidine atom N11 at (1 − x, 3 − y, 1 − z), which lies in the dimer centred at (1/2,3/2,1/2). Together, these interactions generate a complex chain along [010] (Fig. 3), which consists, in effect, of cages fused along the Sr···Sr vector. The combination of the [010] and [001] chains generates a (100) sheet and this is reinforced by the single inter-dimer N—H···O hydrogen bond.
Amino atom N16 at (x, y, z) acts as a hydrogen-bond donor, via atom H16A, to amidic atom O24 at (x, 1 + y, z − 1), so generating by translation a C(11) chain running parallel to the [011] direction. Propagation of this hydrogen bond by translation and inversion generates a chain of edge-fused rings, in which the (SrNO)2 rings alternate with hydrogen-bonded R22(24) rings (Fig. 4). Alternatively, this substructure can be regarded as a molecular ladder, in which a pair of antiparallel C(11) chains form the uprights, while the (SrNO)2 rings form the rungs.
Two further O—H···O hydrogen bonds generate chains running parallel to the [110] and [101] directions. Water atom O1 at (x, y, z), part of the dimer centred at (1/2,1/2,1/2), acts as a hydrogen-bond donor, via atom H1A, to amidic atom O12 at (-x, 2 − y, 1 − z), which lies in the dimer centred at (−1/2,3/2,1/2). Propagation of this hydrogen bond generates a chain of edge-fused rings along [110], in which Sr2O2 rings alternate with hydrogen-bonded R22(16) rings (Fig. 5). Finally, water atom O2 at (x, y, z) acts as a donor, via atom H2B, to nitroso atom O25 at (-x, 1 − y, 2 − z), which lies in the dimer centred at (−1/2,1/2,3/2), and propagation of this hydrogen bond generates a chain of spiro-fused rings along [101], in which Sr2O2 rings alternate with hydrogen-bonded R22(16) rings (Fig. 6). The combination of the [010] and [001] chains with either of the [110] or [101] chains is itself sufficient to generate a single three-dimensional framework.