Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110033135/gg3238sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270110033135/gg3238Isup2.hkl |
CCDC reference: 798581
The title compound was prepared using the following procedure. An aqueous suspension (312 ml) of cis-[Pt(DACH)Cl2] (0.041 mol, 15.6 g) was mixed with 1.935 equivalents of AgNO3 (0.079 mol, 13.5 g) and the reaction mixture was stirred in the absence of light at 318 K for 4 h. The by-product, AgCl, was removed by filtration through an ultra-filter (Ø 0.22 mm; Sigma–Aldrich) and a layer of active carbon. The colourless filtrate was evaporated and dried (Buchi Rotavapor RII rotary evaporator, 318 K, 2 kPa). The resulting white powder, crude cis-[Pt(DACH)(NO3)2], was recrystallized from acetonitrile. Single crystals of cis-[Pt(CH3CN)2(DACH)](NO3)2.H2O, (I), suitable for X-ray diffraction analysis, were obtained from a solution of cis-[Pt(DACH)(NO3)2] (3.1 mg, 0.0072 mmol) in acetonitrile (0.24 ml) by spontaneous precipitation under slow programmed cooling.
The title structure exhibits strong pseudo-symmetry in space group P21/c. Using this symmetry, the cyclohexane ring showed disorder. After refinement in this space group, the R factors converged to 0.042, but large anisotropic displacement parameters (ADPs) were shown by the NO3 atoms and three of the six C atoms of the cyclohexane ring. These C atoms were split and the ADPs changed to isotropic, and two chairs appeared with the refinement converging to 0.039 and goodness-of-fit 0.023. However, the H atoms of the water molecule and diamine groups were not visible in the difference Fourier map. Therefore, the sample was remeasured at a lower temperature, which showed that the reflections violating the c-glide plane were real violations, not admixtures present in low-quality data. Therefore, the model was transformed to subgroup P21. For expansion of the structure model, the inversion was used as a merohedric twinning operation. In this case the volume fraction of the inversion twin is the Flack parameter (Flack, 1983). This parameter refined to a final value of 0.027 (5), which confirms both that the above configuration is the correct absolute structure and that there is no twinning in the crystal structure. The noncentrosymmetric refinement converged to R factors close to 0.01, reasonable ADPs of the C atoms in the cyclohexane ring and all H atoms visible in the difference Fourier maps. There are no significant differences between the individual cations in space groups P21 and P21/c, apart from the disorder of the C atoms in the cyclohexane ring shown in P21/c which is non-existent in P21. As to the two cations in the asymmetric unit in P21, they show few significant differences in bond distances and angles, but several are noted for the torsion angles.
O- and N-bound H atoms were refined, with N—H restrained to 0.87 (2) Å and O—H restrained to 0.80 (3) Å. All other H atoms were positioned geometrically and refined using a riding model, with C—H = 0.96 Å and with Uiso(H) = 1.2Ueq(C).
The search for novel platinum-based anticancer complexes remains one of the expanding areas of the contemporary pharmaceutical industry. The driving force in this group of active anticancer therapeutics is the discovery of more active and less toxic analogues of the chemotherapy complexes used in today's clinical practice (cisplatin, carboplatin, oxaliplatin etc.) (Ho et al., 2003; Galanski et al., 2003; Abu-Surrah & Kettunen, 2006). Some of the novel structures are based on the platinum (1R,2R)-1,2-diaminocyclohexane (DACH) carrier ligand and various leaving groups bound to the central Pt metal atom. There are several synthetic routes used for the preparation of DACH–platinum-based complexes (Fuertes et al., 2004; Leh & Wolf, 1976). One of the interesting routes for the preparation of oxaliplatin, AP5346 and other DACH–Pt complexes is the synthetic method starting from cis-[Pt(DACH)(NO3)2]. This compound is a valuable precursor of the DACH–Pt-based cytostatics (Pasini et al., 1993). This is prepared by a simple method where cis-[Pt(DACH)Cl2], prepared by the quantitative transformation of DACH with K2[PtCl4], reacts with silver nitrate. The title compound, (I), crystallizes only from acetonitrile with residual water in such a way that the molecule forms a monohydrate.
The single-crystal structure of (I) is built up from discrete molecules in the monoclinic space group P21, with two molecules in the asymmetric unit. The [Pt(C2H3N)2(C6H14N2)]2+ complex cation is formed by one cyclohexane ring with a chair conformation, a five-membered diamine ring with a central Pt atom and two leaving groups of acetonitrile (N≡ C—CH3). This dication is balanced by two nitrate groups and one neutral water molecule.
The [Pt(C2H3N)2(C6H14N2)]2+ cation is nearly planar, with the dihedral angle between the N1A—N2A—N3A—N4A plane and the cyclohexane plane (C3A—C6A—N1A—N2A) being 4.96°, unlike some other known DACH structures, such as cis-[Pt(DACH)Br2] or cis-[Pt(DACH)Cl2], where dihedral angles are between 50 and 70° (Lock & Pilon, 1981). The Pt—N1A bond is shorter than the same bond in cis-[Pt(DACH)Br2] and similar to that in cis-[Pt(DACH)Cl2] (Lock & Pilon, 1981). As for the two cations, they show few significant differences in bond distances and angles, apart from the analogous Pt1—N3—C7 angle which is 178.6 (3)° (molecule A) and 174.1 (3)° (molecule B). Comparable torsion angles about the Pt atoms, e.g. N4—Pt1—N2—C2, differ by up to 8° in molecules A and B. The N—O bonds in the NO3 group lie within expected ranges and these nitrate groups are positioned in such a manner that the O atoms of the NO3 group are oriented towards the H atoms of the water and the diamine group, forming hydrogen bonds.
There are three systems of supramolecular chains interacting by hydrogen bonds: one formed by bifurcated N—H···(O,O) interactions linking an N atom of the diamine group with O atoms of the nitrate group, and two bifurcated O—H···(O,O) chains linking an O atom of the nitrate group to the water O atom. The first is parallel to [001] (c axis) and takes the form (O1B,O3B)iii–N2Ai–(O2A,O3A)–N5A–(O1A,O3A)–N2Biv –(O2B,O3B)vi–(O1B,O3B)vi when viewed down the b axis (Fig. 1) [Fig. 2?]. Also present are chains parallel to [010] (b axis) (Fig. 3) between the water molecule and nitrate groups, of the form O5A–N6A–(O4A,O6A)–O7A–O5Aiii when viewed down the c axis; the second chain running parallel to the b axis is O5Bvi–O7B–(O4B,O6B)–N6B–O5B. Details of hydrogen bonds are given in Table 1 and the C—H···O interactions are considered weak.
Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: ORTEP-3 (Farrugia, 1999) and Mercury (Version 2.3; Macrae et al., 2006); software used to prepare material for publication: JANA2006 (Petříček et al., 2006).
[Pt(C2H3N)2(C6H14N2)](NO3)2·H2O | F(000) = 1032 |
Mr = 533.4 | Dx = 1.994 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 14954 reflections |
a = 12.6799 (3) Å | θ = 2.8–28.3° |
b = 12.0326 (3) Å | µ = 7.94 mm−1 |
c = 11.6791 (2) Å | T = 120 K |
β = 94.5495 (17)° | Block, colourless |
V = 1776.29 (7) Å3 | 0.49 × 0.20 × 0.10 mm |
Z = 4 |
Oxford Xcalibur Atlas Gemini Ultra diffractometer | 7866 independent reflections |
Radiation source: X-ray tube | 7374 reflections with I > 3σ(I) |
Unknown monochromator | Rint = 0.014 |
Detector resolution: 10.3784 pixels mm-1 | θmax = 28.3°, θmin = 2.8° |
ω scans | h = −16→16 |
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2008; Clark & Reid, 1995)] | k = −15→15 |
Tmin = 0.110, Tmax = 0.544 | l = −15→15 |
16828 measured reflections |
Refinement on F2 | H atoms treated by a mixture of independent and constrained refinement |
R[F > 3σ(F)] = 0.012 | Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.0004I2] |
wR(F) = 0.030 | (Δ/σ)max = 0.046 |
S = 1.02 | Δρmax = 0.34 e Å−3 |
7866 reflections | Δρmin = −0.18 e Å−3 |
480 parameters | Absolute structure: Flack (1983), with 3554 Friedel pairs |
12 restraints | Absolute structure parameter: 0.027 (5) |
129 constraints |
[Pt(C2H3N)2(C6H14N2)](NO3)2·H2O | V = 1776.29 (7) Å3 |
Mr = 533.4 | Z = 4 |
Monoclinic, P21 | Mo Kα radiation |
a = 12.6799 (3) Å | µ = 7.94 mm−1 |
b = 12.0326 (3) Å | T = 120 K |
c = 11.6791 (2) Å | 0.49 × 0.20 × 0.10 mm |
β = 94.5495 (17)° |
Oxford Xcalibur Atlas Gemini Ultra diffractometer | 7866 independent reflections |
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2008; Clark & Reid, 1995)] | 7374 reflections with I > 3σ(I) |
Tmin = 0.110, Tmax = 0.544 | Rint = 0.014 |
16828 measured reflections |
R[F > 3σ(F)] = 0.012 | H atoms treated by a mixture of independent and constrained refinement |
wR(F) = 0.030 | Δρmax = 0.34 e Å−3 |
S = 1.02 | Δρmin = −0.18 e Å−3 |
7866 reflections | Absolute structure: Flack (1983), with 3554 Friedel pairs |
480 parameters | Absolute structure parameter: 0.027 (5) |
12 restraints |
x | y | z | Uiso*/Ueq | ||
Pt1A | 0.164710 (9) | 0.632731 | 0.694934 (7) | 0.01606 (4) | |
Pt1B | 0.834036 (9) | 0.367277 (8) | 0.812672 (7) | 0.01626 (4) | |
O1A | 0.0643 (2) | 0.2325 (3) | 0.63327 (19) | 0.0345 (9) | |
O1B | 0.9214 (2) | 0.7597 (2) | 0.85663 (19) | 0.0290 (8) | |
N6A | 0.5244 (2) | 0.6448 (3) | 0.5943 (2) | 0.0272 (9) | |
N6B | 0.4834 (2) | 0.3710 (4) | 0.9117 (2) | 0.0264 (9) | |
O2A | 0.0855 (2) | 0.3163 (3) | 0.47192 (19) | 0.0348 (9) | |
O2B | 0.9037 (2) | 0.6925 (2) | 1.02632 (18) | 0.0326 (9) | |
N2A | 0.1038 (2) | 0.7847 (3) | 0.7220 (2) | 0.0183 (9) | |
N2B | 0.8951 (2) | 0.2146 (3) | 0.7899 (2) | 0.0176 (9) | |
C8A | 0.3288 (3) | 0.3007 (3) | 0.6382 (3) | 0.0369 (13) | |
C8B | 0.6592 (3) | 0.6910 (3) | 0.8741 (3) | 0.0333 (12) | |
N1A | 0.3035 (3) | 0.7046 (3) | 0.7512 (2) | 0.0210 (10) | |
N1B | 0.6977 (2) | 0.2982 (2) | 0.7449 (2) | 0.0183 (9) | |
O4A | 0.5931 (2) | 0.6122 (3) | 0.5315 (2) | 0.0410 (10) | |
O4B | 0.3996 (3) | 0.3973 (3) | 0.9473 (3) | 0.0672 (14) | |
C6A | 0.3810 (3) | 0.8923 (3) | 0.8032 (3) | 0.0288 (12) | |
C6B | 0.6238 (3) | 0.1130 (3) | 0.6787 (2) | 0.0236 (10) | |
C3A | 0.1612 (3) | 0.9785 (3) | 0.7805 (3) | 0.0250 (12) | |
C3B | 0.8407 (3) | 0.0226 (3) | 0.7214 (3) | 0.0238 (11) | |
O5A | 0.5096 (3) | 0.7450 (3) | 0.6105 (2) | 0.0536 (12) | |
O5B | 0.5004 (3) | 0.2716 (3) | 0.8817 (2) | 0.0400 (9) | |
O3A | −0.0694 (2) | 0.3084 (3) | 0.53597 (19) | 0.0328 (9) | |
O3B | 1.0573 (2) | 0.6882 (2) | 0.95542 (17) | 0.0262 (8) | |
C4A | 0.2533 (3) | 1.0452 (3) | 0.8383 (2) | 0.0281 (10) | |
C4B | 0.7447 (3) | −0.0545 (3) | 0.7001 (3) | 0.0279 (10) | |
N3A | 0.2331 (2) | 0.4863 (3) | 0.6716 (2) | 0.0212 (10) | |
N3B | 0.7650 (2) | 0.5128 (3) | 0.8332 (2) | 0.0209 (10) | |
C7A | 0.2735 (3) | 0.4047 (3) | 0.6581 (3) | 0.0249 (11) | |
C7B | 0.7191 (3) | 0.5919 (3) | 0.8503 (2) | 0.0209 (11) | |
N5A | 0.0274 (3) | 0.2875 (3) | 0.5462 (2) | 0.0252 (10) | |
N5B | 0.9605 (3) | 0.7129 (3) | 0.9461 (2) | 0.0219 (9) | |
O7A | 0.6206 (2) | 0.3849 (3) | 0.5308 (2) | 0.0325 (9) | |
O7B | 0.3664 (2) | 0.6285 (3) | 0.98147 (18) | 0.0284 (7) | |
N4A | 0.0220 (2) | 0.5784 (3) | 0.6364 (2) | 0.0203 (9) | |
N4B | 0.9733 (3) | 0.4210 (3) | 0.8770 (2) | 0.0214 (9) | |
C9A | −0.0620 (3) | 0.5645 (3) | 0.6008 (2) | 0.0200 (10) | |
C9B | 1.0588 (3) | 0.4373 (3) | 0.9133 (2) | 0.0212 (11) | |
C10A | −0.1710 (3) | 0.5519 (3) | 0.5536 (3) | 0.0273 (11) | |
C10B | 1.1674 (3) | 0.4530 (3) | 0.9599 (3) | 0.0243 (11) | |
C1A | 0.2910 (2) | 0.8275 (2) | 0.7408 (2) | 0.0193 (8) | |
C1B | 0.7213 (2) | 0.1879 (2) | 0.6948 (2) | 0.0184 (8) | |
C2A | 0.1853 (2) | 0.8555 (2) | 0.7870 (2) | 0.0189 (8) | |
C2B | 0.8065 (2) | 0.1338 (2) | 0.7711 (2) | 0.0170 (7) | |
C5A | 0.3585 (2) | 1.0169 (2) | 0.7917 (3) | 0.0323 (10) | |
C5B | 0.6548 (2) | 0.0020 (2) | 0.6263 (3) | 0.0296 (10) | |
O6A | 0.4723 (3) | 0.5750 (3) | 0.6417 (3) | 0.0668 (12) | |
O6B | 0.5544 (2) | 0.4383 (3) | 0.9073 (3) | 0.0607 (12) | |
H1C8A | 0.375985 | 0.283549 | 0.704164 | 0.0442* | |
H2C8A | 0.278145 | 0.241852 | 0.625316 | 0.0442* | |
H3C8A | 0.368535 | 0.308519 | 0.572029 | 0.0442* | |
H1C8B | 0.700211 | 0.736716 | 0.928379 | 0.04* | |
H2C8B | 0.643562 | 0.731855 | 0.804196 | 0.04* | |
H3C8B | 0.594414 | 0.670054 | 0.905481 | 0.04* | |
H1C6A | 0.446008 | 0.875306 | 0.77005 | 0.0345* | |
H2C6A | 0.386907 | 0.87206 | 0.883012 | 0.0345* | |
H1C6B | 0.570665 | 0.148635 | 0.628286 | 0.0283* | |
H2C6B | 0.596494 | 0.099862 | 0.751877 | 0.0283* | |
H1C3A | 0.098138 | 0.993462 | 0.818226 | 0.03* | |
H2C3A | 0.149532 | 1.00045 | 0.701448 | 0.03* | |
H1C3B | 0.892291 | −0.012055 | 0.774391 | 0.0285* | |
H2C3B | 0.871787 | 0.035601 | 0.65031 | 0.0285* | |
H1C4A | 0.239471 | 1.123199 | 0.828273 | 0.0337* | |
H2C4A | 0.257772 | 1.032148 | 0.919585 | 0.0337* | |
H1C4B | 0.719841 | −0.076184 | 0.772337 | 0.0335* | |
H2C4B | 0.765637 | −0.120961 | 0.662528 | 0.0335* | |
H1C10A | −0.186136 | 0.474593 | 0.540365 | 0.0328* | |
H2C10A | −0.217799 | 0.58114 | 0.606871 | 0.0328* | |
H3C10A | −0.181036 | 0.591733 | 0.482306 | 0.0328* | |
H1C10B | 1.1886 | 0.528311 | 0.947215 | 0.0291* | |
H2C10B | 1.172653 | 0.437807 | 1.040843 | 0.0291* | |
H3C10B | 1.212864 | 0.403235 | 0.922426 | 0.0291* | |
H1C1A | 0.292759 | 0.849094 | 0.661826 | 0.0231* | |
H1C1B | 0.744201 | 0.19927 | 0.619259 | 0.0221* | |
H1C2A | 0.186315 | 0.83935 | 0.867599 | 0.0227* | |
H1C2B | 0.781113 | 0.115182 | 0.843996 | 0.0204* | |
H1C5A | 0.356725 | 1.037958 | 0.712295 | 0.0388* | |
H2C5A | 0.41403 | 1.057833 | 0.833404 | 0.0388* | |
H1C5B | 0.676456 | 0.014516 | 0.550483 | 0.0355* | |
H2C5B | 0.594325 | −0.046228 | 0.619253 | 0.0355* | |
H1N2A | 0.0841 (19) | 0.809 (2) | 0.6536 (9) | −0.003 (6)* | |
H1N2B | 0.933 (2) | 0.217 (3) | 0.7308 (18) | 0.030 (10)* | |
H2N2A | 0.0473 (12) | 0.781 (3) | 0.759 (2) | 0.010 (7)* | |
H1N1A | 0.328 (2) | 0.678 (3) | 0.8172 (13) | 0.009 (8)* | |
H1O7A | 0.581 (3) | 0.347 (3) | 0.491 (3) | 0.036 (12)* | |
H2N2B | 0.930 (3) | 0.200 (4) | 0.855 (2) | 0.078 (17)* | |
H1N1B | 0.663 (3) | 0.286 (3) | 0.805 (2) | 0.054 (13)* | |
H2O7A | 0.594 (3) | 0.4446 (14) | 0.539 (3) | 0.033 (11)* | |
H2N1A | 0.3603 (13) | 0.689 (3) | 0.717 (2) | 0.019 (8)* | |
H2N1B | 0.680 (4) | 0.321 (5) | 0.675 (2) | 0.09 (2)* | |
H1O7B | 0.404 (2) | 0.670 (3) | 1.019 (3) | 0.039 (12)* | |
H2O7B | 0.381 (3) | 0.5639 (9) | 0.981 (3) | 0.031 (11)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Pt1A | 0.01677 (8) | 0.01570 (9) | 0.01556 (5) | −0.00101 (6) | 0.00036 (4) | −0.00043 (5) |
Pt1B | 0.01640 (8) | 0.01584 (9) | 0.01622 (5) | −0.00146 (6) | −0.00077 (4) | −0.00084 (5) |
O1A | 0.0386 (17) | 0.0417 (17) | 0.0231 (11) | 0.0115 (13) | 0.0028 (10) | 0.0097 (10) |
O1B | 0.0218 (13) | 0.0367 (16) | 0.0282 (11) | 0.0035 (11) | 0.0012 (9) | 0.0091 (10) |
N6A | 0.0208 (15) | 0.031 (2) | 0.0284 (12) | 0.0019 (14) | −0.0070 (10) | −0.0030 (13) |
N6B | 0.0232 (16) | 0.0275 (17) | 0.0282 (12) | −0.0004 (14) | 0.0009 (10) | 0.0031 (13) |
O2A | 0.0379 (17) | 0.0407 (18) | 0.0263 (11) | −0.0098 (13) | 0.0068 (10) | 0.0019 (11) |
O2B | 0.0380 (17) | 0.0346 (16) | 0.0272 (11) | −0.0082 (12) | 0.0155 (11) | 0.0026 (10) |
N2A | 0.0186 (16) | 0.0206 (17) | 0.0159 (11) | −0.0005 (13) | 0.0018 (10) | 0.0011 (10) |
N2B | 0.0169 (16) | 0.0175 (16) | 0.0179 (12) | 0.0006 (12) | −0.0024 (10) | −0.0018 (10) |
C8A | 0.039 (2) | 0.029 (2) | 0.0409 (19) | 0.0115 (18) | −0.0090 (16) | −0.0061 (16) |
C8B | 0.042 (2) | 0.0192 (19) | 0.0396 (18) | 0.0076 (16) | 0.0096 (16) | 0.0039 (14) |
N1A | 0.0161 (18) | 0.029 (2) | 0.0180 (12) | 0.0017 (14) | 0.0004 (11) | −0.0011 (11) |
N1B | 0.0203 (18) | 0.0133 (16) | 0.0207 (13) | −0.0015 (13) | −0.0021 (11) | −0.0014 (11) |
O4A | 0.0310 (16) | 0.0392 (19) | 0.0552 (14) | 0.0032 (14) | 0.0185 (12) | 0.0115 (14) |
O4B | 0.0302 (19) | 0.041 (2) | 0.136 (3) | 0.0083 (15) | 0.0372 (18) | 0.000 (2) |
C6A | 0.020 (2) | 0.030 (2) | 0.0370 (16) | −0.0058 (16) | 0.0045 (13) | −0.0079 (15) |
C6B | 0.0189 (18) | 0.023 (2) | 0.0278 (14) | −0.0011 (15) | −0.0046 (11) | −0.0053 (13) |
C3A | 0.025 (2) | 0.024 (2) | 0.0259 (16) | 0.0044 (17) | 0.0055 (14) | −0.0033 (14) |
C3B | 0.026 (2) | 0.016 (2) | 0.0287 (16) | −0.0015 (16) | 0.0023 (14) | −0.0028 (13) |
O5A | 0.087 (3) | 0.0311 (17) | 0.0403 (14) | 0.0198 (17) | −0.0077 (15) | −0.0047 (12) |
O5B | 0.0477 (18) | 0.0298 (16) | 0.0406 (13) | 0.0188 (13) | −0.0074 (12) | −0.0036 (11) |
O3A | 0.0292 (16) | 0.0396 (17) | 0.0287 (11) | 0.0064 (12) | −0.0032 (10) | −0.0063 (10) |
O3B | 0.0260 (15) | 0.0269 (15) | 0.0250 (10) | 0.0048 (11) | −0.0024 (9) | 0.0012 (9) |
C4A | 0.0349 (19) | 0.0192 (16) | 0.0313 (16) | −0.0029 (13) | 0.0097 (14) | −0.0071 (13) |
C4B | 0.0289 (19) | 0.0187 (16) | 0.0359 (17) | −0.0027 (13) | 0.0014 (14) | −0.0037 (13) |
N3A | 0.0201 (18) | 0.0199 (19) | 0.0237 (13) | −0.0007 (14) | 0.0024 (11) | −0.0010 (11) |
N3B | 0.0220 (19) | 0.0190 (19) | 0.0210 (13) | −0.0037 (14) | −0.0036 (11) | 0.0003 (11) |
C7A | 0.028 (2) | 0.023 (2) | 0.0232 (14) | −0.0034 (17) | −0.0001 (13) | 0.0000 (13) |
C7B | 0.0215 (19) | 0.022 (2) | 0.0191 (13) | −0.0026 (15) | 0.0013 (12) | 0.0008 (12) |
N5A | 0.0311 (19) | 0.0244 (18) | 0.0202 (12) | −0.0011 (14) | 0.0024 (11) | −0.0051 (11) |
N5B | 0.0286 (17) | 0.0137 (16) | 0.0234 (12) | −0.0006 (12) | 0.0021 (11) | −0.0001 (10) |
O7A | 0.0331 (15) | 0.0289 (18) | 0.0338 (12) | 0.0044 (13) | −0.0087 (10) | −0.0007 (12) |
O7B | 0.0295 (14) | 0.0222 (13) | 0.0322 (11) | −0.0026 (12) | −0.0058 (9) | −0.0011 (12) |
N4A | 0.0201 (17) | 0.0168 (16) | 0.0239 (12) | −0.0018 (12) | 0.0015 (11) | −0.0001 (10) |
N4B | 0.0237 (18) | 0.0166 (16) | 0.0234 (12) | −0.0019 (13) | −0.0003 (11) | 0.0013 (11) |
C9A | 0.023 (2) | 0.0157 (18) | 0.0208 (13) | −0.0020 (14) | 0.0024 (12) | −0.0002 (11) |
C9B | 0.028 (2) | 0.0166 (18) | 0.0192 (13) | −0.0005 (15) | 0.0036 (13) | 0.0008 (11) |
C10A | 0.024 (2) | 0.031 (2) | 0.0271 (15) | −0.0023 (16) | −0.0027 (13) | −0.0003 (14) |
C10B | 0.0179 (19) | 0.026 (2) | 0.0288 (15) | −0.0034 (15) | 0.0004 (12) | 0.0014 (14) |
C1A | 0.0236 (15) | 0.0183 (13) | 0.0164 (12) | −0.0018 (10) | 0.0044 (11) | −0.0012 (10) |
C1B | 0.0211 (15) | 0.0161 (13) | 0.0180 (13) | −0.0024 (10) | 0.0016 (10) | −0.0033 (10) |
C2A | 0.0182 (13) | 0.0220 (14) | 0.0167 (11) | −0.0050 (10) | 0.0021 (10) | −0.0021 (12) |
C2B | 0.0181 (13) | 0.0164 (12) | 0.0166 (11) | −0.0019 (10) | 0.0023 (9) | −0.0021 (12) |
C5A | 0.0314 (17) | 0.0231 (16) | 0.0439 (18) | −0.0116 (12) | 0.0118 (15) | −0.0109 (13) |
C5B | 0.0290 (17) | 0.0250 (16) | 0.0340 (17) | −0.0073 (12) | −0.0021 (13) | −0.0085 (13) |
O6A | 0.065 (2) | 0.057 (2) | 0.086 (2) | −0.0322 (17) | 0.0487 (18) | −0.0302 (17) |
O6B | 0.0420 (18) | 0.062 (2) | 0.080 (2) | −0.0274 (15) | 0.0193 (16) | −0.0110 (17) |
Pt1A—N2A | 2.019 (3) | C6B—H1C6B | 0.96 |
Pt1A—N1A | 2.023 (3) | C6B—H2C6B | 0.96 |
Pt1A—N3A | 1.992 (3) | C3A—C4A | 1.530 (5) |
Pt1A—N4A | 1.993 (3) | C3A—C2A | 1.512 (5) |
Pt1B—N2B | 2.019 (3) | C3A—H1C3A | 0.96 |
Pt1B—N1B | 2.022 (3) | C3A—H2C3A | 0.96 |
Pt1B—N3B | 1.981 (3) | C3B—C4B | 1.535 (5) |
Pt1B—N4B | 1.972 (3) | C3B—C2B | 1.534 (4) |
O1A—N5A | 1.271 (4) | C3B—H1C3B | 0.96 |
O1B—N5B | 1.255 (4) | C3B—H2C3B | 0.96 |
N6A—O4A | 1.246 (4) | O3A—N5A | 1.249 (4) |
N6A—O5A | 1.237 (5) | O3B—N5B | 1.258 (4) |
N6A—O6A | 1.229 (5) | C4A—C5A | 1.518 (5) |
N6B—O4B | 1.213 (5) | C4A—H1C4A | 0.96 |
N6B—O5B | 1.270 (5) | C4A—H2C4A | 0.96 |
N6B—O6B | 1.215 (5) | C4B—C5B | 1.533 (4) |
O2A—N5A | 1.231 (4) | C4B—H1C4B | 0.96 |
O2B—N5B | 1.250 (4) | C4B—H2C4B | 0.96 |
N2A—C2A | 1.499 (4) | N3A—C7A | 1.124 (5) |
N2A—H1N2A | 0.870 (14) | N3B—C7B | 1.141 (5) |
N2A—H2N2A | 0.87 (2) | O7A—H1O7A | 0.80 (3) |
N2B—C2B | 1.489 (4) | O7A—H2O7A | 0.80 (2) |
N2B—H1N2B | 0.87 (3) | O7B—H1O7B | 0.80 (3) |
N2B—H2N2B | 0.87 (3) | O7B—H2O7B | 0.800 (14) |
C8A—C7A | 1.462 (6) | N4A—C9A | 1.125 (5) |
C8A—H1C8A | 0.96 | N4B—C9B | 1.149 (5) |
C8A—H2C8A | 0.96 | C9A—C10A | 1.455 (5) |
C8A—H3C8A | 0.96 | C9B—C10B | 1.454 (5) |
C8B—C7B | 1.452 (6) | C10A—H1C10A | 0.96 |
C8B—H1C8B | 0.96 | C10A—H2C10A | 0.96 |
C8B—H2C8B | 0.96 | C10A—H3C10A | 0.96 |
C8B—H3C8B | 0.96 | C10B—H1C10B | 0.96 |
N1A—C1A | 1.492 (4) | C10B—H2C10B | 0.96 |
N1A—H1N1A | 0.870 (19) | C10B—H3C10B | 0.96 |
N1A—H2N1A | 0.87 (2) | C1A—C2A | 1.521 (4) |
N1B—C1B | 1.490 (4) | C1A—H1C1A | 0.96 |
N1B—H1N1B | 0.87 (3) | C1B—C2B | 1.495 (4) |
N1B—H2N1B | 0.87 (3) | C1B—H1C1B | 0.96 |
C6A—C1A | 1.520 (4) | C2A—H1C2A | 0.96 |
C6A—C5A | 1.531 (5) | C2B—H1C2B | 0.96 |
C6A—H1C6A | 0.96 | C5A—H1C5A | 0.96 |
C6A—H2C6A | 0.96 | C5A—H2C5A | 0.96 |
C6B—C1B | 1.529 (5) | C5B—H1C5B | 0.96 |
C6B—C5B | 1.533 (5) | C5B—H2C5B | 0.96 |
N2A—Pt1A—N1A | 84.03 (13) | H1C3B—C3B—H2C3B | 108.7835 |
N2A—Pt1A—N3A | 176.63 (12) | C3A—C4A—C5A | 112.7 (3) |
N2A—Pt1A—N4A | 90.14 (12) | C3A—C4A—H1C4A | 109.4715 |
N1A—Pt1A—N3A | 92.60 (13) | C3A—C4A—H2C4A | 109.4714 |
N1A—Pt1A—N4A | 173.85 (13) | C5A—C4A—H1C4A | 109.4714 |
N3A—Pt1A—N4A | 93.23 (12) | C5A—C4A—H2C4A | 109.4704 |
N2B—Pt1B—N1B | 84.21 (12) | H1C4A—C4A—H2C4A | 106.0307 |
N2B—Pt1B—N3B | 176.32 (12) | C3B—C4B—C5B | 111.6 (3) |
N2B—Pt1B—N4B | 90.43 (12) | C3B—C4B—H1C4B | 109.4707 |
N1B—Pt1B—N3B | 92.20 (12) | C3B—C4B—H2C4B | 109.4713 |
N1B—Pt1B—N4B | 174.63 (13) | C5B—C4B—H1C4B | 109.4715 |
N3B—Pt1B—N4B | 93.16 (13) | C5B—C4B—H2C4B | 109.4711 |
O4A—N6A—O5A | 121.3 (4) | H1C4B—C4B—H2C4B | 107.2691 |
O4A—N6A—O6A | 118.5 (4) | Pt1A—N3A—C7A | 178.6 (3) |
O5A—N6A—O6A | 120.3 (3) | Pt1B—N3B—C7B | 174.1 (3) |
O4B—N6B—O5B | 120.8 (4) | C8A—C7A—N3A | 178.0 (4) |
O4B—N6B—O6B | 120.9 (4) | C8B—C7B—N3B | 178.6 (4) |
O5B—N6B—O6B | 118.2 (3) | O1A—N5A—O2A | 120.5 (3) |
Pt1A—N2A—C2A | 109.7 (2) | O1A—N5A—O3A | 118.5 (3) |
Pt1A—N2A—H1N2A | 104.6 (16) | O2A—N5A—O3A | 120.9 (3) |
Pt1A—N2A—H2N2A | 112 (2) | O1B—N5B—O2B | 119.9 (3) |
C2A—N2A—H1N2A | 114.1 (17) | O1B—N5B—O3B | 119.8 (3) |
C2A—N2A—H2N2A | 109.6 (17) | O2B—N5B—O3B | 120.3 (3) |
H1N2A—N2A—H2N2A | 107 (2) | H1O7A—O7A—H2O7A | 109 (3) |
Pt1B—N2B—C2B | 108.75 (19) | H1O7B—O7B—H2O7B | 119 (3) |
Pt1B—N2B—H1N2B | 108 (3) | Pt1A—N4A—C9A | 169.4 (3) |
Pt1B—N2B—H2N2B | 104 (3) | Pt1B—N4B—C9B | 170.5 (3) |
C2B—N2B—H1N2B | 111 (2) | N4A—C9A—C10A | 177.4 (4) |
C2B—N2B—H2N2B | 109 (3) | N4B—C9B—C10B | 177.6 (4) |
H1N2B—N2B—H2N2B | 116 (3) | C9A—C10A—H1C10A | 109.4709 |
C7A—C8A—H1C8A | 109.4713 | C9A—C10A—H2C10A | 109.4716 |
C7A—C8A—H2C8A | 109.4709 | C9A—C10A—H3C10A | 109.4711 |
C7A—C8A—H3C8A | 109.4712 | H1C10A—C10A—H2C10A | 109.4706 |
H1C8A—C8A—H2C8A | 109.4715 | H1C10A—C10A—H3C10A | 109.4717 |
H1C8A—C8A—H3C8A | 109.4716 | H2C10A—C10A—H3C10A | 109.4714 |
H2C8A—C8A—H3C8A | 109.4708 | C9B—C10B—H1C10B | 109.4703 |
C7B—C8B—H1C8B | 109.4712 | C9B—C10B—H2C10B | 109.4709 |
C7B—C8B—H2C8B | 109.4712 | C9B—C10B—H3C10B | 109.4718 |
C7B—C8B—H3C8B | 109.4717 | H1C10B—C10B—H2C10B | 109.4706 |
H1C8B—C8B—H2C8B | 109.4716 | H1C10B—C10B—H3C10B | 109.4721 |
H1C8B—C8B—H3C8B | 109.4709 | H2C10B—C10B—H3C10B | 109.4716 |
H2C8B—C8B—H3C8B | 109.4707 | N1A—C1A—C6A | 113.4 (2) |
Pt1A—N1A—C1A | 108.2 (2) | N1A—C1A—C2A | 106.4 (2) |
Pt1A—N1A—H1N1A | 111.6 (19) | N1A—C1A—H1C1A | 109.6274 |
Pt1A—N1A—H2N1A | 119.3 (17) | C6A—C1A—C2A | 111.4 (2) |
C1A—N1A—H1N1A | 118 (2) | C6A—C1A—H1C1A | 104.3832 |
C1A—N1A—H2N1A | 105 (2) | C2A—C1A—H1C1A | 111.7114 |
H1N1A—N1A—H2N1A | 94 (2) | N1B—C1B—C6B | 112.8 (3) |
Pt1B—N1B—C1B | 109.1 (2) | N1B—C1B—C2B | 108.2 (2) |
Pt1B—N1B—H1N1B | 103 (2) | N1B—C1B—H1C1B | 108.5941 |
Pt1B—N1B—H2N1B | 113 (4) | C6B—C1B—C2B | 110.8 (2) |
C1B—N1B—H1N1B | 107 (3) | C6B—C1B—H1C1B | 105.8029 |
C1B—N1B—H2N1B | 88 (4) | C2B—C1B—H1C1B | 110.6521 |
H1N1B—N1B—H2N1B | 134 (4) | N2A—C2A—C3A | 113.7 (2) |
C1A—C6A—C5A | 109.4 (3) | N2A—C2A—C1A | 106.6 (2) |
C1A—C6A—H1C6A | 109.4713 | N2A—C2A—H1C2A | 109.643 |
C1A—C6A—H2C6A | 109.4717 | C3A—C2A—C1A | 112.3 (2) |
C5A—C6A—H1C6A | 109.4708 | C3A—C2A—H1C2A | 103.5918 |
C5A—C6A—H2C6A | 109.4716 | C1A—C2A—H1C2A | 111.1002 |
H1C6A—C6A—H2C6A | 109.5667 | N2B—C2B—C3B | 113.2 (2) |
C1B—C6B—C5B | 109.4 (3) | N2B—C2B—C1B | 107.7 (2) |
C1B—C6B—H1C6B | 109.4708 | N2B—C2B—H1C2B | 108.9042 |
C1B—C6B—H2C6B | 109.4718 | C3B—C2B—C1B | 111.5 (2) |
C5B—C6B—H1C6B | 109.471 | C3B—C2B—H1C2B | 104.911 |
C5B—C6B—H2C6B | 109.471 | C1B—C2B—H1C2B | 110.6513 |
H1C6B—C6B—H2C6B | 109.5564 | C6A—C5A—C4A | 110.6 (3) |
C4A—C3A—C2A | 110.3 (3) | C6A—C5A—H1C5A | 109.4706 |
C4A—C3A—H1C3A | 109.471 | C6A—C5A—H2C5A | 109.4709 |
C4A—C3A—H2C3A | 109.4713 | C4A—C5A—H1C5A | 109.4715 |
C2A—C3A—H1C3A | 109.4707 | C4A—C5A—H2C5A | 109.4717 |
C2A—C3A—H2C3A | 109.471 | H1C5A—C5A—H2C5A | 108.3271 |
H1C3A—C3A—H2C3A | 108.6576 | C6B—C5B—C4B | 111.4 (2) |
C4B—C3B—C2B | 110.2 (3) | C6B—C5B—H1C5B | 109.4712 |
C4B—C3B—H1C3B | 109.4706 | C6B—C5B—H2C5B | 109.4706 |
C4B—C3B—H2C3B | 109.4705 | C4B—C5B—H1C5B | 109.4717 |
C2B—C3B—H1C3B | 109.4722 | C4B—C5B—H2C5B | 109.4713 |
C2B—C3B—H2C3B | 109.4715 | H1C5B—C5B—H2C5B | 107.4709 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1N1A···O7B | 0.870 (19) | 2.030 (17) | 2.892 (3) | 171 (2) |
N1A—H2N1A···O5A | 0.87 (2) | 2.44 (2) | 3.232 (5) | 151 (3) |
N1A—H2N1A···O6A | 0.87 (2) | 2.21 (3) | 3.013 (5) | 154 (3) |
N2A—H1N2A···O2Ai | 0.870 (14) | 2.51 (2) | 3.190 (4) | 136 (2) |
N2A—H1N2A···O3Ai | 0.870 (14) | 2.207 (11) | 3.023 (3) | 156 (2) |
N2A—H2N2A···O1Bii | 0.87 (2) | 2.05 (2) | 2.914 (4) | 174 (3) |
N2A—H2N2A···O3Bii | 0.87 (2) | 2.54 (3) | 3.064 (3) | 119.4 (18) |
O7A—H1O7A···O5Aiii | 0.80 (3) | 2.00 (3) | 2.802 (4) | 175 (3) |
O7A—H2O7A···O4A | 0.80 (2) | 2.019 (17) | 2.757 (5) | 153 (3) |
O7A—H2O7A···O6A | 0.80 (2) | 2.57 (3) | 3.291 (5) | 151 (3) |
N1B—H1N1B···O5B | 0.87 (3) | 2.32 (3) | 3.090 (4) | 148 (3) |
N1B—H1N1B···O6B | 0.87 (3) | 2.63 (4) | 3.207 (4) | 125 (3) |
N1B—H2N1B···O7A | 0.87 (3) | 1.95 (4) | 2.813 (4) | 171 (5) |
N2B—H1N2B···O1Aiv | 0.87 (3) | 2.10 (3) | 2.936 (4) | 160 (2) |
N2B—H1N2B···O3Aiv | 0.87 (3) | 2.53 (3) | 3.238 (3) | 140 (3) |
N2B—H2N2B···O2Bv | 0.87 (3) | 2.43 (4) | 3.213 (4) | 150 (4) |
N2B—H2N2B···O3Bv | 0.87 (3) | 2.21 (2) | 3.005 (3) | 152 (4) |
O7B—H1O7B···O5Bvi | 0.80 (3) | 2.02 (3) | 2.818 (4) | 177 (3) |
O7B—H2O7B···O4B | 0.800 (14) | 2.059 (14) | 2.846 (5) | 168 (3) |
O7B—H2O7B···O6B | 0.800 (14) | 2.85 (3) | 3.464 (5) | 135 (3) |
Symmetry codes: (i) −x, y+1/2, −z+1; (ii) x−1, y, z; (iii) −x+1, y−1/2, −z+1; (iv) x+1, y, z; (v) −x+2, y−1/2, −z+2; (vi) −x+1, y+1/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | [Pt(C2H3N)2(C6H14N2)](NO3)2·H2O |
Mr | 533.4 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 120 |
a, b, c (Å) | 12.6799 (3), 12.0326 (3), 11.6791 (2) |
β (°) | 94.5495 (17) |
V (Å3) | 1776.29 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 7.94 |
Crystal size (mm) | 0.49 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Oxford Xcalibur Atlas Gemini Ultra |
Absorption correction | Analytical [CrysAlis PRO (Oxford Diffraction, 2008; Clark & Reid, 1995)] |
Tmin, Tmax | 0.110, 0.544 |
No. of measured, independent and observed [I > 3σ(I)] reflections | 16828, 7866, 7374 |
Rint | 0.014 |
(sin θ/λ)max (Å−1) | 0.666 |
Refinement | |
R[F > 3σ(F)], wR(F), S | 0.012, 0.030, 1.02 |
No. of reflections | 7866 |
No. of parameters | 480 |
No. of restraints | 12 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.34, −0.18 |
Absolute structure | Flack (1983), with 3554 Friedel pairs |
Absolute structure parameter | 0.027 (5) |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SUPERFLIP (Palatinus & Chapuis, 2007), JANA2006 (Petříček et al., 2006), ORTEP-3 (Farrugia, 1999) and Mercury (Version 2.3; Macrae et al., 2006).
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1N1A···O7B | 0.870 (19) | 2.030 (17) | 2.892 (3) | 171 (2) |
N1A—H2N1A···O5A | 0.87 (2) | 2.44 (2) | 3.232 (5) | 151 (3) |
N1A—H2N1A···O6A | 0.87 (2) | 2.21 (3) | 3.013 (5) | 154 (3) |
N2A—H1N2A···O2Ai | 0.870 (14) | 2.51 (2) | 3.190 (4) | 136 (2) |
N2A—H1N2A···O3Ai | 0.870 (14) | 2.207 (11) | 3.023 (3) | 156 (2) |
N2A—H2N2A···O1Bii | 0.87 (2) | 2.05 (2) | 2.914 (4) | 174 (3) |
N2A—H2N2A···O3Bii | 0.87 (2) | 2.54 (3) | 3.064 (3) | 119.4 (18) |
O7A—H1O7A···O5Aiii | 0.80 (3) | 2.00 (3) | 2.802 (4) | 175 (3) |
O7A—H2O7A···O4A | 0.80 (2) | 2.019 (17) | 2.757 (5) | 153 (3) |
O7A—H2O7A···O6A | 0.80 (2) | 2.57 (3) | 3.291 (5) | 151 (3) |
N1B—H1N1B···O5B | 0.87 (3) | 2.32 (3) | 3.090 (4) | 148 (3) |
N1B—H1N1B···O6B | 0.87 (3) | 2.63 (4) | 3.207 (4) | 125 (3) |
N1B—H2N1B···O7A | 0.87 (3) | 1.95 (4) | 2.813 (4) | 171 (5) |
N2B—H1N2B···O1Aiv | 0.87 (3) | 2.10 (3) | 2.936 (4) | 160 (2) |
N2B—H1N2B···O3Aiv | 0.87 (3) | 2.53 (3) | 3.238 (3) | 140 (3) |
N2B—H2N2B···O2Bv | 0.87 (3) | 2.43 (4) | 3.213 (4) | 150 (4) |
N2B—H2N2B···O3Bv | 0.87 (3) | 2.21 (2) | 3.005 (3) | 152 (4) |
O7B—H1O7B···O5Bvi | 0.80 (3) | 2.02 (3) | 2.818 (4) | 177 (3) |
O7B—H2O7B···O4B | 0.800 (14) | 2.059 (14) | 2.846 (5) | 168 (3) |
O7B—H2O7B···O6B | 0.800 (14) | 2.85 (3) | 3.464 (5) | 135 (3) |
Symmetry codes: (i) −x, y+1/2, −z+1; (ii) x−1, y, z; (iii) −x+1, y−1/2, −z+1; (iv) x+1, y, z; (v) −x+2, y−1/2, −z+2; (vi) −x+1, y+1/2, −z+2. |
The search for novel platinum-based anticancer complexes remains one of the expanding areas of the contemporary pharmaceutical industry. The driving force in this group of active anticancer therapeutics is the discovery of more active and less toxic analogues of the chemotherapy complexes used in today's clinical practice (cisplatin, carboplatin, oxaliplatin etc.) (Ho et al., 2003; Galanski et al., 2003; Abu-Surrah & Kettunen, 2006). Some of the novel structures are based on the platinum (1R,2R)-1,2-diaminocyclohexane (DACH) carrier ligand and various leaving groups bound to the central Pt metal atom. There are several synthetic routes used for the preparation of DACH–platinum-based complexes (Fuertes et al., 2004; Leh & Wolf, 1976). One of the interesting routes for the preparation of oxaliplatin, AP5346 and other DACH–Pt complexes is the synthetic method starting from cis-[Pt(DACH)(NO3)2]. This compound is a valuable precursor of the DACH–Pt-based cytostatics (Pasini et al., 1993). This is prepared by a simple method where cis-[Pt(DACH)Cl2], prepared by the quantitative transformation of DACH with K2[PtCl4], reacts with silver nitrate. The title compound, (I), crystallizes only from acetonitrile with residual water in such a way that the molecule forms a monohydrate.
The single-crystal structure of (I) is built up from discrete molecules in the monoclinic space group P21, with two molecules in the asymmetric unit. The [Pt(C2H3N)2(C6H14N2)]2+ complex cation is formed by one cyclohexane ring with a chair conformation, a five-membered diamine ring with a central Pt atom and two leaving groups of acetonitrile (N≡ C—CH3). This dication is balanced by two nitrate groups and one neutral water molecule.
The [Pt(C2H3N)2(C6H14N2)]2+ cation is nearly planar, with the dihedral angle between the N1A—N2A—N3A—N4A plane and the cyclohexane plane (C3A—C6A—N1A—N2A) being 4.96°, unlike some other known DACH structures, such as cis-[Pt(DACH)Br2] or cis-[Pt(DACH)Cl2], where dihedral angles are between 50 and 70° (Lock & Pilon, 1981). The Pt—N1A bond is shorter than the same bond in cis-[Pt(DACH)Br2] and similar to that in cis-[Pt(DACH)Cl2] (Lock & Pilon, 1981). As for the two cations, they show few significant differences in bond distances and angles, apart from the analogous Pt1—N3—C7 angle which is 178.6 (3)° (molecule A) and 174.1 (3)° (molecule B). Comparable torsion angles about the Pt atoms, e.g. N4—Pt1—N2—C2, differ by up to 8° in molecules A and B. The N—O bonds in the NO3 group lie within expected ranges and these nitrate groups are positioned in such a manner that the O atoms of the NO3 group are oriented towards the H atoms of the water and the diamine group, forming hydrogen bonds.
There are three systems of supramolecular chains interacting by hydrogen bonds: one formed by bifurcated N—H···(O,O) interactions linking an N atom of the diamine group with O atoms of the nitrate group, and two bifurcated O—H···(O,O) chains linking an O atom of the nitrate group to the water O atom. The first is parallel to [001] (c axis) and takes the form (O1B,O3B)iii–N2Ai–(O2A,O3A)–N5A–(O1A,O3A)–N2Biv –(O2B,O3B)vi–(O1B,O3B)vi when viewed down the b axis (Fig. 1) [Fig. 2?]. Also present are chains parallel to [010] (b axis) (Fig. 3) between the water molecule and nitrate groups, of the form O5A–N6A–(O4A,O6A)–O7A–O5Aiii when viewed down the c axis; the second chain running parallel to the b axis is O5Bvi–O7B–(O4B,O6B)–N6B–O5B. Details of hydrogen bonds are given in Table 1 and the C—H···O interactions are considered weak.