In the 1:1 monohydrated molecular adduct 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride 2,4-diamino-6-methyl-1,3,5-triazine monohydrate, C4H8N5+·Cl-·C4H7N5·H2O, formed between 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride (acetoguanaminium chloride) and 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), and in triaminopyrimidinediium dichloride dihydrate, C4H9N52+·2Cl-·2H2O, whose cationic component lies across a twofold rotation axis, the protonation occurs at the ring N atoms and the bond distances in the protonated molecules indicate significant bond alterations, consistent with charge-separated polar forms. The supramolecular structures of both compounds are stabilized by systems of hydrogen bonds forming complex sheets, interlinked by sets of hydrogen bonds involving the solvent water molecules and the chloride anions.
Supporting information
CCDC references: 669191; 669192
Compounds (I) and (II) (0.5 mmol, Aldrich, 98% purity) were dissolved without further purification in 8 ml of hot dimethylformamide and in 10 ml of methanol/chloroform (3:1), respectively. While stirring, HCl (6 mol l−1) was added dropwise until the pH reached 2. After several days, colourless single crystals suitable for X-ray experiments were obtained by slow evaporation of the solvents.
All H atoms of both compounds were found in difference maps. In (I), positional and isotropic parameters of H atoms of the amino groups and of the triazine ring, as well as positional parameters of H atoms of the water molecule for which Uiso(H) values were set equal to 1.5Ueq(O1), were refined. H atoms from the methyl groups were positioned with idealized geometry and refined isotropically using a riding model [C—H = 0.88–0.91 Å and Uiso(H) = 1.5Ueq(C)]. In (II), positional and isotropic displacement parameters of all H atoms were refined.
For both compounds, data collection: XCS (Colapietro et al., 1992); cell refinement: XCS (Colapietro et al., 1992); data reduction: XCS (Colapietro et al., 1992); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
(I) 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride 2,4-diamino-6-methyl-1,3,5-triazine monohydrate
top
Crystal data top
C4H8N5+·Cl−·C4H7N5·H2O | Z = 2 |
Mr = 304.77 | F(000) = 320 |
Triclinic, P1 | Dx = 1.473 Mg m−3 |
Hall symbol: -P 1' | Mo Kα radiation, λ = 0.710689 Å |
a = 7.3808 (9) Å | Cell parameters from 96 reflections |
b = 9.4538 (10) Å | θ = 15–20° |
c = 10.3942 (9) Å | µ = 0.29 mm−1 |
α = 90.971 (12)° | T = 298 K |
β = 101.554 (14)° | Block, colorless |
γ = 104.252 (16)° | 0.20 × 0.20 × 0.10 mm |
V = 687.03 (13) Å3 | |
Data collection top
Huber CS four-circle diffractometer | 2246 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.018 |
Graphite monochromator | θmax = 25.0°, θmin = 2.0° |
ω scan | h = 0→8 |
Absorption correction: ψ scan (North et al., 1968) | k = −10→10 |
Tmin = 0.940, Tmax = 0.971 | l = −12→12 |
2758 measured reflections | 3 standard reflections every 97 reflections |
2324 independent reflections | intensity decay: 2% |
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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0548P)2 + 0.205P] where P = (Fo2 + 2Fc2)/3 |
2324 reflections | (Δ/σ)max < 0.001 |
227 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
Crystal data top
C4H8N5+·Cl−·C4H7N5·H2O | γ = 104.252 (16)° |
Mr = 304.77 | V = 687.03 (13) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.3808 (9) Å | Mo Kα radiation |
b = 9.4538 (10) Å | µ = 0.29 mm−1 |
c = 10.3942 (9) Å | T = 298 K |
α = 90.971 (12)° | 0.20 × 0.20 × 0.10 mm |
β = 101.554 (14)° | |
Data collection top
Huber CS four-circle diffractometer | 2246 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.018 |
Tmin = 0.940, Tmax = 0.971 | 3 standard reflections every 97 reflections |
2758 measured reflections | intensity decay: 2% |
2324 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | Δρmax = 0.23 e Å−3 |
2324 reflections | Δρmin = −0.24 e Å−3 |
227 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N1 | 0.30571 (18) | 1.40729 (13) | 0.84837 (12) | 0.0328 (3) | |
C2 | 0.2554 (2) | 1.26503 (15) | 0.80213 (14) | 0.0293 (3) | |
N3 | 0.27914 (17) | 1.21687 (13) | 0.68572 (12) | 0.0313 (3) | |
C4 | 0.3592 (2) | 1.32133 (16) | 0.61422 (14) | 0.0297 (3) | |
N5 | 0.41924 (18) | 1.46575 (13) | 0.65268 (12) | 0.0338 (3) | |
C6 | 0.3882 (2) | 1.50059 (16) | 0.76911 (15) | 0.0322 (3) | |
C8 | 0.4509 (3) | 1.65832 (18) | 0.81332 (18) | 0.0466 (4) | |
H8A | 0.4709 | 1.6685 | 0.9022 | 0.070* | |
H8B | 0.3592 | 1.7029 | 0.7774 | 0.070* | |
H8C | 0.5608 | 1.6998 | 0.7873 | 0.070* | |
N6 | 0.1773 (2) | 1.16622 (16) | 0.87846 (15) | 0.0413 (3) | |
H61 | 0.159 (3) | 1.194 (2) | 0.947 (2) | 0.051 (6)* | |
H62 | 0.144 (3) | 1.076 (3) | 0.852 (2) | 0.058 (6)* | |
N7 | 0.3846 (2) | 1.28211 (17) | 0.49635 (13) | 0.0395 (3) | |
H71 | 0.432 (3) | 1.353 (2) | 0.4562 (19) | 0.042 (5)* | |
H72 | 0.342 (3) | 1.196 (2) | 0.468 (2) | 0.046 (5)* | |
N11 | 0.21773 (18) | 0.71853 (14) | 0.27590 (13) | 0.0328 (3) | |
H11 | 0.228 (3) | 0.676 (2) | 0.208 (2) | 0.043 (5)* | |
C12 | 0.1397 (2) | 0.63373 (15) | 0.36561 (14) | 0.0307 (3) | |
N13 | 0.11409 (18) | 0.69417 (13) | 0.47482 (12) | 0.0327 (3) | |
C14 | 0.1703 (2) | 0.84119 (16) | 0.49031 (14) | 0.0321 (3) | |
N15 | 0.24954 (19) | 0.93143 (13) | 0.40286 (13) | 0.0354 (3) | |
C16 | 0.2686 (2) | 0.86615 (16) | 0.29708 (15) | 0.0326 (3) | |
C18 | 0.3468 (3) | 0.95142 (18) | 0.19338 (17) | 0.0433 (4) | |
H18A | 0.3235 | 0.8943 | 0.1212 | 0.065* | |
H18B | 0.4709 | 0.9866 | 0.2203 | 0.065* | |
H18C | 0.2924 | 1.0240 | 0.1770 | 0.065* | |
N16 | 0.0889 (2) | 0.49105 (15) | 0.34208 (16) | 0.0398 (3) | |
H161 | 0.100 (3) | 0.457 (2) | 0.276 (2) | 0.044 (5)* | |
H162 | 0.034 (3) | 0.443 (2) | 0.395 (2) | 0.042 (5)* | |
N17 | 0.1487 (2) | 0.90502 (16) | 0.59694 (14) | 0.0433 (4) | |
H171 | 0.186 (3) | 0.995 (3) | 0.611 (2) | 0.049 (5)* | |
H172 | 0.103 (3) | 0.858 (2) | 0.649 (2) | 0.049 (6)* | |
Cl1 | 0.00214 (7) | 0.20585 (4) | 0.14171 (4) | 0.04651 (16) | |
O1 | 0.2077 (3) | 0.57992 (19) | 0.04704 (14) | 0.0621 (4) | |
H1 | 0.247 (4) | 0.526 (3) | 0.019 (3) | 0.093* | |
H2 | 0.135 (4) | 0.623 (3) | −0.013 (3) | 0.093* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0420 (7) | 0.0270 (6) | 0.0301 (6) | 0.0057 (5) | 0.0129 (5) | 0.0006 (5) |
C2 | 0.0334 (7) | 0.0271 (7) | 0.0279 (7) | 0.0071 (5) | 0.0080 (5) | 0.0032 (6) |
N3 | 0.0399 (7) | 0.0247 (6) | 0.0294 (6) | 0.0053 (5) | 0.0109 (5) | 0.0028 (5) |
C4 | 0.0344 (7) | 0.0275 (7) | 0.0278 (7) | 0.0076 (5) | 0.0085 (5) | 0.0040 (5) |
N5 | 0.0432 (7) | 0.0259 (6) | 0.0331 (6) | 0.0046 (5) | 0.0146 (5) | 0.0035 (5) |
C6 | 0.0355 (7) | 0.0274 (7) | 0.0335 (7) | 0.0056 (6) | 0.0099 (6) | 0.0018 (6) |
C8 | 0.0624 (11) | 0.0283 (8) | 0.0472 (9) | −0.0001 (7) | 0.0223 (8) | −0.0036 (7) |
N6 | 0.0627 (9) | 0.0288 (7) | 0.0341 (7) | 0.0039 (6) | 0.0241 (6) | 0.0031 (6) |
N7 | 0.0602 (9) | 0.0282 (7) | 0.0316 (7) | 0.0047 (6) | 0.0213 (6) | 0.0025 (6) |
N11 | 0.0439 (7) | 0.0265 (6) | 0.0285 (7) | 0.0079 (5) | 0.0104 (5) | 0.0002 (5) |
C12 | 0.0335 (7) | 0.0255 (7) | 0.0325 (7) | 0.0072 (6) | 0.0060 (6) | 0.0027 (6) |
N13 | 0.0419 (7) | 0.0234 (6) | 0.0332 (6) | 0.0066 (5) | 0.0111 (5) | 0.0025 (5) |
C14 | 0.0394 (8) | 0.0253 (7) | 0.0311 (7) | 0.0069 (6) | 0.0077 (6) | 0.0027 (6) |
N15 | 0.0475 (7) | 0.0238 (6) | 0.0339 (7) | 0.0053 (5) | 0.0112 (5) | 0.0021 (5) |
C16 | 0.0370 (7) | 0.0268 (7) | 0.0328 (7) | 0.0065 (6) | 0.0063 (6) | 0.0038 (6) |
C18 | 0.0566 (10) | 0.0340 (8) | 0.0405 (9) | 0.0071 (7) | 0.0185 (7) | 0.0073 (7) |
N16 | 0.0583 (9) | 0.0241 (7) | 0.0379 (8) | 0.0064 (6) | 0.0176 (7) | −0.0009 (6) |
N17 | 0.0721 (10) | 0.0224 (7) | 0.0362 (8) | 0.0039 (6) | 0.0238 (7) | 0.0011 (6) |
Cl1 | 0.0694 (3) | 0.0358 (2) | 0.0400 (2) | 0.01252 (19) | 0.0258 (2) | 0.00338 (17) |
O1 | 0.0835 (10) | 0.0724 (10) | 0.0405 (7) | 0.0330 (8) | 0.0207 (7) | −0.0053 (7) |
Geometric parameters (Å, º) top
N1—C6 | 1.3372 (19) | N11—H11 | 0.83 (2) |
N1—C2 | 1.3559 (19) | C12—N16 | 1.313 (2) |
C2—N6 | 1.333 (2) | C12—N13 | 1.3297 (19) |
C2—N3 | 1.3444 (19) | N13—C14 | 1.3459 (19) |
N3—C4 | 1.3381 (19) | C14—N17 | 1.309 (2) |
C4—N7 | 1.336 (2) | C14—N15 | 1.375 (2) |
C4—N5 | 1.3538 (19) | N15—C16 | 1.301 (2) |
N5—C6 | 1.327 (2) | C16—C18 | 1.481 (2) |
C6—C8 | 1.483 (2) | C18—H18A | 0.8790 |
C8—H8A | 0.9055 | C18—H18B | 0.8790 |
C8—H8B | 0.9055 | C18—H18C | 0.8790 |
C8—H8C | 0.9055 | N16—H161 | 0.78 (2) |
N6—H61 | 0.80 (2) | N16—H162 | 0.83 (2) |
N6—H62 | 0.85 (2) | N17—H171 | 0.83 (2) |
N7—H71 | 0.84 (2) | N17—H172 | 0.78 (2) |
N7—H72 | 0.82 (2) | O1—H1 | 0.73 (3) |
N11—C16 | 1.3548 (19) | O1—H2 | 0.91 (3) |
N11—C12 | 1.3626 (19) | | |
| | | |
C6—N1—C2 | 114.37 (12) | C12—N11—H11 | 117.5 (14) |
N6—C2—N3 | 117.97 (13) | N16—C12—N13 | 120.40 (14) |
N6—C2—N1 | 117.21 (14) | N16—C12—N11 | 118.88 (14) |
N3—C2—N1 | 124.83 (13) | N13—C12—N11 | 120.72 (13) |
C4—N3—C2 | 115.01 (12) | C12—N13—C14 | 116.13 (13) |
N7—C4—N3 | 118.48 (13) | N17—C14—N13 | 118.07 (14) |
N7—C4—N5 | 116.65 (13) | N17—C14—N15 | 116.57 (13) |
N3—C4—N5 | 124.87 (13) | N13—C14—N15 | 125.36 (14) |
C6—N5—C4 | 114.82 (12) | C16—N15—C14 | 115.70 (12) |
N5—C6—N1 | 126.06 (13) | N15—C16—N11 | 122.13 (14) |
N5—C6—C8 | 116.02 (13) | N15—C16—C18 | 120.92 (13) |
N1—C6—C8 | 117.92 (14) | N11—C16—C18 | 116.95 (14) |
C6—C8—H8A | 109.5 | C16—C18—H18A | 109.5 |
C6—C8—H8B | 109.5 | C16—C18—H18B | 109.5 |
H8A—C8—H8B | 109.5 | H18A—C18—H18B | 109.5 |
C6—C8—H8C | 109.5 | C16—C18—H18C | 109.5 |
H8A—C8—H8C | 109.5 | H18A—C18—H18C | 109.5 |
H8B—C8—H8C | 109.5 | H18B—C18—H18C | 109.5 |
C2—N6—H61 | 119.0 (15) | C12—N16—H161 | 119.4 (15) |
C2—N6—H62 | 119.1 (15) | C12—N16—H162 | 116.5 (13) |
H61—N6—H62 | 122 (2) | H161—N16—H162 | 124 (2) |
C4—N7—H71 | 113.2 (13) | C14—N17—H171 | 120.4 (15) |
C4—N7—H72 | 118.4 (15) | C14—N17—H172 | 120.1 (16) |
H71—N7—H72 | 128 (2) | H171—N17—H172 | 119 (2) |
C16—N11—C12 | 119.95 (13) | H1—O1—H2 | 114 (3) |
C16—N11—H11 | 122.5 (14) | | |
| | | |
C6—N1—C2—N6 | 178.21 (14) | C16—N11—C12—N16 | 179.00 (14) |
C6—N1—C2—N3 | −1.6 (2) | C16—N11—C12—N13 | −0.6 (2) |
N6—C2—N3—C4 | −179.64 (13) | N16—C12—N13—C14 | −179.92 (14) |
N1—C2—N3—C4 | 0.2 (2) | N11—C12—N13—C14 | −0.4 (2) |
C2—N3—C4—N7 | −178.96 (13) | C12—N13—C14—N17 | −179.59 (14) |
C2—N3—C4—N5 | 1.7 (2) | C12—N13—C14—N15 | 0.4 (2) |
N7—C4—N5—C6 | 178.76 (14) | N17—C14—N15—C16 | −179.50 (14) |
N3—C4—N5—C6 | −1.9 (2) | N13—C14—N15—C16 | 0.5 (2) |
C4—N5—C6—N1 | 0.2 (2) | C14—N15—C16—N11 | −1.5 (2) |
C4—N5—C6—C8 | −179.46 (14) | C14—N15—C16—C18 | 178.20 (14) |
C2—N1—C6—N5 | 1.4 (2) | C12—N11—C16—N15 | 1.6 (2) |
C2—N1—C6—C8 | −178.93 (14) | C12—N11—C16—C18 | −178.12 (14) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N6—H61···Cl1i | 0.80 (2) | 2.54 (2) | 3.3044 (16) | 160.4 (19) |
N6—H62···Cl1ii | 0.85 (2) | 2.63 (2) | 3.4265 (16) | 157 (2) |
N7—H71···N5iii | 0.84 (2) | 2.25 (2) | 3.082 (2) | 174.8 (17) |
N7—H72···N15 | 0.82 (2) | 2.47 (2) | 3.287 (2) | 172.5 (18) |
N11—H11···O1 | 0.83 (2) | 1.85 (2) | 2.6753 (19) | 170.8 (19) |
N16—H161···Cl1 | 0.78 (2) | 2.60 (2) | 3.2315 (16) | 139.6 (19) |
N16—H162···N13ii | 0.83 (2) | 2.15 (2) | 2.983 (2) | 176.3 (18) |
N17—H171···N3 | 0.83 (2) | 2.12 (2) | 2.9368 (19) | 169 (2) |
N17—H172···Cl1ii | 0.78 (2) | 2.49 (2) | 3.2328 (16) | 160 (2) |
O1—H1···N1iv | 0.73 (3) | 2.25 (3) | 2.9182 (19) | 153 (3) |
O1—H2···Cl1v | 0.91 (3) | 2.40 (3) | 3.2881 (19) | 165 (2) |
Symmetry codes: (i) x, y+1, z+1; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+3, −z+1; (iv) x, y−1, z−1; (v) −x, −y+1, −z. |
(II) triaminopyrimidinediium dichloride dihydrate
top
Crystal data top
C4H9N52+·2Cl−·2H2O | F(000) = 488 |
Mr = 234.09 | Dx = 1.467 Mg m−3 |
Monoclinic, I2/a | Mo Kα radiation, λ = 0.710689 Å |
Hall symbol: -I 2ya' | Cell parameters from 84 reflections |
a = 9.4045 (10) Å | θ = 16–21° |
b = 8.6089 (9) Å | µ = 0.59 mm−1 |
c = 13.7420 (12) Å | T = 298 K |
β = 107.742 (10)° | Block, colorless |
V = 1059.67 (18) Å3 | 0.20 × 0.15 × 0.10 mm |
Z = 4 | |
Data collection top
Huber CS four-circle diffractometer | 1066 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.020 |
Graphite monochromator | θmax = 27.0°, θmin = 2.8° |
ω scan | h = 0→11 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→10 |
Tmin = 0.891, Tmax = 0.943 | l = −17→16 |
1788 measured reflections | 3 standard reflections every 97 reflections |
1106 independent reflections | intensity decay: 1% |
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)] = 0.023 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.070 | All H-atom parameters refined |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0413P)2 + 0.3402P] where P = (Fo2 + 2Fc2)/3 |
1106 reflections | (Δ/σ)max = 0.001 |
87 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.14 e Å−3 |
Crystal data top
C4H9N52+·2Cl−·2H2O | V = 1059.67 (18) Å3 |
Mr = 234.09 | Z = 4 |
Monoclinic, I2/a | Mo Kα radiation |
a = 9.4045 (10) Å | µ = 0.59 mm−1 |
b = 8.6089 (9) Å | T = 298 K |
c = 13.7420 (12) Å | 0.20 × 0.15 × 0.10 mm |
β = 107.742 (10)° | |
Data collection top
Huber CS four-circle diffractometer | 1066 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.020 |
Tmin = 0.891, Tmax = 0.943 | 3 standard reflections every 97 reflections |
1788 measured reflections | intensity decay: 1% |
1106 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.023 | 0 restraints |
wR(F2) = 0.070 | All H-atom parameters refined |
S = 1.10 | Δρmax = 0.19 e Å−3 |
1106 reflections | Δρmin = −0.14 e Å−3 |
87 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N3 | 0.81645 (11) | 0.06971 (11) | 0.44232 (7) | 0.0351 (2) | |
H3 | 0.8550 (18) | 0.023 (2) | 0.4021 (13) | 0.052 (4)* | |
C2 | 0.7500 | −0.0097 (2) | 0.5000 | 0.0341 (3) | |
C4 | 0.81671 (12) | 0.22948 (14) | 0.43916 (9) | 0.0353 (3) | |
C5 | 0.7500 | 0.31123 (19) | 0.5000 | 0.0392 (4) | |
H5 | 0.7500 | 0.427 (3) | 0.5000 | 0.050 (6)* | |
N6 | 0.7500 | −0.16178 (18) | 0.5000 | 0.0450 (4) | |
H61 | 0.7904 (18) | −0.214 (2) | 0.4615 (12) | 0.053 (5)* | |
N7 | 0.88457 (15) | 0.29255 (16) | 0.37791 (10) | 0.0484 (3) | |
H71 | 0.918 (2) | 0.238 (2) | 0.3422 (14) | 0.063 (5)* | |
H72 | 0.8823 (19) | 0.386 (2) | 0.3736 (12) | 0.052 (4)* | |
Cl1 | 0.96356 (4) | −0.05460 (4) | 0.28698 (2) | 0.05036 (15) | |
O1 | 0.84391 (14) | −0.36716 (12) | 0.37089 (8) | 0.0523 (3) | |
H1 | 0.755 (3) | −0.385 (3) | 0.3220 (17) | 0.088 (7)* | |
H2 | 0.894 (3) | −0.319 (3) | 0.3407 (19) | 0.102 (8)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N3 | 0.0402 (5) | 0.0351 (5) | 0.0345 (5) | 0.0026 (4) | 0.0182 (4) | −0.0018 (4) |
C2 | 0.0342 (7) | 0.0341 (7) | 0.0331 (7) | 0.000 | 0.0088 (6) | 0.000 |
C4 | 0.0365 (5) | 0.0369 (6) | 0.0356 (5) | −0.0001 (4) | 0.0153 (4) | 0.0026 (4) |
C5 | 0.0480 (9) | 0.0308 (8) | 0.0454 (9) | 0.000 | 0.0242 (7) | 0.000 |
N6 | 0.0581 (9) | 0.0326 (7) | 0.0471 (9) | 0.000 | 0.0201 (7) | 0.000 |
N7 | 0.0612 (7) | 0.0427 (6) | 0.0548 (7) | 0.0013 (5) | 0.0378 (6) | 0.0053 (5) |
Cl1 | 0.0494 (2) | 0.0601 (2) | 0.0483 (2) | 0.00133 (13) | 0.02482 (15) | −0.01271 (13) |
O1 | 0.0606 (6) | 0.0490 (6) | 0.0508 (5) | −0.0047 (5) | 0.0220 (5) | −0.0038 (4) |
Geometric parameters (Å, º) top
N3—C2 | 1.3369 (13) | C5—H5 | 1.00 (2) |
N3—C4 | 1.3762 (15) | N6—H61 | 0.867 (16) |
N3—H3 | 0.850 (18) | N7—H71 | 0.81 (2) |
C2—N6 | 1.310 (2) | N7—H72 | 0.80 (2) |
C4—N7 | 1.3183 (16) | O1—H1 | 0.91 (2) |
C4—C5 | 1.3811 (14) | O1—H2 | 0.83 (3) |
| | | |
C2—N3—C4 | 122.35 (11) | C4—C5—C4i | 118.73 (15) |
C2—N3—H3 | 120.8 (12) | C4—C5—H5 | 120.64 (7) |
C4—N3—H3 | 116.7 (12) | C2—N6—H61 | 121.4 (12) |
N6—C2—N3 | 120.73 (7) | C4—N7—H71 | 119.8 (14) |
N3i—C2—N3 | 118.53 (15) | C4—N7—H72 | 116.8 (13) |
N7—C4—N3 | 115.95 (11) | H71—N7—H72 | 123.0 (19) |
N7—C4—C5 | 125.04 (12) | H1—O1—H2 | 105 (2) |
N3—C4—C5 | 118.99 (11) | | |
| | | |
C4—N3—C2—N6 | 178.97 (8) | C2—N3—C4—C5 | 2.03 (16) |
C4—N3—C2—N3i | −1.03 (8) | N7—C4—C5—C4i | −179.77 (14) |
C2—N3—C4—N7 | −179.06 (10) | N3—C4—C5—C4i | −0.96 (7) |
Symmetry code: (i) −x+3/2, y, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···Cl1 | 0.850 (18) | 2.230 (18) | 3.0686 (11) | 169.0 (16) |
N6—H61···O1 | 0.867 (16) | 1.979 (16) | 2.8301 (14) | 166.8 (16) |
N7—H71···Cl1 | 0.81 (2) | 2.70 (2) | 3.4074 (14) | 147.0 (17) |
N7—H71···Cl1ii | 0.81 (2) | 2.967 (19) | 3.2983 (12) | 107.2 (15) |
N7—H72···O1iii | 0.80 (2) | 2.16 (2) | 2.9521 (18) | 170.4 (18) |
O1—H1···Cl1iv | 0.91 (2) | 2.21 (2) | 3.1143 (13) | 175 (2) |
O1—H2···Cl1 | 0.83 (3) | 2.53 (3) | 3.2599 (12) | 146 (2) |
Symmetry codes: (ii) −x+2, y+1/2, −z+1/2; (iii) x, y+1, z; (iv) −x+3/2, −y−1/2, −z+1/2. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | C4H8N5+·Cl−·C4H7N5·H2O | C4H9N52+·2Cl−·2H2O |
Mr | 304.77 | 234.09 |
Crystal system, space group | Triclinic, P1 | Monoclinic, I2/a |
Temperature (K) | 298 | 298 |
a, b, c (Å) | 7.3808 (9), 9.4538 (10), 10.3942 (9) | 9.4045 (10), 8.6089 (9), 13.7420 (12) |
α, β, γ (°) | 90.971 (12), 101.554 (14), 104.252 (16) | 90, 107.742 (10), 90 |
V (Å3) | 687.03 (13) | 1059.67 (18) |
Z | 2 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.29 | 0.59 |
Crystal size (mm) | 0.20 × 0.20 × 0.10 | 0.20 × 0.15 × 0.10 |
|
Data collection |
Diffractometer | Huber CS four-circle diffractometer | Huber CS four-circle diffractometer |
Absorption correction | ψ scan (North et al., 1968) | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.940, 0.971 | 0.891, 0.943 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2758, 2324, 2246 | 1788, 1106, 1066 |
Rint | 0.018 | 0.020 |
(sin θ/λ)max (Å−1) | 0.595 | 0.638 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.092, 1.09 | 0.023, 0.070, 1.10 |
No. of reflections | 2324 | 1106 |
No. of parameters | 227 | 87 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.23, −0.24 | 0.19, −0.14 |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N6—H61···Cl1i | 0.80 (2) | 2.54 (2) | 3.3044 (16) | 160.4 (19) |
N6—H62···Cl1ii | 0.85 (2) | 2.63 (2) | 3.4265 (16) | 157 (2) |
N7—H71···N5iii | 0.84 (2) | 2.25 (2) | 3.082 (2) | 174.8 (17) |
N7—H72···N15 | 0.82 (2) | 2.47 (2) | 3.287 (2) | 172.5 (18) |
N11—H11···O1 | 0.83 (2) | 1.85 (2) | 2.6753 (19) | 170.8 (19) |
N16—H161···Cl1 | 0.78 (2) | 2.60 (2) | 3.2315 (16) | 139.6 (19) |
N16—H162···N13ii | 0.83 (2) | 2.15 (2) | 2.983 (2) | 176.3 (18) |
N17—H171···N3 | 0.83 (2) | 2.12 (2) | 2.9368 (19) | 169 (2) |
N17—H172···Cl1ii | 0.78 (2) | 2.49 (2) | 3.2328 (16) | 160 (2) |
O1—H1···N1iv | 0.73 (3) | 2.25 (3) | 2.9182 (19) | 153 (3) |
O1—H2···Cl1v | 0.91 (3) | 2.40 (3) | 3.2881 (19) | 165 (2) |
Symmetry codes: (i) x, y+1, z+1; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+3, −z+1; (iv) x, y−1, z−1; (v) −x, −y+1, −z. |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···Cl1 | 0.850 (18) | 2.230 (18) | 3.0686 (11) | 169.0 (16) |
N6—H61···O1 | 0.867 (16) | 1.979 (16) | 2.8301 (14) | 166.8 (16) |
N7—H71···Cl1 | 0.81 (2) | 2.70 (2) | 3.4074 (14) | 147.0 (17) |
N7—H71···Cl1i | 0.81 (2) | 2.967 (19) | 3.2983 (12) | 107.2 (15) |
N7—H72···O1ii | 0.80 (2) | 2.16 (2) | 2.9521 (18) | 170.4 (18) |
O1—H1···Cl1iii | 0.91 (2) | 2.21 (2) | 3.1143 (13) | 175 (2) |
O1—H2···Cl1 | 0.83 (3) | 2.53 (3) | 3.2599 (12) | 146 (2) |
Symmetry codes: (i) −x+2, y+1/2, −z+1/2; (ii) x, y+1, z; (iii) −x+3/2, −y−1/2, −z+1/2. |
Selected geometric parameters (Å) for Guana, (I) and (II). top | Guana | n = nilb | n = 1b | n = nilc | Δd | Δe |
Nn1-Cn2 | 1.360 (1) | 1.356 (2) | 1.363 (2) | — | .007 (2) | - |
Nn5-Cn4 | 1.360 (1) | 1.354 (2) | 1.375 (2) | — | .021 (2) | - |
Nn1-Cn6 | 1.328 (1) | 1.337 (2) | 1.355 (2) | — | .018 (2) | - |
Nn5-Cn6 | 1.325 (1) | 1.327 (2) | 1.301 (2) | — | -.026 (2) | - |
Nn3-Cn2 | 1.340 (1) | 1.344 (2) | 1.330 (2) | 1.337 (1) | -.014 (2) | -.007 (2) |
Nn3-Cn4 | 1.338 (1) | 1.338 (2) | 1.346 (2) | 1.376 (2) | .008 (2) | .038 (2) |
Nn6-Cn2 | 1.333 (1) | 1.333 (2) | 1.313 (2) | 1.310 (2) | -.020 (2) | -.023 (2) |
Nn7-Cn4 | 1.331 (1) | 1.336 (2) | 1.309 (2) | 1.318 (2) | -.027 (2) | -.018 (2) |
Notes: (a) Portalone (2007); (b) this work, compound (I); (c) this work, compound (II); (d) Δ is defined as the difference (Å) between corresponding Nn—Cn bond distances (n = 1 for AceguH+ and n = nil for Acegu) in (I); (e) Δ is defined as the difference (Å) between corresponding Nn—Cn bond distances (n = 1 for TripidH+ and n = nil for Acegu) in (II) and (I). |
We report here the structures of the 1:1 monohydrated molecular adduct C4H8N5+·Cl−·C4H7N5. H2O, (I), formed between 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride (acetoguanaminium chloride, AceguH+) and 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine, Acegu), which we compare with the structure of 2,4,6-triaminopyrimidinediium dichloride dihydrate, C4H9N52+·2Cl−·2H2O, (II) (TripidH22+). The heterocyclic system in (I) differs from that in (II) only in the replacement of one amino substituent on the triazine ring by a methyl substituent and by the substitution of an N atom for a C atom in the triazine ring, and this provides an opportunity to observe the effects that simple changes of substituent and in the heterocyclic skeleton exert upon the site of protonation and the supramolecular aggregation. This work is a continuation of our studies on crystal adducts of DNA/RNA pyrimidine bases coupled with amino-derivatives of aromatic N-heterocycles via multiple hydrogen bonds to mimic the base-pairing of nucleic acids (Portalone et al., 1999, 2002; Brunetti et al., 2000, 2002; Portalone & Colapietro, 2004a,b, 2006, 2007a,b,c,d; Portalone, 2007). In this context, our attention has been focused on the protonated form of the two previously mentioned aromatic N-heterocycles, as polyaminopyrimidine and polyamino-1,3,5-triazine are capable of interacting with RNA through Watson–Crick pairing (Gilbert et al., 2006), and the relevance of proton transfer in DNA/RNA systems was demonstrated many years ago (Steenken, 1989, 1997).
The asymmetric unit of compound (I) consists of one protonated (AceguH+) and one neutral (Acegu) acetoguanamine molecules, a chloride anion, and a water molecule of crystallization (Fig. 1). Of the different sites available in the acetoguanamine molecule, protonation occurs at one of the two ring N atoms ortho to the C atom bearing the methyl group. Comparison of the molecular geometry of the planar heterocyclic ring of Acegu with that reported for guanamine (Portalone, 2007) shows that the corresponding bond lengths and angles are equal within experimental error and conform to Cs symmetry (Table 3). The effects of protonation can be appreciated by comparing the molecular geometry of the AceguH+ cation with that of the free base (Table 3), and can be summarized as follows: (i) an increase of the N11—C12 and N11—C16 bond distances by 0.007 (2) Å and 0.018 (2) Å, respectively; (ii) a decrease of the N13—C12, N15—C16, N16—C12 and N17—C14 bond distances by 0.014 (2)–0.026 (2) Å; (iii) an increase of the C12—N11—C16 bond angle by 5.6 (1)°; (iv) a decrease of the N11—C12—N13 and N11—C16—N15 bond angles by 4.1 (1) and 4.0 (1)°, respectively.
Protonation of atom N11 causes a redistribution of π-electron density so that the resulting distortions in the molecular geometry of the cation, which have been observed in the only two previously reported crystal structures containing the 2,4-diamino-6-methyl-1,3,5-triazin-1-ium unit (Wijaya et al., 2004; Perpétuo & Janczak, 2007), point to the importance of the charge-separated quininoid forms (Ia) and (Ib) (see scheme) as significant contributors.
As previously mentioned, compound (I) crystallizes as a 1:1 monohydrated molecular adduct. In the crystal structure, the hydrogen-bonding scheme is rather complex and involves all available hydrogen-bond donor/acceptor sites except atom O1, which participates as a hydrogen-bond acceptor in only one intermolecular interaction [please clarify; implies that O1 only participates in 1 bond as acceptor, while next sentence states it is actually involved in 3 as donor/acceptor]. In total, the supramolecular structure of (I) is characterized by 11 two-center hydrogen bonds, namely nine N—H···X (X = N, O and Cl−) and two O—H···Y bonds (Y = N and Cl−) (Table 1), and is dominated by two main motifs. Firstly, an R22(8) ring (Etter et al., 1990; Bernstein et al., 1995; Motherwell et al., 1999) forms from N—H···N double intermolecular hydrogen bonds between centrosymmetric coplanar Acegu pairs. These pairs further self-organize through R22(8) N—H···N double intermolecular hydrogen bonds with centrosymmetric coplanar R22(8) AceguH+ pairs to generate infinite chains of rings running approximately parallel to the [010] direction (Fig. 2). In other words, this hydrogen-bonding scheme corresponds to an alternating double repetition of AceguH+ and Acegu molecules. These infinite chains are then crosslinked by one N+—H···O, one O—H···N and four N—H···Cl− intermolecular hydrogen bonds between pairs of Acegu and AceguH+ molecules, forming a sheet-like structure via four adjoining hydrogen-bonded rings [R23(8), R23(8), R24(8) and R34(12)], and form the second major motif, also shown in Fig. 2. The hydrogen bonds so far discussed in the two-dimensional arrays in the bc plane are bridged by water molecules via O—H ···Cl− interactions. It is noteworthy that in AceguH+, where the charge-separated forms (Ia) and (Ib) are significant, the intermolecular N—H···Cl− and N—H···N hydrogen bonds are characterized by shorter N···Cl− and N···N distances (Table 1) than those in Acegu, where the development of comparable charge-separated forms is not possible.
The asymmetric unit of compound (II) comprises a planar half-molecule of 2,4,6-triaminopyrimidine disposed about a twofold axis along the line joining atoms N6, C2 and C5 and protonated at the ring N atom (TripidH+), a chloride anion and a water molecule of crystallization (Fig. 3). Comparison of the molecular geometry of TripidH+ with that reported for the free base (Schwalbe & Williams, 1982) was not possible because of the low accuracy of this structure determination (twinned crystals, R = 0.104 with a data-to-parameter ratio of 4.9 and standard deviations of 0.01 Å in bond lengths and 0.8° in bond angles for the two molecules in the asymmetric unit). Consequently, the effects of protonation can be appreciated by matching the molecular geometry of the TripidH+ cation with that of Acegu (Table 3). As for (I), the observed geometrical distortions suggest that the charge-separated quininoid forms (IIa), (IIb) and (IIc) (see scheme) are significant contributors to the overall molecular–electronic structure.
The crystal packing of (II) involves all available hydrogen donor/acceptor sites, and is stabilized by seven hydrogen bonds, namely five N—H···X (X = O and Cl−) and two O—H···Cl− (Table 2). The supramolecular structure takes the form of sheets generated by a combination of N—H···Cl−, N—H···O and O—H···Cl− hydrogen bonds (Fig. 4); this may be contrasted with (I), where N—H···N and O—H···N hydrogen bonds were present. Moreover, at variance with the previously observed supramolecular organization of (I), in the two-dimensional arrays water molecules and Cl− anions act as bridges between TripidH22+ cations, forming three different types of hydrogen-bonded rings, one of R22(8) type, one of R12(6) type and one of R34(8) type. The (010)-nets thus formed are themselves linked into a three-dimensional network by pairs of O1—H1···Cl1iii [symmetry code: (iii) −x + 3/2, −y − 1/2, −z + 1/2] hydrogen bonds, so forming centrosymmetric hydrogen-bonded rings of R24(8) motif and approximately in the [001] direction (Fig. 4). In one of the three N—H···Cl− interactions, where atom N7 acts as a hydrogen-bond donor via atom H71, there is some uncertainty as to whether this is a hydrogen bond or not. However, as is very frequently found for bifurcated hydrogen bonds, the sum of the inter-bond angles at the H atom is close to 360° and the H···Cl− distance can be greater than the van der Waals separation (Jeffrey & Saenger, 1991; Desiraju & Steiner, 1999; Steiner, 2002).