The crystal structures of
N,
N-dimethylbiguanidium oxalate monohydrate, C
4H
13N
52+·C
2O
42−·H
2O, (I), and
N,
N-dimethylbiguanidium sulfate monohydrate, C
4H
13N
52+·SO
42−·H
2O, (II), show that both compounds contain the same
N,
N-dimethylbiguanidium dication. In (I), two independent oxalate ions lie about inversion centres. Strong double hydrogen bonds, with
DA distances of 2.658 (2) and 2.830 (3) Å in (I), and 2.722 (3) and 2.815 (3) Å in (II), are present between N atoms of the
N,
N-dimethylbiguanidium moieties and either the carboxylate group of the oxalate anion or the sulfate anion.
Supporting information
CCDC references: 254933; 254934
All chemicals were commercially available from the Beijing Chemical Reagents Company, People's Republic of China, were of reagent grade and were used without further purification. N,N-Dimethylbiguanide was obtained from a 1:1 molar ratio of N,N-dimethylbiguanide hydrochloride and NaOH in 2-propanol. The suspension was stirred for an hour at 313 K and then filtered. The filtrate was evaporated and a white solid, without Cl− (checked by 0.1 M AgNO3 solution), was collected. Compounds (I) and (II) were prepared by dissolving N,N-dimethylbiguanide (10.0 mmol) in water (5 ml) and adding either oxalic or sulfuric acid, adjusting the pH to 4. Crystals of both compounds were obtained from their respective solutions after several weeks, by slow evaporation of the aqueous solvent at room temperature.
In both (I) and (II), H atoms attached to C and N atoms were placed in idealized positions [Csp3—H = 0.96 Å and Nsp2—H = 0.86 Å] and constrained to ride on their parent atoms, with Uiso(H) values of 1.5Ueq(C) or 1.2Ueq(N). H atoms attached to O atoms were located from difference Fourier maps and their parameters were refined, assuming a common Uiso(H) value. The O—H distances are in the range 0.819–0.821 Å.
For both compounds, data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2000); program(s) used to refine structure: SHELXL97 (Sheldrick, 2000); molecular graphics: SHELXTL/PC (Sheldrick, 1999); software used to prepare material for publication: SHELXTL/PC.
(I)
N,
N-dimethylbiguanidium oxalate hydrate
top
Crystal data top
C4H13N52+·C2O42−·H2O | F(000) = 504 |
Mr = 237.23 | Dx = 1.468 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 1102 reflections |
a = 6.775 (2) Å | θ = 2.3–22.0° |
b = 10.762 (3) Å | µ = 0.13 mm−1 |
c = 14.731 (4) Å | T = 298 K |
β = 92.561 (4)° | Block, colorless |
V = 1073.1 (5) Å3 | 0.40 × 0.18 × 0.12 mm |
Z = 4 | |
Data collection top
Brker SMART 1K CCD area-detector diffractometer | 1885 independent reflections |
Radiation source: fine-focus sealed tube | 1295 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.059 |
ω scan | θmax = 25.0°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | h = −8→7 |
Tmin = 0.614, Tmax = 0.974 | k = −12→6 |
4303 measured reflections | l = −17→17 |
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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.102 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0368P)2] where P = (Fo2 + 2Fc2)/3 |
1885 reflections | (Δ/σ)max < 0.001 |
155 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
Crystal data top
C4H13N52+·C2O42−·H2O | V = 1073.1 (5) Å3 |
Mr = 237.23 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 6.775 (2) Å | µ = 0.13 mm−1 |
b = 10.762 (3) Å | T = 298 K |
c = 14.731 (4) Å | 0.40 × 0.18 × 0.12 mm |
β = 92.561 (4)° | |
Data collection top
Brker SMART 1K CCD area-detector diffractometer | 1885 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | 1295 reflections with I > 2σ(I) |
Tmin = 0.614, Tmax = 0.974 | Rint = 0.059 |
4303 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.102 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | Δρmax = 0.24 e Å−3 |
1885 reflections | Δρmin = −0.23 e Å−3 |
155 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 | |
C1 | 0.4687 (4) | 1.0035 (2) | 0.86910 (16) | 0.0431 (7) | |
H4A | 0.5299 | 0.9571 | 0.9184 | 0.065* | |
H4B | 0.3413 | 1.0322 | 0.8860 | 0.065* | |
H4C | 0.5501 | 1.0735 | 0.8555 | 0.065* | |
C2 | 0.2794 (4) | 0.8373 (2) | 0.78772 (17) | 0.0429 (7) | |
H3A | 0.1598 | 0.8807 | 0.7704 | 0.064* | |
H3B | 0.2680 | 0.8021 | 0.8471 | 0.064* | |
H3C | 0.3012 | 0.7722 | 0.7448 | 0.064* | |
C3 | 0.5704 (3) | 0.9300 (2) | 0.72262 (14) | 0.0255 (5) | |
C4 | 0.6255 (3) | 0.8159 (2) | 0.58361 (15) | 0.0273 (5) | |
N1 | 0.4456 (3) | 0.92407 (19) | 0.78902 (12) | 0.0299 (5) | |
N2 | 0.7407 (3) | 0.98811 (17) | 0.72951 (12) | 0.0300 (5) | |
H21 | 0.7765 | 1.0251 | 0.7793 | 0.036* | |
H22 | 0.8165 | 0.9892 | 0.6842 | 0.036* | |
N3 | 0.5085 (3) | 0.87860 (18) | 0.64082 (12) | 0.0285 (5) | |
H3 | 0.3858 | 0.8867 | 0.6244 | 0.034* | |
N4 | 0.7931 (3) | 0.76763 (18) | 0.61228 (13) | 0.0337 (5) | |
H41 | 0.8628 | 0.7259 | 0.5756 | 0.040* | |
H42 | 0.8342 | 0.7775 | 0.6679 | 0.040* | |
N5 | 0.5575 (3) | 0.8030 (2) | 0.49935 (12) | 0.0376 (6) | |
H51 | 0.6241 | 0.7618 | 0.4612 | 0.045* | |
H52 | 0.4462 | 0.8359 | 0.4822 | 0.045* | |
C5 | 0.9501 (3) | 0.9780 (2) | 0.95391 (15) | 0.0281 (6) | |
O1 | 0.8822 (3) | 0.86957 (16) | 0.95187 (10) | 0.0422 (5) | |
O2 | 0.9466 (2) | 1.05278 (16) | 0.88959 (10) | 0.0419 (5) | |
C6 | 0.1005 (3) | 0.5310 (2) | 0.01310 (15) | 0.0268 (5) | |
O3 | 0.1527 (2) | 0.53023 (16) | 0.09624 (10) | 0.0365 (4) | |
O4 | 0.1963 (2) | 0.57688 (16) | −0.04908 (10) | 0.0373 (4) | |
O1W | 0.1800 (3) | 0.20718 (18) | 0.69388 (12) | 0.0563 (6) | |
H11 | 0.1521 | 0.2556 | 0.6522 | 0.071 (8)* | |
H12 | 0.1575 | 0.1395 | 0.6702 | 0.071 (8)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0453 (15) | 0.0503 (18) | 0.0344 (14) | 0.0026 (14) | 0.0092 (12) | −0.0109 (13) |
C2 | 0.0375 (15) | 0.0486 (18) | 0.0431 (16) | −0.0060 (14) | 0.0091 (12) | 0.0012 (14) |
C3 | 0.0279 (12) | 0.0240 (13) | 0.0244 (12) | 0.0072 (11) | −0.0005 (10) | 0.0008 (10) |
C4 | 0.0262 (12) | 0.0243 (13) | 0.0318 (13) | −0.0022 (11) | 0.0040 (11) | −0.0020 (11) |
N1 | 0.0277 (10) | 0.0355 (12) | 0.0268 (11) | 0.0015 (10) | 0.0052 (8) | −0.0029 (9) |
N2 | 0.0306 (11) | 0.0351 (13) | 0.0246 (10) | −0.0040 (10) | 0.0035 (8) | −0.0086 (9) |
N3 | 0.0192 (9) | 0.0384 (12) | 0.0277 (10) | 0.0037 (9) | −0.0006 (8) | −0.0086 (10) |
N4 | 0.0258 (11) | 0.0365 (13) | 0.0387 (12) | 0.0063 (10) | −0.0003 (9) | −0.0118 (10) |
N5 | 0.0364 (12) | 0.0456 (14) | 0.0307 (11) | 0.0093 (11) | 0.0008 (9) | −0.0151 (10) |
C5 | 0.0254 (12) | 0.0328 (15) | 0.0266 (13) | −0.0060 (11) | 0.0068 (10) | −0.0019 (12) |
O1 | 0.0589 (12) | 0.0358 (11) | 0.0318 (10) | −0.0172 (10) | 0.0008 (8) | −0.0013 (9) |
O2 | 0.0514 (11) | 0.0453 (12) | 0.0284 (9) | −0.0186 (9) | −0.0064 (8) | 0.0094 (9) |
C6 | 0.0250 (12) | 0.0276 (14) | 0.0278 (13) | 0.0028 (11) | 0.0014 (10) | −0.0028 (11) |
O3 | 0.0345 (9) | 0.0481 (11) | 0.0265 (9) | −0.0051 (8) | −0.0034 (7) | 0.0005 (8) |
O4 | 0.0345 (9) | 0.0478 (12) | 0.0298 (9) | −0.0109 (9) | 0.0037 (8) | −0.0002 (8) |
O1W | 0.0872 (16) | 0.0414 (12) | 0.0395 (11) | 0.0030 (11) | −0.0079 (10) | 0.0005 (9) |
Geometric parameters (Å, º) top
C1—N1 | 1.460 (3) | N2—H22 | 0.8600 |
C1—H4A | 0.9600 | N3—H3 | 0.8600 |
C1—H4B | 0.9600 | N4—H41 | 0.8600 |
C1—H4C | 0.9600 | N4—H42 | 0.8600 |
C2—N1 | 1.463 (3) | N5—H51 | 0.8600 |
C2—H3A | 0.9600 | N5—H52 | 0.8600 |
C2—H3B | 0.9600 | C5—O2 | 1.243 (3) |
C2—H3C | 0.9600 | C5—O1 | 1.254 (3) |
C3—N2 | 1.312 (3) | C5—C5i | 1.563 (4) |
C3—N1 | 1.323 (3) | C6—O4 | 1.248 (2) |
C3—N3 | 1.374 (3) | C6—O3 | 1.260 (3) |
C4—N4 | 1.302 (3) | C6—C6ii | 1.549 (4) |
C4—N5 | 1.312 (3) | O1W—H11 | 0.8209 |
C4—N3 | 1.361 (3) | O1W—H12 | 0.8191 |
N2—H21 | 0.8600 | | |
| | | |
N1—C1—H4A | 109.5 | C1—N1—C2 | 116.05 (18) |
N1—C1—H4B | 109.5 | C3—N2—H21 | 120.0 |
H4A—C1—H4B | 109.5 | C3—N2—H22 | 120.0 |
N1—C1—H4C | 109.5 | H21—N2—H22 | 120.0 |
H4A—C1—H4C | 109.5 | C4—N3—C3 | 125.4 (2) |
H4B—C1—H4C | 109.5 | C4—N3—H3 | 117.3 |
N1—C2—H3A | 109.5 | C3—N3—H3 | 117.3 |
N1—C2—H3B | 109.5 | C4—N4—H41 | 120.0 |
H3A—C2—H3B | 109.5 | C4—N4—H42 | 120.0 |
N1—C2—H3C | 109.5 | H41—N4—H42 | 120.0 |
H3A—C2—H3C | 109.5 | C4—N5—H51 | 120.0 |
H3B—C2—H3C | 109.5 | C4—N5—H52 | 120.0 |
N2—C3—N1 | 123.7 (2) | H51—N5—H52 | 120.0 |
N2—C3—N3 | 119.5 (2) | O2—C5—O1 | 126.1 (2) |
N1—C3—N3 | 116.7 (2) | O2—C5—C5i | 117.3 (3) |
N4—C4—N5 | 122.0 (2) | O1—C5—C5i | 116.5 (3) |
N4—C4—N3 | 121.4 (2) | O4—C6—O3 | 125.7 (2) |
N5—C4—N3 | 116.6 (2) | O4—C6—C6ii | 117.9 (2) |
C3—N1—C1 | 121.4 (2) | O3—C6—C6ii | 116.5 (2) |
C3—N1—C2 | 122.6 (2) | H11—O1W—H11 | 102.3 |
| | | |
N2—C3—N1—C1 | 13.0 (3) | N4—C4—N3—C3 | 20.3 (3) |
N3—C3—N1—C1 | −162.6 (2) | N5—C4—N3—C3 | −161.9 (2) |
N2—C3—N1—C2 | −166.1 (2) | N2—C3—N3—C4 | 41.0 (3) |
N3—C3—N1—C2 | 18.3 (3) | N1—C3—N3—C4 | −143.1 (2) |
Symmetry codes: (i) −x+2, −y+2, −z+2; (ii) −x, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H21···O2 | 0.86 | 1.97 | 2.774 (2) | 155 |
N3—H3···O3iii | 0.86 | 1.85 | 2.658 (2) | 157 |
N4—H41···O1iv | 0.86 | 2.10 | 2.873 (2) | 149 |
N4—H42···O1Wv | 0.86 | 2.18 | 2.926 (3) | 145 |
N5—H51···O1iv | 0.86 | 2.26 | 2.986 (3) | 143 |
N5—H52···O4iii | 0.86 | 1.97 | 2.830 (3) | 175 |
O1W—H12···O3vi | 0.82 | 2.13 | 2.934 (3) | 169 |
O1W—H11···O1vii | 0.82 | 1.97 | 2.786 (2) | 173 |
N2—H22···O4viii | 0.86 | 2.20 | 2.874 (2) | 135 |
Symmetry codes: (iii) x, −y+3/2, z+1/2; (iv) x, −y+3/2, z−1/2; (v) −x+1, y+1/2, −z+3/2; (vi) x, −y+1/2, z+1/2; (vii) −x+1, y−1/2, −z+3/2; (viii) −x+1, y+1/2, −z+1/2. |
(II)
N,
N-dimethylbiguanidium sulfate hydrate
top
Crystal data top
C4H13N52+·O4S2−·H2O | Z = 2 |
Mr = 245.27 | F(000) = 260 |
Triclinic, P1 | Dx = 1.512 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.056 (3) Å | Cell parameters from 1531 reflections |
b = 8.862 (4) Å | θ = 2.5–26.9° |
c = 9.462 (4) Å | µ = 0.32 mm−1 |
α = 99.830 (6)° | T = 293 K |
β = 96.020 (7)° | Block, colorless |
γ = 110.099 (7)° | 0.32 × 0.15 × 0.15 mm |
V = 538.8 (4) Å3 | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1741 independent reflections |
Radiation source: fine-focus sealed tube | 1508 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.040 |
ω scan | θmax = 25.0°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | h = −8→6 |
Tmin = 0.094, Tmax = 0.966 | k = −10→10 |
2516 measured reflections | l = −11→10 |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.162 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.18 | w = 1/[σ2(Fo2) + (0.0993P)2 + 0.1217P] where P = (Fo2 + 2Fc2)/3 |
1739 reflections | (Δ/σ)max < 0.001 |
139 parameters | Δρmax = 0.37 e Å−3 |
0 restraints | Δρmin = −0.36 e Å−3 |
Crystal data top
C4H13N52+·O4S2−·H2O | γ = 110.099 (7)° |
Mr = 245.27 | V = 538.8 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.056 (3) Å | Mo Kα radiation |
b = 8.862 (4) Å | µ = 0.32 mm−1 |
c = 9.462 (4) Å | T = 293 K |
α = 99.830 (6)° | 0.32 × 0.15 × 0.15 mm |
β = 96.020 (7)° | |
Data collection top
Bruker SMART 1K CCD area-detector diffractometer | 1741 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2000) | 1508 reflections with I > 2σ(I) |
Tmin = 0.094, Tmax = 0.966 | Rint = 0.040 |
2516 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.162 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.18 | Δρmax = 0.37 e Å−3 |
1739 reflections | Δρmin = −0.36 e Å−3 |
139 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 | |
C1 | 1.0935 (6) | 0.5395 (4) | 0.3032 (5) | 0.0492 (10) | |
H1A | 0.9725 | 0.4717 | 0.3327 | 0.074* | |
H1B | 1.2128 | 0.5445 | 0.3657 | 0.074* | |
H1C | 1.0961 | 0.4932 | 0.2044 | 0.074* | |
C2 | 1.2107 (6) | 0.8309 (4) | 0.4479 (4) | 0.0474 (9) | |
H2A | 1.3532 | 0.8719 | 0.4404 | 0.071* | |
H2B | 1.1936 | 0.7815 | 0.5308 | 0.071* | |
H2C | 1.1621 | 0.9203 | 0.4595 | 0.071* | |
C3 | 0.9666 (4) | 0.7343 (3) | 0.2191 (3) | 0.0271 (7) | |
C4 | 0.8455 (5) | 0.9577 (4) | 0.1907 (3) | 0.0274 (7) | |
N1 | 1.0919 (4) | 0.7060 (3) | 0.3139 (3) | 0.0314 (6) | |
N2 | 0.8228 (4) | 0.6166 (3) | 0.1207 (3) | 0.0315 (6) | |
H22 | 0.8079 | 0.5154 | 0.1165 | 0.038* | |
H21 | 0.7437 | 0.6409 | 0.0605 | 0.038* | |
N3 | 0.9962 (4) | 0.8966 (3) | 0.2180 (3) | 0.0297 (6) | |
H3 | 1.1208 | 0.9656 | 0.2361 | 0.036* | |
N4 | 0.6618 (4) | 0.8843 (3) | 0.2172 (3) | 0.0319 (6) | |
H41 | 0.5697 | 0.9263 | 0.2046 | 0.038* | |
H42 | 0.6331 | 0.7941 | 0.2472 | 0.038* | |
N5 | 0.8969 (4) | 1.0953 (3) | 0.1448 (3) | 0.0340 (7) | |
H51 | 0.8085 | 1.1406 | 0.1311 | 0.041* | |
H52 | 1.0191 | 1.1404 | 0.1284 | 0.041* | |
S1 | 0.47039 (11) | 0.24350 (8) | 0.19611 (7) | 0.0258 (3) | |
O1 | 0.3021 (3) | 0.2777 (3) | 0.1209 (2) | 0.0368 (6) | |
O2 | 0.6393 (3) | 0.2732 (3) | 0.1132 (2) | 0.0362 (6) | |
O3 | 0.3956 (3) | 0.0702 (3) | 0.2107 (3) | 0.0405 (6) | |
O4 | 0.5446 (4) | 0.3507 (3) | 0.3411 (3) | 0.0487 (7) | |
O1W | 0.6623 (4) | 0.6879 (3) | 0.4229 (3) | 0.0565 (8) | |
H11 | 0.6325 | 0.7086 | 0.5035 | 0.066 (10)* | |
H12 | 0.6286 | 0.5895 | 0.3867 | 0.066 (10)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.050 (2) | 0.0320 (17) | 0.063 (2) | 0.0180 (16) | −0.0140 (18) | 0.0121 (16) |
C2 | 0.052 (2) | 0.0405 (19) | 0.040 (2) | 0.0134 (17) | −0.0123 (17) | 0.0043 (15) |
C3 | 0.0298 (17) | 0.0273 (15) | 0.0301 (15) | 0.0132 (13) | 0.0103 (13) | 0.0131 (12) |
C4 | 0.0340 (17) | 0.0261 (15) | 0.0242 (15) | 0.0150 (13) | 0.0026 (12) | 0.0046 (11) |
N1 | 0.0327 (14) | 0.0281 (13) | 0.0339 (14) | 0.0119 (11) | 0.0007 (11) | 0.0098 (11) |
N2 | 0.0407 (16) | 0.0242 (12) | 0.0309 (14) | 0.0145 (11) | −0.0003 (11) | 0.0078 (11) |
N3 | 0.0189 (13) | 0.0213 (12) | 0.0452 (15) | 0.0024 (10) | 0.0031 (11) | 0.0103 (11) |
N4 | 0.0280 (14) | 0.0291 (13) | 0.0429 (15) | 0.0128 (11) | 0.0081 (11) | 0.0130 (11) |
N5 | 0.0286 (14) | 0.0304 (14) | 0.0500 (17) | 0.0141 (11) | 0.0096 (12) | 0.0185 (12) |
S1 | 0.0274 (5) | 0.0227 (4) | 0.0288 (5) | 0.0098 (3) | 0.0042 (3) | 0.0092 (3) |
O1 | 0.0327 (12) | 0.0432 (13) | 0.0408 (13) | 0.0171 (10) | 0.0045 (10) | 0.0204 (10) |
O2 | 0.0367 (13) | 0.0305 (11) | 0.0484 (14) | 0.0162 (10) | 0.0140 (11) | 0.0149 (10) |
O3 | 0.0325 (13) | 0.0286 (12) | 0.0658 (16) | 0.0119 (10) | 0.0104 (11) | 0.0216 (11) |
O4 | 0.0619 (17) | 0.0455 (14) | 0.0299 (13) | 0.0130 (12) | 0.0011 (11) | 0.0043 (11) |
O1W | 0.083 (2) | 0.0428 (15) | 0.0516 (16) | 0.0231 (14) | 0.0326 (14) | 0.0193 (12) |
Geometric parameters (Å, º) top
C1—N1 | 1.466 (4) | N2—H22 | 0.8600 |
C1—H1A | 0.9600 | N2—H21 | 0.8600 |
C1—H1B | 0.9600 | N3—H3 | 0.8600 |
C1—H1C | 0.9600 | N4—H41 | 0.8600 |
C2—N1 | 1.482 (4) | N4—H42 | 0.8600 |
C2—H2A | 0.9600 | N5—H51 | 0.8600 |
C2—H2B | 0.9600 | N5—H52 | 0.8600 |
C2—H2C | 0.9600 | S1—O4 | 1.457 (2) |
C3—N1 | 1.308 (4) | S1—O1 | 1.467 (2) |
C3—N2 | 1.314 (4) | S1—O2 | 1.468 (2) |
C3—N3 | 1.383 (4) | S1—O3 | 1.479 (2) |
C4—N4 | 1.308 (4) | O1W—H11 | 0.8195 |
C4—N5 | 1.310 (4) | O1W—H12 | 0.8202 |
C4—N3 | 1.370 (4) | | |
| | | |
N1—C1—H1A | 109.5 | C1—N1—C2 | 117.0 (3) |
N1—C1—H1B | 109.5 | C3—N2—H22 | 120.0 |
H1A—C1—H1B | 109.5 | C3—N2—H21 | 120.0 |
N1—C1—H1C | 109.5 | H22—N2—H21 | 120.0 |
H1A—C1—H1C | 109.5 | C4—N3—C3 | 126.1 (2) |
H1B—C1—H1C | 109.5 | C4—N3—H3 | 117.0 |
N1—C2—H2A | 109.5 | C3—N3—H3 | 117.0 |
N1—C2—H2B | 109.5 | C4—N4—H41 | 120.0 |
H2A—C2—H2B | 109.5 | C4—N4—H42 | 120.0 |
N1—C2—H2C | 109.5 | H41—N4—H42 | 120.0 |
H2A—C2—H2C | 109.5 | C4—N5—H51 | 120.0 |
H2B—C2—H2C | 109.5 | C4—N5—H52 | 120.0 |
N1—C3—N2 | 123.1 (3) | H51—N5—H52 | 120.0 |
N1—C3—N3 | 117.8 (3) | O4—S1—O1 | 109.78 (15) |
N2—C3—N3 | 118.9 (3) | O4—S1—O2 | 109.13 (15) |
N4—C4—N5 | 122.4 (3) | O1—S1—O2 | 109.81 (13) |
N4—C4—N3 | 120.4 (3) | O4—S1—O3 | 108.73 (14) |
N5—C4—N3 | 117.2 (3) | O1—S1—O3 | 109.52 (13) |
C3—N1—C1 | 120.4 (3) | O2—S1—O3 | 109.85 (13) |
C3—N1—C2 | 121.9 (3) | H11—O1W—H12 | 115.0 |
| | | |
N2—C3—N1—C1 | 7.4 (5) | N4—C4—N3—C3 | 26.4 (4) |
N3—C3—N1—C1 | −168.6 (3) | N5—C4—N3—C3 | −157.0 (3) |
N2—C3—N1—C2 | −162.2 (3) | N1—C3—N3—C4 | −144.4 (3) |
N3—C3—N1—C2 | 21.8 (4) | N2—C3—N3—C4 | 39.4 (4) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H22···O2 | 0.86 | 2.06 | 2.854 (3) | 153 |
N2—H21···O1i | 0.86 | 2.01 | 2.784 (3) | 150 |
N3—H3···O3ii | 0.86 | 1.90 | 2.722 (3) | 159 |
N4—H41···O3iii | 0.86 | 2.05 | 2.895 (3) | 167 |
N4—H42···O1W | 0.86 | 2.07 | 2.825 (4) | 146 |
N5—H51···O2iii | 0.86 | 1.96 | 2.810 (3) | 172 |
N5—H52···O1ii | 0.86 | 1.97 | 2.815 (3) | 169 |
O1W—H11···O4iv | 0.82 | 2.05 | 2.799 (4) | 152 |
O1W—H12···O4 | 0.82 | 1.95 | 2.755 (4) | 168 |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x+1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | C4H13N52+·C2O42−·H2O | C4H13N52+·O4S2−·H2O |
Mr | 237.23 | 245.27 |
Crystal system, space group | Monoclinic, P21/c | Triclinic, P1 |
Temperature (K) | 298 | 293 |
a, b, c (Å) | 6.775 (2), 10.762 (3), 14.731 (4) | 7.056 (3), 8.862 (4), 9.462 (4) |
α, β, γ (°) | 90, 92.561 (4), 90 | 99.830 (6), 96.020 (7), 110.099 (7) |
V (Å3) | 1073.1 (5) | 538.8 (4) |
Z | 4 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.13 | 0.32 |
Crystal size (mm) | 0.40 × 0.18 × 0.12 | 0.32 × 0.15 × 0.15 |
|
Data collection |
Diffractometer | Brker SMART 1K CCD area-detector diffractometer | Bruker SMART 1K CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2000) | Multi-scan (SADABS; Sheldrick, 2000) |
Tmin, Tmax | 0.614, 0.974 | 0.094, 0.966 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4303, 1885, 1295 | 2516, 1741, 1508 |
Rint | 0.059 | 0.040 |
(sin θ/λ)max (Å−1) | 0.595 | 0.596 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.102, 1.02 | 0.044, 0.162, 1.18 |
No. of reflections | 1885 | 1739 |
No. of parameters | 155 | 139 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.24, −0.23 | 0.37, −0.36 |
Selected geometric parameters (Å, º) for (I) topC3—N2 | 1.312 (3) | C4—N4 | 1.302 (3) |
C3—N1 | 1.323 (3) | C4—N5 | 1.312 (3) |
C3—N3 | 1.374 (3) | C4—N3 | 1.361 (3) |
| | | |
N2—C3—N1 | 123.7 (2) | N4—C4—N3 | 121.4 (2) |
N2—C3—N3 | 119.5 (2) | N5—C4—N3 | 116.6 (2) |
N1—C3—N3 | 116.7 (2) | C4—N3—C3 | 125.4 (2) |
N4—C4—N5 | 122.0 (2) | | |
| | | |
N4—C4—N3—C3 | 20.3 (3) | N2—C3—N3—C4 | 41.0 (3) |
N5—C4—N3—C3 | −161.9 (2) | N1—C3—N3—C4 | −143.1 (2) |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H21···O2 | 0.86 | 1.97 | 2.774 (2) | 155 |
N3—H3···O3i | 0.86 | 1.85 | 2.658 (2) | 157 |
N4—H41···O1ii | 0.86 | 2.10 | 2.873 (2) | 149 |
N4—H42···O1Wiii | 0.86 | 2.18 | 2.926 (3) | 145 |
N5—H51···O1ii | 0.86 | 2.26 | 2.986 (3) | 143 |
N5—H52···O4i | 0.86 | 1.97 | 2.830 (3) | 175 |
O1W—H12···O3iv | 0.82 | 2.13 | 2.934 (3) | 169 |
O1W—H11···O1v | 0.82 | 1.97 | 2.786 (2) | 173 |
N2—H22···O4vi | 0.86 | 2.20 | 2.874 (2) | 135 |
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x, −y+3/2, z−1/2; (iii) −x+1, y+1/2, −z+3/2; (iv) x, −y+1/2, z+1/2; (v) −x+1, y−1/2, −z+3/2; (vi) −x+1, y+1/2, −z+1/2. |
Selected geometric parameters (Å, º) for (II) topC3—N1 | 1.308 (4) | C4—N4 | 1.308 (4) |
C3—N2 | 1.314 (4) | C4—N5 | 1.310 (4) |
C3—N3 | 1.383 (4) | C4—N3 | 1.370 (4) |
| | | |
N1—C3—N2 | 123.1 (3) | N4—C4—N3 | 120.4 (3) |
N1—C3—N3 | 117.8 (3) | N5—C4—N3 | 117.2 (3) |
N2—C3—N3 | 118.9 (3) | C4—N3—C3 | 126.1 (2) |
N4—C4—N5 | 122.4 (3) | | |
| | | |
N4—C4—N3—C3 | 26.4 (4) | N1—C3—N3—C4 | −144.4 (3) |
N5—C4—N3—C3 | −157.0 (3) | N2—C3—N3—C4 | 39.4 (4) |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H22···O2 | 0.86 | 2.06 | 2.854 (3) | 153 |
N2—H21···O1i | 0.86 | 2.01 | 2.784 (3) | 150 |
N3—H3···O3ii | 0.86 | 1.90 | 2.722 (3) | 159 |
N4—H41···O3iii | 0.86 | 2.05 | 2.895 (3) | 167 |
N4—H42···O1W | 0.86 | 2.07 | 2.825 (4) | 146 |
N5—H51···O2iii | 0.86 | 1.96 | 2.810 (3) | 172 |
N5—H52···O1ii | 0.86 | 1.97 | 2.815 (3) | 169 |
O1W—H11···O4iv | 0.82 | 2.05 | 2.799 (4) | 152 |
O1W—H12···O4 | 0.82 | 1.95 | 2.755 (4) | 168 |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x+1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1. |
An N-substituted derivative of biguanide, metformin (N,N-dimethylbiguanide), is a powerful oral antihyperglycaemic drug that has been used in many countries for over 40 years for treating diabetic patients with non-insulin-dependent diabetes mellitus. However, the mechanism of action of this drug is still unknown. Because this compound contains a biguanidinium group, it can form complexes with many metal ions (Ray, 1961; Zhu et al., 2002a,2002b,2002c; Lu et al., 2004b). Recently, we found that N,N-dimethybiguanidium loses its ability to lower blood glucose levels when forming a monodentate [mononuclear?] complex with Zn2+, but retains this ability when forming bidentate [binuclear?] complexes with Cu2+ and Ni2+ (Zhu et al. 2004). On the other hand, guanidinium may play an important role in recognizing anions, such as carboxylates, phosphates, sulfates and nitrates, in biological systems (Baggio et al., 1997; Liu et al., 2001; Lu et al., 2001; Best et al., 2003). It has been proven that a strong interaction between the guanidinium groups and anions through charge pairing and hydrogen bonding facilitates the recognition of small target anions by receptors containing guanidinium groups in competitive solvent systems (Best et al., 2003). We elucidate here the possible mechanism of N,N-dimethybiguanide interacting with target molecules by reporting the crystal structures of N,N-dimethybiguanidinium oxalate(I) and N,N-dimethybiguanidinium sulfate(II).
Some features of the molecular geometries of (I) and (II) are listed in Table 1. The molecular conformation is illustrated in Figs.1 and 2. Compound (I) contains one N,N-dimethybiguanidinium dication, one oxalate anion and one water molecule. Compound (II) consists of one N,N-dimethybiguanidinium dication, one sulfate anion and one water molecule. Both compounds thus contain the same N,N-dimethybiguanidinium dication. The C—N bonds of the biguanidinium moiety in both compounds range from 1.302 (3) to 1.374 (3) Å in (I) and 1.308 (4) to 1.383 (4) Å in (II); this situation differs from that in N,N-dimethybiguanidinium nitrate, in which the C—N bonds are more uniform [1.324 (3)–1.343 (3) Å; Zhu et al., 2003). The dihedral angles between the two guanidine group planes are 52.8 (1) and 56.1 (1)° in (I) and (II)?, respectively. Therefore, the anions slightly influence the structure of N,N-dimethybiguanide.
The hydrogen-bonding geometries in (I) and (II) are listed in Table 2 and illustrated in Figs. 3 and 4. A number of intra- and intermolecular hydrogen bonds stabilize crystal structure of each compound. These hydrogen bonds are formed mainly between the biguanidinium groups and the oxalate or sulfate anion, between the biguanidinium groups and the water molecules, and between? the carboxylate or sulfate and water molecules. Strong double hydrogen bonds are formed between either the carboxylate groups of the oxalate anion or the sulfate groups and atoms N3 and N5 of the biguanidinium groups of the cation. The D···A distances are 2.658 (2) and 2.830 (3) Å in (I), and 2.722 (3) and 2.815 (3) Å in (II), giving rise to an elongated hexagon. Double hydrogen bonds are also found in N,N-dimethybiguanidium nitrate at the corresponding N3- and N5-atom sites, but these bonds are formed between a pair of N,N-dimethybiguanidium cations, not between the N,N-dimethybiguanidium cations and the nitrate anions (Zhu et al., 2003). Therefore, the N,N-dimethybiguanidium cation exhibits a common characteristic that the N3- and N5-atom sites take part in the formation of double hydrogen bonds, in contrast to the double hydrogen bonds formed in biguanidinium nitrate, in which double hydrogen bonds are formed between nitrate anions and atoms N1 and N2 or N4 and N5 of the biguanidinium cation (Lu et al., 2004a). Because N,N-dimethybiguanidium loses its ability to lower blood glucose levels when complexing with the Zn2+ ion at the N3-atom site (perhaps interfering the formation of double hydrogen bonds), and yet retains this ability when forming bidentate [binuclear?] complexes with Cu2+ and Ni2+ ions at the N2 and N4 sites, we speculate that this double hydrogen bond between N,N-dimethybiguanide and its target molecules plays an important role in the interaction with target molecules in biological systems.