In the title compound, 3-[(4-amino-2-methyl-5-pyrimidin-1-io)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium(2+) bis(tetrafluoroborate), C
12H
18N
4OS
2+·2BF
4−, the divalent thiamine cation (in the
F conformation) is associated with BF
4− anions
via two characteristic bridging interactions between the thiazolium and pyrimidinium rings,
i.e. C—H
BF
4−pyrimidinium and N—H
BF
4−thiazolium interactions. Thiamine molecules are linked by N—H
O hydrogen bonds to form a helical chain structure.
Supporting information
CCDC reference: 173364
Crystals of (I) were obtained at room temperature by the slow evaporation of an
aqueous solution (pH = 2) of thiamine chloride hydrochloride (69.2 mg, 0.2 mmol) and NaBF4 (43.9 mg, 0.4 mmol).
Each of the two BF4- ions is disordered at two positions around the common B
atom. The occupancy factors were refined to give 0.538 and 0.462 for anion A
and 0.752 and 0.248 for anion B. All H atoms were located from difference
Fourier maps and refined isotropically, except for those of methyl groups,
which were added at ideal positions.
Data collection: XSCANS (Siemens, 1994b); cell refinement: XSCANS; data reduction: SHELXTL (Siemens, 1994a); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
3-[(4-amino-2-methyl-5-pyrimidinio)methyl]-5-(2-hydroxyethyl)-
4-methylthiazolium(2+) bis(tetrafluoroborate)
top
Crystal data top
C12H18N4OS2+·2BF4− | F(000) = 896 |
Mr = 439.98 | Dx = 1.536 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 13.849 (1) Å | Cell parameters from 20 reflections |
b = 7.565 (1) Å | θ = 6.5–11.2° |
c = 18.554 (5) Å | µ = 0.26 mm−1 |
β = 101.90 (1)° | T = 293 K |
V = 1902.1 (6) Å3 | Tabular, colourless |
Z = 4 | 0.45 × 0.40 × 0.12 mm |
Data collection top
Siemens P4 diffractometer | Rint = 0.022 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 1.7° |
Graphite monochromator | h = −1→16 |
ω scans | k = −1→8 |
4564 measured reflections | l = −22→21 |
3348 independent reflections | 3 standard reflections every 100 reflections |
1501 reflections with I > 2σ(I) | intensity decay: none |
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)] = 0.055 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.124 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.99 | w = 1/[σ2(Fo2) + (0.040P)2] where P = (Fo2 + 2Fc2)/3 |
3348 reflections | (Δ/σ)max = −0.011 |
377 parameters | Δρmax = 0.24 e Å−3 |
41 restraints | Δρmin = −0.19 e Å−3 |
Crystal data top
C12H18N4OS2+·2BF4− | V = 1902.1 (6) Å3 |
Mr = 439.98 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 13.849 (1) Å | µ = 0.26 mm−1 |
b = 7.565 (1) Å | T = 293 K |
c = 18.554 (5) Å | 0.45 × 0.40 × 0.12 mm |
β = 101.90 (1)° | |
Data collection top
Siemens P4 diffractometer | Rint = 0.022 |
4564 measured reflections | 3 standard reflections every 100 reflections |
3348 independent reflections | intensity decay: none |
1501 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.055 | 41 restraints |
wR(F2) = 0.124 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.99 | Δρmax = 0.24 e Å−3 |
3348 reflections | Δρmin = −0.19 e Å−3 |
377 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
S1 | 0.86029 (8) | 0.9675 (2) | 0.09574 (8) | 0.0764 (5) | |
C2 | 0.7621 (3) | 1.1002 (6) | 0.0884 (3) | 0.0620 (14) | |
H2 | 0.694 (3) | 1.052 (6) | 0.090 (2) | 0.088 (15)* | |
N3 | 0.7860 (2) | 1.2677 (5) | 0.0908 (2) | 0.0466 (9) | |
C4 | 0.8874 (3) | 1.2973 (6) | 0.0976 (2) | 0.0514 (12) | |
C5 | 0.9382 (3) | 1.1454 (6) | 0.1006 (2) | 0.0556 (12) | |
C41 | 0.9253 (3) | 1.4818 (6) | 0.1022 (3) | 0.0764 (15) | |
H41A | 0.9133 | 1.5381 | 0.1478 | 0.092* | |
H41B | 0.8907 | 1.5496 | 0.0589 | 0.092* | |
H41C | 0.9970 | 1.4807 | 0.1031 | 0.092* | |
C51 | 1.0476 (3) | 1.1195 (9) | 0.1112 (3) | 0.071 (2) | |
H51A | 1.076 (3) | 1.237 (7) | 0.108 (2) | 0.089 (18)* | |
H51B | 1.061 (3) | 1.039 (6) | 0.072 (2) | 0.092 (19)* | |
C52 | 1.0920 (4) | 1.0447 (10) | 0.1868 (3) | 0.076 (2) | |
H52A | 1.165 (3) | 1.033 (6) | 0.188 (2) | 0.085 (15)* | |
H52B | 1.078 (3) | 1.124 (6) | 0.224 (2) | 0.081 (17)* | |
O53 | 1.0552 (2) | 0.8716 (6) | 0.1954 (2) | 0.0740 (10) | |
H53 | 1.089 (4) | 0.783 (6) | 0.176 (3) | 0.14 (3)* | |
C35' | 0.7137 (3) | 1.4136 (6) | 0.0881 (3) | 0.0528 (13) | |
H35A | 0.712 (3) | 1.478 (6) | 0.042 (2) | 0.081 (16)* | |
H35B | 0.743 (3) | 1.495 (5) | 0.1262 (19) | 0.052 (13)* | |
N1' | 0.4992 (3) | 1.3065 (5) | 0.1719 (2) | 0.0593 (11) | |
H1' | 0.484 (3) | 1.307 (6) | 0.215 (2) | 0.070 (16)* | |
C2' | 0.4354 (3) | 1.2319 (6) | 0.1155 (3) | 0.0545 (12) | |
N3' | 0.4534 (2) | 1.2214 (5) | 0.0490 (2) | 0.0554 (10) | |
C4' | 0.5417 (3) | 1.2823 (6) | 0.0380 (2) | 0.0512 (11) | |
C5' | 0.6144 (3) | 1.3514 (6) | 0.0972 (2) | 0.0468 (11) | |
C6' | 0.5886 (3) | 1.3609 (6) | 0.1624 (3) | 0.0539 (12) | |
H6' | 0.627 (3) | 1.402 (5) | 0.204 (2) | 0.054 (13)* | |
C2'1 | 0.3424 (3) | 1.1584 (7) | 0.1308 (3) | 0.080 (2) | |
H21A | 0.3153 | 1.2406 | 0.1631 | 0.096* | |
H21B | 0.3559 | 1.0425 | 0.1556 | 0.096* | |
H21C | 0.2939 | 1.1431 | 0.0839 | 0.096* | |
N4'1 | 0.5546 (3) | 1.2715 (6) | −0.0303 (2) | 0.0652 (13) | |
H41D | 0.514 (3) | 1.229 (6) | −0.062 (2) | 0.066 (17)* | |
H41E | 0.610 (3) | 1.312 (6) | −0.049 (2) | 0.079 (15)* | |
B1 | 0.6254 (5) | 0.8429 (10) | 0.2014 (4) | 0.074 (2) | |
F1 | 0.6361 (15) | 0.7025 (14) | 0.2470 (5) | 0.157 (6) | 0.538 (12) |
F2 | 0.5288 (8) | 0.886 (2) | 0.1902 (10) | 0.227 (8) | 0.538 (12) |
F3 | 0.6501 (9) | 0.7912 (13) | 0.1359 (4) | 0.108 (5) | 0.538 (12) |
F4 | 0.6834 (8) | 0.9605 (19) | 0.2405 (6) | 0.128 (6) | 0.538 (12) |
F1' | 0.5659 (10) | 0.7213 (15) | 0.2179 (7) | 0.109 (4) | 0.462 (12) |
F2' | 0.5802 (7) | 0.9266 (11) | 0.1393 (4) | 0.082 (4) | 0.462 (12) |
F3' | 0.7124 (7) | 0.7753 (15) | 0.1906 (14) | 0.213 (10) | 0.462 (12) |
F4' | 0.6395 (15) | 0.9955 (19) | 0.2462 (9) | 0.167 (9) | 0.462 (12) |
B2 | 0.7827 (5) | 1.3773 (12) | −0.1096 (4) | 0.077 (2) | |
F5 | 0.8093 (5) | 1.3984 (12) | −0.1743 (3) | 0.119 (3) | 0.752 (9) |
F6 | 0.8223 (5) | 1.5208 (8) | −0.0626 (3) | 0.130 (3) | 0.752 (9) |
F7 | 0.6836 (3) | 1.4009 (11) | −0.1203 (4) | 0.132 (3) | 0.752 (9) |
F8 | 0.8041 (8) | 1.2226 (9) | −0.0764 (3) | 0.150 (3) | 0.752 (9) |
F5' | 0.8725 (11) | 1.301 (3) | −0.0782 (9) | 0.105 (6) | 0.248 (9) |
F6' | 0.7282 (19) | 1.448 (4) | −0.0688 (11) | 0.165 (12) | 0.248 (9) |
F7' | 0.7292 (19) | 1.245 (3) | −0.1631 (15) | 0.225 (15) | 0.248 (9) |
F8' | 0.807 (2) | 1.510 (4) | −0.1594 (15) | 0.24 (2) | 0.248 (9) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
S1 | 0.0512 (7) | 0.0543 (8) | 0.1232 (12) | 0.0060 (7) | 0.0170 (7) | 0.0063 (9) |
C2 | 0.040 (3) | 0.053 (3) | 0.092 (4) | −0.002 (2) | 0.012 (2) | 0.006 (3) |
N3 | 0.036 (2) | 0.049 (2) | 0.054 (2) | −0.001 (2) | 0.006 (2) | 0.006 (2) |
C4 | 0.040 (2) | 0.057 (3) | 0.055 (3) | −0.008 (2) | 0.005 (2) | 0.001 (2) |
C5 | 0.042 (2) | 0.057 (3) | 0.067 (3) | 0.002 (3) | 0.011 (2) | 0.008 (3) |
C41 | 0.049 (3) | 0.068 (4) | 0.110 (4) | −0.016 (3) | 0.011 (3) | 0.000 (3) |
C51 | 0.043 (3) | 0.080 (4) | 0.090 (4) | 0.010 (3) | 0.017 (3) | 0.018 (4) |
C52 | 0.047 (3) | 0.096 (5) | 0.085 (4) | 0.008 (4) | 0.012 (3) | −0.002 (4) |
O53 | 0.062 (2) | 0.086 (3) | 0.079 (2) | 0.017 (2) | 0.025 (2) | 0.013 (2) |
C35' | 0.044 (3) | 0.049 (3) | 0.063 (3) | 0.001 (2) | 0.006 (3) | 0.000 (3) |
N1' | 0.051 (2) | 0.070 (3) | 0.058 (3) | 0.002 (2) | 0.015 (2) | −0.002 (2) |
C2' | 0.039 (2) | 0.055 (3) | 0.069 (3) | 0.003 (2) | 0.009 (2) | 0.000 (3) |
N3' | 0.040 (2) | 0.064 (3) | 0.061 (2) | −0.003 (2) | 0.006 (2) | −0.003 (2) |
C4' | 0.048 (3) | 0.054 (3) | 0.052 (3) | 0.008 (2) | 0.010 (2) | 0.002 (3) |
C5' | 0.038 (2) | 0.048 (3) | 0.051 (3) | 0.002 (2) | 0.001 (2) | 0.005 (2) |
C6' | 0.047 (3) | 0.060 (3) | 0.051 (3) | −0.002 (3) | 0.001 (3) | 0.000 (3) |
C2'1 | 0.055 (3) | 0.091 (4) | 0.098 (4) | −0.010 (3) | 0.028 (3) | −0.005 (3) |
N4'1 | 0.055 (3) | 0.085 (3) | 0.053 (3) | −0.016 (3) | 0.006 (2) | −0.009 (3) |
B1 | 0.063 (4) | 0.079 (5) | 0.073 (5) | 0.000 (5) | −0.002 (4) | 0.002 (5) |
F1 | 0.309 (18) | 0.088 (6) | 0.072 (5) | 0.042 (10) | 0.031 (8) | 0.019 (5) |
F2 | 0.113 (8) | 0.230 (17) | 0.299 (18) | 0.055 (9) | −0.046 (10) | −0.033 (14) |
F3 | 0.144 (9) | 0.121 (8) | 0.069 (5) | −0.060 (8) | 0.045 (5) | −0.021 (5) |
F4 | 0.092 (6) | 0.195 (15) | 0.087 (5) | −0.062 (8) | −0.005 (4) | −0.064 (7) |
F1' | 0.132 (9) | 0.085 (8) | 0.127 (10) | −0.039 (8) | 0.068 (7) | 0.028 (7) |
F2' | 0.076 (6) | 0.088 (6) | 0.067 (5) | −0.013 (5) | −0.021 (4) | 0.021 (5) |
F3' | 0.087 (8) | 0.096 (8) | 0.44 (3) | 0.019 (6) | 0.017 (11) | 0.031 (14) |
F4' | 0.26 (2) | 0.071 (7) | 0.168 (12) | −0.017 (11) | 0.026 (12) | −0.017 (7) |
B2 | 0.068 (5) | 0.101 (6) | 0.067 (5) | 0.005 (5) | 0.024 (4) | 0.005 (5) |
F5 | 0.106 (4) | 0.186 (8) | 0.071 (3) | 0.037 (5) | 0.035 (3) | 0.015 (4) |
F6 | 0.147 (5) | 0.125 (5) | 0.115 (4) | −0.036 (4) | 0.017 (4) | −0.008 (4) |
F7 | 0.072 (3) | 0.202 (8) | 0.136 (5) | −0.016 (4) | 0.052 (3) | −0.007 (6) |
F8 | 0.225 (9) | 0.103 (5) | 0.105 (4) | 0.019 (5) | −0.009 (5) | 0.016 (4) |
F5' | 0.094 (11) | 0.093 (14) | 0.129 (13) | 0.012 (10) | 0.028 (10) | −0.008 (10) |
F6' | 0.19 (3) | 0.22 (3) | 0.103 (14) | 0.05 (2) | 0.075 (17) | −0.021 (17) |
F7' | 0.21 (2) | 0.120 (17) | 0.33 (4) | −0.036 (18) | 0.02 (3) | −0.02 (2) |
F8' | 0.23 (3) | 0.27 (4) | 0.28 (4) | −0.13 (3) | 0.19 (3) | −0.11 (3) |
Geometric parameters (Å, º) top
S1—C2 | 1.673 (4) | N3'—C4' | 1.361 (5) |
S1—C5 | 1.715 (4) | C4'—N4'1 | 1.318 (5) |
C2—N3 | 1.308 (5) | C4'—C5' | 1.427 (5) |
C2—H2 | 1.01 (4) | C5'—C6' | 1.332 (6) |
N3—C4 | 1.403 (5) | C6'—H6' | 0.89 (4) |
N3—C35' | 1.484 (5) | C2'1—H21A | 0.99 |
C4—C5 | 1.342 (5) | C2'1—H21B | 0.99 |
C4—C41 | 1.488 (6) | C2'1—H21C | 0.99 |
C5—C51 | 1.501 (6) | N4'1—H41D | 0.79 (4) |
C41—H41A | 0.99 | N4'1—H41E | 0.96 (5) |
C41—H41B | 0.99 | B1—F1' | 1.313 (10) |
C41—H41C | 0.99 | B1—F4 | 1.313 (12) |
C51—C52 | 1.521 (7) | B1—F2' | 1.349 (9) |
C51—H51A | 0.98 (5) | B1—F1 | 1.347 (11) |
C51—H51B | 0.99 (5) | B1—F4' | 1.413 (15) |
C52—O53 | 1.426 (7) | B1—F3 | 1.384 (9) |
C52—H52A | 1.01 (4) | B1—F3' | 1.362 (12) |
C52—H52B | 0.96 (4) | B1—F2 | 1.350 (11) |
O53—H53 | 0.93 (3) | B2—F6' | 1.290 (14) |
C35'—C5' | 1.496 (5) | B2—F8 | 1.327 (9) |
C35'—H35A | 0.97 (4) | B2—F5 | 1.336 (9) |
C35'—H35B | 0.96 (4) | B2—F7 | 1.357 (8) |
N1'—C2' | 1.347 (5) | B2—F5' | 1.386 (14) |
N1'—C6' | 1.350 (5) | B2—F6 | 1.429 (9) |
N1'—H1' | 0.86 (4) | B2—F8' | 1.45 (2) |
C2'—N3' | 1.309 (5) | B2—F7' | 1.49 (2) |
C2'—C2'1 | 1.483 (6) | | |
| | | |
S1···O53 | 3.029 (3) | C2'···F2 | 3.117 (17) |
N1'···F2' | 3.188 (11) | C6'···F4 | 3.495 (16) |
C2'···F2' | 3.031 (11) | C4···F6 | 3.377 (7) |
N3'···F2' | 3.106 (9) | C2···F8 | 3.359 (9) |
C4'···F2' | 3.263 (8) | N3···F8 | 3.183 (7) |
C5'···F2' | 3.364 (9) | C4···F8 | 3.247 (7) |
C6'···F2' | 3.312 (10) | C5···F8 | 3.472 (8) |
N1'···F4' | 3.179 (19) | C4···F5' | 3.226 (18) |
C6'···F4' | 3.178 (17) | C5···F5' | 3.460 (18) |
N1'···F2 | 3.217 (17) | N3···F6' | 3.21 (2) |
| | | |
C2—S1—C5 | 91.5 (2) | C2'—N3'—C4' | 118.2 (4) |
N3—C2—S1 | 112.5 (3) | N4'1—C4'—N3' | 115.3 (4) |
N3—C2—H2 | 125 (3) | N4'1—C4'—C5' | 123.2 (4) |
S1—C2—H2 | 122 (3) | N3'—C4'—C5' | 121.5 (4) |
C2—N3—C4 | 113.5 (4) | C6'—C5'—C4' | 116.1 (4) |
C2—N3—C35' | 123.8 (3) | C6'—C5'—C35' | 120.7 (4) |
C4—N3—C35' | 122.7 (4) | C4'—C5'—C35' | 123.2 (4) |
C5—C4—N3 | 111.9 (4) | C5'—C6'—N1' | 121.8 (4) |
C5—C4—C41 | 128.8 (4) | C5'—C6'—H6' | 125 (2) |
N3—C4—C41 | 119.3 (4) | N1'—C6'—H6' | 114 (2) |
C4—C5—C51 | 128.6 (5) | C2'—C2'1—H21A | 109.5 |
C4—C5—S1 | 110.6 (3) | C2'—C2'1—H21B | 109.5 |
C51—C5—S1 | 120.8 (4) | H21A—C2'1—H21B | 109.5 |
C4—C41—H41A | 109.5 | C2'—C2'1—H21C | 109.5 |
C4—C41—H41B | 109.5 | H21A—C2'1—H21C | 109.5 |
H41A—C41—H41B | 109.5 | H21B—C2'1—H21C | 109.5 |
C4—C41—H41C | 109.5 | C4'—N4'1—H41D | 122 (3) |
H41A—C41—H41C | 109.5 | C4'—N4'1—H41E | 127 (3) |
H41B—C41—H41C | 109.5 | H41D—N4'1—H41E | 111 (4) |
C5—C51—C52 | 112.0 (4) | F1'—B1—F2' | 109.0 (8) |
C5—C51—H51A | 106 (3) | F4—B1—F1 | 102.2 (10) |
C52—C51—H51A | 108 (3) | F1'—B1—F4' | 116.9 (10) |
C5—C51—H51B | 108 (3) | F2'—B1—F4' | 95.9 (10) |
C52—C51—H51B | 111 (3) | F4—B1—F3 | 116.4 (8) |
H51A—C51—H51B | 112 (4) | F1—B1—F3 | 108.3 (8) |
O53—C52—C51 | 111.0 (5) | F1'—B1—F3' | 112.9 (9) |
O53—C52—H52A | 107 (3) | F2'—B1—F3' | 108.7 (11) |
C51—C52—H52A | 105 (2) | F4'—B1—F3' | 112.0 (10) |
O53—C52—H52B | 112 (3) | F4—B1—F2 | 113.3 (9) |
C51—C52—H52B | 109 (3) | F1—B1—F2 | 105.2 (11) |
H52A—C52—H52B | 113 (4) | F3—B1—F2 | 110.5 (9) |
C52—O53—H53 | 114 (4) | F8—B2—F5 | 116.5 (7) |
N3—C35'—C5' | 113.0 (4) | F8—B2—F7 | 107.8 (8) |
N3—C35'—H35A | 107 (3) | F5—B2—F7 | 108.1 (6) |
C5'—C35'—H35A | 114 (2) | F6'—B2—F5' | 120.6 (13) |
N3—C35'—H35B | 106 (2) | F8—B2—F6 | 111.5 (6) |
C5'—C35'—H35B | 112 (2) | F5—B2—F6 | 108.4 (7) |
H35A—C35'—H35B | 104 (3) | F7—B2—F6 | 103.8 (7) |
C2'—N1'—C6' | 119.9 (4) | F6'—B2—F8' | 109.2 (16) |
C2'—N1'—H1' | 118 (3) | F5'—B2—F8' | 104.4 (12) |
C6'—N1'—H1' | 122 (3) | F6'—B2—F7' | 113.4 (15) |
N3'—C2'—N1' | 122.4 (4) | F5'—B2—F7' | 106.2 (12) |
N3'—C2'—C2'1 | 119.9 (4) | F8'—B2—F7' | 100.9 (14) |
N1'—C2'—C2'1 | 117.7 (4) | | |
| | | |
S1—C5—C51—C52 | −67.5 (7) | C2—N3—C35'—C5' | 11.4 (7) |
C5—C51—C52—O53 | 64.4 (7) | N3—C35'—C5'—C4' | −82.8 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···F3 | 1.01 (4) | 2.29 (4) | 3.035 (8) | 130 (3) |
C2—H2···F2′ | 1.01 (4) | 2.20 (4) | 3.154 (11) | 156 (3) |
N4′1—H41D···F2′i | 0.79 (4) | 2.09 (5) | 2.875 (8) | 169 (4) |
N4′1—H41D···F3i | 0.79 (4) | 2.41 (4) | 3.132 (12) | 153 (4) |
N4′1—H41E···F7 | 0.96 (5) | 1.94 (5) | 2.859 (7) | 158 (4) |
N4′1—H41E···F6′ | 0.96 (5) | 2.02 (5) | 2.96 (3) | 165 (4) |
N1′—H1′···O53ii | 0.86 (4) | 1.92 (4) | 2.763 (6) | 166 (4) |
O53—H53···F5iii | 0.93 (3) | 1.97 (4) | 2.855 (8) | 157 (5) |
O53—H53···F5′iii | 0.93 (3) | 2.09 (5) | 2.886 (16) | 143 (5) |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x+3/2, y+1/2, −z+1/2; (iii) −x+2, −y+2, −z. |
Experimental details
Crystal data |
Chemical formula | C12H18N4OS2+·2BF4− |
Mr | 439.98 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 13.849 (1), 7.565 (1), 18.554 (5) |
β (°) | 101.90 (1) |
V (Å3) | 1902.1 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.26 |
Crystal size (mm) | 0.45 × 0.40 × 0.12 |
|
Data collection |
Diffractometer | Siemens P4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4564, 3348, 1501 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.055, 0.124, 0.99 |
No. of reflections | 3348 |
No. of parameters | 377 |
No. of restraints | 41 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.24, −0.19 |
Selected geometric parameters (Å, º) topS1—C2 | 1.673 (4) | N1'—C2' | 1.347 (5) |
S1—C5 | 1.715 (4) | N1'—C6' | 1.350 (5) |
C2—N3 | 1.308 (5) | C2'—N3' | 1.309 (5) |
N3—C4 | 1.403 (5) | N3'—C4' | 1.361 (5) |
N3—C35' | 1.484 (5) | C4'—N4'1 | 1.318 (5) |
C4—C5 | 1.342 (5) | C4'—C5' | 1.427 (5) |
C35'—C5' | 1.496 (5) | C5'—C6' | 1.332 (6) |
| | | |
N1'···F2' | 3.188 (11) | C2'···F2 | 3.117 (17) |
C2'···F2' | 3.031 (11) | C4···F6 | 3.377 (7) |
N3'···F2' | 3.106 (9) | N3···F8 | 3.183 (7) |
N1'···F4' | 3.179 (19) | C4···F8 | 3.247 (7) |
C6'···F4' | 3.178 (17) | C4···F5' | 3.226 (18) |
N1'···F2 | 3.217 (17) | N3···F6' | 3.21 (2) |
| | | |
C2—S1—C5 | 91.5 (2) | C2'—N1'—C6' | 119.9 (4) |
N3—C2—S1 | 112.5 (3) | N3'—C2'—N1' | 122.4 (4) |
C2—N3—C4 | 113.5 (4) | C2'—N3'—C4' | 118.2 (4) |
C2—N3—C35' | 123.8 (3) | N3'—C4'—C5' | 121.5 (4) |
C4—N3—C35' | 122.7 (4) | C6'—C5'—C4' | 116.1 (4) |
C5—C4—N3 | 111.9 (4) | C6'—C5'—C35' | 120.7 (4) |
C4—C5—S1 | 110.6 (3) | C4'—C5'—C35' | 123.2 (4) |
N3—C35'—C5' | 113.0 (4) | C5'—C6'—N1' | 121.8 (4) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···F3 | 1.01 (4) | 2.29 (4) | 3.035 (8) | 130 (3) |
C2—H2···F2' | 1.01 (4) | 2.20 (4) | 3.154 (11) | 156 (3) |
N4'1—H41D···F2'i | 0.79 (4) | 2.09 (5) | 2.875 (8) | 169 (4) |
N4'1—H41D···F3i | 0.79 (4) | 2.41 (4) | 3.132 (12) | 153 (4) |
N4'1—H41E···F7 | 0.96 (5) | 1.94 (5) | 2.859 (7) | 158 (4) |
N4'1—H41E···F6' | 0.96 (5) | 2.02 (5) | 2.96 (3) | 165 (4) |
N1'—H1'···O53ii | 0.86 (4) | 1.92 (4) | 2.763 (6) | 166 (4) |
O53—H53···F5iii | 0.93 (3) | 1.97 (4) | 2.855 (8) | 157 (5) |
O53—H53···F5'iii | 0.93 (3) | 2.09 (5) | 2.886 (16) | 143 (5) |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x+3/2, y+1/2, −z+1/2; (iii) −x+2, −y+2, −z. |
Thiamine pyrophosphate is a coenzyme for a number of metabolic enzymes (Krampitz, 1969). Studies of the thiamine-anion system as a model for coenzyme-substrate interactions are of interest because, in the reactions catalyzed by thiamine, a substrate anion such as pyruvate directly interacts with thiamine at the C2 site (Breslow, 1958).
Thiamine exists either as a monovalent cation with a quaternary N on the thiazolium moiety or as a divalent one (H-thiamine) with an additional proton at N1' of the pyrimidine ring. It has been observed (Aoki et al., 1991) that in thiamine-anion complexes the anions are associated with thiamine through two types of characteristic bridging interactions, forming host–guest-like anion complexation. Moreover, thiamine molecules themselves form various hydrogen-bonded structures and, together with anions in some cases, build up distinct higher-order supramolecular structures (Aoki et al., 1993, 1999). There are two types of hydrogen-bonded chain structures depending on whether N1' of the pyrimidine moiety is protonated. One type of chain structure incorporates an O53—H···N1' hydrogen bond, such as in N1'-unprotonated thiamine·ClO4·H2O (Kozioł et al., 1987), thiamine(BF4)·H2O (Aoki et al., 1990) and thiamine(PF6)·H2O (Aoki et al., 1988). Another type has an N1'—H···O53 hydrogen bond, as in N1'-protonated H-thiamine·(ClO4)2 (Aoki et al., 1988). These observations led us to further examine (i) the host–guest-like thiamine-anion complexation in H-thiamine(BF4)2, (I), and (ii) whether a chain structure similar to that in H-thiamine(ClO4)2 occurs in (I). \sch
The structure of (I) contains a divalent thiamine cation with N1' protonated and two disordered BF4- ions (denoted A and B), as shown in Fig. 1. The molecular dimensions of thiamine in (I) are in agreement with another known N1'-protonated thiamine (Cramer et al., 1981). The protonation at N1' influences the C2'—N1'—C6' bond angle and the opposite C4'—N4'1 bond length. These values are 119.9 (4)° and 1.318 (5) Å in (I) while they are 115.0 (3)° and 1.337 (4) Å in thiamine·BF4·H2O, which has an N1'-unprotonated pyrimidine ring. The C5 hydroxyethyl side chain folds back towards the thiazolium ring with the torsion angles (Pletcher et al., 1977): ϕ5α (S1—C5—C51—C52) = -67.5 (7)° and ϕ5β (C5—C51—C52—O53) = 64.4 (7)°. This conformation results in a close contact between O53 and the electropositive S1 atom (Jordan, 1974) with O53···S1 = 3.029 (3) Å, which is a common structural feature of thiamine compounds.
Thiamine molecule adopts the usual F conformation in terms of the torsion angles (Pletcher et al., 1977): ϕT (C5'—C35'—N3—C2) = 11.4 (7)°, and ϕP (N3—C35'—C5'—C4') = -82.8 (5)°. Aoki et al. (1993) have noted that when thiamine is in the F form there are two well defined 'anion holes' between the thiazolium and pyrimidine rings. The area denoted 'anion hole I' is occupied by an anion which bridges the two rings through a C2—H···anion···pyrimidine-ring interaction, and 'anion hole II' is occupied by an anion which bridges the two rings through an N4'1-H···anion···thiazolium-ring interaction. In (I), the A anion accepts a hydrogen bond from C2 (C2—H···F3 or C2—H···F2', see Table 3) and makes a close stacking interaction with the pyrimidinium ring (Table 2), thus being located in 'anion hole I'. The B anion lies in 'anion hole II' to form an N4'1-H···F7 or N4'1-H···F6' hydrogen bond (Table 3) and a close contact with the thiazolium ring (Table 2). These two types of thiamine-anion complexation also exist in thiamine(BF4)·H2O in which 'anion hole II' is occupied by a water molecule (Aoki et al., 1990). The anion complexation at 'anion hole I' occurs only for the F conformation but not for the other two energetically favourable conformations, S (ϕT= ±100°, ϕP= ±150°) and V (ϕT= ±90°, ϕP= ∓90°), thus being peculiar to the F form. On the other hand, the anion complexation at 'anion hole II' is also possible for a thiamine molecule in the S form, but it requires large anions such as CdCl42- (Richardson et al., 1975) and HgCl42- (Hadjiliadis et al., 1983) rather than small anions like ClO4- or BF4-. In the V form, none of these 'anion holes' are available. It therefore appears that thiamine-anion complexation plays an important role in determining molecular conformations, and vice versa.
As expected, a helical chain structure in the 'head-to-tail' fashion is formed along the twofold screw axis in the b direction through N1'-H···O53 hydrogen bonds, where O53 acts as an acceptor, between the pyrimidinium 'head' of a thiamine molecule and the hydroxyethyl 'tail' of the other one (Fig. 2). The repeat period of the helical chain is the length of the b axis (7.565 Å). The A anion is located inside the spiral and is attached to the chain through the C2—H···BF4-···pyrimidinium interaction, as mentioned above. The B anion lies outside of the spiral and interacts with the chain through the N4'1—H···BF4-···thiazolium contact and, at the same time, links two neighbouring chains by N4'1—H···BF4-···H—O53 hydrogen bonds. This chain structure is similar to that in H-thiamine·(ClO4)2 but different from that in thiamine·ClO4·H2O and thiamine·BF4·H2O, where the molecular chain is constructed through O53—H···N1' hydrogen bonds, with longer repeat periods of 11.234 and 11.134 Å, respectively.
It is of interest to note the molecular self-association in thiamine-anion systems. For example, a polymeric chain structure with each anion molecule held between hydrogen-bonded thiamine-thiamine dimers is commonly formed for [PtCl4]2- (Cramer et al., 1988), [PtCl6]2- (Aoki et al., 1993) and [Pt(NO2)4]2- (Hu et al., 2001) anions, while the linear SCN- anion facilitates the formation of a triple helical structure (Hu & Zhang, 1993) in which each helical chain consists of alternate thiamine and anion molecules. Therefore, the higher-order structures in thiamine-anion systems depend on not only the nature of thiamine itself but also that of the anions.