Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807046156/ng2330sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807046156/ng2330Isup2.hkl |
CCDC reference: 663824
Key indicators
- Single-crystal X-ray study
- T = 200 K
- Mean (C-C) = 0.003 Å
- R factor = 0.048
- wR factor = 0.142
- Data-to-parameter ratio = 16.0
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C13 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C23
Alert level G PLAT793_ALERT_1_G Check the Absolute Configuration of C12 = ... R PLAT793_ALERT_1_G Check the Absolute Configuration of C22 = ... S
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
For synthesis of the title compound, see Reetz & Heimbach (1983). For the crystal structures of 1-hydroxy-1-carboxylic acids with hydrophobic residues of similar size, see Betz & Klüfers (2007a, 2007b, 2007c).
The title compound was prepared according to a published procedure (Reetz & Heimbach, 1983) upon addition of tert-butyl chloride to tris(trimethylsilyloxyethene). Crystals suitable for X-ray analysis were directly obtained from the crystallized reaction product.
All H atoms were located in a difference map. Methyl H atoms were refined as riding with one common isotropic temperature parameter. Individual isotropic temperature parameters were refined for the other H atoms. The positional parameters of O-bonded H atoms were refined freely.
tert-Butylglycolic acid was prepared as a chelating molecule bearing the sterically demanding tert-butyl group as a substituent. In order to estimate the influence of chelation on structural parameters of the chelating molecule, the structure of the parent compound was investigated.
The molecular structure of (I) comprises a tert-butyl group attached to hydroxy acetic acid (glycolic acid). The two molecules present in the asymmetric unit differ only slightly from each other by the arrangement of the tert-butyl group relative to the carboxyl group.
Hydrogen bonds between hydroxyl donors and carboxyl-O acceptors connect pairs of molecules to centrosymmetric dimers. Each dimer is incorporated in three-dimensional network by means of two carboxyl-donor and two hydroxyl-acceptor sites. Figure 2 shows hydrophobic channels along 0,0,z and 1/2,1/2,z running through the hydrogen-bonded network of the hydrophilic functions.
For synthesis of the title compound, see Reetz & Heimbach (1983). For the crystal structures of 1-hydroxy-1-carboxylic acids with hydrophobic residues of similar size, see Betz & Klüfers (2007a, 2007b, 2007c).
Data collection: CrysAlis CCD (Oxford Diffraction, 2005); cell refinement: CrysAlis RED (Oxford Diffraction, 2005); data reduction: CrysAlis RED (Oxford Diffraction, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
C6H12O3 | Z = 16 |
Mr = 132.16 | F(000) = 1152 |
Monoclinic, C2/c | Dx = 1.156 Mg m−3 |
Hall symbol: -C 2yc | Mo Kα radiation, λ = 0.71073 Å |
a = 21.236 (2) Å | θ = 3.9–26.0° |
b = 13.4486 (13) Å | µ = 0.09 mm−1 |
c = 11.4351 (13) Å | T = 200 K |
β = 111.537 (10)° | Block, colourless |
V = 3037.8 (6) Å3 | 0.44 × 0.36 × 0.16 mm |
Oxford Diffraction XCalibur diffractometer | 3003 independent reflections |
Radiation source: fine-focus sealed tube | 2266 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
ω scans | θmax = 26.0°, θmin = 4.5° |
Absorption correction: analytical (de Meulenaer & Tompa, 1965) | h = −19→26 |
Tmin = 0.972, Tmax = 0.988 | k = −16→12 |
7814 measured reflections | l = −14→14 |
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)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0759P)2 + 0.3594P] where P = (Fo2 + 2Fc2)/3 |
3003 reflections | (Δ/σ)max < 0.001 |
188 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C6H12O3 | V = 3037.8 (6) Å3 |
Mr = 132.16 | Z = 16 |
Monoclinic, C2/c | Mo Kα radiation |
a = 21.236 (2) Å | µ = 0.09 mm−1 |
b = 13.4486 (13) Å | T = 200 K |
c = 11.4351 (13) Å | 0.44 × 0.36 × 0.16 mm |
β = 111.537 (10)° |
Oxford Diffraction XCalibur diffractometer | 3003 independent reflections |
Absorption correction: analytical (de Meulenaer & Tompa, 1965) | 2266 reflections with I > 2σ(I) |
Tmin = 0.972, Tmax = 0.988 | Rint = 0.025 |
7814 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.19 e Å−3 |
3003 reflections | Δρmin = −0.21 e Å−3 |
188 parameters |
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. Treatment of H atoms: GEOM for methyl Hs, 1 common isotropic U. GEOM for methylidine Hs, individual isotropic Us All H-atom parameters refined for O-bonded Hs |
x | y | z | Uiso*/Ueq | ||
O12 | 0.19291 (6) | 0.25485 (9) | 0.62987 (11) | 0.0395 (3) | |
H12 | 0.2237 (12) | 0.2390 (17) | 0.608 (2) | 0.073 (7)* | |
O22 | 0.05822 (6) | 0.37302 (10) | 0.12597 (12) | 0.0476 (3) | |
H22 | 0.0265 (11) | 0.4000 (15) | 0.074 (2) | 0.051 (6)* | |
O111 | 0.17753 (5) | 0.27864 (10) | 0.38322 (12) | 0.0534 (4) | |
O112 | 0.06607 (5) | 0.27901 (10) | 0.33272 (12) | 0.0508 (4) | |
H112 | 0.0644 (11) | 0.3065 (18) | 0.267 (2) | 0.072 (7)* | |
O211 | 0.07378 (6) | 0.56407 (9) | 0.05469 (13) | 0.0541 (4) | |
O212 | 0.18526 (5) | 0.54759 (10) | 0.15797 (12) | 0.0487 (4) | |
H212 | 0.1857 (13) | 0.612 (2) | 0.156 (2) | 0.090 (8)* | |
C11 | 0.12818 (7) | 0.26207 (11) | 0.40870 (15) | 0.0358 (4) | |
C12 | 0.13211 (7) | 0.21920 (11) | 0.53441 (14) | 0.0347 (4) | |
H121 | 0.0932 | 0.2472 | 0.5531 | 0.035 (4)* | |
C13 | 0.12590 (8) | 0.10491 (12) | 0.53469 (16) | 0.0400 (4) | |
C14 | 0.18576 (10) | 0.05486 (14) | 0.5147 (2) | 0.0636 (6) | |
H141 | 0.2279 | 0.0739 | 0.5828 | 0.0897 (19)* | |
H142 | 0.1875 | 0.0761 | 0.4340 | 0.0897 (19)* | |
H143 | 0.1803 | −0.0175 | 0.5146 | 0.0897 (19)* | |
C15 | 0.06016 (9) | 0.07141 (15) | 0.4313 (2) | 0.0570 (5) | |
H151 | 0.0548 | −0.0005 | 0.4374 | 0.0897 (19)* | |
H152 | 0.0618 | 0.0875 | 0.3489 | 0.0897 (19)* | |
H153 | 0.0218 | 0.1058 | 0.4413 | 0.0897 (19)* | |
C16 | 0.12455 (12) | 0.07342 (17) | 0.6625 (2) | 0.0714 (7) | |
H161 | 0.0866 | 0.1060 | 0.6762 | 0.0897 (19)* | |
H162 | 0.1671 | 0.0930 | 0.7292 | 0.0897 (19)* | |
H163 | 0.1192 | 0.0011 | 0.6640 | 0.0897 (19)* | |
C21 | 0.12311 (8) | 0.51224 (12) | 0.10414 (15) | 0.0387 (4) | |
C22 | 0.11975 (7) | 0.40017 (12) | 0.11120 (15) | 0.0380 (4) | |
H221 | 0.1578 | 0.3786 | 0.1889 | 0.031 (4)* | |
C23 | 0.12843 (9) | 0.34628 (13) | −0.00079 (17) | 0.0464 (4) | |
C24 | 0.07322 (13) | 0.3743 (2) | −0.1234 (2) | 0.0892 (8) | |
H241 | 0.0290 | 0.3595 | −0.1188 | 0.0897 (19)* | |
H242 | 0.0787 | 0.3360 | −0.1920 | 0.0897 (19)* | |
H243 | 0.0761 | 0.4455 | −0.1390 | 0.0897 (19)* | |
C25 | 0.19713 (11) | 0.37017 (18) | −0.0065 (2) | 0.0713 (6) | |
H251 | 0.1996 | 0.4414 | −0.0226 | 0.0897 (19)* | |
H252 | 0.2033 | 0.3319 | −0.0744 | 0.0897 (19)* | |
H253 | 0.2328 | 0.3527 | 0.0737 | 0.0897 (19)* | |
C26 | 0.12598 (15) | 0.23381 (17) | 0.0209 (3) | 0.0888 (8) | |
H261 | 0.1634 | 0.2152 | 0.0983 | 0.0897 (19)* | |
H262 | 0.1302 | 0.1978 | −0.0504 | 0.0897 (19)* | |
H263 | 0.0828 | 0.2167 | 0.0286 | 0.0897 (19)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O12 | 0.0292 (6) | 0.0446 (7) | 0.0392 (7) | 0.0007 (5) | 0.0061 (5) | −0.0006 (5) |
O22 | 0.0284 (6) | 0.0597 (8) | 0.0526 (8) | 0.0021 (5) | 0.0122 (6) | 0.0249 (6) |
O111 | 0.0270 (6) | 0.0774 (9) | 0.0543 (8) | 0.0029 (5) | 0.0130 (6) | 0.0266 (6) |
O112 | 0.0255 (6) | 0.0817 (10) | 0.0420 (7) | 0.0054 (5) | 0.0087 (6) | 0.0214 (6) |
O211 | 0.0310 (6) | 0.0446 (7) | 0.0766 (9) | 0.0029 (5) | 0.0080 (6) | 0.0077 (6) |
O212 | 0.0310 (6) | 0.0433 (8) | 0.0611 (8) | −0.0029 (5) | 0.0044 (6) | 0.0050 (6) |
C11 | 0.0262 (8) | 0.0383 (9) | 0.0396 (9) | 0.0010 (6) | 0.0082 (7) | 0.0058 (6) |
C12 | 0.0254 (7) | 0.0407 (9) | 0.0357 (8) | 0.0006 (6) | 0.0085 (7) | 0.0019 (6) |
C13 | 0.0348 (8) | 0.0396 (9) | 0.0437 (9) | −0.0042 (7) | 0.0123 (8) | 0.0049 (7) |
C14 | 0.0508 (11) | 0.0393 (10) | 0.1000 (17) | 0.0027 (8) | 0.0269 (12) | −0.0026 (10) |
C15 | 0.0463 (10) | 0.0557 (12) | 0.0621 (12) | −0.0151 (8) | 0.0116 (10) | −0.0018 (9) |
C16 | 0.0837 (16) | 0.0688 (14) | 0.0574 (13) | −0.0183 (11) | 0.0210 (12) | 0.0173 (10) |
C21 | 0.0301 (8) | 0.0464 (10) | 0.0381 (9) | −0.0002 (7) | 0.0107 (7) | 0.0042 (7) |
C22 | 0.0261 (8) | 0.0447 (9) | 0.0401 (9) | −0.0005 (6) | 0.0085 (7) | 0.0124 (7) |
C23 | 0.0378 (9) | 0.0447 (10) | 0.0552 (11) | 0.0003 (7) | 0.0153 (8) | 0.0006 (8) |
C24 | 0.0748 (16) | 0.135 (2) | 0.0494 (13) | 0.0289 (15) | 0.0132 (12) | −0.0139 (13) |
C25 | 0.0602 (13) | 0.0745 (15) | 0.0925 (17) | −0.0056 (10) | 0.0437 (13) | −0.0153 (12) |
C26 | 0.106 (2) | 0.0496 (13) | 0.126 (2) | −0.0121 (12) | 0.0607 (19) | −0.0130 (13) |
O12—C12 | 1.4331 (18) | C15—H152 | 0.9800 |
O12—H12 | 0.81 (2) | C15—H153 | 0.9800 |
O22—C22 | 1.4253 (18) | C16—H161 | 0.9800 |
O22—H22 | 0.80 (2) | C16—H162 | 0.9800 |
O111—C11 | 1.2071 (18) | C16—H163 | 0.9800 |
O112—C11 | 1.3058 (18) | C21—C22 | 1.512 (2) |
O112—H112 | 0.82 (2) | C22—C23 | 1.540 (2) |
O211—C21 | 1.2116 (19) | C22—H221 | 1.0000 |
O212—C21 | 1.3230 (19) | C23—C24 | 1.508 (3) |
O212—H212 | 0.87 (3) | C23—C25 | 1.519 (3) |
C11—C12 | 1.522 (2) | C23—C26 | 1.537 (3) |
C12—C13 | 1.543 (2) | C24—H241 | 0.9800 |
C12—H121 | 1.0000 | C24—H242 | 0.9800 |
C13—C14 | 1.528 (2) | C24—H243 | 0.9800 |
C13—C15 | 1.529 (2) | C25—H251 | 0.9800 |
C13—C16 | 1.532 (3) | C25—H252 | 0.9800 |
C14—H141 | 0.9800 | C25—H253 | 0.9800 |
C14—H142 | 0.9800 | C26—H261 | 0.9800 |
C14—H143 | 0.9800 | C26—H262 | 0.9800 |
C15—H151 | 0.9800 | C26—H263 | 0.9800 |
C12—O12—H12 | 106.5 (17) | H161—C16—H163 | 109.5 |
C22—O22—H22 | 110.7 (14) | H162—C16—H163 | 109.5 |
C11—O112—H112 | 112.3 (16) | O211—C21—O212 | 123.66 (16) |
C21—O212—H212 | 111.4 (17) | O211—C21—C22 | 123.27 (14) |
O111—C11—O112 | 124.16 (14) | O212—C21—C22 | 113.06 (13) |
O111—C11—C12 | 123.12 (14) | O22—C22—C21 | 108.95 (12) |
O112—C11—C12 | 112.72 (13) | O22—C22—C23 | 111.89 (14) |
O12—C12—C11 | 108.32 (12) | C21—C22—C23 | 113.71 (13) |
O12—C12—C13 | 112.68 (12) | O22—C22—H221 | 107.3 |
C11—C12—C13 | 113.84 (13) | C21—C22—H221 | 107.3 |
O12—C12—H121 | 107.2 | C23—C22—H221 | 107.3 |
C11—C12—H121 | 107.2 | C24—C23—C25 | 109.8 (2) |
C13—C12—H121 | 107.2 | C24—C23—C26 | 109.5 (2) |
C14—C13—C15 | 109.16 (16) | C25—C23—C26 | 107.77 (18) |
C14—C13—C16 | 109.19 (17) | C24—C23—C22 | 111.46 (15) |
C15—C13—C16 | 108.95 (15) | C25—C23—C22 | 110.27 (15) |
C14—C13—C12 | 111.24 (13) | C26—C23—C22 | 107.92 (17) |
C15—C13—C12 | 110.27 (14) | C23—C24—H241 | 109.5 |
C16—C13—C12 | 107.99 (15) | C23—C24—H242 | 109.5 |
C13—C14—H141 | 109.5 | H241—C24—H242 | 109.5 |
C13—C14—H142 | 109.5 | C23—C24—H243 | 109.5 |
H141—C14—H142 | 109.5 | H241—C24—H243 | 109.5 |
C13—C14—H143 | 109.5 | H242—C24—H243 | 109.5 |
H141—C14—H143 | 109.5 | C23—C25—H251 | 109.5 |
H142—C14—H143 | 109.5 | C23—C25—H252 | 109.5 |
C13—C15—H151 | 109.5 | H251—C25—H252 | 109.5 |
C13—C15—H152 | 109.5 | C23—C25—H253 | 109.5 |
H151—C15—H152 | 109.5 | H251—C25—H253 | 109.5 |
C13—C15—H153 | 109.5 | H252—C25—H253 | 109.5 |
H151—C15—H153 | 109.5 | C23—C26—H261 | 109.5 |
H152—C15—H153 | 109.5 | C23—C26—H262 | 109.5 |
C13—C16—H161 | 109.5 | H261—C26—H262 | 109.5 |
C13—C16—H162 | 109.5 | C23—C26—H263 | 109.5 |
H161—C16—H162 | 109.5 | H261—C26—H263 | 109.5 |
C13—C16—H163 | 109.5 | H262—C26—H263 | 109.5 |
O111—C11—C12—O12 | 32.7 (2) | O211—C21—C22—O22 | −34.9 (2) |
O112—C11—C12—O12 | −147.03 (13) | O212—C21—C22—O22 | 144.80 (14) |
O111—C11—C12—C13 | −93.44 (19) | O211—C21—C22—C23 | 90.67 (19) |
O112—C11—C12—C13 | 86.80 (16) | O212—C21—C22—C23 | −89.66 (17) |
O12—C12—C13—C14 | −58.85 (19) | O22—C22—C23—C24 | 62.7 (2) |
C11—C12—C13—C14 | 64.99 (18) | C21—C22—C23—C24 | −61.3 (2) |
O12—C12—C13—C15 | 179.89 (14) | O22—C22—C23—C25 | −175.10 (15) |
C11—C12—C13—C15 | −56.26 (18) | C21—C22—C23—C25 | 60.93 (19) |
O12—C12—C13—C16 | 60.95 (18) | O22—C22—C23—C26 | −57.62 (19) |
C11—C12—C13—C16 | −175.21 (15) | C21—C22—C23—C26 | 178.40 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12···O111i | 0.81 (2) | 2.08 (2) | 2.8456 (17) | 159 (2) |
O22—H22···O211ii | 0.80 (2) | 2.15 (2) | 2.9308 (18) | 163.4 (19) |
O112—H112···O22 | 0.82 (2) | 1.81 (3) | 2.6317 (18) | 177 (2) |
O212—H212···O12iii | 0.87 (3) | 1.82 (3) | 2.6883 (18) | 170 (2) |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x, −y+1, −z; (iii) x, −y+1, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C6H12O3 |
Mr | 132.16 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 200 |
a, b, c (Å) | 21.236 (2), 13.4486 (13), 11.4351 (13) |
β (°) | 111.537 (10) |
V (Å3) | 3037.8 (6) |
Z | 16 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.44 × 0.36 × 0.16 |
Data collection | |
Diffractometer | Oxford Diffraction XCalibur |
Absorption correction | Analytical (de Meulenaer & Tompa, 1965) |
Tmin, Tmax | 0.972, 0.988 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7814, 3003, 2266 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.142, 1.10 |
No. of reflections | 3003 |
No. of parameters | 188 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.19, −0.21 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2005), CrysAlis RED (Oxford Diffraction, 2005), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPIII (Burnett & Johnson, 1996).
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12···O111i | 0.81 (2) | 2.08 (2) | 2.8456 (17) | 159 (2) |
O22—H22···O211ii | 0.80 (2) | 2.15 (2) | 2.9308 (18) | 163.4 (19) |
O112—H112···O22 | 0.82 (2) | 1.81 (3) | 2.6317 (18) | 177 (2) |
O212—H212···O12iii | 0.87 (3) | 1.82 (3) | 2.6883 (18) | 170 (2) |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x, −y+1, −z; (iii) x, −y+1, z−1/2. |
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tert-Butylglycolic acid was prepared as a chelating molecule bearing the sterically demanding tert-butyl group as a substituent. In order to estimate the influence of chelation on structural parameters of the chelating molecule, the structure of the parent compound was investigated.
The molecular structure of (I) comprises a tert-butyl group attached to hydroxy acetic acid (glycolic acid). The two molecules present in the asymmetric unit differ only slightly from each other by the arrangement of the tert-butyl group relative to the carboxyl group.
Hydrogen bonds between hydroxyl donors and carboxyl-O acceptors connect pairs of molecules to centrosymmetric dimers. Each dimer is incorporated in three-dimensional network by means of two carboxyl-donor and two hydroxyl-acceptor sites. Figure 2 shows hydrophobic channels along 0,0,z and 1/2,1/2,z running through the hydrogen-bonded network of the hydrophilic functions.