The title compound, C6H13NO5, adopts a zwitterionic form where the carboxylic acid H atom is transferred to the amino group. The methyl-glycine backbone is planar. The tris(hydroxymethyl)methyl group is rotated as a rigid group around the amino-methyl bond by 22 (1)° and the carboxylic acid plane is rotated by 19.76 (12)° from the plane of the main skeleton. Apart from their H atoms, the three hydroxymethyl groups adopt a propeller-like conformation around the amino-methyl bond, close to C3 symmetry.
Supporting information
CCDC reference: 163909
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA (Spek, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97; molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
N-[tris(hydroxymethyl)methyl]glycine or
N-(2-hydroxy-1,1-bis[hydroxymethyl]ethyl)glycine
top
Crystal data top
C6H13NO5 | Dx = 1.523 Mg m−3 |
Mr = 179.18 | Melting point: 459(2) K |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 6.2806 (16) Å | Cell parameters from 25 reflections |
b = 13.5616 (13) Å | θ = 9.7–14.1° |
c = 9.6165 (10) Å | µ = 0.13 mm−1 |
β = 107.488 (11)° | T = 293 K |
V = 781.2 (2) Å3 | Prism, colourless |
Z = 4 | 0.49 × 0.20 × 0.12 mm |
F(000) = 384 | |
Data collection top
Enraf-Nonius CAD-4 diffractometer | Rint = 0.020 |
Radiation source: fine-focus sealed tube | θmax = 30.0°, θmin = 3.0° |
Graphite monochromator | h = 0→8 |
profile data from ω–2θ scans | k = 0→19 |
2434 measured reflections | l = −13→12 |
2255 independent reflections | 3 standard reflections every 180 min |
1920 reflections with I > 2σ(I) | intensity decay: 1.1% |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.030 | Only H-atom coordinates refined |
wR(F2) = 0.089 | w = 1/[σ2(Fo2) + (0.0479P)2 + 0.1832P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max < 0.001 |
2255 reflections | Δρmax = 0.39 e Å−3 |
149 parameters | Δρmin = −0.19 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.069 (6) |
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 | |
O1 | 0.56659 (13) | −0.09470 (6) | 0.61101 (8) | 0.02764 (18) | |
O2 | 0.73866 (14) | −0.11426 (6) | 0.84884 (8) | 0.02991 (19) | |
O3 | −0.04126 (12) | 0.10578 (5) | 0.42452 (7) | 0.02200 (16) | |
H3 | −0.012 (3) | 0.1509 (12) | 0.3772 (17) | 0.033* | |
O4 | 0.08633 (14) | 0.07186 (6) | 0.86253 (8) | 0.0321 (2) | |
H4 | 0.128 (3) | 0.0723 (13) | 0.955 (2) | 0.048* | |
O5 | 0.52284 (12) | 0.25370 (5) | 0.73708 (8) | 0.02664 (18) | |
H5 | 0.601 (3) | 0.2944 (12) | 0.7037 (17) | 0.040* | |
N1 | 0.32148 (12) | 0.05764 (5) | 0.65388 (8) | 0.01638 (16) | |
H1A | 0.362 (2) | 0.0642 (9) | 0.5727 (14) | 0.020* | |
H1B | 0.229 (2) | 0.0034 (9) | 0.6388 (13) | 0.020* | |
C1 | 0.61573 (15) | −0.06833 (7) | 0.74002 (10) | 0.01924 (18) | |
C2 | 0.52084 (16) | 0.02846 (7) | 0.77614 (10) | 0.0230 (2) | |
H2A | 0.631 (2) | 0.0780 (11) | 0.7941 (15) | 0.028* | |
H2B | 0.472 (2) | 0.0191 (10) | 0.8634 (15) | 0.028* | |
C3 | 0.19535 (14) | 0.15021 (6) | 0.67019 (9) | 0.01603 (17) | |
C4 | −0.04097 (15) | 0.13842 (7) | 0.56471 (10) | 0.01931 (18) | |
H4A | −0.121 (2) | 0.2010 (10) | 0.5605 (14) | 0.023* | |
H4B | −0.119 (2) | 0.0884 (9) | 0.6017 (14) | 0.023* | |
C5 | 0.17907 (17) | 0.15926 (7) | 0.82451 (10) | 0.02172 (19) | |
H5A | 0.083 (2) | 0.2180 (10) | 0.8285 (15) | 0.026* | |
H5B | 0.323 (2) | 0.1727 (10) | 0.8919 (15) | 0.026* | |
C6 | 0.31037 (16) | 0.24088 (7) | 0.63172 (10) | 0.02139 (19) | |
H6A | 0.212 (2) | 0.2996 (10) | 0.6324 (14) | 0.026* | |
H6B | 0.329 (2) | 0.2318 (10) | 0.5356 (15) | 0.026* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0325 (4) | 0.0312 (4) | 0.0196 (3) | 0.0082 (3) | 0.0084 (3) | −0.0005 (3) |
O2 | 0.0363 (4) | 0.0299 (4) | 0.0211 (3) | 0.0148 (3) | 0.0050 (3) | 0.0046 (3) |
O3 | 0.0247 (3) | 0.0230 (3) | 0.0168 (3) | −0.0050 (2) | 0.0038 (2) | −0.0011 (2) |
O4 | 0.0386 (4) | 0.0375 (4) | 0.0213 (4) | −0.0138 (3) | 0.0109 (3) | 0.0009 (3) |
O5 | 0.0249 (4) | 0.0259 (4) | 0.0271 (4) | −0.0103 (3) | 0.0048 (3) | −0.0002 (3) |
N1 | 0.0169 (3) | 0.0154 (3) | 0.0154 (3) | 0.0010 (2) | 0.0027 (3) | −0.0010 (2) |
C1 | 0.0186 (4) | 0.0199 (4) | 0.0201 (4) | 0.0027 (3) | 0.0072 (3) | 0.0021 (3) |
C2 | 0.0222 (4) | 0.0223 (4) | 0.0197 (4) | 0.0058 (3) | −0.0011 (3) | −0.0020 (3) |
C3 | 0.0174 (4) | 0.0142 (3) | 0.0160 (3) | 0.0003 (3) | 0.0042 (3) | −0.0012 (3) |
C4 | 0.0171 (4) | 0.0216 (4) | 0.0183 (4) | 0.0009 (3) | 0.0039 (3) | −0.0001 (3) |
C5 | 0.0263 (4) | 0.0221 (4) | 0.0175 (4) | −0.0010 (3) | 0.0077 (3) | −0.0028 (3) |
C6 | 0.0245 (4) | 0.0170 (4) | 0.0211 (4) | −0.0038 (3) | 0.0046 (3) | 0.0002 (3) |
Geometric parameters (Å, º) top
O1—C1 | 1.2379 (11) | C1—C2 | 1.5241 (13) |
O2—C1 | 1.2623 (11) | C2—H2A | 0.944 (15) |
O3—C4 | 1.4184 (11) | C2—H2B | 0.985 (14) |
O3—H3 | 0.816 (16) | C3—C5 | 1.5229 (12) |
O4—C5 | 1.4163 (12) | C3—C6 | 1.5268 (12) |
O4—H4 | 0.851 (19) | C3—C4 | 1.5338 (12) |
O5—C6 | 1.4230 (12) | C4—H4A | 0.981 (13) |
O5—H5 | 0.862 (17) | C4—H4B | 0.966 (13) |
N1—C2 | 1.4906 (11) | C5—H5A | 1.005 (14) |
N1—C3 | 1.5175 (11) | C5—H5B | 0.960 (14) |
N1—H1A | 0.896 (13) | C6—H6A | 1.009 (14) |
N1—H1B | 0.923 (13) | C6—H6B | 0.974 (13) |
| | | |
C4—O3—H3 | 111.1 (11) | N1—C3—C4 | 106.07 (7) |
C5—O4—H4 | 104.1 (12) | C5—C3—C4 | 108.53 (7) |
C6—O5—H5 | 109.3 (11) | C6—C3—C4 | 110.98 (7) |
C2—N1—C3 | 118.62 (7) | O3—C4—C3 | 112.69 (7) |
C2—N1—H1A | 108.7 (8) | O3—C4—H4A | 112.1 (8) |
C3—N1—H1A | 107.6 (8) | C3—C4—H4A | 108.6 (8) |
C2—N1—H1B | 104.7 (8) | O3—C4—H4B | 106.0 (8) |
C3—N1—H1B | 110.5 (8) | C3—C4—H4B | 109.1 (8) |
H1A—N1—H1B | 106.0 (11) | H4A—C4—H4B | 108.2 (11) |
O1—C1—O2 | 126.47 (9) | O4—C5—C3 | 109.72 (7) |
O1—C1—C2 | 118.71 (8) | O4—C5—H5A | 110.9 (8) |
O2—C1—C2 | 114.82 (8) | C3—C5—H5A | 108.5 (8) |
N1—C2—C1 | 110.01 (7) | O4—C5—H5B | 111.3 (8) |
N1—C2—H2A | 110.6 (9) | C3—C5—H5B | 110.3 (8) |
C1—C2—H2A | 109.8 (9) | H5A—C5—H5B | 106.1 (11) |
N1—C2—H2B | 107.6 (8) | O5—C6—C3 | 109.67 (7) |
C1—C2—H2B | 109.0 (8) | O5—C6—H6A | 110.1 (8) |
H2A—C2—H2B | 109.7 (12) | C3—C6—H6A | 107.4 (8) |
N1—C3—C5 | 110.94 (7) | O5—C6—H6B | 109.7 (8) |
N1—C3—C6 | 109.97 (7) | C3—C6—H6B | 109.2 (8) |
C5—C3—C6 | 110.27 (7) | H6A—C6—H6B | 110.8 (11) |
| | | |
C3—N1—C2—C1 | 177.57 (7) | C6—C3—C4—O3 | 73.02 (9) |
O1—C1—C2—N1 | 19.76 (12) | N1—C3—C5—O4 | −53.88 (10) |
O2—C1—C2—N1 | −159.87 (9) | C6—C3—C5—O4 | −175.96 (8) |
C2—N1—C3—C5 | −39.57 (11) | C4—C3—C5—O4 | 62.28 (10) |
C2—N1—C3—C6 | 82.69 (10) | N1—C3—C6—O5 | −66.90 (9) |
C2—N1—C3—C4 | −157.24 (8) | C5—C3—C6—O5 | 55.75 (10) |
N1—C3—C4—O3 | −46.39 (9) | C4—C3—C6—O5 | 176.05 (7) |
C5—C3—C4—O3 | −165.66 (7) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O1i | 0.896 (13) | 1.991 (13) | 2.8830 (11) | 173.0 (12) |
N1—H1B···O3ii | 0.923 (13) | 1.876 (13) | 2.7894 (11) | 170.3 (11) |
O3—H3···O5iii | 0.816 (16) | 1.928 (16) | 2.7347 (11) | 170.2 (15) |
O4—H4···O2iv | 0.851 (19) | 1.904 (19) | 2.7220 (11) | 160.9 (17) |
O5—H5···O2v | 0.862 (17) | 1.764 (17) | 2.6224 (11) | 174.0 (16) |
C2—H2A···O5 | 0.944 (15) | 2.494 (14) | 3.0781 (13) | 120.2 (10) |
C2—H2B···O4 | 0.985 (14) | 2.523 (14) | 3.1380 (15) | 120.4 (10) |
C4—H4B···O4 | 0.966 (13) | 2.462 (13) | 2.8775 (12) | 105.7 (9) |
C5—H5B···O5 | 0.960 (14) | 2.473 (13) | 2.8460 (13) | 103.0 (9) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x, −y, −z+1; (iii) x−1/2, −y+1/2, z−1/2; (iv) −x+1, −y, −z+2; (v) −x+3/2, y+1/2, −z+3/2. |