Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803004938/na6209sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803004938/na6209Isup2.hkl |
CCDC reference: 209942
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.004 Å
- R factor = 0.049
- wR factor = 0.141
- Data-to-parameter ratio = 12.1
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
Alert Level C:
REFLT_03 From the CIF: _diffrn_reflns_theta_max 25.16 From the CIF: _reflns_number_total 1215 TEST2: Reflns within _diffrn_reflns_theta_max Count of symmetry unique reflns 1281 Completeness (_total/calc) 94.85% Alert C: < 95% complete
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check
The title compound was produced of 2 mmol 2,2,6,6-tetramethyl-4-piperidone in 5 ml CHCl3 in the presence of 3 mmol trifluoroacetic acid at ambient temperature. Colourless crystals of (I) were grown by storing this solution at room temperature for 2 d. 1H NMR (CDCl3, internal TMS): δ 1.26 (s, 4 × CH3), 2.34 (s, 2 × CH2), 5.67 (s, br, NH2). 13C{1H} NMR (CDCl3, internal TMS): δ 30.8 (s, CH3), 52.7 (s, 2 CH2), 56.8 (s, 2 × NCMe), 116.5 (q, CF3, 1JFC = 292.8 Hz), 161.7 (q, CO2, 2JFC = 35.1 Hz).
H atoms bonded to C atoms were refined with fixed individual displacement parameters [Uiso(H) = 1.2Ueq(C) or 1.5 Ueq(Cmethyl)] using a riding model, with C—H = 0.99 Å or methyl C—H = 0.98 Å. H atoms bonded to N atoms were refined isotropically.
Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991).
C9H18NO+·C2F3O2− | F(000) = 284 |
Mr = 269.26 | Dx = 1.332 Mg m−3 |
Monoclinic, P21/m | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yb | Cell parameters from 3675 reflections |
a = 6.6117 (14) Å | θ = 3.7–25.1° |
b = 9.1388 (15) Å | µ = 0.12 mm−1 |
c = 11.3024 (19) Å | T = 173 K |
β = 100.450 (17)° | Block, colourless |
V = 671.6 (2) Å3 | 0.29 × 0.18 × 0.11 mm |
Z = 2 |
Stoe IPDS-II two-circle diffractometer | 1215 independent reflections |
Radiation source: fine-focus sealed tube | 906 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
ω scans | θmax = 25.2°, θmin = 3.9° |
Absorption correction: multi-scan (MULABS; Spek, 1990; Blessing, 1995) | h = −7→7 |
Tmin = 0.966, Tmax = 0.984 | k = −10→10 |
3390 measured reflections | l = −12→13 |
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)] = 0.049 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0836P)2 + 0.1272P] where P = (Fo2 + 2Fc2)/3 |
1215 reflections | (Δ/σ)max < 0.001 |
100 parameters | Δρmax = 0.55 e Å−3 |
0 restraints | Δρmin = −0.43 e Å−3 |
C9H18NO+·C2F3O2− | V = 671.6 (2) Å3 |
Mr = 269.26 | Z = 2 |
Monoclinic, P21/m | Mo Kα radiation |
a = 6.6117 (14) Å | µ = 0.12 mm−1 |
b = 9.1388 (15) Å | T = 173 K |
c = 11.3024 (19) Å | 0.29 × 0.18 × 0.11 mm |
β = 100.450 (17)° |
Stoe IPDS-II two-circle diffractometer | 1215 independent reflections |
Absorption correction: multi-scan (MULABS; Spek, 1990; Blessing, 1995) | 906 reflections with I > 2σ(I) |
Tmin = 0.966, Tmax = 0.984 | Rint = 0.041 |
3390 measured reflections |
R[F2 > 2σ(F2)] = 0.049 | 0 restraints |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.55 e Å−3 |
1215 reflections | Δρmin = −0.43 e Å−3 |
100 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. 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. |
x | y | z | Uiso*/Ueq | ||
N1 | 0.1327 (4) | 0.7500 | 0.2166 (2) | 0.0230 (6) | |
H1A | 0.247 (6) | 0.7500 | 0.185 (3) | 0.031 (9)* | |
H1B | 0.028 (6) | 0.7500 | 0.152 (4) | 0.035 (9)* | |
C2 | 0.1211 (3) | 0.6051 (2) | 0.2819 (2) | 0.0271 (5) | |
C21 | 0.3163 (3) | 0.5754 (3) | 0.3743 (2) | 0.0383 (6) | |
H21A | 0.3323 | 0.6512 | 0.4366 | 0.057* | |
H21B | 0.4358 | 0.5767 | 0.3341 | 0.057* | |
H21C | 0.3057 | 0.4793 | 0.4112 | 0.057* | |
C22 | 0.0948 (4) | 0.4877 (3) | 0.1846 (3) | 0.0393 (6) | |
H22A | 0.2170 | 0.4855 | 0.1469 | 0.059* | |
H22B | −0.0266 | 0.5100 | 0.1236 | 0.059* | |
H22C | 0.0770 | 0.3922 | 0.2207 | 0.059* | |
C3 | −0.0696 (3) | 0.6116 (2) | 0.3424 (2) | 0.0300 (5) | |
H3A | −0.1951 | 0.6051 | 0.2798 | 0.036* | |
H3B | −0.0683 | 0.5262 | 0.3964 | 0.036* | |
C4 | −0.0778 (5) | 0.7500 | 0.4142 (3) | 0.0319 (7) | |
O4 | −0.0941 (5) | 0.7500 | 0.5186 (3) | 0.0531 (8) | |
C11 | 0.5875 (4) | 0.7500 | 0.0563 (3) | 0.0282 (7) | |
O11 | 0.5203 (3) | 0.7500 | 0.1524 (2) | 0.0363 (6) | |
O12 | 0.7679 (3) | 0.7500 | 0.0396 (2) | 0.0384 (6) | |
C12 | 0.4247 (5) | 0.7500 | −0.0594 (3) | 0.0423 (9) | |
F11 | 0.2320 (3) | 0.7500 | −0.0403 (2) | 0.0487 (6) | |
F12 | 0.4369 (3) | 0.8677 (4) | −0.1246 (3) | 0.1345 (14) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0179 (12) | 0.0293 (13) | 0.0217 (15) | 0.000 | 0.0032 (11) | 0.000 |
C2 | 0.0235 (10) | 0.0275 (11) | 0.0302 (13) | 0.0006 (7) | 0.0051 (8) | 0.0021 (8) |
C21 | 0.0276 (12) | 0.0411 (12) | 0.0433 (16) | 0.0051 (9) | −0.0009 (10) | 0.0103 (11) |
C22 | 0.0393 (13) | 0.0321 (12) | 0.0474 (16) | 0.0012 (9) | 0.0099 (10) | −0.0054 (10) |
C3 | 0.0261 (10) | 0.0329 (11) | 0.0317 (14) | −0.0017 (8) | 0.0066 (9) | 0.0037 (9) |
C4 | 0.0254 (15) | 0.0397 (17) | 0.032 (2) | 0.000 | 0.0095 (13) | 0.000 |
O4 | 0.0736 (19) | 0.0555 (16) | 0.0353 (18) | 0.000 | 0.0241 (14) | 0.000 |
C11 | 0.0212 (14) | 0.0313 (15) | 0.0318 (19) | 0.000 | 0.0035 (12) | 0.000 |
O11 | 0.0216 (10) | 0.0553 (14) | 0.0315 (14) | 0.000 | 0.0036 (9) | 0.000 |
O12 | 0.0198 (11) | 0.0597 (15) | 0.0353 (15) | 0.000 | 0.0042 (9) | 0.000 |
C12 | 0.0226 (16) | 0.066 (2) | 0.037 (2) | 0.000 | 0.0017 (14) | 0.000 |
F11 | 0.0217 (10) | 0.0727 (14) | 0.0481 (14) | 0.000 | −0.0029 (8) | 0.000 |
F12 | 0.0538 (12) | 0.225 (3) | 0.108 (2) | −0.0508 (15) | −0.0288 (12) | 0.120 (2) |
N1—C2i | 1.525 (2) | C22—H22C | 0.9800 |
N1—C2 | 1.525 (2) | C3—C4 | 1.509 (3) |
N1—H1A | 0.89 (4) | C3—H3A | 0.9900 |
N1—H1B | 0.91 (4) | C3—H3B | 0.9900 |
C2—C22 | 1.523 (3) | C4—O4 | 1.204 (4) |
C2—C21 | 1.530 (3) | C4—C3i | 1.509 (3) |
C2—C3 | 1.541 (3) | C11—O12 | 1.240 (4) |
C21—H21A | 0.9800 | C11—O11 | 1.246 (4) |
C21—H21B | 0.9800 | C11—C12 | 1.536 (5) |
C21—H21C | 0.9800 | C12—F12i | 1.314 (3) |
C22—H22A | 0.9800 | C12—F12 | 1.314 (3) |
C22—H22B | 0.9800 | C12—F11 | 1.330 (4) |
C2i—N1—C2 | 120.6 (2) | C2—C22—H22C | 109.5 |
C2i—N1—H1A | 108.4 (10) | H22A—C22—H22C | 109.5 |
C2—N1—H1A | 108.4 (10) | H22B—C22—H22C | 109.5 |
C2i—N1—H1B | 106.7 (10) | C4—C3—C2 | 112.52 (18) |
C2—N1—H1B | 106.7 (10) | C4—C3—H3A | 109.1 |
H1A—N1—H1B | 105 (3) | C2—C3—H3A | 109.1 |
C22—C2—N1 | 105.75 (19) | C4—C3—H3B | 109.1 |
C22—C2—C21 | 109.84 (18) | C2—C3—H3B | 109.1 |
N1—C2—C21 | 111.98 (18) | H3A—C3—H3B | 107.8 |
C22—C2—C3 | 110.61 (17) | O4—C4—C3i | 123.03 (14) |
N1—C2—C3 | 107.39 (16) | O4—C4—C3 | 123.03 (14) |
C21—C2—C3 | 111.13 (19) | C3i—C4—C3 | 113.9 (3) |
C2—C21—H21A | 109.5 | O12—C11—O11 | 129.6 (3) |
C2—C21—H21B | 109.5 | O12—C11—C12 | 114.6 (3) |
H21A—C21—H21B | 109.5 | O11—C11—C12 | 115.9 (3) |
C2—C21—H21C | 109.5 | F12i—C12—F12 | 109.8 (4) |
H21A—C21—H21C | 109.5 | F12i—C12—F11 | 104.4 (2) |
H21B—C21—H21C | 109.5 | F12—C12—F11 | 104.4 (2) |
C2—C22—H22A | 109.5 | F12i—C12—C11 | 111.8 (2) |
C2—C22—H22B | 109.5 | F12—C12—C11 | 111.8 (2) |
H22A—C22—H22B | 109.5 | F11—C12—C11 | 114.0 (3) |
C2i—N1—C2—C22 | 169.11 (18) | C2—C3—C4—C3i | 55.8 (3) |
C2i—N1—C2—C21 | −71.3 (3) | O12—C11—C12—F12i | 61.8 (3) |
C2i—N1—C2—C3 | 51.0 (3) | O11—C11—C12—F12i | −118.2 (3) |
C22—C2—C3—C4 | −164.4 (2) | O12—C11—C12—F12 | −61.8 (3) |
N1—C2—C3—C4 | −49.5 (3) | O11—C11—C12—F12 | 118.2 (3) |
C21—C2—C3—C4 | 73.3 (3) | O12—C11—C12—F11 | 180.0 |
C2—C3—C4—O4 | −125.7 (3) | O11—C11—C12—F11 | 0.0 |
Symmetry code: (i) x, −y+3/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O11 | 0.89 (4) | 1.91 (4) | 2.787 (3) | 168 (3) |
N1—H1B···O12ii | 0.91 (4) | 1.94 (4) | 2.840 (3) | 168 (3) |
Symmetry code: (ii) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C9H18NO+·C2F3O2− |
Mr | 269.26 |
Crystal system, space group | Monoclinic, P21/m |
Temperature (K) | 173 |
a, b, c (Å) | 6.6117 (14), 9.1388 (15), 11.3024 (19) |
β (°) | 100.450 (17) |
V (Å3) | 671.6 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.12 |
Crystal size (mm) | 0.29 × 0.18 × 0.11 |
Data collection | |
Diffractometer | Stoe IPDS-II two-circle diffractometer |
Absorption correction | Multi-scan (MULABS; Spek, 1990; Blessing, 1995) |
Tmin, Tmax | 0.966, 0.984 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3390, 1215, 906 |
Rint | 0.041 |
(sin θ/λ)max (Å−1) | 0.598 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.049, 0.141, 1.05 |
No. of reflections | 1215 |
No. of parameters | 100 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.55, −0.43 |
Computer programs: X-AREA (Stoe & Cie, 2001), X-AREA, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP in SHELXTL-Plus (Sheldrick, 1991).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O11 | 0.89 (4) | 1.91 (4) | 2.787 (3) | 168 (3) |
N1—H1B···O12i | 0.91 (4) | 1.94 (4) | 2.840 (3) | 168 (3) |
Symmetry code: (i) x−1, y, z. |
Piperdine derivates have found widespread use as bulky bases in organic chemistry. We report here the reaction of 2,2,6,6-tetramethyl-4-piperidone with trifluoroacetic acid and the X-ray crystal structure analysis of 2,2,6,6-tetramethyl-4-oxopiperidium trifluoroacetate, (I). The synthesis of (I) was achieved by transforming 2,2,6,6-tetramethyl-4-piperidone, as indicated in the Scheme below.
Both ions of (I) are located on a crystallographic mirror plane. Only the methyl groups and the sp3 C atoms of the piperidone ring and one of the F atoms are located on a general position. Bond lengths and angles are in the usual ranges. The piperidone ring adopts an almost ideal chair conformation, with Q = 0.525 (2) Å, θ = 176.2 (3)°, ϕ = 360 (3)° (Cremer & Pople, 1975). Anions and cations form infinite hydrogen-bonded chains along the crystallographic a axis.