organic compounds
of morpholin-4-ium cinnamate
aScience and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
*Correspondence e-mail: g.smith@qut.edu.au
In the anhydrous salt formed from the reaction of morpholine with cinnamic acid, C4H10NO+·C9H7O2−, the acid side chain in the trans-cinnamate anion is significantly rotated out of the benzene plane [C—C—C— C torsion angle = 158.54 (17)°]. In the crystal, one of the the aminium H atoms is involved in an asymmetric three-centre cation–anion N—H⋯(O,O′) R12(4) hydrogen-bonding interaction with the two carboxylate O-atom acceptors of the anion. The second aminium-H atom forms an inter-species N—H⋯Ocarboxylate hydrogen bond. The result of the hydrogen bonding is the formation of a chain structure extending along [100]. Chains are linked by C—H⋯O interactions, forming a supramolecular layer parallel to (01-1).
Keywords: crystal structure; salt; morpholinium; cinnamate; hydrogen bonding.
CCDC reference: 1430629
1. Related literature
For background on morpholine compounds and the structure of an aliphatic morpholine salt, see: Kelley et al. (2013). For the structures of analogous morpholinate salts of some aromatic acid analogues, see: Chumakov et al. (2006); Ishida et al. (2001a,b,c); Smith & Lynch (2015).
2. Experimental
2.1. Crystal data
|
2.3. Refinement
|
Data collection: CrysAlis PRO (Agilent, 2014); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supporting information
CCDC reference: 1430629
https://doi.org/10.1107/S2056989015019179/tk5397sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989015019179/tk5397Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989015019179/tk5397Isup3.cml
The title compound was prepared by the dropwise addition of morpholine at room temperature to a solution of cinnamic acid (150 mg) in ethanol (10 ml). Room temperature evaporation of the solution gave an oil which was redissolved in ethanol, finally giving thin colourless plates of the title compound from which a specimen was cleaved for the X-ray analysis.
Hydrogen atoms were placed in calculated positions [C—Haromatic = 0.95 Å or C—Hmethylene = 0.99 Å] and were allowed to ride in the refinements, with Uiso(H) = 1.2Ueq(C). The aminium H atoms were located in a difference-Fourier analysis and were allowed to refine with distance restraints [d(N—H) = 0.92 (2) Å and Uiso(H) = 1.2Ueq(N)
Morpholine (tetrahydro-2H-1,4-oxazine) forms salts with organic acids, and the crystal structures of a limited number of these with either aliphatic acids, e.g. the acetate (Kelley et al., 2013) or aromatic acids, e.g. the 4-nitrobenzoate (Chumakov et al., 2006), have been reported. With the salts of the aromatic acids, particularly those with non-associative substituent groups, cation–anion N—H···Ocarboxyl hydrogen-bonding interactions generate either one-dimensional chains or discrete cyclic heterotetrameric structures. In the present work, the title morpholinium salt of cinnamic acid, C4H10NO+ C9H7O2- was prepared and its structure is reported herein.
The π–π interactions are present in the structure.
of the title salt comprises a morpholinium cation (B and a cinnamate anion (A), (Fig. 1). In the trans- cinnamate anion, the acid side chain is significantly rotated out of the benzene plane [defining torsion angle C6A—C1A—C11A— C12A = 158.54 (17)°]. In the crystal, a primary asymmetric three-centre R21(4) N1B—H···(O,O')carboxyl hydrogen-bonding interaction is present [N···O = 2.6643 (17) and 3.1868 (17) Å] (Table 1). The hydrogen-bonding extension involves the second aminium H atom of the cation to the carboxyl O14Ai acceptor of the anion, resulting in a one-dimensional ribbon structure extending along a (Fig. 2). Present also in the structure are minor weak inter-unit C—H···O interactions. C4A—H···O4Bii; C6B—H··· O13Aiii. NoThese ribbon structures are similar to those found in the morpholinium salt of one of the five isomeric chloro-nitrobenzoic acids (2,4-) (Ishida et al., 2001a). In the other four isomers [(2,5-), (4,3-), (4,2-), (5,2-)] (Ishida, 2001a, 2001b, 2001c), the cyclic heterotetrameric structures are found. However, among a set of four morpholinium salts of phenoxyacetic acid analogues (Smith & Lynch, 2015), there are four one-dimensional polymers and one cyclic heterotetramer.
For background on morpholine compounds and the structure of an aliphatic morpholine salt, see: Kelley et al. (2013). For the structures of analogous morpholinate salts of some aromatic acid analogues, see: Chumakov et al. (2006); Ishida et al. (2001a,b,c); Smith & Lynch (2015).
Data collection: CrysAlis PRO (Agilent, 2014); cell
CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).Fig. 1. The atom-numbering scheme and the molecular conformation of the morpholinium anion (B) and the cinnamate cation (A) in the title salt, with displacement ellipsoids drawn at the 40% probability level. The cation–anion hydrogen bonds are shown as dashed lines. | |
Fig. 2. The one-dimensional hydrogen-bonded polymeric structure extending along a. For symmetry codes, see Table 1. |
C4H10NO+·C9H7O2− | Z = 2 |
Mr = 235.27 | F(000) = 252 |
Triclinic, P1 | Dx = 1.281 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.7365 (7) Å | Cell parameters from 1133 reflections |
b = 9.7526 (10) Å | θ = 3.6–28.4° |
c = 11.7760 (11) Å | µ = 0.09 mm−1 |
α = 103.270 (8)° | T = 200 K |
β = 93.468 (9)° | Plate, colourless |
γ = 105.493 (10)° | 0.52 × 0.24 × 0.05 mm |
V = 612.69 (12) Å3 |
Oxford Diffraction Gemini-S CCD-detector diffractometer | 2393 independent reflections |
Radiation source: Enhance (Mo) X-ray source | 1860 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
Detector resolution: 16.077 pixels mm-1 | θmax = 26.0°, θmin = 3.2° |
ω scans | h = −6→7 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014) | k = −12→12 |
Tmin = 0.965, Tmax = 0.990 | l = −14→14 |
4253 measured reflections |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0429P)2 + 0.0676P] where P = (Fo2 + 2Fc2)/3 |
2393 reflections | (Δ/σ)max < 0.001 |
160 parameters | Δρmax = 0.15 e Å−3 |
2 restraints | Δρmin = −0.15 e Å−3 |
C4H10NO+·C9H7O2− | γ = 105.493 (10)° |
Mr = 235.27 | V = 612.69 (12) Å3 |
Triclinic, P1 | Z = 2 |
a = 5.7365 (7) Å | Mo Kα radiation |
b = 9.7526 (10) Å | µ = 0.09 mm−1 |
c = 11.7760 (11) Å | T = 200 K |
α = 103.270 (8)° | 0.52 × 0.24 × 0.05 mm |
β = 93.468 (9)° |
Oxford Diffraction Gemini-S CCD-detector diffractometer | 2393 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014) | 1860 reflections with I > 2σ(I) |
Tmin = 0.965, Tmax = 0.990 | Rint = 0.023 |
4253 measured reflections |
R[F2 > 2σ(F2)] = 0.043 | 2 restraints |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.15 e Å−3 |
2393 reflections | Δρmin = −0.15 e Å−3 |
160 parameters |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles |
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 > 2sigma(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 | ||
O13A | 0.72059 (18) | 0.32720 (13) | 0.51574 (9) | 0.0370 (4) | |
O14A | 0.50422 (18) | 0.43517 (12) | 0.63746 (10) | 0.0323 (4) | |
C1A | 0.0669 (3) | 0.04440 (16) | 0.29775 (13) | 0.0256 (5) | |
C2A | −0.1554 (3) | 0.00183 (17) | 0.34093 (15) | 0.0299 (5) | |
C3A | −0.3583 (3) | −0.09424 (18) | 0.26731 (16) | 0.0365 (6) | |
C4A | −0.3450 (3) | −0.14842 (18) | 0.14947 (16) | 0.0388 (6) | |
C5A | −0.1258 (3) | −0.10770 (18) | 0.10580 (15) | 0.0384 (6) | |
C6A | 0.0789 (3) | −0.01381 (17) | 0.17959 (14) | 0.0321 (5) | |
C11A | 0.2852 (3) | 0.14762 (17) | 0.37395 (14) | 0.0262 (5) | |
C12A | 0.2907 (3) | 0.24300 (17) | 0.47379 (14) | 0.0276 (5) | |
C13A | 0.5213 (3) | 0.34254 (17) | 0.54714 (13) | 0.0258 (5) | |
O4B | 1.2058 (2) | 0.63511 (13) | 0.93100 (10) | 0.0398 (4) | |
N1B | 1.0764 (2) | 0.48489 (14) | 0.68969 (11) | 0.0253 (4) | |
C2B | 1.0246 (3) | 0.40701 (18) | 0.78354 (14) | 0.0310 (5) | |
C3B | 1.2089 (3) | 0.48633 (18) | 0.89057 (14) | 0.0354 (6) | |
C5B | 1.2676 (3) | 0.71057 (18) | 0.84191 (15) | 0.0355 (6) | |
C6B | 1.0875 (3) | 0.64183 (17) | 0.73241 (14) | 0.0298 (5) | |
H2A | −0.16720 | 0.03930 | 0.42160 | 0.0360* | |
H3A | −0.50810 | −0.12330 | 0.29790 | 0.0440* | |
H4A | −0.48570 | −0.21320 | 0.09880 | 0.0470* | |
H5A | −0.11570 | −0.14440 | 0.02480 | 0.0460* | |
H6A | 0.22990 | 0.01130 | 0.14920 | 0.0390* | |
H11A | 0.43820 | 0.14510 | 0.34830 | 0.0310* | |
H12A | 0.14000 | 0.24890 | 0.50070 | 0.0330* | |
H11B | 1.227 (3) | 0.4752 (17) | 0.6663 (13) | 0.0300* | |
H12B | 0.951 (3) | 0.4376 (17) | 0.6261 (12) | 0.0300* | |
H21B | 1.03230 | 0.30470 | 0.75550 | 0.0370* | |
H22B | 0.85830 | 0.40330 | 0.80370 | 0.0370* | |
H31B | 1.17210 | 0.43540 | 0.95390 | 0.0420* | |
H32B | 1.37370 | 0.48430 | 0.87120 | 0.0420* | |
H51B | 1.43250 | 0.70830 | 0.82290 | 0.0430* | |
H52B | 1.27130 | 0.81480 | 0.87160 | 0.0430* | |
H61B | 0.92430 | 0.65020 | 0.74950 | 0.0360* | |
H62B | 1.13770 | 0.69400 | 0.67100 | 0.0360* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O13A | 0.0181 (6) | 0.0508 (8) | 0.0320 (7) | 0.0093 (5) | −0.0013 (5) | −0.0075 (6) |
O14A | 0.0217 (6) | 0.0368 (7) | 0.0304 (6) | 0.0073 (5) | −0.0001 (5) | −0.0048 (5) |
C1A | 0.0255 (8) | 0.0211 (8) | 0.0289 (9) | 0.0061 (7) | −0.0022 (7) | 0.0063 (7) |
C2A | 0.0265 (8) | 0.0251 (9) | 0.0334 (9) | 0.0043 (7) | −0.0008 (7) | 0.0035 (7) |
C3A | 0.0259 (9) | 0.0273 (9) | 0.0516 (12) | 0.0036 (7) | −0.0029 (8) | 0.0075 (8) |
C4A | 0.0375 (10) | 0.0242 (9) | 0.0453 (11) | 0.0036 (8) | −0.0174 (8) | 0.0026 (8) |
C5A | 0.0522 (11) | 0.0299 (10) | 0.0279 (9) | 0.0099 (9) | −0.0062 (8) | 0.0026 (8) |
C6A | 0.0349 (9) | 0.0279 (9) | 0.0312 (9) | 0.0069 (8) | 0.0013 (7) | 0.0065 (7) |
C11A | 0.0213 (8) | 0.0277 (9) | 0.0294 (9) | 0.0065 (7) | 0.0021 (6) | 0.0080 (7) |
C12A | 0.0191 (8) | 0.0311 (9) | 0.0303 (9) | 0.0072 (7) | 0.0019 (6) | 0.0039 (7) |
C13A | 0.0213 (8) | 0.0295 (9) | 0.0261 (9) | 0.0076 (7) | 0.0007 (6) | 0.0064 (7) |
O4B | 0.0518 (8) | 0.0356 (7) | 0.0241 (6) | 0.0068 (6) | −0.0002 (5) | 0.0001 (5) |
N1B | 0.0185 (6) | 0.0305 (8) | 0.0222 (7) | 0.0066 (6) | −0.0013 (5) | −0.0007 (6) |
C2B | 0.0287 (8) | 0.0269 (9) | 0.0361 (10) | 0.0057 (7) | 0.0024 (7) | 0.0085 (8) |
C3B | 0.0402 (10) | 0.0363 (10) | 0.0286 (9) | 0.0101 (8) | −0.0011 (7) | 0.0088 (8) |
C5B | 0.0380 (10) | 0.0257 (9) | 0.0351 (10) | 0.0009 (8) | 0.0011 (8) | 0.0032 (8) |
C6B | 0.0296 (9) | 0.0280 (9) | 0.0321 (9) | 0.0082 (7) | 0.0045 (7) | 0.0085 (7) |
O13A—C13A | 1.258 (2) | C2A—H2A | 0.9500 |
O14A—C13A | 1.2553 (19) | C3A—H3A | 0.9500 |
O4B—C3B | 1.425 (2) | C4A—H4A | 0.9500 |
O4B—C5B | 1.424 (2) | C5A—H5A | 0.9500 |
N1B—C2B | 1.480 (2) | C6A—H6A | 0.9500 |
N1B—C6B | 1.480 (2) | C11A—H11A | 0.9500 |
N1B—H11B | 0.944 (18) | C12A—H12A | 0.9500 |
N1B—H12B | 0.943 (15) | C2B—C3B | 1.503 (2) |
C1A—C6A | 1.390 (2) | C5B—C6B | 1.501 (2) |
C1A—C2A | 1.396 (2) | C2B—H21B | 0.9900 |
C1A—C11A | 1.471 (2) | C2B—H22B | 0.9900 |
C2A—C3A | 1.381 (2) | C3B—H31B | 0.9900 |
C3A—C4A | 1.382 (3) | C3B—H32B | 0.9900 |
C4A—C5A | 1.382 (3) | C5B—H51B | 0.9900 |
C5A—C6A | 1.382 (2) | C5B—H52B | 0.9900 |
C11A—C12A | 1.314 (2) | C6B—H61B | 0.9900 |
C12A—C13A | 1.493 (2) | C6B—H62B | 0.9900 |
C3B—O4B—C5B | 109.75 (12) | C1A—C6A—H6A | 120.00 |
C2B—N1B—C6B | 111.05 (12) | C12A—C11A—H11A | 117.00 |
C6B—N1B—H11B | 110.9 (10) | C1A—C11A—H11A | 117.00 |
C2B—N1B—H12B | 107.7 (10) | C11A—C12A—H12A | 118.00 |
H11B—N1B—H12B | 109.8 (14) | C13A—C12A—H12A | 118.00 |
C2B—N1B—H11B | 107.0 (10) | N1B—C2B—C3B | 109.50 (14) |
C6B—N1B—H12B | 110.3 (10) | O4B—C3B—C2B | 110.91 (14) |
C2A—C1A—C11A | 121.67 (14) | O4B—C5B—C6B | 111.36 (14) |
C6A—C1A—C11A | 120.00 (15) | N1B—C6B—C5B | 109.46 (14) |
C2A—C1A—C6A | 118.33 (15) | N1B—C2B—H21B | 110.00 |
C1A—C2A—C3A | 120.55 (16) | N1B—C2B—H22B | 110.00 |
C2A—C3A—C4A | 120.46 (17) | C3B—C2B—H21B | 110.00 |
C3A—C4A—C5A | 119.55 (16) | C3B—C2B—H22B | 110.00 |
C4A—C5A—C6A | 120.21 (16) | H21B—C2B—H22B | 108.00 |
C1A—C6A—C5A | 120.88 (16) | O4B—C3B—H31B | 109.00 |
C1A—C11A—C12A | 126.79 (16) | O4B—C3B—H32B | 109.00 |
C11A—C12A—C13A | 123.45 (16) | C2B—C3B—H31B | 109.00 |
O13A—C13A—O14A | 123.98 (15) | C2B—C3B—H32B | 109.00 |
O13A—C13A—C12A | 118.14 (14) | H31B—C3B—H32B | 108.00 |
O14A—C13A—C12A | 117.87 (15) | O4B—C5B—H51B | 109.00 |
C1A—C2A—H2A | 120.00 | O4B—C5B—H52B | 109.00 |
C3A—C2A—H2A | 120.00 | C6B—C5B—H51B | 109.00 |
C4A—C3A—H3A | 120.00 | C6B—C5B—H52B | 109.00 |
C2A—C3A—H3A | 120.00 | H51B—C5B—H52B | 108.00 |
C3A—C4A—H4A | 120.00 | N1B—C6B—H61B | 110.00 |
C5A—C4A—H4A | 120.00 | N1B—C6B—H62B | 110.00 |
C6A—C5A—H5A | 120.00 | C5B—C6B—H61B | 110.00 |
C4A—C5A—H5A | 120.00 | C5B—C6B—H62B | 110.00 |
C5A—C6A—H6A | 120.00 | H61B—C6B—H62B | 108.00 |
C3B—O4B—C5B—C6B | 61.19 (17) | C1A—C2A—C3A—C4A | −0.7 (3) |
C5B—O4B—C3B—C2B | −61.29 (17) | C2A—C3A—C4A—C5A | 1.0 (3) |
C2B—N1B—C6B—C5B | 54.09 (17) | C3A—C4A—C5A—C6A | 0.2 (3) |
C6B—N1B—C2B—C3B | −54.46 (17) | C4A—C5A—C6A—C1A | −1.8 (3) |
C2A—C1A—C6A—C5A | 2.1 (2) | C1A—C11A—C12A—C13A | 178.94 (15) |
C6A—C1A—C11A—C12A | 158.54 (17) | C11A—C12A—C13A—O13A | −5.0 (2) |
C11A—C1A—C6A—C5A | −178.16 (16) | C11A—C12A—C13A—O14A | 175.97 (16) |
C2A—C1A—C11A—C12A | −21.7 (3) | N1B—C2B—C3B—O4B | 57.95 (17) |
C6A—C1A—C2A—C3A | −0.8 (2) | O4B—C5B—C6B—N1B | −57.43 (18) |
C11A—C1A—C2A—C3A | 179.41 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1B—H11B···O14Ai | 0.94 (2) | 1.77 (2) | 2.7052 (17) | 170 (2) |
N1B—H12B···O13A | 0.94 (2) | 1.73 (2) | 2.6643 (17) | 172 (2) |
N1B—H12B···O14A | 0.94 (2) | 2.57 (2) | 3.1868 (17) | 123 (1) |
C4A—H4A···O4Bii | 0.95 | 2.46 | 3.393 (2) | 167 |
C11A—H11A···O13A | 0.95 | 2.48 | 2.812 (2) | 101 |
C6B—H62B···O13Aiii | 0.99 | 2.37 | 3.234 (2) | 145 |
Symmetry codes: (i) x+1, y, z; (ii) x−2, y−1, z−1; (iii) −x+2, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1B—H11B···O14Ai | 0.944 (18) | 1.770 (18) | 2.7052 (17) | 170.2 (15) |
N1B—H12B···O13A | 0.943 (15) | 1.728 (16) | 2.6643 (17) | 171.5 (15) |
N1B—H12B···O14A | 0.943 (15) | 2.569 (18) | 3.1868 (17) | 123.4 (12) |
C4A—H4A···O4Bii | 0.95 | 2.46 | 3.393 (2) | 167 |
C6B—H62B···O13Aiii | 0.99 | 2.37 | 3.234 (2) | 145 |
Symmetry codes: (i) x+1, y, z; (ii) x−2, y−1, z−1; (iii) −x+2, −y+1, −z+1. |
Acknowledgements
GS acknowledges financial support from the Science and Engineering Faculty and the University Library, Queensland University of Technology.
References
Agilent (2014). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England. Google Scholar
Altomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343–350. CrossRef Web of Science IUCr Journals Google Scholar
Chumakov, Y. M., Simonov, Y. A., Grosav, M., Crisan, M., Bocelli, G., Yakovenco, A. A. & Lyubetsky, D. (2006). Central Eur. J. Chem. 4, 458–475. CAS Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Ishida, H., Rahman, B. & Kashino, S. (2001a). Acta Cryst. C57, 1450–1453. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Ishida, H., Rahman, B. & Kashino, S. (2001b). Acta Cryst. E57, o627–o629. Web of Science CSD CrossRef IUCr Journals Google Scholar
Ishida, H., Rahman, B. & Kashino, S. (2001c). Acta Cryst. E57, o630–o632. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kelley, S. P., Narita, A., Holbrey, J. D., Green, K. D., Reichert, W. M. & Rogers, R. D. (2013). Cryst. Growth Des. 13, 965–975. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Smith, G. & Lynch, D. E. (2015). Acta Cryst. E71, 1392–1396. CSD CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Morpholine (tetrahydro-2H-1,4-oxazine) forms salts with organic acids, and the crystal structures of a limited number of these with either aliphatic acids, e.g. the acetate (Kelley et al., 2013) or aromatic acids, e.g. the 4-nitrobenzoate (Chumakov et al., 2006), have been reported. With the salts of the aromatic acids, particularly those with non-associative substituent groups, cation–anion N—H···Ocarboxyl hydrogen-bonding interactions generate either one-dimensional chains or discrete cyclic heterotetrameric structures. In the present work, the title morpholinium salt of cinnamic acid, C4H10NO+ C9H7O2- was prepared and its structure is reported herein.
The asymmetric unit of the title salt comprises a morpholinium cation (B and a cinnamate anion (A), (Fig. 1). In the trans- cinnamate anion, the acid side chain is significantly rotated out of the benzene plane [defining torsion angle C6A—C1A—C11A— C12A = 158.54 (17)°]. In the crystal, a primary asymmetric three-centre R21(4) N1B—H···(O,O')carboxyl hydrogen-bonding interaction is present [N···O = 2.6643 (17) and 3.1868 (17) Å] (Table 1). The hydrogen-bonding extension involves the second aminium H atom of the cation to the carboxyl O14Ai acceptor of the anion, resulting in a one-dimensional ribbon structure extending along a (Fig. 2). Present also in the structure are minor weak inter-unit C—H···O interactions. C4A—H···O4Bii; C6B—H··· O13Aiii. No π–π interactions are present in the structure.
These ribbon structures are similar to those found in the morpholinium salt of one of the five isomeric chloro-nitrobenzoic acids (2,4-) (Ishida et al., 2001a). In the other four isomers [(2,5-), (4,3-), (4,2-), (5,2-)] (Ishida, 2001a, 2001b, 2001c), the cyclic heterotetrameric structures are found. However, among a set of four morpholinium salts of phenoxyacetic acid analogues (Smith & Lynch, 2015), there are four one-dimensional polymers and one cyclic heterotetramer.