1-(2-Aminophenyl)-3-(4-pyridyl)prop-2-en-1-one: A three-dimensional framework structure built from N - H...N, C - H...O and C - H...π(arene) hydrogen bonds

Article abstract of DOI:10.1107/S0108270110040825

The intra-molecular dimensions of the title compound, C₁₄H ₁₂N₂O, provide evidence for a polarized electronic structure. The mol-ecule, which is almost completely planar, contains an intra-molecular N - H...O hydrogen bond

Full text of DOI:10.1107/S0108270110040825

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
Compound (I) crystallizes in the space group C2/c with
Z0 = 1, whereas the closely related compound (II) crystallizes
with Z0 = 2 in the space group P1, where the pattern of
hydrogen bonding clearly rules out any possibility of addi-
tional crystallographic symmetry (Cuervo et al., 2007). The
molecule of (I) is very nearly planar, as indicated by the key
torsion angles (Table 1). For the molecular fragment between
atoms C11 and N34 (Fig. 1), the maximum deviations from the
ISSN 0108-2701
1-(2-Aminophenyl)-3-(4-pyridyl)prop-
2-en-1-one: a three-dimensional
framework structure built from
N—Hꢀ ꢀ ꢀN, C—Hꢀ ꢀ ꢀO and
˚
mean plane through the non-H atoms are 0.069 (2) A for atom
˚
O1 and 0.050 (2) A for atom C11. The dihedral angle between
this plane and that of the C11–C16 ring is only 8.62 (9)ꢁ. As in
compounds (II)–(VI) (Cuervo et al., 2007; Low et al., 2004),
there is an intramolecular N—Hꢀ ꢀ ꢀO hydrogen bond in (I),
forming an S(6) motif (Bernstein et al., 1995), and this may
have some influence on the overall molecular conformation.
C—Hꢀ ꢀ ꢀp(arene) hydrogen bonds
a
a
b
´
´
Fernando Cuenu, ‡ Rodrigo Abonıa, Justo Cobo and
Christopher Glidewellc*
a
´
Departamento de Quımica, Universidad de Valle, AA 25360 Cali, Colombia,
b
´
´
´
´
Departamento de Quımica Inorganica y Organica, Universidad de Jaen, 23071
Jaen, Spain, and cSchool of Chemistry, University of St Andrews, Fife KY16 9ST,
´
Scotland
Correspondence e-mail: cg@st-andrews.ac.uk
Received 21 September 2010
Accepted 11 October 2010
Online 6 November 2010
The intramolecular dimensions of the title compound,
C14H12N2O, provide evidence for a polarized electronic
structure. The molecule, which is almost completely planar,
contains an intramolecular N—Hꢀ ꢀ ꢀO hydrogen bond, and the
molecules are linked by a combination of N—Hꢀ ꢀ ꢀN,
C—Hꢀ ꢀ ꢀO and C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds to form a
three-dimensional framework structure.
Comment
Chalcones (1,3-diarylpropenones) are very versatile synthetic
intermediates (Awad et al., 1960; Carrie & Rochard, 1963;
Coudert et al., 1988; Insuasty et al., 1992, 1997; Kolos et al.,
1996). We report here the molecular and supramolecular
structure of the title compound, (I) (Fig. 1), which we compare
with the structure of the related compound 1-(6-amino-1,3-
benzodioxol-5-yl)-3-(4-pyridyl)prop-2-en-1-one, (II) (Cuervo
et al., 2007), which is itself closely related to the series of
compounds (III)–(V) (Low et al., 2004) and (VI) (Low et al.,
2002) (see scheme). 2-Aminochalcones are key intermediates
in the synthesis of 6,7-methylenedioxytetrahydroquinolin-4-
ones, compounds with interesting biological and pharmaco-
logical properties (Prager & Thredgold, 1968; Donnelly &
Farell, 1990; Kurasawa et al., 2002), while more generally,
many compounds, both synthetic and naturally occurring,
containing the 1,3-dioxolyl group are of importance because of
their pharmacological properties (Krause & Goeber, 1972;
Ohta & Kimoto, 1976; Ma et al., 1987; Gabrielsen et al.,
1992).
A more significant factor influencing the conformation of
(I) may be the electronic polarization indicated by the intra-
molecular distances (Table 1). Within the C11–C16 ring, the
C13—C14 and C15—C16 distances are significantly shorter
than the other C—C distances, indicating some degree of
o-quinonoid bond fixation. In addition, the exocyclic bonds
Figure 1
The molecular structure of (I), showing the atom-labelling scheme and
the intramolecular N—Hꢀ ꢀ ꢀO hydrogen bond (dashed line). Displace-
ment ellipsoids are drawn at the 50% probability level.
´
‡ Present address: Laboratorio de Quımica Inorganica y Catalisis, Universidad
del Quindio, Cra 15, Cll 12N Armenia, Colombia.
´
´
Acta Cryst. (2010). C66, o589–o592
doi:10.1107/S0108270110040825
# 2010 International Union of Crystallography o589

organic compounds
Figure 2
Part of the crystal structure of (I), showing the formation of a cyclic
centrosymmetric dimer built from paired C—Hꢀ ꢀ ꢀO hydrogen bonds. For
the sake of clarity, H atoms bonded to C atoms but not involved in the
motif shown have been omitted. Atoms marked with an asterisk (*) are at
the symmetry position (1 ꢃ x, 2 ꢃ y, 1 ꢃ z).
C12—N12 and C11—C1 are both short for their types [mean
˚
values (Allen et al., 1987) = 1.355 and 1.488 A, respectively;
˚
lower quartile values = 1.340 and 1.468 A, respectively].
Similar patterns were observed for the C—C and C—N
distances in each of (II)–(VI) (Cuervo et al., 2007; Low et al.,
2002, 2004). However, the C1—O1 distance in (I) is not
particularly long compared with those in (II)–(VI), which
Figure 3
A stereoview of part of the crystal structure of (I), showing the formation
of a hydrogen-bonded sheet parallel to (101) and containing N—Hꢀ ꢀ ꢀO,
N—Hꢀ ꢀ ꢀN and C—Hꢀ ꢀ ꢀO hydrogen bonds. For the sake of clarity, H
atoms bonded to C atoms but not involved in the motifs shown have been
omitted.
˚
˚
range from 1.237 (2) to 1.253 (2) A, with a mean of 1.245 A,
for ten independent values [compounds (II), (V) and (VI) all
crystallize with Z0 = 2, while there are two polymorphs of (IV),
one monoclinic and the other triclinic, with Z0 = 1 and 2,
respectively]. These observations indicate the charge-sepa-
rated form (Ia) as a significant contributor to the overall
electronic structure. Form (Ia) is certainly consistent with the
near coplanarity observed between the C11–C16 ring and the
rest of the molecular structure, despite the rather short
Figure 4
˚
intramolecular H2ꢀ ꢀ ꢀH16 distance of only 2.04 A. By way of
Part of the crystal structure of (I), showing the formation of a cyclic dimer
built from paired C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds. For the sake of
clarity, H atoms not involved in the motif shown have been omitted. The
atom marked with a hash (#) is at the symmetry position (1 ꢃ x, y, 12 ꢃ z).
comparison, the corresponding intramolecular distance
involving the pyridyl ring, H2ꢀ ꢀ ꢀH32, is somewhat longer at
˚
2.26 A, even though the pyridyl ring is effectively coplanar
with the spacer unit containing atoms C1–C3. It is tempting,
therefore, to interpret the orientation of the C11–C16 ring in
terms of the competing effects of the intramolecular hydrogen
bond and the electronic polarization on the one hand, and a
repulsive intramolecular Hꢀ ꢀ ꢀH contact on the other.
rotation axis into another type of cyclic dimer (Fig. 4). The
effect of this cyclic motif is to link each (101) sheet to the two
adjacent sheets, so linking the molecules into a continuous
three-dimensional framework structure.
The molecules of (I) are linked by N—Hꢀ ꢀ ꢀN, C—Hꢀ ꢀ ꢀO
and C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds, the first two of which
are almost linear (Table 2). It is convenient to consider as the
basic building block in the hydrogen-bonded structure the
cyclic centrosymmetric R22(14) dimer unit built from paired
C—Hꢀ ꢀ ꢀO hydrogen bonds (Fig. 2). The reference dimer is
It is of interest briefly to compare the hydrogen-bonded
structure of (II) (Cuervo et al., 2007) with that reported here
for (I). The close similarity between the molecular constitu-
tions of (I) and (II) might have been expected to lead to some
similarities in their modes of intermolecular aggregation, but
in fact the aggregation in (I) and (II) is very different. As
noted above, (II) crystallizes with Z0 = 2, and each of the two
independent molecules is linked by a combination of N—
Hꢀ ꢀ ꢀN and C—Hꢀ ꢀ ꢀO hydrogen bonds, just as in (I), although
C—Hꢀ ꢀ ꢀꢀ(arene) hydrogen bonds are absent from the struc-
ture of (II). However, each of the independent molecules
forms an independent substructure, with no hydrogen bonds
between molecules of the two types. More striking is the
difference between the two substructures: one consists of a
chain of edge-fused R22(14) and R46(16) rings, while the other
consists of sheets containing equal numbers of S(6) and R45(33)
1
centred at (12, 1, ) and is directly linked, by means of N—
2
Hꢀ ꢀ ꢀN hydrogen bonds, to four further dimers, centred at
(0, 12, 0), (0, 23, 0), (1, 12, 1) and (1, 32, 1), so forming a sheet lying
parallel to (101) (Fig. 3). In addition to the S(6) rings, the sheet
contains equal numbers of centrosymmetric large and small
rings, arranged alternately in a chess-board fashion. The small
rings are of R22(14) type. If the large rings are taken to include
the intramolecular hydrogen bond, then they are of R810(38)
type, otherwise they are of R66(42) type. The C—Hꢀ ꢀ ꢀꢀ(arene)
hydrogen bond links a pair of molecules related by a twofold
ꢂ
´
o590 Cuenu et al. C14H12N2O
Acta Cryst. (2010). C66, o589–o592

organic compounds
Table 1
Selected geometric parameters (A, ).
rings (Cuervo et al., 2007). Thus, the only point of similarity
between the hydrogen-bonded structures of (I) and (II) lies in
the formation of centrosymmetric R22(14) rings containing
paired C—Hꢀ ꢀ ꢀO hydrogen bonds, as formed by (I) and by
one of the molecular types in (II). It is thus worth emphasizing
that the molecular constitutions of (I) and (II) differ only by
the presence in (II) of a fused dioxolane ring, which does not
occupy any of the hydrogen-bonding sites utilized in (I). While
this additional ring participates in sheet formation in (II), it
plays no role in the formation of the chain of edge-fused rings.
This chain in (II) is built from two hydrogen bonds, one each
of N—Hꢀ ꢀ ꢀN and C—Hꢀ ꢀ ꢀO types, which utilize exactly the
same atoms as donors and acceptors as those in (I), except that
these hydrogen bonds are mediated by different symmetry
operators in the two compounds, consequent upon their
different space groups.
ꢁ
˚
C11—C12
C12—C13
C13—C14
C14—C15
C15—C16
C16—C11
1.409 (3)
1.395 (3)
1.338 (3)
1.374 (3)
1.356 (3)
1.392 (3)
C12—N12
C1—C11
C1—O1
C1—C2
C2—C3
C3—C31
1.331 (3)
1.452 (3)
1.224 (2)
1.473 (2)
1.299 (2)
1.451 (2)
C12—C11—C1—C2
C11—C1—C2—C3
169.49 (17)
ꢃ178.21 (18)
C1—C2—C3—C31
C2—C3—C31—C32
ꢃ178.49 (18)
2.6 (3)
Table 2
Hydrogen-bond geometry (A, ).
ꢁ
˚
Cg1 represents the centroid of the C11–C16 ring.
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
N12—H12Aꢀ ꢀ ꢀO1
N12—H12Bꢀ ꢀ ꢀN34i
C36—H36ꢀ ꢀ ꢀO1ii
C32—H32ꢀ ꢀ ꢀCg1iii
0.88
0.88
0.93
0.93
1.93
2.10
2.36
2.87
2.621 (3)
2.982 (3)
3.283 (3)
3.611 (3)
134
174
170
137
Experimental
A mixture of 20-aminoacetophenone (2.8 mmol), pyridine-4-carb-
aldehyde (2.8 mmol), ethanol (10 ml) and 20% aqueous sodium
hydroxide solution (0.5 ml) was heated under reflux for 20 min. The
mixture was cooled to ambient temperature, and the resulting solid
precipitate was collected by filtration, washed successively with
ethanol (2 ꢄ 0.5 ml) and water (2 ꢄ 0.5 ml), and finally dried under
reduced pressure to yield the title compound as an orange solid (yield
82%; m.p. 440 K). MS (70 eV) m/z (%): 224 (23) (M+), 223 (12), 195
(8), 146 (100). Crystals of (I) suitable for single-crystal X-ray
diffraction were grown by slow evaporation, at ambient temperature
and in air, of a solution in ethanol.
1
2
3
2
1
2
Symmetry codes: (i) x þ ; ꢃy þ ; z þ ; (ii) ꢃx þ 1; ꢃy þ 2; ꢃz þ 1; (iii) ꢃx þ 1; y,
1
ꢃz þ .
2
(Duisenberg et al., 2003); program(s) used to solve structure: SIR2004
(Burla et al., 2005); program(s) used to refine structure: SHELXL97
(Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); soft-
ware used to prepare material for publication: SHELXL97 and
PLATON.
´
The authors thank the Centro de Instrumentacion Cientı-
fico-Tecnica of the Universidad de Jaen and the staff for the
´
´
´
Crystal data
´
data collection. JC thanks the Consejerıa de Innovacion,
Ciencia y Empresa (Junta de Andalucıa, Spain), the Univer-
´
3
˚
C14H12N2O
Mr = 224.26
V = 2305.2 (8) A
Z = 8
´
´
sidad de Jaen (project reference UJA_07_16_33) and the
Ministerio de Ciencia e Innovacion (project reference
SAF2008-04685-C02-02) for financial support. RA and FC
thank the Universidad del Valle and the Universidad del
Quindio for financial support.
Monoclinic, C2=c
Mo Kꢂ radiation
ꢃ = 0.08 mmꢃ1
T = 296 K
0.30 ꢄ 0.17 ꢄ 0.16 mm
˚
a = 27.922 (6) A
´
˚
b = 6.4261 (8) A
˚
c = 14.668 (3) A
ꢁ = 118.849 (18)ꢁ
Data collection
Bruker–Nonius KappaCCD area-
detector diffractometer
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
Tmin = 0.954, Tmax = 0.987
17566 measured reflections
2141 independent reflections
1403 reflections with I > 2ꢄ(I)
Rint = 0.036
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: EG3062). Services for accessing these data are
described at the back of the journal.
References
Refinement
R[F2 > 2ꢄ(F2)] = 0.049
wR(F2) = 0.126
S = 1.08
154 parameters
H-atom parameteꢃrs3 constrained
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor,
R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
Awad, W., El-Neweihy, M. & Selim, F. (1960). J. Org. Chem. 25, 1333–1336.
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem.
Int. Ed. Engl. 34, 1555–1573.
˚
Áꢅmax = 0.13 e A
ꢃ3
˚
2141 reflections
Áꢅmin = ꢃ0.15 e A
Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De
Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38,
381–388.
Carrie, R. & Rochard, J. (1963). C. R. Acad. Sci. 257, 2849–2851.
Coudert, P., Couquelet, J. & Tronche, P. (1988). J. Heterocycl. Chem. 25, 799–
802.
All H atoms were located in difference maps and then treated as
riding. H atoms bonded to C atoms were permitted to ride in
˚
geometrically idealized positions, with C—H = 0.93 A and Uiso(H) =
1.2Ueq(C). The H atoms bonded to atom N12 were permitted to ride
at the positions deduced from the difference maps, with Uiso(H) =
˚
1.2Ueq(N), giving N—H = 0.88 A.
´
Cuervo, P., Abonıa, R., Cobo, J., Low, J. N. & Glidewell, C. (2007). Acta Cryst.
C63, o99–o101.
Donnelly, J. A. & Farell, D. F. (1990). Tetrahedron, 46, 885–894.
Duisenberg, A. J. M., Hooft, R. W. W., Schreurs, A. M. M. & Kroon, J. (2000).
J. Appl. Cryst. 33, 893–898.
Data collection: COLLECT (Nonius, 1999); cell refinement:
DIRAX/LSQ (Duisenberg et al., 2000); data reduction: EVALCCD
ꢂ
´
Acta Cryst. (2010). C66, o589–o592
Cuenu et al. C14H12N2O o591

organic compounds
Duisenberg, A. J. M., Kroon-Batenburg, L. M. J. & Schreurs, A. M. M. (2003).
J. Appl. Cryst. 36, 220–229.
Low, J. N., Cobo, J., Nogueras, M., Cuervo, P., Abonia, R. & Glidewell, C.
(2004). Acta Cryst. C60, o744–o750.
´
Low, J. N., Cobo, J., Nogueras, M., Sanchez, A., Albornoz, A. & Abonia, R.
(2002). Acta Cryst. C58, o42–o45.
Ma, G., Li, H., Huang, H., Yan, L. & Hong, S. (1987). Zhongcaoyao, 18, 342–
345.
Gabrielsen, B., Monath, T., Huggins, J., Kefauver, D., Pettit, G., Groszek, G.,
Hollingshead, M., Kirsi, J. & Shannon, W. (1992). J. Nat. Prod. 55, 1569–
1581.
´
Insuasty, B., Abonıa, R. & Quiroga, J. (1992). An. Quim. 88, 718–720.
Insuasty, B., Quiroga, J. & Meier, H. (1997). Trends Heterocycl. Chem. 5, 83–
89.
Kolos, N., Orlov, V., Arisa, D., Shishkin, O., Struchkov, T. & Vorobiova, N.
(1996). Khim. Geterotsikl. Soedin. pp. 87–95.
Krause, W. & Goeber, B. (1972). Pharmazie, 27, 419–420.
Kurasawa, Y., Tsuruoka, A., Rikiishi, N., Fujiwara, N., Okamoto, Y. & Kim,
H. S. (2002). J. Heterocycl. Chem. 37, 791–798.
Nonius (1999). COLLECT. Nonius BV, Delft, The Netherlands.
Ohta, S. & Kimoto, S. (1976). Chem. Pharm. Bull. 24, 2977–2984.
Prager, R. & Thredgold, M. (1968). Aust. J. Chem. 21, 229–241.
¨
Sheldrick, G. M. (2003). SADABS. Version 2.10. University of Gottingen,
Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
ꢂ
´
o592 Cuenu et al. C14H12N2O
Acta Cryst. (2010). C66, o589–o592