Two polymorphs of N 1,N 4-bis-(5-hy-droxy-penta-1,3- diyn-yl)-N 1,N 4-di-phenyl-benzene-1,4-diamine

Article abstract of DOI:10.1107/S0108270111045951

The title compound, C₂₈H₂₀N₂O₂, forms two conformational polymorphs, (I) and (II), where the mol-ecular structures are similar except for the orientation of the two hy-droxy groups. In (I), which was obtained by

Full text of DOI:10.1107/S0108270111045951

organic compounds
Acta Crystallographica Section C
Crystal Structure
In (I), the structures around the N atoms, viz. the N1/C1/C7/
˚
C19 (r.m.s. deviation = 0.010 A) and N2/C4/C13/C24 planes
Communications
˚
r.m.s. deviation = 0.003 A), are planar. The dihedral angles
(
between the plane of the C1–C6 ring and the N1/C1/C7/C19
ISSN 0108-2701
ꢀ
and N2/C4/C13/C24 planes are 49.15 (8) and 31.92 (8) ,
ꢁ
3
˚
respectively. A large residual density of 0.65 e A is located
near atom C28, which has rather elongated displacement
ellipsoids. This is presumably due to thermal motion of the
hydroxymethyl group.
1
4
Two polymorphs of N ,N -bis(5-
hydroxypenta-1,3-diynyl)-N ,N -di-
phenylbenzene-1,4-diamine
1
4
Hideyuki Tabata, Natsuki Kubo and Tsunehisa Okuno*
Department of Material Science and Chemistry, Wakayama University, Sakaedani,
Wakayama, 640-8510, Japan
Correspondence e-mail: okuno@center.wakayama-u.ac.jp
Received 13 September 2011
Accepted 1 November 2011
Online 5 November 2011
In (II), the structures around the N atoms, viz. the
˚
N1/C1/C7/C19 (r.m.s. deviation = 0.045 A) and N2/C4/C13/
The title compound, C H N O , forms two conformational
20
28
2
2
polymorphs, (I) and (II), where the molecular structures are
similar except for the orientation of the two hydroxy groups.
In (I), which was obtained by slow evaporation from
chloroform, the two hydroxy groups have an anti conforma-
tion. The molecules form a sheet structure within the ac plane,
where the hydroxy groups form zigzag hydrogen bonds. In
(II), which was obtained by slow evaporation from acetoni-
trile, the two hydroxy groups have a syn conformation. The
molecules form a double-sheet structure within the ab plane,
where the hydroxy groups form 4-helix hydrogen bonds.
Comment
Benzene-1,4-diamines show electron-donating ability and are
able to act as ꢀ-conjugated linkers. Acetylene derivatives
which have amino groups as substituents are named ynamines,
and they are known to be unstable because of their high
reactivity. In the course of our research into ynamine
compounds (Okuno et al., 2006), we succeeded in the
preparation and characterization of the title compound, which
0
incorporates an N,N -diethynylbenzene-1,4-diamine skeleton.
The molecule is a key unit in the formation of two-leg ladder
polydiacetylenes by solid-state polymerization. We also found
conformational polymorphism (Bernstein, 2002) dependant
on the recrystallization solvent of the title compound, shown
in the orientation of the hydroxy groups. Either crystal could
be obtained independently, as judged by powder X-ray
diffraction. In order to clarify the difference in the hydrogen-
bonding patterns and crystal packings caused by the different
hydroxy-group orientations, the crystal structures of the two
polymorphs, (I) and (II), were determined.
Displacement ellipsoid plots of the two polymorphs are
shown in Fig. 1. The bond lengths and angles of both poly-
morphs are almost similar (Tables 1 and 3). These structural
geometries are consistent with those of the reported ynamines
(Galli et al., 1988, 1989; Mayerle & Flandera, 1978; Okuno et
al., 2006).
Figure 1
The asymmetric units of (a) polymorph (I) and (b) polymorph (II) of the
title compound, showing the atom-numbering schemes. Displacement
ellipsoids are drawn at the 50% probability level. The disordered H atoms
in polymorph (I) are identified by suffixes A and B.
o492 # 2011 International Union of Crystallography
doi:10.1107/S0108270111045951
Acta Cryst. (2011). C67, o492–o495

organic compounds
Figure 2
Views of (a) polymorph (I) and (b) polymorph (II), projected along the
N1ꢂ ꢂ ꢂN2 direction, with the benzene rings horizontal.
˚
C24 planes (r.m.s. deviation = 0.007 A), are planar. The
Figure 4
Schematic presentations of (a) the zigzag hydrogen-bonding network of
I) and (b) the 4-helix hydrogen-bonding network of (II). The hydrogen
dihedral angles between the C1–C6 ring and the N1/C1/C7/
ꢀ
(
C19 and N2/C4/C13/C24 planes are 57.36 (8) and 46.98 (8) ,
respectively.
bonds involving the disordered H atoms of (I) are identified by black and
3
grey lines. [Symmetry codes: (i) ꢁx + 1, ꢁy + 1, ꢁz + 1; (ii) x ꢁ 1, ꢁy + ,
2
1
1
2
1
2
z + ; (iii) ꢁx + 1, y ꢁ , ꢁz + ; (iv) x ꢁ 1, y, z; (v) x + 1, y + 1, z; (vi) ꢁx + 3,
In both polymorphs, intramolecular conjugation between
the two diacetylene units, i.e. overlap of p- or ꢀ-orbitals, is
2
1
1
2
3
2
1
2
y + , ꢁz + ; (vii) ꢁx + 2, y + , ꢁz + ; (viii) x, y + 1, z.]
2
2
estimated by the value of cos ꢁ, where ꢁ is the torsion angle
2
between the two orbitals. Even in the case of the smallest cos ꢁ
the hydrogen bonds connect two sheets above and below
Fig. 3) to give zigzag intermolecular hydrogen bonds. The H
ꢀ
with ꢁ = 57.36 in (II), the value is 0.29, suggesting the two
diacetylene units are conjugated effectively.
(
atoms of both hydroxy groups are disordered and there are
four types of O—Hꢂ ꢂ ꢂO hydrogen bonds (Table 2). Therefore,
two kinds of zigzag intermolecular hydrogen bonds are
observed, which are distinguished by black and grey lines in
We now discuss the differences between the molecular
structures in the two polymorphs. A significant difference
between the structures of (I) and (II) is the orientation of the
hydroxy groups to the C23/N1/N2/C28 planes. The hydroxy
groups in (I) have an anti conformation, while those in (II)
have a syn conformation (Fig. 2), affording different types of
intermolecular hydrogen bonds and different molecular
ipn at ce kr ai nc gt i os tnr su. ctures. There are no significant ꢀ–ꢀ or C—Hꢂ ꢂ ꢂꢀ
Fig. 4. When the structure of (I) was solved in the P2 /c space
1
group without disorder, the distances between the O-bound H
atoms became too close, because the hydrogen-bonded pair of
molecules are related by inversion symmetry. The remaining
peaks around the O atoms were also high, indicating the
existence of disorder. The possibility of solving the structure in
The molecules in (I) and (II) form similar sheet structures,
which are parallel to the ac and ab planes, respectively. In (I),
the space group P2 was examined carefully, but the disorder
1
Figure 3
A view of the hydrogen-bonding interactions in (I) (dashed lines).
Figure 5
A view of the hydrogen-bonding interactions in (II) (dashed lines).
3
1
1
1
[
Symmetry codes: (i) ꢁx + 1, ꢁy + 1, ꢁz + 1; (ii) x ꢁ 1, ꢁy + , z + ; (iii)
[Symmetry codes: (i) x + 1, y + 1, z; (ii) ꢁx + 3, y + , ꢁz + ; (iii) ꢁx + 2,
2
2
2
2
1
1
3
2
1
2
ꢁ
x + 1, y ꢁ , ꢁz + ; (iv) x ꢁ 1, y, z.]
y + , ꢁz + ; (iv) x, y + 1, z.]
2
2
ꢃ
Acta Cryst. (2011). C67, o492–o495
Tabata et al.
Two polymorphs of C28H N
20 2
O
2
o493

organic compounds
was still present, as indicated by large peaks around the O
atoms.
In (II), intermolecular hydrogen bonds are limited within
two sheets (Table 4), giving double-sheet structures (Fig. 5).
The hydrogen-bonding pattern was classified as a 4-helix
Refinement
2
2
R[F > 2ꢅ(F )] = 0.051
wR(F ) = 0.133
S = 1.06
H atoms treated by a mixture of
independent and constrained
refinement
2
˚
ꢁ3
Áꢆmax = 0.65 e A
4
842 reflections
358 parameters
1 restraints
Áꢆmin = ꢁ0.53 e A˚ ꢁ
3
8
(Fig. 4) (Taylor & Macrae, 2001).
In spite of the difference in sheet packing, (I) and (II) have
almost the same unit-cell volume and calculated densities of
1
Polymorph (II)
ꢁ
3
.304 and 1.309 Mg m , respectively.
Crystal data
˚
V = 2113.0 (9) A
3
C
28
H N
20 2
O
2
Experimental
M
r
= 416.46
Z = 4
Mo Kꢃ radiation
ꢄ = 0.08 mm
T = 100 K
Monoclinic, P2 =c
˚
a = 15.530 (4) A
b = 8.831 (2) A
c = 17.108 (4) A˚
1
The title compound was prepared according to the method of Tabata
et al. (2012). A suspension of copper(I) chloride (0.81 g, 7.8 mmol) in
acetone (15 ml) was degassed by argon bubbling for 30 min, and then
tetramethylethylenediamine (TMEDA; 400 ml, 2.6 mmol) was added
and the suspension stirred for 30 min. The supernatant solution
containing the CuCl–TMEDA catalyst was transferred to a mix-
ꢁ1
˚
0.22 ꢄ 0.18 ꢄ 0.05 mm
ꢀ
ꢂ = 115.766 (3)
Data collection
1
4
1
4
ture of N ,N -diethynyl-N ,N -diphenylbenzene-1,4-diamine (1.00 g,
Bruker APEXII CCD area-detector
diffractometer
Absorption correction: empirical
11897 measured reflections
4826 independent reflections
3150 reflections with F > 2ꢅ(F )
3
.24 mmol) and 2-propyn-1-ol (2.7 ml, 45 mmol) in acetone (63 ml) at
53 K. The solution was stirred for 2 d under an oxygen atmosphere.
2
2
2
(
using intensity measurements)
Rint = 0.046
The solvent was evaporated and the residue extracted with
dichloromethane (200 ml). The solution was washed with 5%
ammonium hydroxide (300 ml) and the water layer was extracted
twice with dichloromethane (200 ml). The combined organic layer
was washed with water (300 ml) and dried over anhydrous sodium
sulfate. After the solvent had evaporated, the residue was purified by
gel permeation chromatography to give the title compound as a white
powder (yield 0.68 g, yield 50%). Slow evaporation from solutions in
chloroform or acetonitrile gave polymorphs (I) and (II), respectively.
(
T
SADABS; Sheldrick, 1996)
min = 0.982, Tmax = 0.996
Refinement
2
R[F > 2ꢅ(F )] = 0.048
wR(F ) = 0.111
S = 1.05
826 reflections
66 parameters
2
H atoms treated by a mixture of
independent and constrained
refinement
2
˚
ꢁ3
Áꢆmax = 0.24 e A
4
3
Áꢆmin = ꢁ0.24 e A˚
ꢁ3
In polymorph (I), the C-bound H atoms, except for those on atoms
C23 and C28, were obtained from a difference Fourier map and
refined isotropically. The H atoms on C23 and C28 were placed in
Polymorph (I)
Crystal data
˚
idealized locations (C—H = 0.99 A) and were refined as riding on
their parent C atoms, with Uiso(H) = 1.2Ueq(C). The O-bound H
˚
V = 2121.9 (7) A
3
C
M
28
H
20
N
2
O
2
r
= 416.46
Z = 4
Mo Kꢃ radiation
Monoclinic, P2 =c
1
˚
ꢁ1
a = 9.0669 (18) A
ꢄ = 0.08 mm
T = 100 K
˚
b = 7.7778 (16) A
˚
c = 30.135 (6) A
Table 2
0.49 ꢄ 0.16 ꢄ 0.05 mm
˚
ꢀ
Hydrogen-bond geometry (A, ) for polymorph (I).
ꢀ
ꢂ = 93.148 (2)
D—Hꢂ ꢂ ꢂA
D—H
Hꢂ ꢂ ꢂA
Dꢂ ꢂ ꢂA
D—Hꢂ ꢂ ꢂA
Data collection
i
Bruker APEXII CCD area-detector
diffractometer
Absorption correction: empirical
11823 measured reflections
4842 independent reflections
3703 reflections with I > 2ꢅ(I)
O1—H1Aꢂ ꢂ ꢂO1
0.82 (1)
0.82 (3)
0.82 (2)
0.82 (2)
1.97 (2)
1.94 (3)
1.94 (2)
1.94 (2)
2.771 (3)
2.753 (3)
2.753 (3)
2.756 (3)
169 (1)
173 (5)
173 (2)
173 (2)
ii
O1—H1Bꢂ ꢂ ꢂO2
iii
O2—H2Aꢂ ꢂ ꢂO1
iv
O2—H2Bꢂ ꢂ ꢂO2
(using intensity measurements)
Rint = 0.030
(
T
SADABS; Sheldrick, 1996)
min = 0.961, Tmax = 0.996
1
2
1
2
Symmetry codes: (i) ꢁx þ 1; ꢁy þ 1; ꢁz þ 1; (ii) ꢁx þ 2; y ꢁ ; ꢁz þ ; (iii) ꢁx þ 2,
1
1
y þ ; ꢁz þ ; (iv) ꢁx þ 2; ꢁy þ 2; ꢁz.
2
2
Table 1
Selected geometric parameters (A, ) for polymorph (I).
Table 3
Selected geometric parameters (A, ) for polymorph (II).
˚
ꢀ
˚
ꢀ
N1—C19
C19—C20
C20—C21
C21—C22
C22—C23
1.341 (2)
1.200 (2)
1.373 (2)
1.200 (2)
1.466 (2)
N2—C24
C24—C25
C25—C26
C26—C27
C27—C28
1.346 (2)
1.199 (2)
1.375 (2)
1.195 (3)
1.465 (3)
N1—C19
C19—C20
C20—C21
C21—C22
C22—C23
1.348 (3)
1.198 (3)
1.377 (3)
1.194 (3)
1.463 (3)
N2—C24
C24—C25
C25—C26
C26—C27
C27—C28
1.346 (3)
1.195 (3)
1.375 (3)
1.199 (3)
1.462 (3)
N1—C19—C20
C19—C20—C21
C22—C21—C20
C21—C22—C23
179.4 (2)
177.1 (2)
179.7 (2)
170.6 (2)
N2—C24—C25
C24—C25—C26
C27—C26—C25
C26—C27—C28
178.16 (18)
175.7 (2)
178.5 (2)
178.0 (2)
N1—C19—C20
C19—C20—C21
C20—C21—C22
C21—C22—C23
176.1 (2)
179.0 (2)
179.1 (2)
178.83 (17)
N2—C24—C25
C24—C25—C26
C25—C26—C27
C26—C27—C28
177.9 (2)
177.73 (18)
178.6 (3)
179.63 (19)
ꢃ
o494 Tabata et al.
Two polymorphs of C28
20
H N
O
2 2
Acta Cryst. (2011). C67, o492–o495

organic compounds
Table 4
Hydrogen-bond geometry (A, ) for polymorph (II).
program(s) used to solve structure: SHELXS97 (Sheldrick, 2008);
program(s) used to refine structure: SHELXL97 (Sheldrick, 2008);
molecular graphics: ORTEP-3 (Farrugia, 1997); software used to
prepare material for publication: enCIFer (Allen et al., 2004).
˚
ꢀ
D—Hꢂ ꢂ ꢂA
D—H
Hꢂ ꢂ ꢂA
Dꢂ ꢂ ꢂA
D—Hꢂ ꢂ ꢂA
i
O1—H1ꢂ ꢂ ꢂO2
0.90 (3)
0.92 (3)
1.93 (3)
1.86 (3)
2.821 (2)
2.777 (2)
168 (3)
172 (3)
ii
O2—H2ꢂ ꢂ ꢂO1
This work was supported by Research for Promoting
Technological Seeds from the Japan Science and Technology
Agency (JST). The authors thank Dr Yoza of Bruker AXS for
helpful discussions.
1
2
1
2
Symmetry codes: (i) x þ 1; y þ 1; z; (ii) ꢁx þ 2; y ꢁ ; ꢁz þ .
atoms were obtained from a difference Fourier map and found to be
disordered. The occupancies of these H atoms were fixed at 0.5. The
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: UK3036). Services for accessing these data are
described at the back of the journal.
O-bound H-atom positions were refined with the restraint O—H =
˚
0.84 (2) A (DFIX instruction in SHELXL97; Sheldrick, 2008), with
Uiso(H) = 1.2Ueq(O1 and O2). Similar U restraints (SIMU instruction
in SHELXL97) and approximately isotropic restraints (ISOR
instruction in SHELXL97) were applied to atoms C22, C23, C27,
References
˚
2
C28, O1 and O2, with an effective s.u. of 0.005 A . Restraints (SADI
instruction in SHELXL97) were applied to the Cꢂ ꢂ ꢂH distances
C23ꢂ ꢂ ꢂH1A/H1B and C28ꢂ ꢂ ꢂH2A/H2B, the O—H bond lengths O1—
H1A/H1B and O2—H2A/H2B, and the C—O bond lengths C23—O1
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Appl. Cryst. 37, 335–338.
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Oxford University Press Inc.
˚
and C28—O2, with an effective s.u. of 0.004 A. A planarity restraint
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1923.
Galli, R., Neuenschwander, M. & Engel, P. (1989). Helv. Chim. Acta, 72, 1324–
(
FLAT instruction in SHELXL97) was applied to the groups C23/O1/
i
H1A/O1 [symmetry code: (i) ꢁx + 1, ꢁy + 1, ꢁz + 1], C23/O1/H1B/
ii
1
2
1
2
iii
iv
O2 [symmetry code: (ii) ꢁx + 2, y ꢁ , ꢁz + ], C28/O2/H2A/O1
1
1
[
symmetry code: (iii) ꢁx + 2, y + , ꢁz + ] and C28/O2/H2B/O2
2
2
1336.
[symmetry code: (iv) ꢁx + 2, ꢁy + 2, ꢁz].
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In the press.
Taylor, R. & Macrae, C. F. (2001). Acta Cryst. B57, 815–827.
In polymorph (II), the H atoms were obtained from a difference
Fourier map. All H atoms, except H4, H6 and H14, were refined
isotropically. The positions of H4, H6 and H14 were refined, although
their Uiso(H) values were fixed at 1.2Ueq(C).
For both compounds, data collection: APEX2 (Bruker, 2010); cell
refinement: APEX2; data reduction: SAINT (Bruker, 2004);
ꢃ
Acta Cryst. (2011). C67, o492–o495
Tabata et al.
Two polymorphs of C28H N
20 2
O
2
o495