organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
carboxyl group on atom C2 in an equatorial position and that
on atom C3 in an axial position, resulting in the four carboxyl
groups being in a mutually cis conformation, which is similar
to that of tetramethyl cis,cis,cis-1,2,4,5-cyclohexanetetracar-
boxylate, (V) (Robinson et al., 2000). Among the endocyclic
angles, the C3ÐC4ÐC3i angle [114.19 (18)ꢀ] of (I) (Table 1)
and the corresponding angle [114.6 (3)ꢀ] of (V) are the largest
as a result of the 1,3-diaxial repulsion, and the angles at atoms
with axial substituents in both structures [110.67 (14)ꢀ in (I),
and 108.9 (3) and 110.7 (3)ꢀ in (V)] are smaller [symmetry
code: (i) x, y, 12 z]. The two carbonyl groups of the carboxyl
groups in (I) are synperiplanar with respect to an endocyclic
bond [O1ÐC5ÐC2ÐC1 = 8.5 (2)ꢀ and O3ÐC6ÐC3Ð
C2 = 3.0 (2)ꢀ], and all four carbonyl groups in (V) are also
synperiplanar, with larger deviations from an eclipsed position
[the corresponding torsion angles are 13.0 (6) and 21.4 (5)ꢀ
ISSN 0108-2701
cis,cis,cis-1,2,4,5-Cyclohexanetetra-
carboxylic acid and its dianhydride
Akira Uchida,a* Masatoshi Hasegawab and Hiroshi
Manamic
aDepartment of Biomolecular Science, Faculty of Science, Toho University, Miyama
2-2-1, Funabashi, Chiba 274-8510, Japan, bDepartment of Chemistry, Faculty of
Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan, and
cResearch and Development Division, New Japan Chemical Company Ltd, 13
Yoshijima Yaguracho, Fushimi-ku, Kyoto 612-8224, Japan
for the equatorial carboxyl groups, and
25.6 (5)ꢀ for the axial groups].
19.8 (5) and
Correspondence e-mail: auchida@biomol.sci.toho-u.ac.jp
Received 1 May 2003
Accepted 16 June 2003
Online 12 July 2003
cis,cis,cis-1,2,4,5-Cyclohexanetetracarboxylic acid, C10H12O8,
(I), contains a mirror plane and the cyclohexane ring exhibits a
chair conformation. Two crystallographically independent
hydrogen bonds form R22(14), R22(16) and R44(16) ring motifs,
and propagation of these two hydrogen bonds along the c and
b axes generates C22(16) and C22(7) chains. cis,cis,cis-1,2:4,5-
Cyclohexanetetracarboxylic dianhydride, C10H8O6, (II), was
prepared by the reaction of (I) with acetic anhydride. The
cyclohexane ring of (II) exhibits a boat conformation and the
dihedral angle between the two anhydro rings is 117.5 (1)ꢀ.
Comment
Over the past 15 years, considerable efforts have been made to
obtain polyimide ®lms possessing low linear thermal-expan-
sion coef®cients (CTEs) with the aim of reducing thermal
stress (Numata et al., 1986, 1987). Recently, polyimides with
low dielectric constants (") have also been in demand in order
to increase the signal-propagation rate in chips (Matsuura et
al., 1991; Sachdev et al., 1999). We have attempted to develop
polyimides with both low CTE and low " values. According
to the structure±property relationship, promising target
materials include polyimides with stiff linear-chain structures
for low CTEs and with low polarizability for low " values
(Hasegawa, 2001). We have highlighted the combination of
cycloaliphatic 1,2:4,5-cyclohexanetetracarboxylic anhydride,
(II), and rod-like 2,20-bis(tri¯uromethyl)benzidine, (III). The
polyimide ®lm (IV) resulted in low " values, as expected, but
did not show low CTE values (Hasegawa et al., 2001). The
present X-ray investigation was undertaken to obtain struc-
tural information about (II) and its intermediate, 1,2,4,5-
cyclohexanetetracarboxylic acid, (I).
Two crystallographically independent hydrogen bonds
(Table 2 and Fig. 2), viz. O2ÐH2Á Á ÁO3 and O4ÐH4Á Á ÁO1,
form R22(14) rings about an inversion center, R22(16) rings
along a 21 screw axis and R44(16) rigns about a twofold axis
(Etter, 1990; Bernstein et al., 1995). Propagation of these two
hydrogen bonds along the c and b axes generates two chain
motifs, viz. C22(16) and C22(7), resulting in a two-dimensional
network perpendicular to the a axis.
In (II) (Fig. 3 and Table 3), the molecule possesses
approximate C2v symmetry. The displacement ellipsoids of
atoms O3 and O4 are appreciably larger than those of the
other atoms, which may be due to hydrolysis of the anhydro
rings, and the hydrogen bonds associated with atoms O3 and
O4 may promote the reaction (Table 4 and Fig. 4). Crystals
kept at ambient temperature showed degradation of crystal-
linity after a few months.
In (I), atoms C1 and C4 lie on a mirror plane (Fig. 1). The
cyclohexane ring assumes a chair conformation, with the
Acta Cryst. (2003). C59, o435±o438
DOI: 10.1107/S0108270103013362
# 2003 International Union of Crystallography o435
Uchida, Akira
