Supramolecular patterns in benzyladeninium p-toluenesulfonate

Article abstract of DOI:10.1107/S0108270111013424

In the title compound (systematic name: 6-benzylamino-7H-purin-3-ium p-toluene-sulfonate), C₁₂H₁₂N₅ ⁺·C₇H₇O₃S^-, the adenine moiety exists as the N ³-protonated N ⁷ - H tautomer. The dihedral angle between the adenine ring system and the phenyl ring is 82.76 (11)°. Two of the sulfonate O atoms form C - H...O and N - H...O hydrogen bonds with the H atoms on the N and C atoms in the 3- and 8-positions, respectively, of the adenine moiety, leading to a zigzag chain. Two anti-parallel zigzag chains are linked by the remaining sulfonate O atom through Hoogsteen-site H atoms (i.e. those on the N atoms in the 6- and 7-positions) of the adenine moiety, leading to a double chain. An annulus formed by a pair of inversion-related anions and cations has been identified. An intra-molecular toluene-sulfonate-phenyl C - H...π inter-action is also present.

Full text of DOI:10.1107/S0108270111013424

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
al., 2001; Nirmalram et al., 2011; Balasubramanian et al., 1996),
in contrast to adenine systems where the N9—H tautomer
´
´
predominates and the protonation site is N1 (Slosarek et al.,
ISSN 0108-2701
2006). The N3 protonation of the base is confirmed from the
C2—N3—C4 bond angle of 116.9 (2)ꢂ, which is wider than the
value of 110.7 (2)ꢂ in neutral BA (Raghunathan et al., 1983).
The dihedral angle between the benzyl substituent and the
adenine ring system is 82.76 (11)ꢂ. The free N1 position, the
dihedral angle of ca 80ꢂ and the distal orientation of the N6
substituent with respect to N7 are important requisites for
cytokinin activity, and these features also occur in the title
crystal structure.
Supramolecular patterns in benzyl-
adeninium p-toluenesulfonate
Duraisamy Tamilselvi and P. Thomas Muthiah*
School of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamil
Nadu, India
Correspondence e-mail: tommtrichy@yahoo.co.in
Received 17 March 2011
Accepted 10 April 2011
Online 20 April 2011
In the title compound (systematic name: 6-benzylamino-7H-
+
purin-3-ium p-toluenesulfonate), C12H12N5 ꢀC7H7O3Sꢁ, the
adenine moiety exists as the N3-protonated N7—H tautomer.
The dihedral angle between the adenine ring system and the
phenyl ring is 82.76 (11)ꢂ. Two of the sulfonate O atoms form
C—Hꢀ ꢀ ꢀO and N—Hꢀ ꢀ ꢀO hydrogen bonds with the H atoms
on the N and C atoms in the 3- and 8-positions, respectively, of
the adenine moiety, leading to a zigzag chain. Two antiparallel
zigzag chains are linked by the remaining sulfonate O atom
through Hoogsteen-site H atoms (i.e. those on the N atoms in
the 6- and 7-positions) of the adenine moiety, leading to a
double chain. An annulus formed by a pair of inversion-
related anions and cations has been identified. An intra-
molecular toluenesulfonate–phenyl C—Hꢀ ꢀ ꢀꢀ interaction is
also present.
The crystal structure of (I) comprises a three-dimensional
network of N—Hꢀ ꢀ ꢀO, C—Hꢀ ꢀ ꢀO, C—Hꢀ ꢀ ꢀꢀ and ꢀ–ꢀ inter-
actions which gives rise to the following supramolecular
patterns. In the toluenesulfonate anion, all sulfonate O atoms
act as hydrogen-bond acceptors: one (O3) forms an N—Hꢀ ꢀ ꢀO
hydrogen bond with the protonated N3 hydrogen of a BAH+
cation; O2 forms a C—Hꢀ ꢀ ꢀO hydrogen bond with the acidic
C8 hydrogen of adjacent BAH+, leading to a zigzag supra-
molecular chain of graph-set notation C22(9) (Fig. 2). This
chain is crosslinked with an antiparallel chain: the remaining
sulfonate O atom (O1) forms N—Hꢀ ꢀ ꢀO hydrogen bonds to
the Hoogsteen-site H atoms of adenine (N6—H and N7—H),
forming a double chain (Fig. 3) and an R12(7) motif. This motif
has been recently identified in cobalt complexes of the N6-
furfuryladenine cation and N6-benzyladenine cation (Tamil-
selvi & Muthiah, 2010).
Comment
N6-Substituted aminopurine compounds such as N6-furfur-
yladenine (FA), N6-benzyladenine (BA) and trans-zeatin are
plant hormones classified under the name cytokinins. They are
responsible for proliferation, growth regulation, antioxidance,
mutation, enzyme inhibition, etc., in plant cells (Francis &
Sorrell, 2001). The cyclin-dependent kinases (CDK) are
important functional enzymes controlled by cytokinins during
apoptosis, neuronal stimulations and transcription. These
kinases are influenced particularly by 2,9-disubstituted cyto-
Because of the interplay of double chains, two inversion-
related BAH+ cations and two inversion-related sulfonate
anions, a supramolecular annulus (Fig. 4) is formed. In this
´
´ˇ
kinins (Travnıcek & Krystof, 2004). BA enhances the apical
dominance, flowering and sometimes causes heterogeneity
ˇ
´
´ˇ
and inhibition of rooting and growth (Travnıcek et al., 2004).
BA derivatives are used in neurological, antitumour and
parasitic treatments (Bressi et al., 2000; Haung et al., 2007).
Some of the bimetallic BA compounds mimic superoxide
´
dismutase (SOD) and have antidiabetic activity (Dvorak et al.,
2010).
The asymmetric unit of the title compound, (I), consists of
one benzyladeninium cation (BAH+) and one toluene-
sulfonate anion (Fig. 1 and Table 1). BAH+ exists as the N3-
protonated N7—H tautomer, as reported earlier (Umadevi et
Figure 1
A view of the components of (I), with displacement ellipsoids drawn at
the 50% probability level.
o192 # 2011 International Union of Crystallography
doi:10.1107/S0108270111013424
Acta Cryst. (2011). C67, o192–o194

organic compounds
Figure 4
A view of one annulus showing the antiparallel stacking of purine
moieties. H atoms not involved in hydrogen bonding have been omitted
for clarity.
˚
is 3.330 (3) A. These values are well within the range reported
earlier (Garcia-Teran et al., 2004; Verma et al., 2010). Two
annuli are connected by an R44(14) motif. An edge-to-face
(C—Hꢀ ꢀ ꢀꢀ) interaction is observed between the C18—H18
group of toluenesulfonate and the C11–C16 phenyl ring
+
˚
(centroid Cg) of BAH , with a H18ꢀ ꢀ ꢀCg distance of 2.86 A
and a C18—H18ꢀ ꢀ ꢀCg angle of 162ꢂ (Wang et al., 2007). The
double chains are linked by a ꢀ–ꢀ stacking interaction
between the toluenesulfonate and pyrimidine rings, with a
˚
centroid–centroid distance of 3.6127 (15) A (Verma et al.,
2010).
Experimental
N6-Benzyladenine (56.3 mg, 0.25 mmol) was dissolved in methanol
(20 ml). p-Toluenesulfonic acid (47.4 mg, 0.25 mmol) was dissolved in
ethanol (20 ml). The solutions were mixed and heated for 30 min over
a water bath. Colourless needle-shaped crystals of (I) appeared after
a few days of evaporation at room temperature.
Figure 2
A view of the structure of (I), showing the double chains formed by two
C22(9) chains. H atoms not involved in hydrogen bonding have been
omitted for clarity.
Crystal data
C12H12N5 ꢀC7H7O3Sꢁ
+
ꢃ = 116.562 (6)ꢂ
3
˚
Mr = 397.46
Triclinic, P1
a = 9.5741 (10) A
V = 941.87 (18) A
Z = 2
˚
Mo Kꢁ radiation
ꢄ = 0.20 mmꢁ1
T = 296 K
0.12 ꢃ 0.10 ꢃ 0.08 mm
˚
b = 9.9089 (11) A
˚
c = 11.3324 (12) A
ꢁ = 99.957 (6)ꢂ
ꢂ = 90.886 (7)ꢂ
Data collection
Bruker SMART APEXII CCD
area-detector diffractometer
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
17454 measured reflections
6129 independent reflections
3345 reflections with I > 2ꢅ(I)
Rint = 0.063
Tmin = 0.976, Tmax = 0.984
Refinement
R[F2 > 2ꢅ(F2)] = 0.058
wR(F2) = 0.210
S = 0.97
254 parameters
H-atom parameteꢁrs3 constrained
Figure 3
A view of a double chain illustrating the R44(14) motif and C—Hꢀ ꢀ ꢀꢀ
interactions. H atoms not involved in hydrogen bonding have been
omitted for clarity.
˚
Áꢆmax = 0.65 e A
ꢁ3
˚
6129 reflections
Áꢆmin = ꢁ0.65 e A
Methyl H atoms were located in a difference Fourier synthesis and
subsequently idealized and refined as a rigid rotating group, with
˚
C—H = 0.96 A and Uiso(H) = 1.5Ueq(C). Other C-bonded H atoms
were placed in idealized positions and constrained to ride on their
˚
parent atoms, with C—H = 0.93 (aromatic) or 0.97 A (methylene),
and with Uiso(H) = 1.2Ueq(C). All N-bonded H atoms were placed in
˚
idealized positions and constrained to ride 0.86 A from their parent
atoms, with Uiso(H) = 1.2Ueq(N).
annulus, the inversion-related purine rings (N1, C2, N3, C4,
C5, C6, N7, C8 and N9) and [N1i–N9i; symmetry code: (i)
ꢁx + 1, ꢁy, ꢁz + 1] adopt an antiparallel stacking arrange-
ment through face-to-face (ꢀ–ꢀ) interaction with a corre-
sponding centroid–centroid distance of 3.377 (3) A (the
centroid is defined with respect to the nine-atom purine
system); the interplanar distance between stacked purine rings
˚
Tamilselvi and Muthiah C12H12N5 ꢀC7H7O3Sꢁ o193
+
ꢄ
Acta Cryst. (2011). C67, o192–o194

organic compounds
Table 1
Selected geometric parameters (A, ).
Table 2
Hydrogen-bond geometry (A, ).
ꢂ
ꢂ
˚
˚
S1—O1
S1—O2
S1—O3
N1—C2
N3—C2
1.4636 (18)
1.435 (2)
1.4500 (19)
1.304 (3)
1.340 (4)
N6—C10
N6—C6
N7—C8
N7—C5
1.459 (3)
1.324 (3)
1.349 (3)
1.372 (3)
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
N3—H3ꢀ ꢀ ꢀO3i
N6—H6ꢀ ꢀ ꢀO1
N7—H7ꢀ ꢀ ꢀO1
C8—H8ꢀ ꢀ ꢀO2ii
0.86
0.86
0.86
0.93
1.95
2.12
1.99
2.31
2.712 (3)
2.959 (3)
2.770 (2)
3.225 (4)
147
165
150
168
O1—S1—C17
O1—S1—O2
O1—S1—O3
C2—N1—C6
105.96 (10)
111.84 (11)
111.22 (12)
119.3 (2)
C6—N6—C10
C5—N7—C8
C4—N9—C8
123.38 (19)
106.15 (19)
103.0 (2)
Symmetry codes: (i) ꢁx þ 1; ꢁy; ꢁz þ 1; (ii) ꢁx þ 2; ꢁy þ 1; ꢁz þ 1.
Bruker (2008). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison,
Wisconsin, USA.
ˇ
Dvorak, Z., Vrzal, R., Starha, P., Klanicova, A. & Travnıcek, Z. (2010).
´
Toxicol. In Vitro, 24, 425–429.
´
´
´
Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT
(Bruker, 2008); data reduction: SAINT; program(s) used to solve
structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine
structure: SHELXL97 (Sheldrick, 2008); molecular graphics:
PLATON (Spek, 2009); software used to prepare material for
publication: PLATON and Mercury (Macrae et al., 2008).
Francis, D. & Sorrell, D. A. (2001). Plant Growth Regul. 33, 1–12.
Garcia-Teran, J. P., Castillo, O., Luque, A., Garcia-Couceiro, U., Roman, P. &
Lloret, F. (2004). Inorg. Chem. 43, 5761–5770.
Haung, N. K., Chern, Y., Fang, J. M., Lin, C. I., Chen, W. P. & Lin, Y. L. (2007).
J. Nat. Prod. 70, 571–574.
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P.,
Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood,
P. A. (2008). J. Appl. Cryst. 41, 466–470.
Nirmalram, J. S., Tamilselvi, D. & Muthiah, P. T. (2011). J. Chem. Crystallogr.
doi:101007-?/s10870-011-0014-x.
The authors thank the DST–India (FIST programme) for
the use of the Bruker SMART APEXII diffractometer at the
School of Chemistry, Bharathidasan University, Tiruchir-
appalli, Tamilnadu, India.
Raghunathan, S., Sinha, B. K., Pattabhi, V. & Gabe, E. J. (1983). Acta Cryst.
C39, 1545–1547.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
´
´
Slosarek, G., Kozak, M., Gierszewski, J. & Pietraszko, A. (2006). Acta Cryst.
B62, 102–108.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: BM3103). Services for accessing these data are
described at the back of the journal.
Tamilselvi, D. & Muthiah, P. T. (2010). International Symposium on Frontiers
in Inorganic Chemistry (FIC-2010), December 11–13, IACS, Kolkata, India.
´
´ˇ
ˇ
Travnıcek, Z. & Krystof, V. (2004). Acta Cryst. E60, o2324–o2327.
´
´ˇ
ˇ
Travnıcek, Z., Popa, I. & Dolezal, K. (2004). Acta Cryst. C60, o662–o664.
Umadevi, B., Stanley, N., Muthiah, P. T., Bocelli, G. & Cantoni, A. (2001). Acta
Cryst. E57, o881–o883.
References
Balasubramanian, T., Muthiah, P. T., Saravanan, A. & Mazumdar, S. K. (1996).
J. Inorg. Biochem. 63, 175–181.
Bressi, J. C., Choe, J., Hough, M. T., Buckner, F. S., Voorhis, W. C. V., Verlinde,
C. L. M. J., Hol, W. G. J. & Gelb, M. H. (2000). J. Med. Chem. 43, 4135–4150.
Verma, S., Misra, A. K. & Kumar, J. (2010). Acc. Chem. Res. 43, 79–91.
Wang, W. H., Xi, P. H., Su, X. Y., Lan, J. B., Mao, Z. H., You, J. S. & Xie, R. G.
(2007). Cryst. Growth Des. 7, 741–746.
C12H12N5 ꢀC7H7O3Sꢁ
Acta Cryst. (2011). C67, o192–o194
+
ꢄ
o194 Tamilselvi and Muthiah