Table 2 Angles between triazine/phenyl ring and two phenyl rings in the
inclusion structures of 8 with p-xylene and mesitylene
to the Swiss National Science Foundation (R’Equip project
206021_128724).
Angles
8$p-xylene 8$mesitylene
Notes and references
T–P1a
T–P1b
T–P1c
P1a–P2a
P1b–P2b
P1c–P2c
3.49ꢀ
4.05ꢀ
20.04ꢀ
38.85ꢀ
33.35ꢀ
35.90ꢀ
5.46ꢀ
4.12ꢀ
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33.30ꢀ
43.34ꢀ
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ꢀ
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3
ꢀ
volume of 708 A leaves space for about four guest molecules per unit
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bond can be found. Contrary to what the symmetric structure of the
host molecule suggests, it does not show a trigonal symmetry in the
crystal structures. The angles between triazine and phenyl rings
deviate from each other up to 16ꢀ and those between the phenyl rings
in the substituents up to 10ꢀ (Table 2). This proves that trigonal
crystal symmetry is not a prerequisite for the formation of channel-
type inclusion compounds.
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cases. The reaction can be implemented in the synthesis of a variety of
symmetrical 1,3,5-triazines, being substituted with aromatic groups.
The procedure is also useful for the synthesis of partly fluorinated
1,3,5-triazines, although the yields might be lower in particular cases.
Further work to promote the range of application of the present
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progress.
ꢁ
24 J. M. Fraile, J. I. Garcıa, D. Gracia, J. A. Mayoral and E. Pires, J.
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toluene and p-xylene, gives two channels of different sizes existing
both in one crystal, whereas the inclusion of rather big molecules,
such as mesitylene, results in rather big channels with cross-sections
ꢁ
ꢁ
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Acknowledgements
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This work was supported by the European Commission, Human
Potential Programme (RTN ‘‘NanoMatch’’, Contract no. MRTN-
CT-2006-035884). The X-ray diffraction analysis was possible thanks
770 | CrystEngComm, 2012, 14, 768–770
This journal is ª The Royal Society of Chemistry 2012