in 90% yield.15 Investigations using MALDI-TOF mass
spectrometry, UV/vis spectroscopy, and analytical ultracen-
trifugation revealed the successful formation of the metal
coordination arrays and the exceptional stability of these new
grids compared to those of the published systems.16
The described new synthetic strategy to extended pyridine-
based supramolecular ligands opens new avenues for the use
of such systems in supramolecular and polymer chemistry.
2,6-Bis(trimethyltin)pyridine was synthesized in high yields
and multigram quantities as a new central building block.
As first applications the 5-methyl-substituted bipyridines and
terpyridines were synthesized as well as an extended metal
coordination array-forming ligand. Further studies in this
direction are currently in progress.
Scheme 3
Acknowledgment. This study was supported by the
Bayerisches Staatsministerium fu¨r Unterricht, Kultus,
Wissenschaft und Kunst, the Fonds der Chemischen Indus-
trie, and the Deutsche Forschungsgemeinschaft (SFB 266,
Teilprojekt B 15). We thank Prof. Dr.-Ing. Oskar Nuyken
for his support.
OL990808S
In contrast to published multistep procedures with rather
low yields, we here describe a short multigram synthesis of
this very interesting class of supramolecular ligands from
commercially available starting materials in 30% overall
yield. As the first application of this ligand, we synthesized
the corresponding cobalt metal coordination array (Scheme
4, for general information see ref 14). Reaction with
(11) 3 (12.23 g, 30.2 mmol), 4 (13.00 g, 75.6 mmol), and [Pd(PPh3)4]
(2.36 g, 2.03 mmol) were stirred in toluene at 110 °C for 96 h. The solvent
was removed in vacuo and the residue treated with 6 M HCl (3 × 50 mL).
The combined aqueous phases were washed with CH2Cl2 (3 × 30 mL),
neutralized, and extracted with CH2Cl2 (3 × 50 mL). The combined organic
phases were dried over Na2SO4 and evaporated in vacuo, and the residue
was recrystallized from ethyl acetate, yielding 5.44 g (68%) of 6: white
solid, mp 174-175 °C; 1H NMR (CDCl3, 300 MHz) δ (ppm) 2.39 (s, 6 H,
H-7,7′′), 7.63 (dd, 2 H, 8.01 Hz, J ) 2.28 Hz, H-4,4′′), 7.91 (t, 1 H, J )
7.82 Hz, H-4′), 8.38 (d, 2 H, J ) 7.62 Hz, H-3′,5′), 8.49 (d, 2 H, J ) 8.40
Hz, H-3,3′′), 8.50 (s, 2 H, H-6,6′′); MS (EI, 70 eV) m/z (%) ) 261 (100)
[M+]. Anal. C17H15N3 (261.32). Calcd: C, 78.16; H, 5.75; N, 16.09.
Found: C, 77.92; H, 5.73; N, 16.07.
Scheme 4
(12) Schubert, U. S.; Eschbaumer, C.; Hochwimmer, G. Synthesis 1999,
779.
(13) White solid, mp 259 °C; 1H NMR (CDCl3, 300 MHz) δ (ppm) 2.37
(s, 6 H, H-7′′), 7.57 (m, 3 H, H-m, p), 7.69 (dd, 2 H, J ) 8.01, 2.28 Hz,
H-4′′), 8.04 (t, 2 H, J ) 7.82 Hz, H-4′), 8.57 (m, 4 H, H-3′′, 3′/5′), 8.69 (s,
2 H, H-6′′), 8.72-8.79 (m, 4 H, H-o, 3′/5′), 9.64 (s, 1 H, H-5); MS (EI, 70
eV) m/z (%) ) 492.1 (100) [M+]; λmax (CH3CN)/nm (ꢀ) 240 (46 200), 279
(35 800), 311 (15 800).
(14) Hanan, G. S.; Volkmer, D.; Schubert, U. S.; Lehn, J.-M.; Baum,
G.; Fenske, D. Angew. Chem. 1997, 109, 1929; Angew. Chem., Int. Ed.
Engl. 1997, 36, 1842. Waldmann, O.; Hassmann, J.; Mu¨ller, P.; Hanan, G.
S.; Volkmer, D.; Schubert, U. S.; Lehn, J.-M. Phys. ReV. Lett. 1997, 78,
3390. Waldmann, O.; Hassmann, J.; Koch, R.; Mu¨ller, P.; Hanan, G. S.;
Volkmer, D.; Schubert, U. S.; Lehn, J.-M. Mater. Res. Soc. Symp. Proc.
1998, 448, 841. Waldmann, O.; Hassmann, J.; Mu¨ller, P.; Volkmer, D.;
Schubert, U. S.; Lehn, J.-M. Phys. ReV. B 1998, 58, 3277. Schubert, U. S.;
Lehn, J.-M.; Hassmann, J.; Hahn, C. Y.; Hallschmid, N.; Mu¨ller, P. In
Functional Polymers; Patil, A. O., Schulz, D. N., Novak, B. M., Eds.;
American Chemical Society: Washington, DC, 1998, ACS Symp. Ser. 704,
p 248. Semenov, A.; Spatz, J. P.; Mo¨ller, M.; Lehn, J.-M.; Sell, B.; Schubert,
D.; Weidl, C. H.; Schubert, U. S. Angew. Chem. 1999, 111, 2701; Angew.
Chem., Int. Ed. 1999, 38, 2547.
(15) Prepared using Co(OAc)2‚4H2O and a methanol/chloroform mixture
as solvent followed by an anion exchange with NH4PF6 in 90% yield after
recrystallization as brown crystals, mp > 300 °C: MALDI-TOF-MS 3075
[M+ - 2 PF6], 2930 [M+ - 3 PF6], 2785 [M+ - 4 PF6], 2640 [M+ - 5
PF6], 2495 [M+ - 6 PF6], 2350 [M+ - 7 PF6], 2205 [M+ - 8 PF6]. Anal.
C
128H96Co4F48N3P8 (3365.77). Calcd (‚6H2O): C, 44.25; H, 3.05; N, 9.68.
Found: C, 44.37; H, 3.15; N 9.67. λmax (CH3CN)/nm (ꢀ): 239 (45 100),
279 (27 200), 360 (23 400).
(16) See, e.g.: Schubert, D.; Tziatzios, C.; Schuck, P.; Schubert, U. S.
Chem. Eur. J. 1999, 5, 1377. Schubert, U. S.; Eschbaumer, C.; An, Q.;
Salditt, T. Polym. Prepr. (ACS) 1999, 40(1), 414.
equimolar quantities of cobalt(II) acetate in methanol fol-
lowed by an anion exchange gave the [2 × 2] cobalt(II) grid
Org. Lett., Vol. 1, No. 7, 1999
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