Structural and spectroscopic studies of charge-transfer adducts formed between IBr and thioether crowns

Abstract

Charge-transfer complexes [9]aneS₃·2IBr ([9]aneS₃ = 1,4,7-trithiacyclononane), [14]aneS₄·2IBr 1 ([14]aneS₄ = 1,4,8,11-tetrathiacyclotetradecane), [16]aneS₄·4IBr 2 ([16]aneS₄ = 1,5,9,13-tetrathiacyclohexadecane) and [18]aneS₆·2IBr 3 ([18]aneS₆ = 1,4,7,10,13,16-hexathiacyclooctadecane) have been synthesized and the single crystal structures of 1, 2 and 3 determined. The reactions of IBr with [12]aneS₄ (1,4,7,10-tetrathiacyclododecane), [15]aneS₅ (1,4,7,10,13-pentathiacyclopentadecane) and [24]aneS₈ (1,4,7,10,13,16,19,22-octathiacyclotetracosane) have also been examined. All the compounds were prepared by slow evaporation of solutions containing IBr and the appropriate thioether macrocycle in CH₂Cl₂–n-hexane. The structure determination of 1 shows the thioether crown lying across a crystallographic inversion centre with two symmetry-related IBr molecules co-ordinated through their iodine atoms to two exo-oriented S-donors [S(1)–I(1) 2.678(1), I(1)–Br(1) 2.654(2) Å, S(1)–I(1)–Br(1) 175.53(4)°]. The Br  · · ·  Br contacts between consecutive adduct units form polymeric chains of 1 in the crystal lattice. Compound 2 is the only adduct in the present investigation to have all S-donor atoms of the macrocyclic ligand co-ordinated to IBr molecules [S(1)–I(1) 2.618(2), I(1)–Br(1) 2.7049(11), S(5)–I(5) 2.687(2), I(5)–Br(5) 2.6445(12) Å, S(1)–I(1)–Br(1) 177.65(5), S(5)–I(5)–Br(5) 177.57(5)°]. The [16]aneS₄·4IBr units interact with each other through I  · · ·  I and Br  · · ·  I contacts to form ribbons of interconnected molecules of 2 which propagate along the ab face diagonals of the unit cell. Compound 3 shows two symmetry-related IBr molecules co-ordinated to the macrocyclic ligand [S(1)–I(1) 2.619(3), I(1)–Br(1) 2.695(2) Å, S(1)–I(1)–Br(1) 175.00(6)°]. Adduct molecules are stacked along the b axis and held together by S  · · ·  S interactions between [18]aneS₆ units. The structural features and the FT-Raman spectra of the reported IBr adducts are compared with those of the I₂ adducts obtained from the same ligands.

References

1. F. A. Cotton and P. A. Kibala, J. Am. Chem. Soc., 1987, 109, 3308; N. Bricklebank, S. M. Godfrey, A. G. Mackie, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Chem. Commun., 1992, 355; S. M. Godfrey, C. A. McAuliffe, R. G. Pritchard and J. M. Sheffield, J. Chem. Soc., Dalton Trans., 1997, 4823; N. Bricklebank, S. M. Godfrey, H. P. Lane, C. A. McAuliffe, R. G. Pritchard and J. M. Moreno, J. Chem. Soc., Dalton Trans., 1995, 3873; M. Arca, F. Cristiani, F. A. Devillanova, A. Garau, F. Isaia, V. Lippolis and G. Verani, Heteroatom Chem., 1997, 8, 139.
2. P. Deplano, S. M. Godfrey, F. Isaia, C. A. McAuliffe, M. L. Mercuri and E. F. Trogu, Chem. Ber., Recueil, 1997, 130, 299; V. Stenzel, J. Jeske, W.-W. du Mont and P. G. Jones, Inorg. Chem., 1997, 36, 443; F. Ruthe, W.-W. du Mont and P. G. Jones, Chem. Commun., 1997, 1947.
3. H. Bock, Z. Havlas, A. Rauschenbach, C. Näther and M. Kleine, J. Chem. Soc., Chem. Commun., 1996, 1529.
4. (a) A. L. Tipton, M. C. Lonergan, C. L. Stern and D. F. Shriver, Inorg. Chim. Acta, 1992, 201, 23; (b) P. K. Backer, S. D. Harris, M. C. Durrant, D. L. Hughes and R. L. Richards, Acta Crystallogr., Sect. C, 1995, 51, 697; (c) H. Bock, N. Nagel and A. Seibel, Liebig. Ann. Recueil, 1997, 2151; (d) M. Arca, F. Cristiani, F. A. Devillanova, A. Garau, F. Isaia, V. Lippolis, G. Verani and F. Demartin, Polyhedron, 1997, 16, 1983.
5. S. M. Godfrey, C. A. McAuliffe, R. G. Pritchard and S. Sarwar, J. Chem. Soc., Dalton Trans., 1997, 1031, 3501.
6. (a) F. Cristiani, F. Demartin, F. A. Devillanova, F. Isaia, G. Saba and G. Verani, J. Chem. Soc., Dalton Trans., 1992, 3553; (b) F. Cristiani, F. A. Devillanova, F. Isaia, V. Lippolis, G. Verani and F. Demartin, Polyhedron, 1995, 14, 2937; (c) F. Bigoli, P. Deplano, M. L. Mercuri, M. A. Pellinghelli, A. Sabatini, E. F. Trogu and A. Vacca, J. Chem. Soc., Dalton Trans., 1996, 3583.
7. D. C. Apperley, N. Bricklebank, S. L. Burns, D. E. Hibbs, M. B. Hursthouse and K. M. A. Malik, J. Chem. Soc., Dalton Trans., 1998, 1289.
8. M. Arca, F. A. Devillanova, A. Garau, F. Isaia, V. Lippolis, G. Verani and F. Demartin, Z. Anorg. Allg. Chem., 1998, 624, 745.
9. S. M. Godfrey, S. L. Jackson, C. A. McAuliffe and R. G. Pritchard, J. Chem. Soc., Dalton Trans., 1997, 4499.
10. M. D. Rudd, S. V. Lindeman and S. Husebye, Acta Chem. Scand., 1996, 50, 759.
11. M. D. Rudd, S. V. Lindeman and S. Husebye, Acta Chem. Scand., 1997, 51, 689.
12. F. Demartin, P. Deplano, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chem., 1993, 32, 3694.
13. F. Bigoli, M. A. Pellinghelli, P. Deplano, F. A. Devillanova, V. Lippolis, M. L. Mercuri and E. F. Trogu, Gazz. Chim. Ital., 1994, 124, 445; F. Bigoli, P. Deplano, F. A. Devillanova, V. Lippolis, M. L. Mercuri, M. A. Pellinghelli and E. F. Trogu, Eur. J. Inorg. Chem., 1998, 1, 137.
14. (a) F. Demartin, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chim. Acta, 1997, 255, 203; (b) F. A. Devillanova, P. Deplano, F. Isaia, V. Lippolis, M. L. Mercuri, S. Piludu, G. Verani and F. Demartin, Polyhedron, 1998, 17, 305.
15. A. J. Blake, R. O. Gould, C. Radek and M. Schröder, J. Chem. Soc., Chem. Commun., 1993, 1191; F. Cristiani, F. A. Devillanova, F. Isaia, V. Lippolis, G. Verani and F. Demartin, Heteroatom Chem., 1993, 4, 571.
16. (a) A. J. Blake, F. Cristiani, F. A. Devillanova, A. Garau, L. M. Gilby, R. O. Gould, F. Isaia, V. Lippolis, S. Parsons, C. Radek and M. Schröder, J. Chem. Soc., Dalton Trans., 1997, 1337; (b) A. J. Blake, W.-S. Li, V. Lippolis and M. Schröder, Acta Crystallogr., Sect. C, 1997, 53, 886.
17. A. J. Blake, F. A. Devillanova, A. Garau, L. M. Gilby, R. O. Gould, F. Isaia, V. Lippolis, S. Parsons, C. Radek and M. Schröder, J. Chem. Soc., Dalton Trans., 1998, 2037.
18. R. E. DeSimone and M. D. Glick, J. Am. Chem. Soc., 1976, 98, 762.
19. A. J. Blake, R. O. Gould, M. A. Halcrow and M. Schröder, Acta Crystallogr., Sect B, 1993, 49, 773.
20. R. E. Wolf Jr., J. R. Hartman, J. M. E. Storey, B. M. Foxman and S. R. Cooper, J. Am. Chem. Soc., 1987, 109, 4328.
21. L. N. Swink and G. B. Carpenter, Acta Crystallogr., Sect B, 1968, 24, 429.
22. A. F. Wells, Structural Inorganic Chemistry, Clarendon Press, Oxford, 5th edn., 1984.
23. F. Cristiani, F. A. Devillanova, A. Diaz, F. Isaia, V. Lippolis, G. Verani and F. Demartin, Synthesis and Methodologies in Inorganic Chemistry, New Compounds and Materials, eds. S. Daolio, E. Tondello and P. A. Vigato, Litografia, Padova, 1995, vol. 5, p. 478.
24. C. Knobler, C. Baker, H. Hope and J. D. McCullough, Inorg. Chem., 1971, 10, 697.
25. F. H. Herbstein and W. Schwotzer, J. Am. Chem. Soc., 1984, 106, 2367.
26. L. Pauling, in The Nature of the Chemical Bond, 3rd edn., Cornell University Press, Ithaca, New York, 1960; H. G. Bürgi, Angew. Chem., Int. Ed. Engl., 1975, 14, 460.
27. F. Cristiani, F. Demartin, F. A. Devillanova, F. Isaia, V. Lippolis and G. Verani, Inorg. Chem., 1994, 33, 6315.
28. P. Deplano, F. A. Devillanova, J. R. Ferraro, F. Isaia, V. Lippolis and M. L. Mercuri, Appl. Spectrosc., 1992, 11, 1625.
29. J. Cosier and A. M. Glazer, J. Appl. Crystallogr., 1986, 19, 105.
30. G. M. Sheldrick, SHELXS 86, Acta Crystallogr., Sect. A, 1990, 46, 467.
31. G. M. Sheldrick, SHELXL 93, University of Göttingen, 1993.