Substituent effects in the formation of aryloxide-bridged europium complexes

Abstract

The reactivity of europium in liquid ammonia with 2,6-disubstituted phenols has been surveyed and the effect of the 2,6 substituents on the bridging ability of the aryloxides has been examined. Monomeric and tetrameric complexes of Eu^II have been isolated with tert-butyl and isopropyl substituents, Eu(OC₆H₃Bu^t₂-2,6)₂ (NCMe)₄ 1 and Eu₄(µ-OC₆H₃Prⁱ₂-2,6)₄(OC₆H₃Prⁱ₂-2,6)₂(µ₃-OH)₂ (NCMe)₆ 2, respectively, which can be compared to the previously reported bimetallic complex, (dme)₂Eu(µ-OC₆H₃Me₂ -2,6)₃Eu(OC₆H₃Me₂- 2,6)(dme) 3, isolated with methyl substituents (dme = 1,2-dimethoxyethane). Acetonitrile has been found to be an excellent solvating ligand for the formation of crystalline complexes in this series. Complex 1 crystallizes from acetonitrile in the monoclinic space group P2₁/c with a = 11.7117(14), b = 17.616(2), c = 18.263(2) Å, β = 91.318(8)°, U = 3766.8(7) ų and D_c = 1.282 Mg m^-3 for Z = 4. Complex 2 crystallizes from acetonitrile in the monoclinic space group P2₁/n with a = 13.676(3), b = 20.325(4), c = 32.632(6) Å, β = 91.068(12)°, U = 9069(3) ų and D_c = 1.429 Mg m^-3 for Z = 4.

References

1. J. R. McColl and F. C. Palilla, ACS Symp. Ser., 1981, 164, 177; W. A. Thorton, ACS Symp. Ser., 1981, 164, 195; R. C. Ropp, Luminescence and the Solid State, Elsevier, New York, 1991.
2. See, for example, L. G. Hubert-Pfalzgraf, New J. Chem., 1987, 11, 663; K. G. Caulton and L. G. Hubert-Pfalzgraf, Chem. Rev., 1990, 90, 969.
3. (a) J. R. van den Hende, P. B. Hitchcock, S. A. Holmes, M. F. Lappert, W.-P. Leung, T. C. W. Mak and S. Prashar, J. Chem. Soc., Dalton Trans., 1995, 1427; (b) Z. Hou, A. Fujita, T. Yoshimura, A. Jesorka, Y. Zhang, H. Yamazaki and Y. Wakatsuki, Inorg. Chem., 1996, 35, 7190; (c) Z. Hou, H. Yamazaki, K. Kobayashi, Y. Fujiwara and H. Taniguchi, J. Chem. Soc., Chem. Commun., 1992, 722; (d) G. B. Deacon, P. B. Hitchcock, S. A. Holmes, M. F. Lappert, P. MacKinnon and R. H. Newnham, J. Chem. Soc., Chem. Commun., 1989, 935; (e) G. Qi, Q. Q. Shen and Y. Lin, Acta Crystallogr., Sect. C, 1994, 50, 1456; (f) W. J. Evans, R. Anwander, M. A. Ansari and J. W. Ziller, Inorg. Chem., 1995, 34, 5; (g) G. B. Deacon, T. Feng, P. MacKinnon, R. H. Newnham, S. Nickel, B. W. Skelton and A. H. White, Aust. J. Chem., 1993, 46, 387; (h) P. B. Hitchcock, M. F. Lappert and R. G. Smith, Inorg. Chim. Acta, 1987, 139, 183; (i) H. C. Aspinall and M. W. Williams, Inorg. Chem., 1996, 35, 255; (j) C. J. Schaverien, J. H. G. Frijns, H. J. Heeres, J. R. van den Hende, J. H. Teuben and A. L. Speck, J. Chem. Soc., Chem. Commun., 1991, 642.
4. (a) W. J. Evans, W. G. McClelland, M. A. Greci and J. W. Ziller, Eur. J. Solid State Inorg. Chem., 1996, 33, 145; (b) W. J. Evans, J. M. Olofson and J. W. Ziller, Inorg. Chem., 1989, 28, 4308; (c) W. J. Evans, R. E. Golden and J. W. Ziller, Inorg. Chem., 1993, 32, 3041; (d) J. R. van den Hende, P. B. Hitchcock and M. F. Lappert, J. Chem. Soc., Chem. Commun., 1994, 1413; (e) D. M. Barnhart, D. L. Clark, J. C. Gordon, J. C. Huffman, R. L. Vincent, J. G. Watkin and B. D. Zwick, Inorg. Chem., 1994, 33, 3487.
5. W. J. Evans, L. R. Chamberlain, T. A. Ulibarri and J. W. Ziller, J. Am. Chem. Soc., 1988, 110, 6423.
6. D. F. Evans, J. Chem. Soc., 1959, 2003.
7. J. L. Atwood, W. E. Hunter, A. L. Wayda and W. J. Evans, Inorg. Chem., 1981, 20, 4115.
8. D. Nicholls, Inorganic Chemistry in Liquid Ammonia, Elsevier, New York, 1979.
9. XSCANS Software Users Guide, Version 2.1, Siemens Industrial Automation Inc., Madison, WI, 1994.
10. R. W. Broach, CARESS, Argonne National Laboratory, IL, 1978.
11. G. M. Sheldrick, SHELXL Siemens Analytical X-Ray Instruments, Inc., Madison, WI, 1994.
12. International Tables of X-Ray Crystallography, Kluwer, Dordrecht, 1992, vol. C.
13. W. J. Evans and M. A. Hozbor, J. Organomet. Chem., 1987, 326, 299.
14. H. A. Stecher, A. Sen and A. L. Reingold, Inorg. Chem., 1988, 27, 1132.
15. R. D. Shannon, Acta Crystallogr., Sect. A, 1976, 32, 751.
16. (a) W. A. Herrmann, R. Anwander and W. Scherer, Chem. Ber., 1993, 126, 1533; (b) W. A. Herrmann, R. Anwander, M. Kleine and W. Scherer, Chem. Ber., 1992, 125, 1971.
17. V. Chebolu, R. R. Whittle and A. Sen, Inorg. Chem., 1985, 24, 3082.
18. O. Poncelet and L. G. Hubert-Pfalzgraf, Polyhedron, 1989, 17, 2183.
19. (a) D. Harrison, A. Giorgetti and J. G. Bünzli, J. Chem. Soc., Dalton Trans., 1985, 885; (b) G. B. Deacon, T. Feng, S. Nickel, M. I. Ogden and A. H. White, Aust. J. Chem., 1992, 45, 671; (c) H. Schumann, P. R. Lee and J. Loebel, Angew. Chem., Int. Ed. Engl., 1989, 28, 1033; (d) W. J. Evans, M. A. Hozbor, S. G. Bott, G. H. Robinson and J. L. Atwood, Inorg. Chem., 1988, 27, 1990; (e) D. Deng, F. Song, Z. Wang, C. Qian, G. Wu and P. Zheng, Polyhedron, 1992, 11, 2883; (f) P. B. Hitchcock, M. F. Lappert and S. Prashar, J. Organomet. Chem., 1991, 413, 79; (g) H. Schumann, J. Loebel, J. Pickardt, C. Qian and Z. Xie, Organometallics, 1991, 10, 215; (h) W. A. Herrmann, R. Anwander, M. Kleine, K. Öfele, J. Riede and W. Scherer, Chem. Ber., 1992, 125, 2391.
20. See, for example, R. C. Mehrotra and A. Singh, Chem. Soc. Rev., 1996, 1; W. J. Evans, M. S. Sollberger, J. S. Shreeve, J. M. Olofson, J. H. Hain, jun. and J. W. Ziller, Inorg. Chem., 1992, 31, 2992; D. C. Bradley, H. Chudzynska, D. M. Frigo, M. E. Hammond, M. B. Hursthouse and M. A. Mazid, Polyhedron, 1990, 5, 719.
21. J. C. Plakatouras, I. Baxter, M. B. Hursthouse, K. M. Abdul Malik, J. McAleese and S. R. Drake, J. Chem. Soc., Chem. Commun., 1994, 2455.
22. J. C. A. Boeyens and J. P. R. De Villiers, J. Cryst. Mol. Struct., 1972, 2, 197.
23. W. J. Evans, R. E. Golden and J. W. Ziller, Inorg. Chem., 1991, 30, 4963.
24. D. R. Lide, Handbook of Chemistry and Physics, CRC Press, Boca Raton, FL, 71st edn., 1990, p. 9, sect. 2.
25. L. Pauling, The Nature of the Chemical Bond, Cornell University Press, Ithaca, NY, 3rd edn., 1969, p. 261.
26. T. D. Tilley, R. A. Anderson and A. Zalkin, Inorg. Chem., 1984, 23, 2271.