Collect. Czech. Chem. Commun. 2001, 66, 1375-1379

Charge Distribution Within 1,2-Dicarba-closo-dodecaborane: Dipole Moments of Its Phenyl Derivatives

Drahomír Hnyka,*, Václav Všetečkab, Ladislav Drožb and Otto Exnerc

a Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, CZ-250 68 Řež, Czech Republic
b Department of Organic Chemistry, Charles University, Hlavova 2030, CZ-128 40 Prague 2, Czech Republic
c Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, CZ-166 10 Prague 6, Czech Republic


1. Hofmann R., Lipscomb W. N.: J. Chem. Phys. 1962, 36, 3489. <>
2. Laubengayer A. W., Rysz W. R.: Inorg. Chem. 1965, 4, 1513. <>
3. Maruca R., Schroeder H., Laubengayer A. W.: Inorg. Chem. 1967, 6, 572. <>
4. Exner O.: Dipole Moments in Organic Chemistry, Chap. 3.2. Thieme, Stuttgart 1975.
5. Kofod H., Sutton L. E., Jackson J.: J. Chem. Soc. 1952, 1467. <>
6a. Compounds 2a, 2b, 2c and 2d were prepared by allowing to react 6,9-bis(ligand)decaborane(12), 6,9-L2B10H12, where L was CH3CN, with a substituted phenylacetylene, 4-X-C6H4CCH (X = H, CH3, Br, Cl). See, e.g., Heying T. L., Ager J. W., Jr., Clark S. L., Mangold D. J., Goldstein H. L., Hillman M., Polak R. J., Szymanski J. W.: Inorg. Chem. 1963, 2, 1089. <>
6b. Compound 2d was obtained by nitration of 2a: Hawthorne M. F., Berry E. T., Wegner A. P.: J. Am. Chem. Soc. 1965, 87, 4746. The purity of all compounds was checked by analytical TLC and the structures of the molecules were confirmed on the basis of 1H{11B} and 11B{11H} NMR spectra recorded on a Varian Unity-500 instrument in CDCl3 solution. Example: NMR spectrum of 2a (in ppm, see also ref.10 for a comparison): B(3,6) –12.2, B(4,5) –11.7, B(7,11) –13.7, B(8,10) –9.9, B(9) –3.0, B(12) –5.0. The corresponding boron atoms in 2b2d resonated at about the same frequencies as in 2a. <>
7. Dipole moments were measured at 25 °C in benzene (five solutions, weight fraction 1.8 · 10–4 to 1.1 · 10–3) by the method of Guggenheim and Smith8. Relative permittivities were measured at 6 MHz on a home-made DK-meter with direct frequency reading. Refractive indices were measured on an Aerograph refractive index detector (Varian). The following dipole moments were obtained: 1 4.50, 2a 4.94, 2b 5.32, 2c 3.66, 2d 3.64 and 2e 2.26 D; the estimated uncertainty was 0.05 D. For constructing Fig. 1, the following standard bond moments were used: H–Cal 0.3, H–Car 0, Car–Cl 1.6, Car–Br 1.57 and Car–NO2 4.0 D.
8a. Guggenheim E. A.: Trans. Faraday Soc. 1949, 45, 714. <>
8b. Smith J. W.: Trans. Faraday Soc. 1950, 46, 256.
9. Eda B., Ito K.: Bull. Chem. Soc. Jpn. 1954, 30, 164. <>
10. Brain P. T., Cowie J., Donohoe D. J., Hnyk D., Rankin D. W. H., Reed D., Reid B. D., Robertson H. E., Welch A. J.: Inorg. Chem. 1996, 35, 1701. <>
11. Frisch M. J., Trucks G. W., Schlegel H. B., Gill P. M. W., Johnson B. G., Robb M. A., Cheeseman J. R., Keith T., Petterson G. A., Montgomery G. A., Raghavachari K., Al-Laham M. A., Zahrzewski W. G., Ortiz J. V., Foresman J. B., Cioslowski J., Stefanov B. B., Nanayakkra N., Challacombe M., Peng C. Y., Ayala P. Y., Chen Y., Wong M. W., Andres J. L., Replogle E. S., Gomprets R., Martin R. L., Fox D. J., Binkley J. S., Defrees D. J., Baker L., Stewart J. P., Head-Gordon M., Gonzales C., Pople J. A.: Gaussian94, Revision B.2. Gaussian Inc., Pittsburg (PA) 1995.
12a. Reed A. E., Weinstock R. B., Weinhold F.: J. Chem. Phys. 1985, 83, 735. <>
12b. Reed A. E., Weinhold F.: Chem. Rev. (Washington, D. C.) 1988, 88, 899. <>
12c. Reed A. E., Schleyer P. v. R.: J. Am. Chem. Soc. 1990, 112, 1434. <>
13. Hawthorne M. F., Berry T. E., Wegner P. A.: J. Am. Chem. Soc. 1965, 87, 4746. <>
14. Exner O.: Dipole Moments in Organic Chemistry, Chap. 6.3. Thieme, Stuttgart 1975.
15. Exner O., Krygowski T. M.: Chem. Soc. Rev. 1996, 25, 71. <>
16. Fox M. A., MacBride J. A. H., Peace R. J., Wade K.: J. Chem. Soc., Dalton Trans. 1998, 401. <>
17. Albinson B., Baše K., Grüner B., Heřmánek S., Janoušek Z., Kaszynski P., Michl J.: IXth International Meeting on Boron Compounds, Heidelberg, Germany, July 14–18, 1996. Book of Abstracts, Poster No. 128, p. 221.
18. Exner O.: Collect. Czech. Chem. Commun. 1960, 25, 642. <>