Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
권호 표지
DOI QR코드

DOI QR Code

Crystal Structures of Bromine Sorption Complexes of $Ca^{2+}$-Exchanged Zeolite A

  • Published : 1995.12.20
Download PDF
⟨ Previous Next ⟩

Abstract

The structures of dehydrated Ca4Na4-A (a=12.243(1) Å) and of its bromine sorption complex (a=12.214(1) Å) have been determined by single crystal x-ray diffraction techniques in the cubic space groupPm&bar{3}m at 21(1) ℃. Both crystals were dehydrated at 360 ℃ and 2 X 10-3 Torr for 2 days and one crystal was treated with 180 Torr of bromine vapor at 24 ℃ for 1 h. The structures were refined to final error indices, R1=0.066 and R2=0.078 with 192 reflections and R1=0.109 and R2=0.093 with 100 reflections, respectively, for which I>3σ(I). In these structures, four Ca2+ and four Na+ ions are located on two different threefold axes associated with 6-ring oxygens, respectively. In Ca4Na4-A·6Br2, four Ca2+ ions are recessed 0.28(1) Å into the large cavity and four Na+ ions extend 0.63(1) Å into the sodalite unit. A total of six dibromine molecules are sorbed per unit cell. Each Br2 molecule approaches a framework oxide ion axially with O(1)-Br(1)=3.27(2) Å Br(1)-Br(2)=2.66(6) Å and O(1)-Br(1)-Br(2)=172(1)°, indicating a charge-transfer interaction.

Keywords

References

  1. Acta Crystallogr. v.22 Seff, K.;Shoemaker, D.P.
  2. J. Phys. Chem. v.82 Kim, Y.;Seff, K.
  3. Rev. Chem. Soc. v.16 Hassel, O;Romming, C.Q.
  4. International Review of Science(Vol. 3) Paetzold, R.
  5. Z. Kristallogr. Kristallgeom., Kristallphys., Kristallchem. v.123 Meier, W.H.;Shoemaker, D.P.
  6. J. Am. Chem. Soc. v.100 Kim, Y.;Seff, K.
  7. J. Am. Chem. Soc. v.100 Firor, R.L.;Seff, K.
  8. J. Am. Chem. Soc. v.100 Subramanian;Ottersen, T.;Seff, K.
  9. Hung. Mining Res. Inst. v.14 Adam, L.;Kakasy, G.;Pallos, I.
  10. U.S. Patent 3,594,581 Purification of Gases by Adsorption Wearout, J.D.
  11. J. Cryst. Growth. v.8 Charnell, J.F.
  12. J. Phys. Chem. v.88 Seff, K.;Mellum, M.D.
  13. Acc. Chem. Res. v.9 Seff, K.
  14. Calculations were performed using the Structure Determination Packafe Program Frentz, B.A.;Okaya, Y.
  15. Internation Tables for X-ray Crystallography:Kynoth(Vol. Ⅱ)
  16. Inorg. Chem. v.13 Riley, P.E.;Seff, K.
  17. ACta Crystallogr. Sect. A.: Cryst. Phys. Diff. Theor. Gen. Crystallogr. v.24 Doyle, P.A.;Turner, P.S.
  18. International Tables for X-ray Crystallography: Kynoch
  19. International Tables for X-ray Crystallography: Kynoch(Vol. Ⅳ)
  20. Reference 20
  21. J. Am. Chem. Soc. v.100 Firor, R.L.;Seff, K.
  22. Handbook of Chemistry and Physics(70th ed.)
  23. Reference 22
  24. Reference 22
  25. J. Phys. Chem. v.95 Kim, Y.;Lee, S.H.;Kim, D.S.;Seff, K.