STRUCTURAL STUDIES OF DAF-4. ^aP.A. Barrett and ^bR.H. Jones. ^aThe Royal Institution of GB, 21, Albemarle St, London W1X 4BS, UK. The University of Keele, Keele, Staffordshire ST5 5BG, UK.

The current work describes the structure solution of a new Levyne Cobalt substituted aluminophosphate (CoAlPO) analogue by single crystal methods. This new sample of CoAlPO-35 was synthesised hydrothermally from a nutrient gel containing sources of Al, P and Co employing the new template 2-methylcyclohexylamine as the structure directing agent. The unit cell showed there to be a doubling of the c axis compared to Levyne. This structure is known consistent with the strict Al and P alternation expected in an aluminophosphate.

Coordinates for the initial starting model were taken from Levyne. The space group is R-3c a=13.317(3)Å c=45.921(9)Å. This produces 4 crystallographically distinct tetrahedral framework sites. After successful refinement of the framework, the template (2-methylcyclohexylamine) was located using standard Fourier techniques. At this point it was observed that the Al-O bond distances were longer than expected consistent with the partial substitution of Co in place of Al. It proved possible to refine individual cobalt occupancies on these sites, which were consistent with the variation in bond length.