The ยฎrst example of a 2D-layered aluminophosphate with P:Al 18:13 has been synthesized hydrothermally in the presence of 1,8-diaminooctane (DAO) as templating molecule, and its structure has been solved using single crystal X-ray diraction data. It has the composition (C 8 N 2 H 22 ) 8 [Al 13 P 18 O 72 ] ร 6H 2 O and crystallizes in space group R 3 (no. 148) with a 16:508(10)
A and c 48:715(75) A. The structure consists of layers built up mainly from tetrahedrally coordinated Al and P atoms, separated by and hydrogen bonded to doubly protonated DAO molecules. One of the 13 aluminum atoms is octahedrally coordinated and connected to six P tetrahedra, thus forming Al(OP) 6 units. These units are responsible for the unusual layer stoichiometry, never observed previously in 2D-layered aluminophosphates. Two crystallographically dierent DAO molecules were located, one in a general position and one in a special position on the 3-fold axis. For the latter, only the head of the molecule (NH 3 ยฑCH 2 -group) was located. The other atoms are o the 3fold axis, and the chain appears to be disordered. The compound was characterized by multi-dimensional solid state NMR. All 27 Al and 31 P NMR signals have been assigned to the crystallographically non-equivalent Al and P atoms of the structure.