Four- and six-coordinated Al and an encapsulated isopropylamine species in 7AlPO4.2(C3H7NH2).2H2O

Abstract

Abstract. Aluminium phosphate-isopropylamine hydrate, M r = 1007.9, monoclinic, C2/c, a = 24.085 (1), b= 14.393(1), c=8.7122(4)A, fl=94.260(4) °, v =3012A s, z=4, D x=2.22gcm -a, CuK~t, 2=1.5418 A, ~ = 71 cm -1, F(000) = 2032, T_ 295 K, R = 0.039 for 2517 reflections. The framework structure contains tetrahedral P and both tetrahedral and octahedral A1. Two octahedral A1 are connected by three tetrahedral species (two P and one AI) to form a five-atom cluster which consists of three 4-rings. Two clusters are linked by two tetrahedral P to form a lozenge-shaped cage. Sharing of each cluster by adjacent cages produces a zigzag chain. Crosslinking of zigzag chains by twisting chains of 4-rings produces a (100) sheet which is linked to adjacent sheets by several types of 4-rings, most of which belong to an interrupted sheet. Two octahedral A1 share an OH and the encapsulated organic species is probably isopropylammonium ion; thus the chemical formula can be written as {A17PTO28(OH)2.2C3H7NH3 }.

A gel aging effect in the synthesis of open-framework gallium phosphates: structure solution and solid-state NMR of a large-pore, open-framework material

“…This nomenclature is consistent with synthetically related materials: for example AlPO-14A crystallises as a competing phase from a synthesis of AlPO-14 yet has a distinctly different structure. 28 …”

Temperature-Induced Transformations in CoAPO-34 Molecular Sieve: A Combined In Situ X-ray Diffraction and FTIR Study

“…When extra-ligand species are present, they always bridge two Al atoms. This occurs independently of their nature (fluorine anions in this case or OH groups in AlPO-18, 23 AlPO-21, 28 or AlPO-14 29 ) or their number (one in AlPO-18, 23 two in AlPO-21, 28 AlPO-14, 16 and AlPO-34 22,23 ).…”

Open-Framework Inorganic Materials

“…In these cases, water groups or anionic species such as hydroxide complete the coordination sphere of the aluminum, which leads to connection modes already encountered in mineral aluminum phosphates [31] in which [AlO n ] polyhedra may share corners or edges through Al-O-Al linkages. It also results in the formation of oddnumbered rings, as in, for instance, AlPO 4 -14A [32] and AlPO 4 -21 ( Figure 4). [33] In these examples, the channel size appears to be limited as a consequence of the increase of the aluminum coordination, which thus seems to be a drawback for the production of large pores.…”