Octameric and Decameric Aluminophosphates

Abstract

Big Al: The title compounds are not only among the largest molecular aluminophosphates synthesized thus far, but are also rare polyhedral cages that contain AlO4, AlO5, and AlO6 coordination geometries (see structure; red O, blue Al, pink P). The cores of these aluminophosphates represent new structural building units (SBUs) in zeolite chemistry.

Structural Diversity in Organotin Compounds Derived from Bulky Monoaryl Phosphates: Dimeric, Tetrameric, and Polymeric Tin Phosphate Complexes

“…The reaction of 2 equiv:dipp-H 2 with n-butylstannoic acid in acetone at room temperature over a few days produces [(nBuSn) 4 The IR spectrum of 5 shows absorption bands at 1176 and 1150 cm -1 corresponding to presence of Sn-O-P symmetric and asymmetric stretching frequencies. The broad absorption peak observed at 2329 cm -1 is due to the presence of unionized P-OH groups on the phosphate ligands.…”

“…The reaction of the monoorgano tin precursor nBuSn(O)(OH)· xH 2 O with dipp-H 2 takes place in acetone at room temperature to yield the tetrameric cluster 5, which has different structures in the solution and in the solid state. 31 P NMR spectroscopy clearly suggests that 5 has the formula [nBu 4 Sn 4 (µ-O) 2 (µ-dipp-H) 8 ] in solution. The single-crystal Xray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu 4 Sn 4 (µ-OH) 2 (µ-dipp-H) 6 (µ-dipp) 2 ].…”

“…31 P NMR spectroscopy clearly suggests that 5 has the formula [nBu 4 Sn 4 (µ-O) 2 (µ-dipp-H) 8 ] in solution. The single-crystal Xray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu 4 Sn 4 (µ-OH) 2 (µ-dipp-H) 6 (µ-dipp) 2 ]. The use of compounds 1-4 as possible precursors for the preparation of ceramic tin phosphate materials has been investigated.…”

“…[4] Fascinated by the variety of structures obtained for divalent transition metals such as zinc, manganese, and copper as well as the trivalent aluminum with dipp-H 2 , we wished to unravel the types of structures that would be formed in the case of tetravalent tin. Interaction of organotin precursors with acidic hydrogen-containing compounds has been extensively studied in the 1980s and 1990s by Holmes et al, who unraveled several new structural types for tin.…”

“…[2] We have recently shown that 2,6-diisopropylphenylphosphate (dipp-H 2 ) is an ideal starting point for the preparation of both main group and transition-metal phosphate clusters that self-assemble through noncovalent interactions into zeolite-like materials. [3][4][5] For example, by using zinc as the representative example, it is possible to build hierarchical zinc-dipp structures in a systematic way by changing the coligands used.…”