Zeolite isostructural framework

Of the zeolitic materials, AlPO s cut a conspicuous figure because of their structural diversity and the incorporation of other elements into their frameworks. The recently developed VPI-5 (refs. 2, 3) announced the feasibility of synthesis of micoporous structures with windows comprising rings of over 12-T. All AlPO s, SAPO s and MAPO s form a family of microporous structures constructed by or essentially by A1(I) and P(V). Some of them are isostructural with zeolites but a majority have novel structures. The primary building units (PBU) centred by P(V) are invariantly PO4 whereas those centred by A1(I) are AlO in most cases and AIO5 or even AlOs in a few cases. So far all AlPO s, SAPO s and MAPO s have been synthesized exclusively in the presence of amines or... 

Other framework structures based on zeolites have also been synthesized which contain atoms other than aluminium and silicon, such as boron, gallium, germanium, and phosphorus, which are tetrahedrally coordinated by oxygen. Such compounds are known as zeotypes. Pure aluminium phosphate, commonly called ALPO, and its derivatives, can take the same structural forms as some of the zeolites such as sodalite (SOD), faujasite (FAU), and chabazite (CHA) (e.g., ALPO-20 is isostructural... 

An example of a porous framework that is isoreticular, but not isostructural, with MOF-5 is MOF-177, which incorporates the extended organic linker 1,3,5-benzenetribenzoate (BTB). The framework of crystalline MOF-177, Zn40(BTB)2- (DEF)i5(H20)3, where DEF = diethyl formamide, has an ordered structure with an estimated surface area of4,500 m2 g-1, which greatly exceeds those of zeolite Y (904 m2g 1) and carbon (2,030 m2 g-1). 

The reported zeolite minerals are 61 instead of 57 as referred to in the text. This is due to the fact that, for historical and opportunity reasons, different names have been saved for the isostructural couples clinoplilolile-heulandite and harmotome-phillipsite and for the isostructural triplet analcime-pollucite-wairakite. As regards the 3-letter framework-type codes, see [27]. 

The zeolite Linde-L (LTL framework) was first synthesized by [65B1] and was noted to be a large pore zeolite. This has been confirmed by a structme analysis [69B1]. It has 12-ring channels and is isostructural with perlialite as shown later [90A1]. 

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