Materiały MOF, nowa rodzina sit molekularnych o niezwykłych właściwościach i możliwościach zastosowań
Journal Title: Wiadomości Chemiczne - Year 2011, Vol 65, Issue 5
Abstract
The metal organic frameworks (MOFs) are a novel group of molecular sieves discovered in the last decade of the twentieth century. Most of conventional molecular sieves such as microporous zeolites and zeolite-like materials, ordered mesoporous materials (M41S) are typical inorganic compounds. Although their synthesis often involves an assistance of organic compounds acting as structure directing agents and organic solvents are sometimes applied during their crystallization, the organics are always removed from resulted products (mainly by calcinations). The MOFs are crystalline materials build of metal ions or ion clusters coordinatively bonded with organic segments (linkers) that form porous (one-, two-, or threedimensional) structures. The various coordination number of selected metal and the nature of organic linkers allow to prepare a great variety of structures with different properties. The inorganic components comprise a great variety of transition (e.g. Zn Cu, Fe, rare earths) and base metal (e.g. Al) cations of different valence. The organic linkers are functionalized compounds containing O, N, P, S atoms (i.e. carboxylates, phosphonates, sulfonates, cyanides, amines, imidazoles) enable to chelate the inorganic cations. The organic subunits can be additionally modified by substitution of other functional groups (halogens, hydroxyls, aminogroups). The MOF materials are mostly prepared similarly as zeolitic materials by crystallization in solvothermal conditions. The solvents (water or organic compounds) can play a role of templates, although sometimes additional structure directing agents are admitted into the initial mixtures. The crystallization is always conducted in moderate temperatures (20–200°C). After removal of solvents well ordered pore systems are available for selective adsorption and for other applications. The thermal stability of this family of molecular sieves is obviously lower than that of inorganic materials, but most of them can withstand heating at 350–400°C, which still makes them suitable for variety of potential applications. The adsorption properties of MOFs makes them very appealing for practical application. The recorded surface areas of some types are overwhelming and they surpass 5000 m2/g. The high adsorption capacity is very promising for storage of fuels (natural gas, hydrogen) or waste gases (CO2, SO2) as well as for their separation. The great and very fast growing variety of structures and chemical compositions brings also a hope to use them as efficient catalysts. The metal segments, functional groups in organic blocks as well as occluded or encapsulated species can play a role of catalytically active sites. The MOF materials can be also applied as matrices for sensors, pigments, and microelectronic or optical devices.
Authors and Affiliations
Patryk Florczak, Ewa Janiszewska, Kamila Kędzierska, Stanisław Kowalak
Keywords
Related Articles
- EP ID EP591226
- DOI -
- Views 114
- Downloads 0
Droga pod słońce. Wczesna historia witaminy D
Two natural products are called „vitamin D”: (1) vitamin D3 which is biosynthesized in humans and animals and (2) vitamin D2 which is generated in photochemical rearrangement of a sterol of fungy – ergosterol (Fig. 1 and...
60 lat chemii na Uniwersytecie Wrocławskim
Rok 2014 – rok, w którym obchodzona jest 60. rocznica powstania chemii na Uniwersytecie Wrocławskim. W powojennej Polsce znalazło zatrudnienie wielu profesorów uczelni lwowskich. Dobra materialne zostały tam we Lwowie, n...
2,2’-dihydroksy-1,1’-binaftyl (BINOL) i jego pochodne. Wybrane syntezy i zastosowanie. Część. II
An invention of new catalytic strategies for stereoselective synthesis is of current interest to many laboratories worldwide . Over the past few decades a remark - able progress in the field of stereocontrolled synthesis...
Zastosowania enzymów z tkanek zwierzęcych w syntezie organicznej i biokatalizie. Część I. Hydrolazy
This work presents systematically enzymes which can be obtained form animal tissue and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolat...
Nitroksyl (HNO/NO-) - cząsteczka o potencjalnym znaczeniu farmakologicznym
Nitrogen compounds, as an essential component of many reactions occurring in living organisms, become the object of an extensive research. These compounds became the focus of interest after the properties of nitric oxide...