Aerogels of 1D Coordination Polymers: From a Non-Porous Metal-Organic Crystal Structure to a Highly Porous Material

Abstract

Abstract:The processing of an originally non-porous 1D coordination polymer as monolithic gel, xerogel and aerogel is reported as an alternative method to obtain novel metal-organic porous materials, conceptually different to conventional crystalline porous coordination polymer (PCPs) or metal-organic frameworks (MOFs). Although the work herein reported is focused upon a particular kind of coordination polymer ([M(µ-ox)(4-apy) 2 ] n , M: Co(II), Ni(II)), the results are of interest in the field of porous materials and of MOFs, as the employed synthetic approach implies that any coordination polymer could be processable as a mesoporous material. The polymerization conditions were fixed to obtain stiff gels at the synthesis stage. Gels were dried at ambient pressure and at supercritical conditions to render well shaped monolithic xerogels and aerogels, respectively. The monolithic shape of the synthesis product is another remarkable result, as it does not require a post-processing or the use of additives or binders. The aerogels of the 1D coordination polymers are featured by exhibiting high pore volumes and diameters ranging in the mesoporous/macroporous regions which endow to these materials the ability to deal with large-sized molecules. The aerogel monoliths present markedly low densities (0.082-0.311 g¨cm´3), an aspect of interest for applications that persecute light materials.

Multifunctional coordination polymers based on copper with modified nucleobases, easily modulated in size and conductivity

“…Coordination polymers (CPs) are a large family of compounds, generally formed by a metal cation and an organic ligand [1]. The possibilities of combining the building blocks are extraordinary and for about 50 years, researchers have been able to obtain more than 60,000 CPs with different structures and properties [2,3,4,5]. Despite these great advances in synthesis and characterization, new and interesting challenges have appeared for them, so within the wide variety of potential applications that these materials can present, very recently it has been described their ability as nanocarriers at the cellular level [6].…”

Polyimide Aerogels Cross-Linked with Aminated Ag Nanowires: Mechanically Strong and Tough

“…Instead of using small molecule cross-linkers, adding nanoparticles into aerogels appears to be a reliable method for their modification. Nanoparticles such as graphene oxide [ 28 ], nano-silica, carbon nanotubes [ 29 , 30 , 31 ], MOFs (Metal Organic Frameworks) [ 32 ] and cellulose nano-fibers [ 33 ] are showing promise to act as physical cross-linking points and reinforcement at the same time, which may improve the properties of aerogels remarkably.…”

A comprehensive review on the synthesis techniques of porous materials for gas separation and catalysis

“…These are metal‐incorporated coordination polymers having the formula as [M(μ‐oxalate)(4‐aminopyridine) 2 ] n where M is a metal precursor (Co 2+ , Ni 2+ , or Cu 2+ ). [ 77 ] The molar ratio of metal, oxalate, and 4‐aminopyridine was 1:1:2 for the gel‐forming effect. The mixture of ligands and metal ions was prepared in N,N ‐dimethylformamide, and metal–organic gels were formed upon ultrasonication of the mixture.…”