Multifunctional metal-organic frameworks : from academia to industrial applications

After three decades of intense and fundamental research on metal-organic frameworks (MOFs), is there anything left to say or to explain? The synthesis and properties of MOFs have already been comprehensively described elsewhere. It is time, however, to prove the nature of their true usability: technological applications based on these extended materials require development and implementation as a natural consequence of the up-to-known intensive research focused on their design and preparation. The current large number of reviews on MOFs emphasizes practical strategies to develop novel networks with varied crystal size, shape and topology, being mainly devoted to academic concerns. The present survey intends to push the boundaries and summarise the state-of-the-art on the preparation of promising (multi) functional MOFs in worldwide laboratories and their use as materials for industrial implementation. This review starts, on the one hand, to describe several tools and striking examples of remarkable and recent (multi) functional MOFs exhibiting outstanding properties (e.g., in gas adsorption and separation, selective sorption of harmful compounds, heterogeneous catalysis, luminescent and corrosion protectants). On the other hand, and in a second part, it intends to use these examples of MOFs to incite scientists to move towards the transference of knowledge from the laboratories to the industry. Within this context, we exhaustively review the many efforts of several worldwide commercial companies to bring functional MOFs towards the daily use, analysing the various patents and applications reported to date. Overall, this review goes from the very basic concepts of functional MOF engineering and preparation ending up in their industrial production on a large scale and direct applications in society

Redetermination at 180 K of a layered lanthanide–organic framework

The asymmetric unit of the title compound, poly[(μ4-{[bis­(hydrogen phospho­natometh­yl)aza­nium­yl]meth­yl}phospho­nato)lanthanum(III)], [La(C3H9NO9P3)]n, comprises an La3+ center and a H3nmp3− anion (where H3nmp3− is a residue of partially deprotonated nitrilo­tris­(methyl­ene­phospho­nic acid), namely {[bis­(hydrogen phospho­natometh­yl)aza­nium­yl]meth­yl}­phos­pho­nate). This study concerns a structural redetermination using single-crystal X-ray diffraction data, collected at the low temperature of 180 K, of a recently investigated material whose structural details have been proposed from powder X-ray diffraction studies [Silva et al. (2011 ▶). J. Am. Chem. Soc. 133, 15120–15138]. The main difference between the two models rests on the position of the H atoms. While two H atoms were modeled as attached to the same phospho­nate group in the powder determination, in the current model, the same H atoms are instead distributed among two of these groups. The sample studied was an inversion twin

(R)-(1-Ammonio­prop­yl)phospho­nate

The title compound, C3H10NO3P, crystallizes in its zwitterionic form, H3N+CH(C2H5)PO(O−)(OH), with the asymmetric unit being composed by two of such entities (Z′ = 2). The crystal packing leads to a sequence of hydro­phobic and hydro­philic layers. While the hydro­phobic layer comprises the aliphatic substituent groups, the hydro­philic one is held together by a series of strong and rather directional N+—H⋯O and O—H⋯O hydrogen bonds

4,4′-Di-tert-butyl-2,2′-dipyridinium dichloride

In the title compound, C18H26N2 2+·2Cl−, the complete dication is generated by crystallographic inversion symmetry; both N atoms are protonated and engaged in strong and highly directional N—H⋯Cl hydrogen bonds. Additional weak C—H⋯Cl contacts promote the formation of a tape along ca. [110]. The crystal structure can be described by the parallel packing of these tapes. The crystal studied was a non-merohedral twin with twin law [−1 0 0, 0 −1 0, −0.887 0.179 1] and the final BASF parameter refining to 0.026 (2)

Tris(4,4′-di-tert-butyl-2,2′-bipyridine-κ2 N,N′)molybdenum(II) μ6-oxido-dodeca-μ2-oxido-hexa­oxidohexa­molybdate(VI) acetonitrile tetra­solvate

The asymmetric unit of the title compound, [Mo(C18H24N2)3][Mo6O19]·4CH3CN, comprises an [Mo(di-t-Bu-bipy)3]2+ cation (di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine), two halves of Lindqvist-type [Mo6O19]2− anions (with each anion completed by the application of a center of inversion) and four acetonitrile solvent mol­ecules. The geometry around the metal atom of the cation resembles a distorted octa­hedron, with each of the three di-t-Bu-bipy ligands being almost planar [deviation from planarity < 6.3 (2)°]. Supra­molecular inter­actions, namely Mo=O⋯π, C N⋯π, C—H⋯O and C—H⋯N, along with electrostatic forces, mediate the crystal packing. Two of the tert-butyl groups are affected by rotational disorder which was modeled over two distinct positions with major site occupancies of 0.707 (9) and 0.769 (8)

Propyl­ammonium 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dionate

The title salt, C3H10N+·C14H8F3O2 −, constitutes the first organic crystal containing a residue of 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dione. The terminal –CF3 group is disordered over two locations [occupancy ratio = 0.830 (7):0.170 (7)]. Bond delocalization involving the two carbonyl groups and the α-carbon was observed. The crystal packing is mediated by several supra­molecular inter­actions, namely charged-assisted N—H⋯O hydrogen bonds, C—H⋯F and C—F⋯F short contacts and C—H⋯π inter­actions

Poly[[μ2-aqua-tetraaquahexakis(μ4-naph­thalene-2,6-dicarboxylato)tetra­holmium(III)] 1.75-hydrate]

In the title compound, {[Ho4(C12H6O4)6(H2O)5]·1.75H2O}n, which is isostructural with its Tb3+- and Eu3+-containing analogues, there are four crystallographically independent Ho3+ centres, each exhibiting a highly distorted HoO8 bicapped trigonal-prismatic coordination environment. Adjacent polyhedra are inter­connected via the carboxyl­ate groups and one μ2-bridging water mol­ecule, forming one-dimensional chains propagating along [100]. The naphthalene-2,6-dicarboxylate ligands further inter­connect these chains into a three-dimensional framework, which has zigzag channels housing the water mol­ecules. Two naphthalene-2,6-dicarboxylate bridging ligands have their centroids located on crystallographic centres of inversion. One water O atom has a fixed site occupancy factor of 0.75

4,4′-Di-tert-butyl-2,2′-bipyridine

In the title compound, C18H24N2, the mol­ecular unit adopts a trans conformation around the central C—C bond [N—C—C—N torsion angle of 179.2 (3)°], with the two aromatic rings almost coplanar [dihedral angle of only 0.70 (4)°]. The crystal packing is driven by co-operative contacts involving weak C—H⋯N and C—H⋯π inter­actions, and also the need to fill effectively the available space

catena-[1,3-diammoniopropane di-mu2-hydroxodi-mu4-phosphato-trioxotrivanadium dihydrate]: a redetermination at 180 (2) K

The crystal structure of the title compound, (C3H12N2)- [V3O3(OH)2(PO4)2] 2H2O, has been reported by Soghomonian et al. [Chem. Mater. (1993), 5, 1690±1691]. We present here a redetermination of greatly improved precision and at a low temperature of 180 (2) K. The H atoms connected to oxygen have been successfully located and the coordination environments of the two crystallographically independent vanadium centres have been properly elucidated. Large channels, running along the a direction, contain water molecules and 1,3-diammoniopropane cations that are strongly hydrogen bonded to the anionic framework through N+ÐH O and OÐH O interactions. One vanadyl (V O) bond and the central ±CH2± group of 1,3-diammoniopropane are located on a mirror plane

trans-Bis(4,7-diphenyl-1,10-phenanthroline-κ2 N,N′)bis­(nitrato-κ2 O,O′)zinc(II)

The title compound, [Zn(NO3)2(C24H16N2)2], is a twofold axially symmetric coordination compound. Given that the Zn—O interactions [2.4926 (15) and 2.6673 (15) Å] can be considered as weakly bonding and the nitrate ions share the same C 2 axis of the Zn(dpp)2 fragment (dpp is 4,7-diphenyl-1,10-phenanthroline), these anions belong to the coordination sphere of Zn2+, leading to a complex with an overall coordination number of 8 for the metal ion