Synthesis, Structure, Characterization, and Redox Properties of the Porous MIL‐68(Fe) Solid

Abstract

A new porous FeIII‐based MOF, formulated Fe(OH)(BDC)·(dmf)x with x ≈ 1.1 and presenting the MIL‐68 topology, was prepared by reaction of an iron(III) salt and terephthalic acid (H2BDC) in N,N′‐dimethylformamide (dmf) under acidic conditions. The structure and properties of this solid were studied by means of X‐ray diffraction, thermogravimetric analysis, nitrogen sorption, 57Fe Mössbauer spectrometry, and electrochemical lithium insertion.

Structural and elemental influence from various MOFs on the performance of Fe@C catalysts for Fischer–Tropsch synthesis

“…N 2 physisorption at 77 K, TGA and XRD confirmed the presence of MIL-68 [21][22][23] , MIL-88A [24][25][26] , MIL-100 [27][28][29] , MIL-101 [30][31][32] , and MIL-127 [33][34][35] (see Table S1, Figure S1 and Figure S2) ‡. XRD of the F300 Fe-BTC MOF revealed a very low degree of crystallinity, but the MIL-100 topology was confirmed since the isotherm contained an additional step in the micropore regime corresponding to the large cages in the MTN-type framework [27][28] .…”

Probing the Structural Stability of and Enhanced CO2 Storage in MOF MIL‐68(In) under High Pressures by FTIR Spectroscopy

“…[16] Indeed, in the MIL-68(In) framework, 1/3 of the hydroxyl groups point towards the voids of the triangular channels, and 2/3 are oriented towards the hexagonal ones. [7][8] Thus, the band with the higherf requency can be assigned to OH groups in the large pores (hexagonal channels), and that with lower frequency is thus characteristico ft he OH groups in the small pores (triangular channels). Thef requency difference (19 cm À1 )o ft he OH groupsi nt he triangular pores between the as-made and activated framework is likely duet oaf raction of the hydroxyl groups experiencingaweak perturbation with DMF molecules beforea ctivation.…”

“…[5] As eries of MOFs denoted MIL-68 has attracted much recenta ttention because of its distinctive structure, which containst wo typeso fc hannels with different openings izes. The first MIL-68 material( with V as metali on) was synthesized by Ferey and co-workersi n 2004, [6] and severalo ther analogues with different metal ions (Ga, [7] In, [7] Fe, [8] and Al [9] )w ere reported later.A ll these isostructures of MIL-68, whichc rystallize in space group Cmcm,a re built up by the connection of corner-sharing metal-centered octahedral units MO 4 (OH) 2 ,i nw hich the metal center is six coordinatedw ith four oxygen atoms from carboxylate groups of the terephthalate ligandsa nd two hydroxyl oxygen atoms. The adjacento ctahedral units are linked togethert hrough two hydroxylg roups located in trans positionsa nd connected through carboxylate groups (Figure 1a).…”

Dynamic Nuclear Polarization Enhanced Solid‐State NMR Spectroscopy of Functionalized Metal–Organic Frameworks

“…[11] We report here the first application of DNP-enhanced solid-state NMR spectroscopy to MOF materials. The experiments are demonstrated on the N-functionalized MOF compound (In)-MIL-68-NH 2 [4,12,13] (1), on a partially functionalized variant of 1 with a terephthalate:aminoterephthalate ratio of 80:20 (2), and on a 10 % proline-functionalized derivative of 1, [14] (In)-MIL-68-NH-Pro (3) (Scheme 1). These three materials are representatives of an as-synthesized functionalized MOF (compound 1), a partially functionalized MOF (also called MIXMOF, [15] compound 2), and of a postsynthetically modified MOF (compound 3).…”