Direct covalent post-synthetic chemical modification of Cr-MIL-101 using nitrating acid

Bernt, Stephan; Guillerm, Vincent; Serre, Christian; Stock, Norbert

doi:10.1039/c0cc04526h

Cited by 274 publications

(295 citation statements)

References 23 publications

(10 reference statements)

Supporting

Mentioning

277

Contrasting

Unclassified

Order By: Relevance

“…The IR spectra of NH 2 -MIL-101(Cr) show the vibrational bands of the amino-groups at around 3,337 and 3,467 cm −1 [29,30]. The bands at around 1,352 and 1,545 cm −1 confirm the existence of nitro-groups in NO 2 -MIL-101(Cr) [29,30]. The observed powder XRD patterns of these three MOFs (Fig.…”

Section: Preparation Of Nanoscale Mofsmentioning

confidence: 63%

“…2a-c), all the bands of protonated carboxylic groups at around 1,710 cm −1 disappear in these three MOFs, indicating that all of the carboxyl groups were coordinated with Cr 3+ [28]. The IR spectra of NH 2 -MIL-101(Cr) show the vibrational bands of the amino-groups at around 3,337 and 3,467 cm −1 [29,30]. The bands at around 1,352 and 1,545 cm −1 confirm the existence of nitro-groups in NO 2 -MIL-101(Cr) [29,30].…”

Section: Preparation Of Nanoscale Mofsmentioning

confidence: 99%

See 1 more Smart Citation

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

et al. 2017

View full text Add to dashboard Cite

The preparation and development of novel optical thin films are of great importance to functional optical and opto-electric components requiring a low refractive index. In this study, a typical metal-organic framework (MOF), MIL-101(Cr), is selected as the research model. The corresponding MOF nanoparticles are prepared by a hydrothermal method and the optical thin films are successfully prepared by spincoating. The optical properties of the corresponding MOF thin films are controlled by changing the type of functional groups on the benzene ring of the ligand (terephthalic acid) on MOFs. The functional groups are hydrogen atoms (H), electron donating groups (-NH 2, -OH) and electron withdrawing groups (-NO 2, -(NO 2 ) 2 or F 4 ), respectively. It is found that the effective refractive index (n eff ) of MOF thin films decreases along with the increasing voids among MOF nanoparticles. In addition, the extinction coefficient (k) increases with the addition of electron donating groups, and decreases with the addition of electron withdrawing groups. Among the MOFs used in this study, the n eff of NO 2 -MIL-101(Cr) containing electron withdrawing groups is as low as~1.2, and value of k is particularly low, which suggests its potential application in antireflective devices. In addition, the intrinsic refractive index (n dense ) of the dense MOF materials evaluated according to their porosity increases with the number of the functional groups, and the n dense of the two nitro-substituted MOFs is greater than that of the single nitro-substituted one, and the latter is bigger than that of hydroxyl-substituted one, which is close to that of amino-functionalized one. The diversity of ligands in MOFs makes them a promising new generation of optical materials.

show abstract

Section: Preparation Of Nanoscale Mofsmentioning

confidence: 63%

Section: Preparation Of Nanoscale Mofsmentioning

confidence: 99%

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The postsynthetic modification of MIL-101Cr followed the route of nitration by use of mixed nitrating acid (concentrated HNO 3 / concentrated H 2 SO 4 ) to yield MIL-101Cr-NO 2 (3) and subsequent reduction by SnCl 2 /concentrated HCl to obtain MIL-101Cr-NH 2 (1) (Scheme 1) (see Supporting Information). 36 Nitration of the MIL-101Cr sample with a short defined reaction time reproducibly leads to the formation of MIL101Cr samples containing incompletely (78 mol %) nitrated organic linkers, which means it produces mixed-ligand MIL101Cr samples containing both terephthalate and 2-nitroterephthalate (molar ratio ∼1:3.6). This approach opens a new possibility toward the synthesis of mixed-ligand porous materials.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Scheme 1). 36 Moreover, partially functionalized materials (-pNO 2 and -pNH 2 ) with two different organic ligands in the same framework have been synthesized, which are difficult to obtain through direct synthesis. Recently a water sorption study of functional MIL-101Cr materials was reported in the literature.…”

Section: ■ Introductionmentioning

confidence: 99%

Water Sorption Cycle Measurements on Functionalized MIL-101Cr for Heat Transformation Application

et al. 2013

View full text Add to dashboard Cite

ABSTRACT:The water loading capacity and water cycle stability (40 adsorption/ desorption cycles) of four nitro-or amino-functionalized MIL-101Cr materials (1−4) is assessed for heat transformation applications. Amino-or nitro-functionalized (1, 3) and partially amino-or nitro-functionalized MIL-101Cr (2, 4) have been synthesized through time-controlled postsynthetic modification of MIL-101Cr. The partially functionalized materials (2, 4) contain about 78 mol % amino-or nitro-functionalized terephthalate linker. Hydrophilic nitro or amino functionalities were introduced into MIL-101Cr in order to achieve water loading at lower p/p 0 values for possible use in thermally driven adsorption chillers or heat pumps. Among the four materials studied, fully aminated MIL-101Cr-NH 2 , 1, and partially aminated MIL-101Cr-pNH 2 , 2, showed the best water loadings (about 1.0 gH 2 O/gMIL) as well as water stability over 40 adsorption−desorption cycles. After 40 cycles, the X-ray powder diffractogram and Brunauer−Emmett−Teller (BET) surface determination of amino-functionalized materials indicated structural integrity with Δ BET = −6.3% after 40 cycles, while the nitro-functionalized MIL-101Cr exhibited a decrease in their BET surface of Δ BET = −25% and −20% for 3 and 4, respectively.

show abstract

“…A few of these prototypes can even form mixedcomponent (solid-solution) crystals with variable concentration/ ratio of functional building blocks, which in principle allows the structure/property to be adjusted more continuously and precisely 15,16 . However, so far there is no rational strategy to directly monitor/control the composition of solid-solution frameworks during the synthesis process because complicated reaction environments involving solvents and/or liquid reactants are generally required for known direct-synthesis and postsynthetic modification (PSM) 3,7,[17][18][19][20][21] methods. It should be noted that the reaction time/feeding ratio can be hardly used as a parameter for precise control over the reaction progress/ framework composition, since the two variables have complicated relationships.…”

mentioning

confidence: 99%

Self-catalysed aerobic oxidization of organic linker in porous crystal for on-demand regulation of sorption behaviours

Liao

Zhu²,

Zhang

2015

Nat Commun

View full text Add to dashboard Cite

Control over the structure and property of synthetic materials is crucial for practical applications. Here we report a facile, green and controllable solid-gas reaction strategy for on-demand modification of porous coordination polymer. Copper(I) and a methylene-bridged bis-triazolate ligand are combined to construct a porous crystal consisting of both enzyme-like O 2 -activation site and oxidizable organic substrate. Thermogravimetry, singlecrystal X-ray diffraction, electron paramagnetic resonance and infrared spectroscopy showed that the methylene groups can be oxidized by O 2 /air even at room temperature via formation of the highly active Cu(II)-O 2 ? À intermediate, to form carbonyl groups with enhance rigidity and polarity, without destroying the copper(I) triazolate framework. Since the oxidation degree or reaction progress can be easily monitored by the change of sample weight, gas sorption property of the crystal can be continuously and drastically (up to 4 orders of magnitude) tuned to give very high and even invertible selectivity for CO 2 , CH 4 and C 2 H 6 .

show abstract

Direct covalent post-synthetic chemical modification of Cr-MIL-101 using nitrating acid

Cited by 274 publications

References 23 publications

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

Water Sorption Cycle Measurements on Functionalized MIL-101Cr for Heat Transformation Application

Self-catalysed aerobic oxidization of organic linker in porous crystal for on-demand regulation of sorption behaviours

Contact Info

Product

Resources

About