The new nanocomposites, Pd/C/ZrO
, PdO/ZrO
and Pd/PdO/ZrO
, were prepared by thermal conversion of Pd@UiO-66-Zr-NH
(MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly ...distributed on the ZrO
or C/ZrO
matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO-66-Zr-NH
. The most active PdO/ZrO
composite, formed benzophenone with TOF up to 1600 h
, while by using Pd@UiO-66-Zr-NH
, much lower TOF values, 51-95 h
, were achieved. After the reaction, PdO/ZrO
was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO
and PdO/ZrO
catalysts under microwave irradiation.
The new nanocomposites, Pd/C/ZrO2, PdO/ZrO2, and Pd/PdO/ZrO2, were prepared by thermal conversion of Pd@UiO‐66‐Zr−NH2 (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly ...distributed on the ZrO2 or C/ZrO2 matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X‐ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO‐66‐Zr−NH2. The most active PdO/ZrO2 composite, formed benzophenone with TOF up to 1600 h−1, while by using Pd@UiO‐66‐Zr−NH2, much lower TOF values, 51–95 h−1, were achieved. After the reaction, PdO/ZrO2 was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO2 and PdO/ZrO2 catalysts under microwave irradiation.
New Pd/C/ZrO2 and PdO/ZrO2 nanocomposites, obtained by direct pyrolysis of Pd@UiO‐66‐NH2 under nitrogen or air, presented high ability to form benzophenone according to carbonylative Suzuki pathway under 1 atm of CO with TOF up to 1600 h−1. Pd/ZrO2 nanocomposites are superior catalysts of Suzuki–Miyaura and carbonylative Suzuki–Miyaura coupling than the original Pd@UiO‐66‐NH2. Its morphology was preserved during the catalytic reaction.
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•The first application of the Pd(2-pymo)2n framework in hydrogen production from NH3BH3.•Selective transfer hydrogenation of phenylacetylene with NH3BH3 in water.•Evidence for the ...contribution of water as a hydrogen donor in the transfer hydrogenation.
The Pd(2-pymo)2n (2-pymo = 2-pyrimidinolate) framework catalyses the conversion of NH3BH3 to H2 in water. Independently of the amount of NH3BH3, ca. two equivalents of H2 were formed, most probably due to the presence of hydrophobic windows in the MOF structure. The introduction of styrene or phenylacetylene into the system, stopped H2 production. Instead, hydrogen transfer hydrogenation occurred. Mechanistic studies, performed with deuterated substrates, evidenced that water used as a solvent is also a hydrogen donor and contributed to the hydrogenation of styrene and phenylacetylene.
The novel Pd‐nanocomposites, fabricated via calcination of the MOF Pd(2‐pymo)2n (2‐pymo=2‐pyrimidinolate), were used for the first time in the transfer hydrogenation of phenylacetylene with NaBH4. ...The presence of Pd NPs or PdO in the studied materials was evidenced by XPRD, Raman spectroscopy, XPS and HR‐TEM. Under mild reaction conditions, in water as a solvent, Pd‐nanocomposites, Pd/CPYMO and PdO/Pd/CPYMO, provided better catalytic results than the pristine Pd(2‐pymo)2n, producing styrene with good selectivity. These two catalysts showed also good durability in subsequent reuses, while the productivity of PdO/CPYMO decreased after the second run.
Nanocomposites: MOFs‐templated strategy was used to fabricate palladium nanocatalysts for heterogeneous transfer hydrogenation of phenylacetylene with NaBH4 in water. Pd‐nanocomposites, fabricated via calcination of the Pd(2‐pymo)2n, presented high activity and selectivity towards styrene. The presence of Pd NPs or PdO in the studied materials was evidenced by XPRD, Raman spectroscopy, XPS and HR‐TEM. In all catalysts Pd0 was found after catalytic reaction.
UiO-66, MOF-808 and NU-1000 metal–organic frameworks exhibit a differentiated reactivity toward Mg(OMe)2(MeOH)24 related to their pore accessibility. Microporous UiO-66 remains unchanged while ...mesoporous MOF-808 and hierarchical micro/mesoporous NU-1000 materials yield doped systems containing exposed MgZr5O2(OH)6 clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P–F and P–S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions.
Five novel rhodium(II) complexes of general formula Rh2(μ-OOCCH3)4L2, where L is a triazolopyrimidine derivative, in particular dimethyl-1,2,4-triazolo1,5-apyrimidine (dmtp) for (1), ...5,7-diethyl-1,2,4-triazolo1,5-apyrimidine (detp) for (2), 7-isobutyl-5-methyl-1,2,4-triazolo1,5-apyrimidine (ibmtp) for (3), 7-hydroxy-5-methyl-1,2,4-triazolo1,5-apyrimidine (HmtpO) for (4) and 5,7-ditertbutyl-1,2,4-triazolo1,5-apyrimidine (dbtp) for (5) are reported. These first representatives of paddle-wheel dirhodium complexes with triazolopyrimidines have been characterized by IR and NMR spectroscopy as well as by single-crystal X-ray diffraction studies. Three of the new complexes (1), (2) and (5) were thoroughly screened in vitro for their cytotoxicity against human breast cancer cell line MCF-7 and L929 murine fibroblast cells. Favorably, they show significantly less effective inhibition on the cell growth of L929 than cisplatin under identical conditions. Complexes (1) and (5) display moderate cytotoxic activity (IC50 = 16.3–21.5 μM) against MCF-7 cells which is induced via reactive oxygen species-independent pathways. Extensive studies of rhodium complexes (1), (2) and (5) against microorganisms have shown that the tested compounds exhibit antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) while (5) significantly inhibited the growth of Malassezia furfur. The highest antibacterial, and antifungal activity, was observed for (5).
The first representatives of paddle-wheel dirhodium complexes with triazolopyrimidines of general formula Rh2(μ-OOCCH3)4L2, where L = triazolopyrimidine derivatives, were synthesized and structurally characterized. The potential of their biological use has been determined by assays including anticancer activity against MCF-7 cancer cells, toxicity on normal L929 cells, antibacterial and antifungal activity. Display omitted
•First representatives of paddle-wheel dirhodium complexes with triazolopyrimidines.•In vitro activity against human breast cancer cells MCF-7 and L929 murine fibroblasts.•Cytotoxicity on MCF-7 cells induced via reactive oxygen species-independent pathways.•Antibacterial activity against Staphylococcus aureus and Bacillus subtilis.•Antifungal activity against Malassezia furfur.
Spin density matrix elements were extracted from COMPASS data for
exclusive
\rho^{0}
ρ
0
meson muoproduction on a liquid hydrogen target. The measurement cover
the
kinematic range of 1.0 (GeV/
c
c
)
...^2
2
< Q^{2} <
<
Q
2
<
10.0 (GeV/
c
c
)
^2
2
,
5.0 GeV/
c^2
c
2
< W <
<
W
<
17.0 GeV/
c^2
c
2
and 0.01 (GeV/
c
c
)
^2
2
<p^{2}_{T}<
<
p
T
2
<
0.5 (GeV/
c
c
)
^2
2
.
Here,
W
W
denotes the mass of the final hadronic system,
Q^{2}
Q
2
the virtuality of the exchanged photon and
p_{T}
p
T
the transverse momentum of the
\rho^{0}
ρ
0
meson with respect to the virtual-photon direction. We observe a
violation of s-channel helicity conservation for the transition
\gamma^{*}_{T} \to \rho^{0}_{L}
γ
T
*
→
ρ
L
0
.
Additionally, we find a dominant contribution of the
natural-parity-exchange transitions.
Display omitted
•The first use of a metal azolate/carboxylate (MAC) Pd-dmpzc network for transfer hydrogenation.•Semihydrogenation of phenylacetylene in water with NaBH4 as a hydrogen ...source.•Superior catalytic properties of Pd-dmpzc compared to other Pd precursors.
The palladium azolate/carboxylate network (Pd-dmpzc) catalyses the selective hydrogenation of phenylacetylene to styrene in water. Under optimised conditions, at a Pd:NaBH4 ratio of 1:100 at 40 °C, Pd-dmpzc provided much better results than Pd(OAc)2 or PdCl2(CH3CN)2. Analysis of the recovered catalyst revealed the presence of different Pd2+ species and Pd0 NPs which contributed in the catalytic reaction.
Nitrogen and sulfur oxides (NO x and SO x ) emitted from fossil-fuel-fired facilities can be simultaneously absorbed into aqueous mixed solutions of sulfite and FeIIL, a ferrous ion coordinated to a ...ligand L (a chelate compound). Usually, the ligand L represents an anion of ethylenediaminetetraacetic acid (EDTA or edta). Nitrogen oxide (NO) sparingly soluble in water is promptly bound to the FeII(edta)(H2O)2– complex to form the FeII(edta)(NO2–compound. However, FeII(edta)(H2O2– chelate is oxidized to form FeIII(edta)(H2O)− by NO, NO2, and O2, normally coexisting in flue gases. Because the ferric complex does not react with NO, the suppression of these undesired oxidation processes is a very important technological problem to be overcome. Thus, in this work, the reduction kinetics of ferric ion by metal was discussed on the basis of the kinetic data regarding the ferric ion reduction in aqueous solutions of FeIII(edta)(H2O)− containing such pulverized metals as aluminum, tin, and zinc. The rate expression for the reduction of FeIII(edta)(H2O− by a metal powder was derived in terms of the rate-determining step approximation method. Laboratory-scale experiments were conducted in a recirculation-type glass reactor filled with 250 cm3 of solution. The influence of the following parameters on the reduction rate was investigated: (1) FeIII(edta)(H2O)0 – = 0.100–0.010 M, (2) metal0/FeIII(edta)(H2O)0 – = 10–100, (3) pH0 = 3–9, and (4) temperature = 20–80 °C. Zinc and aluminum powders were found to be effective reducing agents for ferric ions coordinated to EDTA. Similar experiments were carried out using a working solution in a simultaneous NO and SO2 removal process as a solvent of FeIII(edta)(H2O)− solution.
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