A porous 3d-4f heterometallic metal–organic framework for hydrogen storage

A heterometallic metal–organic framework, {[Ce(oda)₃Zn_1.5(H₂O)₃]·0.75H₂O}_n (1, H₂oda = oxydiacetic acid), has been synthesized under hydrothermal condition. The single-crystal X-ray diffraction analysis reveals that compound 1 belongs to hexagonal crystal system with space group P6/mcc and exhibits 3D porous framework. The hydrogen adsorption experiments suggest that 1 possesses reversible hydrogen storage capacity, up to 1.34 wt.% at 77 K and 0.86 wt.% at 298 K, respectively.     

Preparation of Titanocene–Gold Compounds Based on Highly Active Gold(I)-N-Heterocyclic Carbene Anticancer Agents: Preliminary in vitro Studies in Renal and Prostate Cancer Cell Lines

Heterometallic titanocene-based compounds containing gold(I)-phosphane fragments have been extremely successful against renal cancer in vitro and in vivo. The exchange of phosphane by N-heterocyclic carbene ligands to improve or modulate their pharmacological profile afforded bimetallic complexes effective against prostate cancer, but less effective against renal cancer in vitro. Herein we report the synthesis of new bimetallic Ti–Au compounds by the incorporation of two previously reported highly active gold(I)-N-heterocyclic carbene fragments derived from 4,5-diarylimidazoles. The two new compounds [(η⁵-C₅H₅)₂TiMe(μ-mba)Au(NHC)] (where NHC=1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene, NHC-Bn 2 a ; or 1,3-diethyl-4,5-diphenylimidazol-2-ylidene, NHC-Et 2 b ) with the dual linker (-OC(O)-p-C₆H₄-S-) containing both a carboxylate and a thiolate group were evaluated in vitro against renal and prostate cancer cell lines. The compounds were found to be more cytotoxic than previously described Ti–Au compounds containing non-optimized gold(I)-N-heterocyclic fragments. We present studies to evaluate their effects on cell death pathways, migration, inhibition of thioredoxin reductase (TrxR) and vascular endothelial growth factor (VEGF) in the PC3 prostate cancer cell line. The results show that the incorporation of a second metallic fragment such as titanocene into biologically active gold(I) compounds improves their pharmacological profile.     

Binary and Ternary Heterometallic (La<Superscript>3+</Superscript>, Gd<Superscript>3+</Superscript>, Y<Superscript>3+</Superscript>)–Eu<Superscript>3+</Superscript> Functionalized SBA-15 Mesoporous Hybrids: Chemically Bonded Assembly and Photoluminescence

A novel kind of organic–inorganic monomer SUASi has been achieved by modifying 5-sulfosalicylic acid (SUA) with 3-aminopropyltrimethoxysilane (APS), subsequently binary and ternary Eu³⁺ mesoporous hybrid materials with 5-sulfosalicylic acid (SUA)-functionalized SBA-15 and 1,10-phenanthroline (phen) are synthesized by co-condensation of SUASi and TEOS in the presence of Eu³⁺ complex and Pluronic P123 as a template. Finally, luminescent hybrid mesoporous materials consisting of active rare earth ions (Eu³⁺)—inert rare earth ions (Y³⁺, La³⁺, Gd³⁺) complex covalently bonded to the mesoporous materials network have been obtained via this sol–gel approach. The physical characterization and photoluminescence of all these resulting materials are studied in detail. Especially the luminescent behavior has been studied with the different ratios of Eu³⁺–(Y³⁺, La³⁺, Gd³⁺), which suggests that the existence of inert rare earth ions can enhance the luminescence intensity of Eu³⁺. This may be due to the intramolecular energy transfer between Y³⁺, La³⁺, Gd³⁺, and Eu³⁺ through the covalently bonded mesoporous framework.     

A 4d-4f heterometallic coordination polymer： Synthesis, crystal structure and near-infrared luminescent properties

A 4d-4f heterometallic coordination polymer, [AgNd(pydc)2]?2H2O (1) (H2pydc=pyridine-3,4-dicarboxylic acid), was synthesized under hydrothermal conditions, and further characterized by elemental analysis, IR, thermogravimetric analysis and single-crystal X-ray dif-fraction. Complex 1 featured a three-dimensional (3D) framework containing one-dimensional (1D) channels occupied by free water molecules, which was constructed from 1D inorganic heterometallic chains and linear pydc linkers. To our knowledge, complex 1 represented a rare example of 3D open-framework 4d-4f heterometallic coordination polymer. After removal of the water molecules from complex 1, the remaining material had high thermal stability. Moreover, the near-infrared luminescent properties of 1 were also investigated in the solid state.     

Solely μ1,1-azido-bridged heterometallic compound

Solely end-on azide-bridged bimetallic Cu(II)–Mn(III) tetranuclear compound [Mn(salophen)(H₂O)]₂[Cu₂(N₃)₆]·4H₂O shows strong ferromagnetic coupling, giving rise to a ground spin state of S = 5.     

Direct synthesis and characterization of novel homo- and heterometallic mixed-ligand tetrazolate complexes, Cu(en)(tz)2 and Cu(en)2Zn(tz)4 [en = ethylenediamine, tz = tetrazolate]

For the first time, tetrazolate complexes have been prepared by direct synthesis. Two novel homo- and heterometallic mixed-ligand complexes, Cu(en)(tz)₂ and Cu(en)₂Zn(tz)₄, have been synthesized using tetrazole (Htz), ethylenediamine (en), metallic copper and zinc oxide as starting materials. Both tetrazolates were characterized by single-crystal X-ray diffraction, IR spectroscopy and thermal analysis. The complexes present 1D coordination polymers, with tetrazolate anions acting as both monodentate and bridging ligands.     

A 3d–3d heterometallic organic framework consisting of two cross-linked coordination polymers

A novel 3d–3d heterometallic metal-organic framework, [Zn₂(ox)₃] [{Cu^I(4,4-bipy) }₂] · C₂H₆O₂ (ox = axalate, 4,4-bipy = 4,4-bipyridine), 1 has been synthesized by using two bidentate ligands under hydrothermal condition. The Cu(II) ion in the starting materials was reduced to Cu(I) along with the partial oxidation of the ethylene alcohol molecules to the oxalate, leading to the formation of 1. Compound 1 is a rare three-dimensional framework constructed by intercalation of the metal oxalate honeycomb sheets with the 1-D coordination polymer.     

Partial oxidation of methane to syngas over SmCoO3-derived catalysts: the effect of the supercritical fluid assisted modification of the perovskite precursor

Syngas is crucial raw for the production of hydrogen-rich gas for green energy and for various petrochemical processes. Herein, we report the Syngas production via partial oxidation of methane (POM) on new SmCoO₃-derived catalysts produced from simple individual precursor. Precursor modified by supercritical antisolvent precipitation (SAS) involving supercritical CO₂ yields SmCoO₃ with finer grains, and the catalytic activity of respective Co/Sm₂O₃ composite formed in situ during POM is considerably enchanced. This catalyst does not undergo coking, and provides CO and H₂ yields of 75–88% for 55 h at 900 °C, thereby being the most efficient POM catalysts derived from non-substituted LnCoO₃. Thus, the prospects of exploiting SAS modification of the precursor for SmCoO₃ to enhance the catalytic activity of the daughter Co/Sm₂O₃ composites are demonstrated for the first time. Given the overall simplicity in production, studied Co/Sm₂O₃ composites can also be convenient systems for further development of POM catalysts.     

Two temperature-dependent 2D heterometallic Cd(II)–Dy(III) coordination polymers exhibiting slow magnetic relaxation and luminescence properties

Two unique two-dimensional (2D) Cd(II)–Dy(III) heterometallic coordination polymers, {[DyCd(HPMA)(PMA)₂(H₂O)₄]·2H₂O}_n (1) and [DyCd(PAA)(PMA)₂(H₂O)₃]_n (2, PAA^– = phenylacetate), were prepared successfully based on the phenylmalonic acid (H₂PMA). The construction of two polymers is sensitive to the reaction temperature and can be synthesized directionally at room temperature and 90 °C, respectively. Complexes 1 and 2 display 2D layer structures that include dinuclear [Dy₂] cluster node and Dy(III)-based 1D zigzag chain motif severally. The Dy(III)-based units in two structures both are spaced well with the adjacent ones by the diamagnetic Cd(II)-based moieties. The magnetic studies reveal that 1 and 2 both display slow magnetic relaxation with temperature-dependent relaxation peaks producing an effective energy barrier (Δτ) of 74.5 and 32.1 K, separately. Furthermore, the solid-state photophysical properties of 1 and 2 show strong characteristic luminescent emissions of Dy(III) ion in the visible region.