Structural, Luminescent, and Magnetic Properties of Three Novel Three-Dimensional Metal-Organic Frameworks Based on Hexadentate N,N′-bis(4-picolinoyl)hydrazine

Metal–organic frameworks based on tetraphenylpyrazine-derived tetracarboxylic acid for electrocatalytic hydrogen evolution reaction and NAC sensing

Tetraphenylpyrazine-derived tetracarboxylic acid-based new MOFs and their promising applications in the electrocatalytic hydrogen evolution reaction.

Tuning of Luminescent and Magnetic Properties via Metal Doping of Zn-BTC Systems

In order to assess how metal doping affects the luminescence and magnetic properties of anionic Metal-Organic Frameworks (MOFs), seven single-metal doped MOFs {M-Zn-BTC}{Me2NH2+} (M = Co, Cu, Ni, Mn, Ca, Mg, Cd) and three dual-metal doped MOFs {Zn-M1-M2-BTC}{Me2NH2+} (M1 = Co, Cu; M2 = Ni, Co) were synthesized. Trace amounts of different metals were doped via addition of another metal salt during the synthetic process. All compounds retained the same crystal structure as that of the parent {Zn-BTC}{Me2NH2+} MOF, which was supported by single crystal and powder X-ray diffraction studies. Thermal Gravimetric Analysis (TGA) of these compounds also revealed that all MOFs had similar stability up to ~450 °C. Solid state photoluminescent studies indicated that {Zn-Mn-BTC}{Me2NH2+}, {Zn-Cd-BTC}{Me2NH2+}, and {Zn-Ca-BTC}{Me2NH2+} had a significant red shifting effect compared to the original {Zn-BTC}{Me2NH2+} MOF. Applications of this doping method to other MOF systems can provide an efficient way to tune the luminescence of such systems, and to obtain a desired wavelength for several applications such as sensors and white light LED materials. Because Zn, Co, Cu, Ni, Mg have magnetic properties, the effect of the doping metal atom on the magnetism of the {Zn-BTC}{Me2NH2+} networks was also studied. To characterize the magnetic behavior of the synthesized MOFs, we conducted low-temperature (10 K) saturation remanence experiments in a 3 Tesla applied field, with the principal goal of identifying the domain state of the synthesized materials (Zn, Zn-Co, Zn-Cu-Co, Zn-Cu-Ni, Zn-Mg, Zn-Mn, Zn-Ni-Co, Zn-Ni). During room/low temperature saturation magnetization experiments, Zn, Zn-Co, Zn-Cu-Co, and Zn-Cu-Ni systems yielded data indicative of superparamagnetic behavior, yet during zero field and field cooled experiments Zn-Co showed a slight paramagnetic effect, Zn showed no temperature dependence on warming and Zn-Cu-Co and Zn-Cu-Ni demonstrated only a slight temperature dependence on warming. These behaviors are consistent with ferromagnetic ordering. Zero field and field cooled experiments indicate that Zn-Mg and Zn-Ni have a ferromagnetic ordering and Zn-Mn and Zn-Ni-Co show paramagnetic ordering behavior.

Controlled synthesis and morphology dependent luminescence of Lu2O2S:Eu3+ phosphors

The dependence of Lu₂O₂S:Eu³⁺ luminescence performance on different morphologies has been explored and possible reasons are proposed.

Syntheses, structures and luminescent properties of six divalent metal terephthalate coordination polymers based on three new flexible bis(imidazole) ligands

Six coordination polymers based on terephthalate and one of three bis(imidazole) ligands are reported.

Novel Zn(II) coordination polymer based on 1,2-bis(4-pyridyl)hydrazine — From two-dimensional to three-dimensional network

Two MOFs were reported based on Zn(II) with 1,2-bis(4-pyridyl)hydrazine (L1); a two-dimensional interpenetrating MOF I of formula [Zn2(L1)2(L2)2]∞ was formed with terephthalic acid (L2) as an additional linker. A three-dimensional MOF II of formula [Zn2(L1)2(L3)2]∞, was formed with the use of a larger spacer 2,6-naphthalenedicarboxylic acid (L3). MOF II consists of large porosity with a total volume of 3746 Å3 that occupies 34.1% of the unit cell.

catena-Poly[[chloridomercury(II)]-μ-1,4-diaza-bicyclo-[2.2.2]octane-κN:N'-[chlorido-mercury(II)]-di-μ-chlorido]

In the title coordination polymer, [Hg(2)Cl(4)(C(6)H(12)N(2))](n), each Hg(II) center within the chain is four-coordinated by one terminal Cl atom, two bridging μ(2)-Cl atoms, and one N-atom donor from a μ(2)-1,4-diaza-bicyclo-[2.2.2]octane (μ(2)-daco) ligand in a distorted tetra-hedral geometry. The daco ligand acts as an end-to-end bridging ligand and bridges adjacent Hg(II) centers, forming a chain running along [001]. Weak C-H⋯Cl hydrogen-bonding inter-actions link the chains into a three-dimensional network. Comparison of the structural differences with previous findings suggests that the space between the two N donors, as well as the skeletal rigidity in N-heterocyclic linear ligands, may play an important role in the construction of such supra-molecular networks.