Coordination of 2,2'-(Trifluoroazanediyl)bis(,'-dimethylacetamide) with U(VI), Nd(III), and Np(V): A Thermodynamic and Structural Study.

Thermodynamic properties of the complexation of 2,2'-(trifluoroazanediyl)bis(,'-dimethylacetamide) (CFABDMA) with U(VI), Nd(III), and Np(V) have been studied in 1.0 M NaNO at 25 °C. Equilibrium constants of the complexation were determined by potentiometry and spectrophotometry.

Complexation of NpO with Amine-Functionalized Diacetamide Ligands in Aqueous Solution: Thermodynamic, Structural, and Computational Studies.

Complexation of Np(V) with three structurally related amine-functionalized diacetamide ligands, including 2,2'-azanediylbis( N, N'-dimethylacetamide) (ABDMA), 2,2'-(methylazanediyl)bis( N, N'-dimethylacetamide) (MABDMA), and 2,2'-(benzylazanediyl)bis( N, N'-dimethylacetamide) (BnABDMA), in aqueous solutions was investigated. The stability constants of two successive complexes, namely, NpOL and NpOL, where L stands for the ligands, were determined by absorption spectrophotometry. The results suggest that the stability constants of corresponding Np(V) complexes follow the trend: MABDMA > ABDMA ≈ BnABDMA.

Thermodynamic, Structural, and Computational Investigation on the Complexation between UO and Amine-Functionalized Diacetamide Ligands in Aqueous Solution.

The stability constants (log β), enthalpies of complexation (ΔH), and entropies of complexation (ΔS) for the complexes of uranium(VI) with a series of amine-functionalized diaetamide ligands, 2,2'-benzylazanediylbis(N,N'-dimethylacetamide) (BnABDMA), 2,2'-azanediylbis(N,N'-dimethylacetamide) (ABDMA), and 2,2'-methylazanediylbis(N,N'-dimethylacetamide) (MABDMA), in aqueous solution were determined by potentiometry and calorimetry. Electronspray ionization mass spectrometry was used to verify the presence of uranium(VI) complexes in solution. The thermodynamic data indicate that the binding strengths of the three ligands with UO follow the order BnABDMA < ABDMA < MABDMA, parallel to the order of the protonation constants as well as the order of the stability of the Nd complexes, suggesting that the complexation of UO with the ligands consist predominantly of electrostatic interactions.

A Uranyl Peroxide Dimer in the Gas Phase.

The gas-phase uranyl peroxide dimer, [(UO)(O)(L)] where L = 2,2'-trifluoroethylazanediyl)bis(N,N'-dimethylacetamide), was synthesized by electrospray ionization of a solution of UO and L. Collision-induced dissociation of this dimer resulted in endothermic O atom elimination to give [(UO)(O)(L)], which was found to spontaneously react with water via exothermic hydrolytic chemisorption to yield [(UO)(OH)(L)]. Density functional theory computations of the energies for the gas-phase reactions are in accord with observations.

Thermodynamic study of the complexation between Nd(3+) and functionalized diacetamide ligands in solution.

A series of amine functionalized ligands, including 2,2'-(benzylazanediyl)bis(N,N'-dimethylacetamide) (BnABDMA), 2,2'-azanediylbis(N,N'-dimethylacetamide) (ABDMA), and 2,2'-(methylazanediyl)bis(N,N'-dimethylacetamide) (MABDMA), are synthesized for the thermodynamic study of their complexation with Nd(3+) ions. Their complexation in solution is investigated using potentiometry, spectrophotometry, calorimetry, and electrospray ionization mass spectrometry. The results suggest that these ligands act as tridentate ligands.

Efficient microwave assisted synthesis of metal-organic framework UiO-66: optimization and scale up.

A highly efficient and scalable microwave assisted synthesis of zirconium-based metal-organic framework UiO-66 was developed. In order to identify the best conditions for optimizing the process, a wide range of parameters was investigated. The efficiency of the process was evaluated with the aid of four quantitative indicators.

A bifunctional, site-isolated metal-organic framework-based tandem catalyst.

Herein, we present the synthesis of a metal-organic framework-based tandem catalyst that contains two distinct catalytic domains. Zn(II)-based IRMOF-9-Irdcppy-NH2 (IRMOF = isoreticular metal-organic framework) has both organocatalytic amine and organometallic Ir(I) groups that were incorporated by both pre- and postsynthetic functionalization methods. The isolated amine and Ir(I) sites of IRMOF-9-Irdcppy-NH2 are shown to be independently catalytically active for performing a Knoevenagel condensation and allylic N-alkylation, respectively.

Modulating H2 sorption in metal-organic frameworks via ordered functional groups.

Herein, we present the use of presynthetic and postsynthetic modification (PSM) approaches to regulate the structural organization of functional groups in the pores of isoreticular metal-organic frameworks (IRMOFs). It has been found that the structural ordering of aryl groups within the IRMOF pores results in hysteretic H2 sorption, while the same aryl groups introduced in a disordered manner displays reversible H2 sorption that is more typical of the IRMOF family.

Cyclometalated metal-organic frameworks as stable and reusable heterogeneous catalysts for allylic N-alkylation of amines.

Metal-organic frameworks (MOFs) functionalized via Ir(I) cyclometalation are shown to be effective as heterogeneous catalysts for the allylic N-alkylation of various amines. The MOF catalysts are one of the first and most effective MOF-based heterogeneous organometallic catalysts for the direct formation of C-N bonds. In addition, these MOFs represent a rare, stable and reusable, class of reactive Ir catalysts.

Dioxole functionalized metal-organic frameworks.

The synthesis and physical properties of dioxole functionalized metal-organic frameworks (MOFs) are reported. Combination of benzo[d][1,3]dioxole-4,7-dicarboxylic acid (dioxole-BDC) and Zn(II) under solvothermal conditions yields either an isoreticular metal-organic framework analog (IRMOF-1-dioxole) or a new MOF material (MOF-1-dioxole). With the addition of a co-ligand, namely 4,4'-bipyridine, a mixed-linker Zn(II)-paddlewheel MOF (BMOF-2-dioxole) is obtained.

Synthesis, breathing, and gas sorption study of the first isoreticular mixed-linker phosphonate based metal-organic frameworks.

The synthesis of the first water stable isoreticular phosphonate based mixed-linker metal-organic frameworks (MOFs) is achieved via the use of the N-donor heterocyclic co-ligands. Furthermore, these isoreticular phosphonate frameworks show selective CO(2)/N(2) uptake at low pressures.

Functional group effects on metal-organic framework topology.

Functionalization of the ligand 1,3,5-tris(4-carboxyphenyl)benzene (H(3)BTB) has been realized with methoxy (H(3)BTB-[OMe](3)) and hydroxy (H(3)BTB-[OH](3)) groups. Combining H(3)BTB-[OMe](3) and Zn(II) results in the formation of the first isostructural, functionalized analogue of MOF-177 (MOF-177-OMe), while the combination of H(3)BTB-[OH](3) and Zn(II) generates a rare, interpenetrated pcu-e framework.

Single-atom ligand changes affect breathing in an extended metal-organic framework.

2-Phenylpyridine-5,4'-dicarboxylic acid (1, dcppy), a derivative of 4,4'-biphenyldicarboxylic (2, bpdc) was used as the organic linking component for several metal-organic frameworks (MOFs). The pyridine component of 1 does not interfere with the solvothermal synthetic procedure, and hence both 1 and 2 form similar isoreticular MOFs. Zr(4+)-based UiO-67-dcppy, Al(3+)-based DUT-5-dcppy, Zn(2+)-based DMOF-1-dcppy, and interpenetrated Zn(2+)-based BMOF-1-dcppy were readily synthesized from 1.

Functional tolerance in an isoreticular series of highly porous metal-organic frameworks.

A series of highly porous University of Michigan Crystalline Material (UMCM-1) type Zn-based metal-organic frameworks (MOFs) were synthesized from mono- and bi-functionalized benzenedicarboxylate (BDC) ligands. In total, 16 new functionalized UMCM-1 derivatives were obtained by a combination of pre- and postsynthetic functionalization. Through postsynthetic modification (PSM), amino-halo bifunctional MOFs were converted into amide-halo materials via solid-state acylation reactions.