This work developed three high-nuclearity {Co14} clusters of C1–C3 with inner [Co8] backbone fixed by six ambient CoCl2 species. The catalyst C1 exhibited highly regio- and stereoselective hydrosilylation of alkynes with primary and secondary silane to produce α-vinylsilanes. More importantly, C1 shows high regioselectivity for electronically unbiased alkyl alkynes, and the α-selectivity of some alkyl alkynes has not been achieved in previous reports. Leaching tests and reusability proved that the reaction is a heterogeneous process.

In this study, four in situ hydro­(solvo)­thermal metal–ligand reactions, including oxidation (H2L1), C–C coupling (H4L2), nitration (H2L3), and condensation (HL4–6), based on bis­[3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl]­methane (H2L0), in the presence of DyIII ions, were carried out. The in situ metal–ligand reaction gave six new ligands existing in eight novel DyIII coordination complexes, which were characterized by crystal structure, mass spectrometry, and magnetism.

Sophisticated aggregation assembly is challenging in assembly chemistry. Monitoring the assembly process helps to understand the assembly mechanism and the create new building blocks. A two-dimensional (2D) cluster-based coordination polymer...

Metal-center-driven spontaneous resolution of a pair of chiral doubly interpenetrated metal−organic frameworks (MOFs), [Ni 3 (ptd) 6 ]• 15.5H 2 O (1), which was synthesized from achiral precursors [ptd = 3-(pyridin-3-yl)-1,2,4-triazine-5,6-diol], shows vertical interpenetrated 2D → 3D frameworks with 1D channels. Interestingly, proceeding with solvothermal recrystallization in methanol, 1, with a high-symmetry tetragonal I4 space group, gives another tilted interpenetrated MOF of [Ni 3 (ptd) 2), with low-symmetry monoclinic C2 space group. Accompanied with the structure transformation, a red shift in circular dichroism (CD) spectrum and a magnetic response (weak ferromagnetic interactions in 1 to weak antiferromagnetic interactions in 2) can be observed. Strikingly, 1 and 2 feature heterogeneous catalytic activities for the Knoevenagel reaction.

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-L-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye-Waller factors for these contributions and a slight reduction in the goodness-of-fit value (f′). Furthermore, the data best fit a model that included a M-M vector at 3.3 and 3.4 Å for Zn(II) and Co(II), respectively, suggesting the formation of a dinuclear site. Multiple scattering contributions from the outer-shell atoms of a histidine-imidazole rings are observed at ~3 and 4 Å for Zn(II)- and Co(II)-loaded ArgE suggesting at least one histidine ligand at each metal binding site. Likewise, EXAFS data for Mn(II)-loaded ArgE are dominated by a peak at 2.19 Å that was best fit assuming six light atom (N,O) scatterers. Due to poor signal to noise ratios for the Mn EXAFS spectra, no Mn-Mn vector could be modeled. Peak intensities for [M(II)_(ArgE)] vs. [M(II)M(II)(ArgE)] suggest the Zn(II), Co(II), and Mn(II) bind to ArgE in a cooperative manner. Since no structural data has been reported for any ArgE enzyme, the EXAFS data reported herein represent the first glimpse for ArgE enzymes. These data also provide a structural foundation for the future design of small molecules that function as inhibitors of ArgE and may potentially function as a new class of antibiotics.