A complex-as-ligand strategy to get a multifunctional molecular material led to a metal-organic framework with the formula (NH(4))(4)[MnCr(2)(ox)(6)]·4H(2)O. Single-crystal X-ray diffraction revealed that the anionic bimetallic coordination network adopts a chiral three-dimensional quartz-like architecture. It hosts ammonium cations and water molecules in functionalized channels. In addition to ferromagnetic ordering below T(C) = 3.0 K related to the host network, the material exhibits a very high proton conductivity of 1.1 × 10(-3) S cm(-1) at room temperature due to the guest molecules.

The first C3 -symmetric 44-core-valence-electron triangular palladium clusters, [{(SAr')(PAr3 )Pd}3 ](+) , have been synthesized by activation of the CS bond of isothioureas. Owing to delocalized metal-metal bonding, these stable complexes are the first noble-metal analogues of the π-aromatic cyclopropenyl cation [C3 H3 ](+) , with their all-metal aromaticity involving d-type atomic orbitals.

Herein, the use of a well-defined low-valent cobalt(I) catalyst [HCo(PMe3)4] capable of performing the highly regio- and stereoselective hydrosilylation of internal alkynes is reported. The reaction can be applied to a variety of hydrosilanes, symmetrical and unsymmetrical alkynes, giving in many cases a single hydrosilylation isomer. Experimental and theoretical studies suggest the key step to be a hydro-cobaltation and that the reaction proceeds through a classical Chalk-Harrod mechanism.

A mixed‐valence {MnII3MnIIIFeII2FeIII2} cyanide‐bridged molecular cube hosting a caesium cation, Cs⊂{Mn4Fe4}, was synthesized and structurally characterized by X‐ray diffraction. Cyclic‐voltammetry measurements show that its electronic state can be switched between five different redox states, which results in a remarkable electrochromic effect. Magnetic measurements on fresh samples point to the occurrence of a spin‐state change near room temperature, which could be ascribed to a metal‐to‐metal electron transfer converting the {FeII−CN−MnIII} pair into a {FeIII−CN−MnII} pair. This feature was only previously observed in the polymeric MnFe Prussian‐blue analogues (PBAs). Moreover, this novel switchable molecule proved to be soluble and stable in organic solvents, paving the way for its integration into advanced materials.

The design and synthesis of switchable molecular tweezers based on a luminescent terpy(Pt-salphen)2 (1; terpy=terpyridine) complex is reported. Upon metal coordination, the tweezers can switch from an open "W"-shaped conformation to a closed "U"-shaped form that is adapted for selective recognition of cations. Closing of the tweezers by metal coordination (M=Zn(2+), Cu(2+), Pb(2+), Fe(2+), Hg(2+)) was monitored by (1)H NMR and/or UV/Vis titrations. During the titration, exclusive formation of the 1:1 complex [M(1)] was observed, without appearance of an intermediate 1:2 complex [M(1)2]. The crystallographic structure of the 1:1 complex was obtained with Pb(2+) and showed a distorted helical structure. Selective intercalation of Hg(2+) cations by the closed "U" form was observed. The tweezers were reopened by selective metal decoordination of the terpyridine ligand by using tris(2-aminoethyl)amine (tren) as a competitive ligand without modification of the Pt-salphen complex. Detailed photophysical studies were performed on the open and closed tweezers. Structured emission was observed in the open form from the Pt-salphen moieties, with a high quantum yield and a long lifetime. The emission is slightly modified upon closing with 1 equivalent of Zn(2+) or Hg(2+), whereas a dramatic quenching was obtained upon intercalation of additional Hg(2+).

The regio-and stereoselective addition of germanium and zinc across the CC triple bond of nitrogen-, sulfur-, oxygen-, and phosphorous-substituted terminal and internal alkynes is achieved by reaction with a combination of R 3 GeH and Et 2 Zn. Diagnostic experiments support a radical-chain mechanism and the -zincated vinylgermanes that show exceptional stability are characterized by NMR spectroscopy and X-ray crystallography. The unique feature of this new radical germylzincation reaction is that the C(sp 2)-Zn bond formed remains available for subsequent in situ Cu(I)-or Pd(0)-mediated CC or C-heteroatom bond formation with retention of the double bond geometry. These protocols offer a modular access to elaborated tri-and tetrasubstituted vinylgermanes decorated with heteroatom substituents  to germanium that are useful for the preparation of stereodefined alkenes. Additional data and discussion, experimental details, NMR spectra for new compounds, and X-ray crystal structures (PDF) Crystallographic information files (CIF)

Being able to easily determine the Cu(II) affinity for biomolecules of moderate affinity is important. Such biomolecules include amyloidogenic peptides, such as the well-known amyloid-β peptide involved in Alzheimer's disease. Here, we report the synthesis of a new water soluble ratiometric Cu(II) dye with a moderate affinity (10 9 M -1 at pH 7.1) and the characterizations of the Cu(II) corresponding complex by X-ray crystallography, EPR and XAS spectroscopic methods. UV-Vis competition were performed on the Aβ peptide as well as on a wide series of modified peptides, leading to an affinity value of 1.6 10 9 M -1 at pH 7.1 for the Aβ peptide and to a coordination model for the Cu(II) site within the Aβ peptide that agrees with the one mostly accepted currently.Copper ions play key biological roles.1 They are essential metal ions that play an important role as catalytic centers in several processes including very fundamental ones like energy production.1 They have also been linked to several diseases. Dyshomeostasis of Cu is very dangerous and is well documented by two lethal genetic diseases, called Wilson's and Menkes' diseases, linked to an overload of Cu and to a depletion of Cu, respectively.2-5 Cu imbalance has also been involved in the etiology of most of neurological disorders6 such as Alzheimer's disease (AD),7-9 Parkinson's disease (PD),10,11 Prion diseases.10,12At a molecular scale, two parameters are important regarding Cu and the peptides or proteins involved in the above-mentioned diseases: (i) the metal environment, i.e. the nature of the atoms surrounding the metal center and (ii) the affinity of the peptides for the metal * Corresponding Author: christelle.hureau@lcc-toulouse.fr. Europe PMC Funders GroupAuthor Manuscript Anal Chem. Author manuscript; available in PMC 2017 December 04. Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts center. In the context of AD which is under focus in the present article, there are many reports on the coordination sites of the Cu(II) center to the amyloid-β peptide (Aβ) (for recent reviews, see refs.8,13-15) and on the Cu(II) affinity for Aβ (see refs.16-18 and refs. therein). Some studies also aim at relating the Cu(II) affinity of modified Aβ peptides with the coordination sites.19-21Determining the affinity of Cu(II) for peptides is thus of interest, first because this is intrinsically an important parameter that mirrors the possibility to have the metal ion-peptide interaction in biological conditions, and second because it give insights into the coordination sphere of the metal center when a series of modified peptides is studied. As a direct consequence, the straightforward and accurate determination of Cu affinity for peptides is an important objective. However, this is an intricate task since it necessitates appropriate analytical tools. The complexity of such studies is well illustrated by the abundant and differing reports on the evaluation of Cu(II) affinities for the Aβ peptide (see refs.16-20 and refs. therein). ...

A heterochiral 1,3,5-benzene tricarboxamide (BTA) monomer, derived from valine dodecyl ester, forms long rods in cyclohexane whilst its homochiral analogue assembles into dimers only at the same concentration. This highly original assembly behaviour is related to the destabilization of the dimeric structure containing the two heterochiral monomers as corroborated by a combined experimental and computational study.