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The combination of physical properties sensitive to molecular chirality in a single system allows the observation of fascinating phenomena such as magneto‐chiral dichroism (MChD) and circularly polarized luminescence (CPL) having potential applications for optical data readout and display technology. Homochiral monodimensional coordination polymers of YbIII were designed from a 2,15‐bis‐ethynyl‐hexahelicenic scaffold decorated with two terminal 4‐pyridyl units. Thanks to the coordination of the chiral organic chromophore to Yb(hfac)3 units (hfac−=1,1,1,5,5,5‐hexafluoroacetylaconate), efficient NIR‐CPL activity is observed. Moreover, the specific crystal field around the YbIII induces a strong magnetic anisotropy which leads to a single‐molecule magnet (SMM) behaviour and a remarkable room temperature MChD. The MChD‐structural correlation is supported by computational investigations. [ABSTRACT FROM AUTHOR]

A novel three-dimensional (3D) coordination polymer with the formula (C3N2H5)4[MnCr2(ox)6]·5H2O (2), where ox = oxalate and C3N2H5 = imidazolium cation, is reported. Single crystal X-ray diffraction reveals that this porous coordination polymer adopts a chiral three-dimensional quartz-like architecture, with the guest imidazolium cations and water molecules being hosted in its pores. This novel multifunctional material exhibits both a ferromagnetic ordering at TC = 3.0 K, related to the host MnCr2 network, and high proton conductivity [1.86 × 10−3 S cm−1 at 295 K and 88% relative humidity (RH)] due to the presence of the acidic imidazolium cations and free water molecules. The similarity of the structure of compound 2 to that of the previously reported analogous compound (NH4)4[MnCr2(ox)6]·4H2O, (1), also allows us to analyse, to a certain extent, the effect of the acidity of the proton donating guest molecules on proton conduction properties. 2 hosts, in one-dimensional (1D) channels, imidazolium cations, which are more acidic than the ammonium ones in 1 and, as a consequence, 2 shows higher proton conduction than 1, highlighting the effect of the pKa of the proton donating guest molecules on proton conductivity. [ABSTRACT FROM AUTHOR]

Three unidimensional compounds were obtained by reacting the polymeric precursor [Ba(hfac)2] (hfac−= 1,1,1,5,5,5-hexafluoroacetylacetonate) either with 2,2′-bipyrimidine (bpm) or the bulkier 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine (Me4bpm). [Ba2(hfac)4(bpm)3(CH3OH)]·0.5 bpm (1) is composed of linear chains where the barium environments are alternatively tricapped trigonal primastic and tetradecahedral. Increasing the bpm-to-metal ratio leads to a unique tetradecahedral coordination environment for Ba(ii) centres in [Ba(hfac)2(bpm)2] (2) zigzag chains. Finally in [Ba(hfac)2(Me4bpm)] (3) zigzag chains, the bulkiness of the Me4bpm reduces the coordination number of the barium atom to eight leading to a distorted square prismatic coordination polyhedron. In 1and 2, terminal bipyrimidine ligands govern the interchain interaction through π-stacking while, in 3, the crystal packing is dictated by the interaction between the perfluorinated moieties of the hfac−ligands. [ABSTRACT FROM AUTHOR]

The reactivity of 1,5-diisopropyl-3-(4′-carboxyphenyl)-6-oxoverdazyl H I i -Pr toward divalent metal ions is dominated by the coordination of the carboxylate moiety onto the metal ions. The formula of the compound obtained by the reaction with the earth-alkaline magnesium (II) is [Mg(I i -Pr) 2 ·2H 2 O] n ·0.35H 2 O (I i -Pr –Mg) whereas the reaction with 3d divalent metal ions yields compounds of general formula [M(I i -Pr) 2 (CH 3 OH) 4 ] (M = Mn (I i -Pr –Mn), Co (I i -Pr –Co), Ni (I i -Pr –Ni), Zn (I i -Pr –Zn)). The single-crystal X-ray diffraction analysis of I i -Pr –Mg reveals that the magnesium (II) adduct forms a one-dimensional (1D) coordination polymer with a terminal radical in a bidentate κ(O,O′) coordination mode and a bridging one in a μ − 1κ(O); 1κ (O′) syn – anti mode. The coordination sphere of the magnesium (II) is completed by two water molecules that established H-bonds with the carboxylate moiety of the terminal radicals that further reinforce the 1D coordination polymer. Adjacent chains interact through π-stacking of head-to-tail radicals. The single-crystal X-ray diffraction analysis of I i -Pr –Mn and I i -Pr –Ni reveals that the two compounds are isostructural. They are composed of mononuclear complexes where the divalent metal is surrounded by two radicals coordinated by monodentate carboxylate and four methanol molecules in the equatorial plane. Two methanol ligands act as H-bond donors toward the second oxygen atom of the carboxylate groups. The complexes interact through π-stacking of head-to-tail radicals and H-bonds between the two remaining methanol ligands and the oxygen atom of the oxoverdazyl moieties. In all of the compounds, the exchange interaction is dominated by the weak antiferromagnetic coupling related to the π-stacking of the radicals. [ABSTRACT FROM AUTHOR]

The reaction of MnCl2·4H2O with salicylaldoxime (H2salox) and the sodium salt of 1,3-bis(carboxypropyl)tetramethyldisiloxane (H2L) in a 1:1:1 molar ratio led to the self-assembly of {[Mn6O2(salox)6(H2salox)(H2O)3(μ-L)]H2salox·1.2H2O}n, a 1D coordination polymer consisting of hexamanganese(III) salicylaldoximate cluster as secondary building unit (SBU) and tetramethyldisiloxane-based dicarboxylate linker, namely, 1,3-bis(carboxypropyl)tetramethyldisiloxane. The structure of the compound was established by single crystal X-ray diffraction. The Mn(III) clusters consist of two staggered μ3-oxo-bridged Mn3 triangles held together by the oxygen atoms of the oxime groups. Because of Jahn-Teller distortion, the Mn-O distances reach 2.5 Å for the oxygen atoms located above and below the triangles mean planes. The compound showed a glass transition peak at around 14 °C in the differential scanning calorimetry (DSC) curve. The magnetic susceptibility data were fitted with a set of three intracluster antiferromagnetic exchange interaction coupling constants: J1 = −0.65 cm-1, J2 = −1.5 cm-1, and J3 = −0.9 cm-1. The ac magnetic susceptibility measurements in the 2-5 K temperature range reveal a frequency-dependent behavior indicative of a slow relaxation of magnetization at low temperature. The coexistence of the lypophilic 1,3-bis(propyl)tetramethyldisiloxane moieties and hydrophilic polar SBUs confers to the structure an amphiphilic character. Dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and transmission (TEM) and scanning (SEM) electron microscopies demonstrate that in dimethylformamide (DMF) the coordination polymer organizes as micelles, whereas in chloroform it tends to form inverse micelles and vesicles. [ABSTRACT FROM AUTHOR]