Synthesis and structural characterization of benzyl-functionalized N-heterocyclic carbene platinum complexes: Dramatic substituent effect on anti-cancer activity

International audienceA series of platinum (II) complexes bearing N-heterocyclic carbene NHC ligands functionalized by various benzyl moieties were synthesized and characterized. The molecular structure of two complexes has been confirmed by X-ray diffraction studies on single crystals. Investigation of in vitro cytotoxic activities against various cancer cell lines revealed a strong substituent effect: IC50 as low as 0.005 μM were obtained depending on the substituent on the benzyl moiety

Modulation of the structural information in shape-defined heterocyclic strands: the case of a (pyridine-hydrazone)₂pyrazine ligand

Metal ions (Ag$^{+}$, Cd$^{2+}$, Eu$^{3+}$, Sm$^{3+}$) and protons can, through coordination and protonation, modulate in three specific ways the structural information contained in the pyrazine-based heterocyclic strand $L$ (obtained from 2,5-bis(methylhydrazino)pyrazine and 2 equivalents of 2-pyridinecarboxaldehyde), thus generating two linear rod-like conformations and a bent one. This conformational diversity is associated with a structural one that consists of two diprotonated forms ($H_{2}L(PF_{6})_{2}$ and $H_{2}L(CF_{3}SO_{3})_{2}$), a polymeric architecture $[AgL]_{n}(CF_{3}SO_{3})_{n}$, two rack-like complexes $([Eu_{2}H_{2}L_{3}(CF_{3}SO_{3})_{6}](PF_{6})_{2}$ and $[Sm_{2}H_{2}L_{3}(CF_{3}SO_{3})_{6}](PF_{6})_{2})$ and a grid-like structure ($[Cd_{4}L_{4}](CF_{3}SO_{3})_{8}$)

Optical spin-state polarization in a binuclear europium complex towards molecule-based coherent light-spin interfaces

The success of the emerging field of solid-state optical quantum information processing (QIP) critically depends on the access to resonant optical materials. Rare-earth ion (REI)-based molecular systems, whose quantum properties could be tuned taking advantage of molecular engineering strategies, are one of the systems actively pursued for the implementation of QIP schemes. Herein, we demonstrate the efficient polarization of ground-state nuclear spins—a fundamental requirement for all-optical spin initialization and addressing—in a binuclear Eu(III) complex, featuring inhomogeneously broadened $^{5}$D0 → $^{7}$F0 optical transition. At 1.4 K, long-lived spectral holes have been burnt in the transition: homogeneous linewidth (Γ$_{h}$) = 22 ± 1 MHz, which translates as optical coherence lifetime (T$_{2opt}$) = 14.5 ± 0.7 ns, and ground-state spin population lifetime (T$_{1spin}$) = 1.6 ± 0.4 s have been obtained. The results presented in this study could be a progressive step towards the realization of molecule-based coherent light-spin QIP interfaces

Chimie de coordination des éléments F avec des ligands donneurs mous (application à la séparation sélective actinides(III)/lanthanides(III))

GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

1,1′-{(1E,1′E)-[Octane-1,8-diylbis(azanylylidene)]bis(methanylylidene)}bis(naphthalen-2-ol) in the zwitterionic form

The title compound, C30H32O2N2, is formed from two units of ortho-hydroxynaphthaldehyde bridged with 1,8-diaminooctane. In the solid state, it exists as a double zwitterion. The N atoms are protonated and the C—O− bonds lengths are 1.265 (2) Å, with intramolecular N—H...O hydrogen bonds forming S(6) ring motifs. The molecule has twofold rotational symmetry, with the twofold axis bisecting the central –CH2—CH2– bond of the bridging octane chain. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains propagating along the [-201] direction. The chains are linked via C—H...O hydrogen bonds, forming a supramolecular three-dimensional framework structure