Octahedral chalcogenide rhenium cluster complexes with imidazole

Reactions of [{Re6Q8}Br6]4−/3− (Q = S, Se) with molten imidazole lead to the formation of two new neutral cluster complexes [{Re6Q8}(imzH)4(imz)2] (imzH = imidazole). The interaction of [{Re6Q8}(imzH)4(imz)2] with hydrohalic acids resulted in cationic complexes [{Re6Q8}(imzH)6]X2 (X = Cl, Br). All compounds were characterised by X-ray single-crystal and powder diffraction analyses, elemental analysis, energy dispersive X-ray and IR spectroscopies. The luminescence of the neutral compounds [{Re6Q8}(imzH)4(imz)2] was also studied

Luminescent coordination polymers based on Ca²⁺ and octahedral cluster anions [{M₆Clⁱ₈}Clᵃ₆}²⁻ (M = Mo, W) : synthesis and thermal stability studies

Luminescent coordination polymers (CPs) based of inexpensive stable precursors are attractive materials for applications. Here we report the synthesis and evaluation of the stability and photophysical characteristics of the first examples of phosphorescent CPs based on octahedral molybdenum and tungsten cluster anions. Specifically 1D CP trans-[{Ca(OPPh₃)₄}{{M₆Clⁱ₈}Clᵃ₆}]∞ (M = Mo, W) can be obtained either directly at increased temperature or via intermediate phases [cis-Ca(OPPh₃)₄(H₂O)₂][{M₆Clⁱ₈}Clᵃ₆]∙2CH₃CN that are stable at room-temperature, but convert to the titled CP at temperatures above 100 °C

New NIR-emissive tetranuclear Er(III) complexes with 4-hydroxo-2,1,3-benzothiadiazolate and dibenzoylmethanate ligands: synthesis and characterization

New tetranuclear heteroleptic complexes [Er4(dbm)6(O-btd)4(OH)2] (1) and [Er4(dbm)4(O-btd)6(OH)2] (2) (O-btd = 4-hydroxo-2,1,3-benzothiadiazolate and dbm = dibenzoylmethanide) and their solvates with toluene, THF and CH2Cl2 were prepared using two synthetic approaches. The structures of the products were confirmed by single-crystal X-ray diffraction. Magnetic properties of 1 and 2 are in good agreement with X-ray data. The effective magnetic moment (μeff) values at 300 K for 1 and 2 corresponds to a system of 4 non-interacting Er(III) ions in the ground state 4J15/2 with g = 6/5. At ambient temperature and upon excitation with λexc = 450 nm, complexes 1 and 2 exhibit luminescence at ∼1530 nm, i.e. in the near infra-red (NIR) region. The luminescence intensity grows with increasing the number of the (O-btd)−ligands in the complexes. This observation suggests (O-btd)− as a new efficient antenna ligand for the lanthanide-based NIR luminescence

Octahedral molybdenum cluster as a photoactive antimicrobial additive to a fluoroplastic

Finding methods that fight bacterial infection or contamination, while minimising our reliance on antibiotics is one of the most pressing needs of this century. Although the utilisation of UV-C light and strong oxidising agents, such as bleach, are still efficacious methods for eliminating bacterial surface contamination, both methods present severe health and/or environmental hazards. Materials with intrinsic photodynamic activity (i.e. a material's ability upon photoexcitation to convert molecular oxygen into reactive oxygen species such as singlet oxygen), which work with light within the visible photomagnetic spectrum could offer a significantly safer alternative. Here we present a new, bespoke molybdenum cluster (Bu4N)2[Mo6I8(n-C7F15COO)6], which is both efficient in the generation of singlet oxygen upon photoirradiation and compatible with the fluoropolymer (F23-L) known for its good oxygen permeability. Thus, (Bu4N)2[Mo6I8(n-C7F15COO)6]/F23-L mixtures have been solution-processed to give homogenous films of smooth and fibrous morphologies and which displayed high photoinduced antibacterial activity against four common pathogens under visible light irradiation. These materials thus have potential in applications ranging from antibacterial coatings to filtration membranes and air conditioners to prevent spread of bacterial infections

Oxazolidine Nitroxide Transformation in a Coordination Sphere of the Ln3+ Ions

Upon the interaction of the hydrated lanthanide(III) salts found in acetonitrile solution with a tripodal paramagnetic compound, 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl (Rad), functionalized by two pyridyl groups, three neutral, structurally characterized complexes with diamagnetic polydentate ligands—[Dy(RadH)(hbpm)Cl2], [Yb2(ipapm)2(NO3)4], and [Ce2(ipapm)2(NO3)4(EtOAc)2]—were obtained. These coordination compounds are minor uncolored crystalline products, which were formed in a reaction mixture due to the Rad transformation in a lanthanide coordination sphere, wherein the processes of its simultaneous disproportionation, hydrolysis, and condensation proceed differently than in the absence of Ln ions. The latter fact was confirmed by the formation of the structurally characterized product of the oxazolidine nitroxide transformation during its crystallization in toluene solution. Such a conversion in the presence of 4f elements ions is unique since no similar phenomenon was observed during the synthesis of the 3d-metal complexes with Rad

Synthesis, crystal structure, and thermal stability of ionic cluster compounds (<i>phen</i>H)₄[Re₄Q₄(CN)₁₂]·<i>n</i>H₂O (Q = S, Se, <i>n</i> = 6; Q = Te, <i>n</i> = 10)

<div><p>Three new salts of tetrahedral rhenium chalcocyanide cluster anions [Re₄Q₄(CN)₁₂]⁴⁻ (Q = S, Se, Te) and 1,10-phenanthroline-1-ium cations, (<i>phen</i>H)₄[Re₄S₄(CN)₁₂]·6H₂O (<b>1</b>), (<i>phen</i>H)₄[Re₄Se₄(CN)₁₂]·6H₂O (<b>2</b>), and (<i>phen</i>H)₄[Re₄Te₄(CN)₁₂]·10H₂O (<b>3</b>), have been synthesized by reactions of K₄[Re₄Q₄(CN)₁₂]·<i>n</i>H₂O with 1,10-phenanthroline in the presence of Nd³⁺ in an acidic aqueous medium (pH 4). <b>1</b> and <b>2</b> exhibit similar 2-D layered supramolecular architectures based on hydrogen bonds between water molecules, CN-groups of cluster anions, and <i>phen</i>H⁺ cations. The latter are involved in <i>π</i>–<i>π</i> and C–H⋯<i>π</i> stacking interactions, connecting the adjacent layers with each other. Complex <b>3</b> demonstrates a 3-D framework based on hydrogen bonds between water molecules and CN-groups, <i>π</i>–<i>π</i> and C–H⋯<i>π</i> interactions. Notably short O···Te contacts of 3.40 and 3.50 Å are found in the structure of <b>3</b>. The thermal properties of <b>1–3</b> have been investigated by TG-DTG.</p></div

Two structural types of dithiocarbamato-chlorido complexes of mercury(II) : Preparation, supramolecular self-assembly, solid-state 13C and 15N NMR characterisation and thermal behaviour of pseudo-polymeric compounds of [Hg2(S2CNBu2)2Cl2] and [Hg4(S2CNiBu2)6][Hg2Cl6]

Two new crystalline dithiocarbamato-chlorido complexes of mercury(II), [Hg2{S2CN(C4H9)2}2Cl2] (1) and [Hg4{S2CN(iso-C4H9)2}6][Hg2Cl6] (2), have been prepared and chemically identified by solution (1H, 13C) NMR and solid-state (13C, 15N) CP-MAS NMR and FT-IR spectroscopy. The crystal, molecular and supramolecular structures of these compounds were established using single-crystal X-ray diffraction (XRD) analysis. The obtained complexes reveal two principally different types of structural organisation. In the structure of the former neutral complex, there are two isomeric doubly-bridged binuclear molecules [Hg2(S2CNBu2)2Cl2] (‘A’ and ‘B’), whereas the latter compound comprises two ionic structural moieties: the tetranuclear cation [Hg4(S2CNiBu2)6]2+ and the binuclear anion [Hg2Cl6]2−. In both ionic units, pairs of iBu2Dtc or chloride ligands, which perform a bridging structural function, combine with neighbouring mercury atoms. In turn, intermolecular/interionic secondary interactions Hg···S/Hg···Cl are involved in the formation of supramolecular structures of complexes 1/2, yielding pseudo-polymeric chains of (···‘A’···‘B’···)n/(···[Hg4(S2CNiBu2)6]···[Hg2Cl6]···)n, which exhibit alternation of isomeric molecules of 1/ionic moieties of 2 along their lengths. Despite the significant structural difference between the above complexes, we established, using simultaneous thermal analysis (STA), that both exhibit very similar thermal behaviour. Moreover, during the thermal transformations of both compounds 1 and 2, the same two substances are generated: HgCl2 and HgS