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A family of luminescent pyrenyl‐(NHC)‐M−Cl coinage metal complexes has been prepared and fully characterized (NHC=N‐heterocyclic carbene). Two classes of complexes are described: (M=Cu (1 a), Ag (2 a), Au (3 a) where pyrenyl‐(NHC)=1‐pyrenyl‐3‐methyl‐Imidazolin‐2‐ylidene and M=Cu (1 b), Ag (2 b), Au (3 b) with pyrenyl‐(NHC)=1‐pyrenyl‐3‐naphthyl‐Imidazolin‐2‐ylidene. The molecular structures of the six complexes were confirmed by single crystal X‐ray diffraction studies. All complexes were found to be emissive both in solution and solid state. The use of the chromophoric‐(NHC) ligand endows to these complexes emissive properties in solution in the blue region (376–397 nm). The presence of the naphthyl‐substituent in the 1 b–3 b series enhances the quantum yields relative to the methyl‐series 1 a–3 a. In particular, the carbene gold complexes were the most emissive and displayed the highest quantum yields. [ABSTRACT FROM AUTHOR]

Thanks to an unusual protodemethylation reaction, a series of luminescent cyclometallated platinum(II) complexes can be prepared, which incorporate a rare NC‐chelating, pyridyl‐pyridylidene ligand, in combination with OO‐coordinating acetylacetonate (acac) or NO‐coordinating 2‐picolinate (pic) or 8‐hydroxyquinolate. The acac and pic complexes show unusual dual emission in a frozen glass. A series of cyclometallated platinum(II) complexes incorporating a rare, N^C‐chelating, pyridyl‐pyridylidene ligand are described, in which the coordination sphere is completed by two chlorides or an L X co‐ligand, namely O O‐coordinating acetylacetonate (acac), or N^O‐coordinating 2‐picolinate (pic) or 8‐hydroxyquinolinate. The acac and pic complexes have been structurally characterized in the solid state by single‐crystal X‐ray diffraction. These two complexes display red phosphorescence in the solid state at room temperature. In a frozen glass at 77 K, all four complexes show two broad emission bands that span much of the visible spectrum, apparently from two unequilibrated excited states. [ABSTRACT FROM AUTHOR]

A series of manganese(I) tricarbonyl complexes formulated as [Mn(8‐HQ)(CO)3Imd] (HQ = hydroxyquinoline and Imd = imidazole derivatives) was synthesized and fully characterized. These structures could be easily accessed from a common dimeric edifice formulated as [Mn2(8‐HQ)2(CO)6]. The structure of this complex has been confirmed by X‐ray diffraction studies. Its reaction with a range of imidazole derivatives (Imd) yielded the monomeric complexes [Mn(8‐hydroxyquinoline)(CO)3Imd] with various functional groups as an anchoring point for a vector. Photoactivation of all these complexes by blue‐light irradiation led to the liberation of 3 mol of CO per mol of complex as determined experimentally. Spectroscopic and computational methods were employed to explore the mechanism of CO release. Finally, a manganese complex including the more elaborate imidazole ligand N‐ and C‐di‐protected histidine was successfully synthesized, opening the way to its direct incorporation in peptides. [ABSTRACT FROM AUTHOR]

The reaction of multi‐bidentate oxamate‐based copper(II) complexes with the [Ni(iPrtacn)Cl2] complex (iPrtacn:1,4,7‐triisopropyl‐1,4,7‐triazacyclononane) has been investigated. X‐ray diffraction studies reveal that for all compounds the oxamato κO,κΟ' bidentate coordination site replaces the two chloride ions in [Ni(iPrtacn)Cl2] to form trimetallic {CuNi2} (1–3), hexametallic {Cu2Ni4} (4) and enneametallic {Cu3Ni6} (5) complexes. The investigation of the magnetic properties shows that Cu−Ni interactions through the oxamato bridge are in the expected range (−111 cm−1, −68 cm−1). For 1–3, both the sign and strength of the magnetic couplings are computed independently from DFT calculations, and these estimates broadly agree with the experiments. The magnetization measurements and EPR studies reveal that 1–3 are anisotropic: a significant portion of the large anisotropy of the [Ni(iPrtacn)Cl2] complex is retained, resulting in a D value for the S=3/2 ground state of 5 cm−1 on average. This is no longer the case for 4 and 5 where the anisotropy of the Ni(II) complexes is diluted due to the high nuclearity of the final edifices. These results show that it is possible to obtain trimetallic complexes with a high anisotropy and a high spin value for the ground state by a judicious choice of the interacting metal ions. [ABSTRACT FROM AUTHOR]

The article titled "A Novel Family of Luminescent Pyrenyl-(N-Heterocyclic Carbene)-Halogenated Coinage Metal Complexes: Synthesis, Crystal Structures, and Optical Properties" discusses the synthesis and characterization of a new family of stable pyrenyl-(NHC)MCl coinage metal complexes. These complexes, which include copper, silver, and gold, were obtained in high yields and their molecular structures were determined through X-ray diffraction studies. The complexes exhibit emissive properties in the blue region, similar to the natural blue light produced by phytoplankton on the ocean's surface at nightfall. The article provides further details on this research. [Extracted from the article]

The cyanidocobaltate of formula fac‐PPh4[CoIII(Me2Tp)(CN)3] ⋅ CH3CN (1) has been used as a metalloligand to prepare polynuclear magnetic complexes (Me2Tp=hydrotris(3,5‐dimethylpyrazol‐1‐yl)borate). The association of 1 with in situ prepared [FeII(bik)2(MeCN)2](OTf)2 (bik=bis(1‐methylimidazol‐2‐yl)ketone) leads to a molecular square of formula {[CoIII{(Me2Tp)}(CN)3]2[FeII(bik)2]2}(OTf)2 ⋅ 4MeCN ⋅ 2H2O (2), whereas the self‐assembly of 1 with preformed cluster [CoII2(OH2)(piv)4(Hpiv)4] in MeCN leads to the two‐dimensional network of formula {[CoII2(piv)3]2[CoIII(Me2Tp)(CN)3]2 ⋅ 2CH3CN}∞ (3). These compounds were structurally characterized via single crystal X‐ray analysis and their spectroscopic (FTIR, UV‐Vis and 59Co NMR) properties and magnetic behaviours were also investigated. Bulk magnetic susceptibility measurements reveal that 1 is diamagnetic and 3 is paramagnetic throughout the explored temperature range, whereas 2 exhibits sharp spin transition centered at ca. 292 K. Compound 2 also exhibits photomagnetic effects at low temperature, selective light irradiations allowing to promote reversibly and repeatedly low‐spin⇔high‐spin conversion. Besides, the diamagnetic nature of the Co(III) building block allows us studying these compounds by means of 59Co NMR spectroscopy. Herein, a 59Co chemical shift has been used as a magnetic probe to corroborate experimental magnetic data obtained from bulk magnetic susceptibility measurements. An influence of the magnetic state of the neighbouring atoms is observed on the 59Co NMR signals. Moreover, for the very first time, 59Co NMR technique has been successfully introduced to investigate molecular materials with distinct magnetic properties. [ABSTRACT FROM AUTHOR]

A library of eleven cationic gold(III) complexes of the general formula [(C C)Au(N N)]+ when C C is either biphenyl or 4,4'‐ditertbutyldiphenyl and N N is a bipyridine, phenanthroline or dipyridylamine derivative have been synthesized and characterized. Contrasting effects on the viability of the triple negative breast cancer cells MDA‐MB‐231 was observed from a preliminary screening. The antiproliferative activity of the seven most active complexes were further assayed on a larger panel of human cancer cells as well as on non‐cancerous cells for comparison. Two complexes stood out for being either highly active or highly selective. Eventually, reactivity studies with biologically meaningful amino acids, glutathione, higher order DNA structures and thioredoxin reductase (TrxR) revealed a markedly different behavior from that of the well‐known coordinatively isomeric [(C N C)Au(NHC)]+ structure. This makes the [(C C)Au(N N)]+ complexes a new class of organogold compounds with an original mode of action. [ABSTRACT FROM AUTHOR]

A general, sustainable dearomatization reaction for nitrogencontaining heterocycles was developed. Under solvent free conditions and without catalyst, the biorenewable methyl coumalate (MC) reacted as an efficient C3 partner to convert nine types of basic aromatic rings into their pyrido[1,2-a] fused derivatives in good to excellent yields. The fluorescence properties of some of the products were harnessed to conjugate fluorescent tags to bovine serum albumin (BSA) and immunoglobulin G. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]