Preserving precise choreography of bonds in Z-stereoretentive olefin metathesis by using quinoxaline-2,3-dithiolate ligand.

The Z-alkene geometry is prevalent in various chemical compounds, including numerous building blocks, fine chemicals, and natural products. Unfortunately, established Mo, W, and Ru Z-selective catalysts lose their selectivity at high temperatures required for industrial processes like reactive distillation, which limits their synthetic applications. To address this issue, we develop a catalyst capable of providing Z-alkenes with high selectivity under harsh conditions.

Structure of a FeO-Heteraadamantane-Type Hexacation Stabilized by Chelating Organophosphine Oxide Ligands.

Metal-containing heteraadamantanes are compounds of interest due to their spectroscopic and magnetic properties, which make them promising materials for non-linear optics and semiconductors. Herein we report the comprehensive structural characterization of a new coordination compound of the formula [(-OH')(OH″)(O = P(Ph)CHCH(Ph)P = O){Fe(-BuOH)}](PF)(Cl) with the chelating ligand PhP(O)-CHCH-P(O)Ph. The compound crystallizes as a polynuclear metal complex with the adamantane-like core [FeO] in the space group -43d of a cubic system.

Heavy silylchalcogenido lanthanates synthesis PhP[CpLa-ESiMe] (E = S, Se, and Te) fluoride-induced demethylation of dimethylcarbonate to PhP[OCOMe] key intermediate.

We report a new high-yield synthesis of so far not accessible tetraphenylphosphonium methylcarbonate PhP[OCOMe] solvothermal fluoride-induced demethylation and MeF elimination at MeCO (DMC) by PhP-F, structurally characterized as λ-fluorophosphoran by XRD. The synthetic value of PhP[OCOMe] key compound for preparing nearly all kinds of other PhP[anion] salts with perfectly crystallizing (not symmetry frustrated) cation is demonstrated by examples beyond ionic liquid research: a complete set of silylchalcogenide salts PhP[ESiMe] (E = S, Se, and Te) including the first example of a structurally characterized non-coordinating, naked [Te-SiMe] anion is presented. With this set of soft Lewis bases and metal organic Lewis acids [CpLa] at hand, a comprehensive series of crystalline 1 : 1 lanthanate complexes PhP[CpLa-ESiMe] has been prepared.

Chalcogenido-Dimethylgallates and -Indates DMPyr [Me M(μ -E)] (M=Ga, In; E=S, Se): Building Blocks for Higher and Lower Order Chalcogenidoindates.

Metalation of the anions in the ionic liquids DMPyr[SH] and DMPyr[SeH] (DMPyr=1,1-dimethylpyrrolidinium) by trimethylgallium and trimethylindium is investigated. The reaction proceeds via pre-coordination of [EH] , methane elimination and formation of an unprecedented series of chalcogenido metalates DMPyr [Me M(μ -E)] (M=Ga, In; E=S, Se). These show the presences of dinuclear dianions with four-membered ring structures displaying highly nucleophilic bridging chalcogenide ligands in their crystallographically determined molecular structures.

Heavy Chalcogenide-Based Ionic Liquids in Syntheses of Metal Chalcogenide Materials near Room Temperature.

This minireview describes two strategically different and unexplored approaches to use ionic liquids (IL) containing weakly solvated and highly reactive chalcogenide anions [E-SiMe ] and [E-H] of the heavy chalcogens (E=S, Se, Te) in materials synthesis near room temperature. The first strategy involves the synthesis of unprecedented trimethylsilyl chalcogenido metalates Cat [M(E-SiMe ) ] (Cat=organic IL cation) of main group and transition metals (M=Ga, In, Sn, Zn, Cu, Ag, Au). These fully characterized homoleptic metalates serve as thermally metastable precursors in low-temperature syntheses of binary, ternary and even quaternary chalcogenide materials such as CIGS and CZTS relevant for semiconductor and photovoltaics (PV) applications.

A Series of Homoleptic Linear Trimethylsilylchalcogenido Cuprates, Argentates and Aurates Cat[MeSiE-M-ESiMe] (M = Cu, Ag, Au; E = S, Se).

The syntheses and XRD molecular structures of a complete series of silylsulfido metalates Cat[M(SSiMe)] (M = Cu, Ag, Au) and corresponding silylselenido metalates Cat[M(SeSiMe)] (M = Cu, Ag, Au) comprising lattice stabilizing organic cations (Cat = PhP or PPN) are reported. Much to our surprise these homoleptic cuprates, argentates, and aurates are stable enough to be isolated even in the absence of any strongly binding phosphines or N-heterocyclic carbenes as coligands. Their metal atoms are coordinated by two silylchalcogenido ligands in a linear fashion.

Homoleptic trimethylsilylchalcogenolato zincates [Zn(ESiMe)] and stannanides [Sn(ESiMe)] (E = S, Se): precursors in solution-based low-temperature binary metal chalcogenide and CuZnSnS (CZTS) synthesis.

Organic cation salts with homoleptic zincate and stannanide anions, Ph4P [Zn(ESiMe3)3] (E = S (1a), Se (1b)) and Cat [Sn(ESiMe3)3] (Cat = Ph4P+ (E = S (2a-Ph4P); Cat = PPN+ (E = S 2a-Ph4P, Se (2a)) are presented and structurally characterized. Efforts to isolate neutral thermally metastable stannane precursors [Sn(ESiMe3)4] (E = S (3), Se(4)) are reported as well. The thermal decomposition of the presented precursors to yield binary sulfides and selenides of zinc and tin is investigated.

Ionic Liquid-Based Low-Temperature Synthesis of Phase-Pure Tetradymite-Type Materials and Their Thermoelectric Properties.

Phase-pure crystalline BiSe and BiTe nanoparticles are formed in reactions of [CCIm][BiI] (CCIm = 1-butyl-3-methylimidazolium) with [CCPyr][ESiMe] (E = Se or Te; CCPyr = 1-butyl-1-methylpyrrolidinium) in the ionic liquid (IL) [CCIm]I. The resulting crystalline tetradymite-type nanoparticles exhibit stoichiometric Bi:E (E = Se or Te) molar ratios (2:3). Because all synthetic steps were performed under strict inert gas conditions, the surfaces of the BiSe and BiTe nanoparticles are free of metal oxide species.

Homoleptic Group 13 Trimethylsilylchalcogenolato Metalates [M(ESiMe)] (M = Ga, In; E = S, Se): Metastable Precursors for Low-Temperature Syntheses of Chalcogenide-Based Materials.

We communicate the synthesis and full characterization of so far unknown tetrakis(trimethylsilylsulfido) and -(trimethylsilylselenido) gallates and indates in form of their organic salts Cat[M(ESiMe)] (M = Ga, In; E = S, Se; Cat = dimethylpyrrolidinium (DMPyr), PhP, (dppe)Cu, (dmpe)Cu). These thermally metastable silylchalcogenolatometalates can act as modular precursors for an ionic-liquid- or organic-solution-based low-temperature synthesis of multinary metal chalcogenide materials such as the CIGS species Cu(InGa)(SSe).

Systematic study on anion-cation interactions via doubly ionic H-bonds in 1,3-dimethylimidazolium salts comprising chalcogenolate anions MMIm [ER] (E = S, Se; R = H, tBu, SiMe).

We present convenient syntheses of so far inaccessible, crystalline and highly pure 1,3-dialkylimidazolium salts with extremely nucleophilic thiolate and selenolate anions [ER] (R = H, tBu, SiMe). While non existent for E = O, the title compounds exist as slightly less basic E = S and Se homologues. The anion cation H-bond interactions in the crystalline state have been studied systematically in six related ionic compounds of varying anion basicity and steric bulk, namely MMIm [SH] (1), MMIm [StBu] (2), and MMIm [SSiMe] (3), as well as MMIm [SeH] (4), MMIm [SetBu] (5) and MMIm [SeSiMe] (6).

N-Heterocyclic Olefin-Carbon Dioxide and -Sulfur Dioxide Adducts: Structures and Interesting Reactivity Patterns.

Depending on the amount of methanol present in solution, CO adducts of N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) have been found to be in fully reversible equilibrium with the corresponding methyl carbonate salts [EMIm][OCO Me] and [EMMIm][OCO Me]. The reactivity pattern of representative 1-ethyl-3-methyl-NHO-CO adduct 4 has been investigated and compared with the corresponding NHC-CO zwitterion: The protonation of 4 with HX led to the imidazolium salts [NHO-CO H][X], which underwent decarboxylation to [EMMIm][X] in the presence of nucleophilic catalysts. NHO-CO zwitterion 4 can act as an efficient carboxylating agent towards CH acids such as acetonitrile.