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. The [EMMIm] cyanoacetate and [EMMIm] cyanomalonate salts formed exemplify the first C-C bond-forming carboxylation reactions with NHO-activated CO . The reaction of the free NHO with dimethyl carbonate selectively led to methoxycarbonylated NHO, which is a perfect precursor for the synthesis of functionalized ILs [NHO-CO Me][X]. The first NHO-SO adduct was synthesized and structurally characterized; it showed a similar reactivity pattern, which allowed the synthesis of imidazolium methyl sulfites upon reaction with methanol.

Phase-pure crystalline Bi 2 Se 3 and Bi 2 Te 3 nanoparticles are formed in reactions of [C 4 C 1 Im] 3 [Bi 3 I 12 ] (C 4 C 1 Im = 1butyl-3-methylimidazolium) with [C 4 C 1 Pyr][ESiMe 3 ] (E = Se or Te; C 4 C 1 Pyr = 1-butyl-1-methylpyrrolidinium) in the ionic liquid (IL) [C 4 C 1 Im]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 Bi 2 Se 3 and Bi 2 Te 3 nanoparticles are free of metal oxide species. As proven by infrared and X-ray photoelectron spectroscopy analyses, the nanoparticle surfaces reveal only minor organic contamination from solvent residues ([C 4 C 1 Im]I). The nanomaterials show high Seebeck coefficients of −124 μV K −1 (Bi 2 Se 3 ) and −155 μV K −1 (Bi 2 Te 3 ) and feature high electrical conductivities (328 and 946 S cm −1 , respectively) at the highest tested temperature (240 °C). The corresponding thermal conductivities (0.8 and 2.3 W m −1 K −1 , respectively, at 30 °C) are comparable to those of single crystals and recently reported ab initio calculations, which is in remarkable contrast to typical findings of nanograined bulk materials obtained from compacted nanoparticles. These findings emphasize the low level of impurities, surface contamination, and, in general, defects produced by the synthetic approach reported here. The figure of merit in the in-plane direction of the compacted pellets reached peak values 0.45 for Bi 2 Se 3 and 0.4 for Bi 2 Te 3 .

Electronic communication between Fe centers in the diiron complexes [{(ηand −C 2 B 10 H 10 − was investigated by spectroscopic (UV−vis and IR), electrochemical (CV and DPV), and single-crystal XRD methods. All experimental results were supported by a DFT computational analysis (B3LYP/Def2SVP) of model complexes that included two other closo-boranes: X = −C 2 B 8 H 8 − and [−B 12 H 10 −] 2− . The DFT analysis focused on the geometry, electronic excitations, IR spectra, charge and spin delocalization, and intramolecular spin−spin exchange interactions in the series of all six complexes and their singly and doubly oxidized analogues. The results demonstrate that [closo-B 10 H 8 -1,10-diyl] 2− has the best ability among the closo-boranes to mediate electronic effects similar to those of 1,4phenylene. This is evident from the observed separation of one-electron-oxidation waves (∼70 mV) and comparable S−T energy gaps in the doubly oxidized species. Article pubs.acs.org/Organometallics

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, SiMe3).