Tetraalkylammonium Salts of Weakly Coordinating Aluminates: Ionic Liquids, Materials for Electrochemical Applications and Useful Compounds for Anion Investigation

In this study, we investigated the tetraalkylammonium salts of the weakly coordinating fluorinated alkoxyaluminates [pftb](-) ([Al(O(C(CF3)(3))(4)](-)) [hfip](-) ([Al(OC(H)-(CF3)(2))(4)](-)) and [hftb](-) ([Al(OC(CH3)(-) (CF3)(2))(4)](-)) in order to obtain information on their undisturbed spectral and structural properties, as well as to study their electrochemical behavior (i.e., conductivities in non-polar solvents and electrochemical windows). Several of the compounds qualify as ionic liquids with melting points as low as 42 degrees C for [NBU4](+)[hfip](-). Simple and quantitative metathesis reactions most yielding these materials in high purity were developed. These [NR4](+) salts serve as model compounds for undisturbed anions and their vibrational spectra-together with simulated spectra based on quantum chemical DFT calculations-were used for the clear assignment of the anion bands. Besides, the ion volumes of the anions (V-ion(-)([pftb](-))=0.736 nm(3), V-ion([hftb](-)) = 0.658 nm(3), V-ion([hfip](-))=0.577 nm(3)) and their decomposition pathways in the mass spectrometric measurements have been established. The salts are highly soluble in non-polar solvents (up to 1.09 mol L-1 are possible for [NBu4](+)[hftb](-) in CH2Cl2 and 0.41 mol L-1 for [NBu4](+)[hfip](-) in CHCl3) and show higher molar conductivities if compared to [NBu4](+)[PF6](-). The electrochemical windows of CH2Cl2, CH3CN and 1,2-F2C6H4 using the [NBu4](+) aluminate electrolytes are up to +0.5 V/-0.7 V larger than those using the standard [NBu4](+)[PF6](-)

Synthesis and Characterization of Terminal [Re(XCO)(CO)2(triphos)] (X=N, P): Isocyanate versus Phosphaethynolate Complexes

The terminal rhenium(I) phosphaethynolate complex [Re(PCO)(CO)2(triphos)] has been prepared in a salt metathesis reaction from Na(OCP) and [Re(OTf)(CO)2(triphos)]. The analogous isocyanato complex [Re(NCO)(CO)2(triphos)] has been likewise prepared for comparison. The structure of both complexes was elucidated by X‐ray diffraction studies. While the isocyanato complex is linear, the phosphaethynolate complex is strongly bent around the pnictogen center. Computations including natural bond orbital (NBO) theory, natural resonance theory (NRT), and natural population analysis (NPA) indicate that the isocyanato complex can be viewed as a classic Werner‐type complex, that is, with an electrostatic interaction between the ReI and the NCO group. The phosphaethynolate complex [Re(PCO)(CO)2(triphos)] is best described as a metallaphosphaketene with a ReI–phosphorus bond of highly covalent character

Zero-valent amino-olefin cobalt complexes as catalysts for oxygen atom transfer reactions from nitrous oxide

The synthesis and characterization of several zero-valent cobalt complexes with a bis(olefin)-amino ligand is presented. Some of these complexes proved to be efficient catalysts for the selective oxidation of secondary and allylic phosphanes, as well as diphosphanes, even with a direct P-P bond. With 5 mol % catalyst loadings the oxidations proceed under mild conditions (25-70 °C, 7-22 h, 2 bar N O) and afford good to excellent yields (65-98 %). In this process, the greenhouse gas N O is catalytically converted into benign N and added-value organophosphorus compounds, some of which are difficult to obtain otherwise