Alkali metal dithiocarbamato carboxylates (DTCCs) – synthesis, properties, and crystal structures

A series of alkali metal salts of dithiocarbamate‐substituted carboxylate (DTCC) anions were prepared by reaction of the parent amino acids with carbon disulfide and an alkali metal hydroxide. The target compounds, which were isolated in anhydrous form or as hydrates, were extensively characterized by elemental analyses, IR and NMR spectroscopy, thermal analyses, cyclic voltammetry, and single‐crystal X‐ray diffraction. The isolated compounds are more or less hygroscopic and display a varying dehydratization and decomposition behavior upon heating. The assumed degradation of the DTCC scaffold was found to depend on the substitution pattern as well as on the alkali metal counterion, and covers a range between 200 and 340 °C. In aqueous solution, the DTCC anions show irreversible electrochemical oxidations, where the corresponding redox potentials are governed by the substitution pattern of the nitrogen atom. Single‐crystal structural analyses of sodium and potassium derivatives revealed that these compounds exist as two‐ or three‐dimensional coordination polymers in the solid state, with the alkali‐metal ions adopting typical irregular coordination environments with coordination numbers of six or higher

Formation and structural characterization of a europium(II) mono(scorpionate) complex and a sterically crowded pyrazabole

The reaction of EuI2(THF)2 with potassium hydrotris(3,5-diisopropylpyrazolyl)borate (K[HB(3,5-iPr2pz)3] (= KTpiPr2, pz = pyrazolyl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis(3,5-diisopropyl-1H-pyrazole)[hydrotris(3,5-diisopropylpyrazolyl)borato]iodidoeuropium(II), [Eu(C27H46BN6)I(C9H16N2)2] or (TpiPr2)(3,5-iPr2pzH)2EuIII, 1, in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyrazabole derivative trans-4,8-bis(3,5-diisopropylpyrazol-1-yl)-1,3,5,7-tetraisopropylpyrazabole, C36H62B2H8 or trans-{(3,5-iPr2pz)HB(μ-3,5-iPr2pz)}2, 2, were formed. Both title compounds have been structurally characterized through single-crystal X-ray diffraction. In 1, two isopropyl groups are each disordered over two orientations with occupancy ratios of 0.574 (10):0.426 (10) and 0.719 (16):0.281 (16). In 2, one isopropyl group is similarly disordered, occupancy ratio 0.649 (9):0.351 (9)

One ligand fits all: lanthanide and actinide sandwich complexes comprising the 1,4-bis(trimethylsilyl)cyclooctatetraenyl (=COT′′) ligand

The series of anionic lanthanide(III) sandwich complexes of the type [Ln(COT'')2]- (COT'' = 1,4-bis(trimethylsilyl)cyclooctatetraenyl dianion) has been largely extended by the synthesis of eight new derivatives ranging from lanthanum to lutetium. The new compounds [Li(DME)3][Ln(COT'')2] (Ln = Y (1), La (2), Pr (3), Gd (4), Tm (6), Lu (8)) and [Li(THF)4][Ln(COT'')2] (Ln = Ho (5), Tm (7)) were prepared in good yields following a straightforward synthetic protocol which involves treatment of LnCl3 with 2 equiv. of in situ-prepared Li2COT’’ in either DME (= 1,2-dimethoxyethane) or THF. The neutral actinide sandwich complexes An(COT'')2 (An = Th (9), U (10)) and An(COT''')2 (COT''' = 1,3,6-tris(trimethylsilyl)cyclooctatetraenyl dianion; An = Th (11), U (12)) were synthesized in a similar manner starting from ThCl4 or UCl4, respectively. The COT'' ligand imparts excellent solubility even in low-polar solvents as well as excellent crystallinity to all new compounds studied. All twelve new f-element sandwich complexes have been structurally authenticated by single-crystal X-ray diffraction. All are nearly perfect sandwich complexes with little deviation from the coplanar arrangement of the substituted COT'' rings. Surprisingly, all six [Li(DME)3][Ln(COT'')2] complexes covering the entire range of Ln3+ ionic radii from La3+ to Lu3+ are isostructural (space group P-1). Compound 10 is the first uranocene derivative for which 13NMR data are reported.JRC.E.4-Nuclear Fuel Safet