Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany.
Published: June 2023
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Article Abstract
We present an approach for preparing chain-type unsaturated molecules with low oxidation state Si(I) and Sb(I) supported by amidinato ligands that exploit to generate heavy analogues of ethane 1,2-diimine. The reduction of antimony dihalide (R-SbCl) with KC in the presence of silylene chloride afforded L─(Cl)Si═Sb─Tip () and L()Si═Sb─Ph (), respectively. Compounds and further undergo reduction with KC to produce Tip─Sb═LSi─LSi═Sb─Tip () and Ph─Sb═LSi─LSi═Sb─Ph (). The solid-state structures and DFT studies show that all compounds have σ-type lone pairs at each Sb atom. It forms a strong pseudo-π-bond with Si. The pseudo-π-bond is formed by the hyperconjugative donation of the π-type lone pair at Sb to the Si-N σ* MO. The quantum mechanical studies indicate that compounds and has delocalized pseudo-π-MOs arising from hyperconjugative interactions. Hence, and can be considered as isoelectronic to imine, while and are isoelectronic to ethane-1,2-diimine. The proton affinity studies indicate that the pseudo-π-bond resulting from the hyperconjugative interaction is more reactive than the σ-type lone pair.
The analysis of the solution absorption spectrum of the plutonyl ion in an aqueous environment was given by Eisenstein and Pryce (E&P) in 1968. In 2011 a new spectrum was published of the (PuO) ion in 1 M HClO. We have been provided with the original data of this spectrum and have found in the data a previously unreported low-lying transition at 7385 cm which we have assigned as a magnetic dipole transition.
Depending on their bandgaps, mixed metal layered chalcogenides are potential candidates for thermoelectric and photovoltaic applications. Herein, we reported the exploratory synthesis of Sr-Zr-Cu- ( = S/Se) systems, resulting in the identification of two novel quaternary chalcogenides: SrZrCuS and SrZrCuSe. These isoelectronic compounds (SrZrCu) crystallized in two different structural types.
The n-type Mg(Sb, Bi) compounds have strong potential for harvesting wasted heat energy due to their effective thermoelectric properties.
Doping with transition element Ag improves the power factor to 19.6 µW cm K and lowers lattice thermal conductivity to approximately 0.5 W m K, resulting in a peak figure of merit (ZT) of 1.64 at 673 K.
A thermoelectric module made from n-type Mg(Sb, Bi) and p-type MgAgSb achieves a conversion efficiency of around 7.9% at a 277 K temperature difference, enhancing sustainable energy recycling technology.
Molecular chains of two-coordinate carbon atoms (cumulenes) have long been targeted, due to interest in the electronic structure and applications of extended π-systems, and their relationship to the carbon allotrope, carbyne. While formal (isoelectronic) B═N for C═C substitution has been employed in two-dimensional (2-D) materials, unsaturated one-dimensional all-inorganic "molecular wires" are unknown. Here, we report high-yielding synthetic approaches to heterocumulenes containing a five-atom BNBNB chain, the geometric structure of which can be modified by choice of end group.
We report the synthesis and characterization of tris(biphenyl-2,2'-diyl)metal complexes of trivalent group 9 elements (, M = Co, Rh, Ir) and their nonplanarly π-extended analogs, tris(1,1'-binaphthyl-2,2'-diyl)metal complexes (, M = Rh, Ir). Single crystal X-ray crystallography reveals the distorted octahedral geometry with an approximate symmetry of trianionic complexes (M = Co, Rh, Ir) and (M = Rh, Ir), which are contacted by three Li ions in the crystal. Complex exhibits yellow luminescence in THF with a photoluminescence quantum yield () of up to 0.
