Complete miscibility of the intermetallic phases (IPs) SrGa2 and BaGa2 forming the solid solution Sr(1-x)Ba(x)Ga2 is shown by means of X-ray diffraction, thermoanalytical and metallographic studies. Regarding the distances of Sr/Ba sites versus substitution degree, a model of isolated substitution centres (ISC) for up to 10% cation substitution is explored to study the influence on the Ga bonding situation. A combined application of NMR spectroscopy and quantum mechanical (QM) calculations proves the electric field gradient (EFG) to be a sensitive measure of different bonding situations. The experimental resolution is boosted by orientation-dependent NMR on magnetically aligned powder samples, revealing in first approximation two different Ga species in the ISC regimes. EFG calculations using superlattice structures within periodic boundary conditions are in fair agreement with the NMR spectroscopy data and are discussed in detail regarding their application on disordered IPs.

The three intermetallic compounds SrAuGa, BaAuAl and BaAuGa were synthesised from the elements in niobium ampoules. The Sr compound crystallises in the orthorhombic KHg -type structure (Imma, a=465.6(1), b=771.8(2), c=792.6(2) pm, wR =0.0740, 324 F values, 13 variables), whereas the Ba compounds were both found to crystallise in the cubic non-centrosymmetric LaIrSi-type structure (P2 3, BaAuAl: a=696.5(1) pm; wR =0.0427, 446 F values, 12 variables; BaAuGa: a=693.49(4) pm, wR =0.0717, 447 F values, 12 variables). The samples were investigated by powder X-ray diffraction and their structures refined on the basis of single-crystal X-ray diffraction data. The title compounds, along with references from the literature (CaAuAl, CaAuGa, CaAuIn, and SrAuIn), were characterised further by susceptibility measurements and Al and Ga solid-state NMR spectroscopy. Theoretical calculations of the density of states (DOS) and the NMR parameters were used for the interpretation of the spectroscopic data. The electron transfer from the alkaline-earth metals and the group 13 elements onto the gold atoms was investigated through X-ray photoelectron spectroscopy (XPS), classifying these intermetallics as aurides.

Abstract. Powder samples as well as red and transparent single crystals of the Zintl phase Cs 7 NaSi 8 were synthesized and characterized by means of X-ray diffraction and differential thermal analysis. Cs 7 NaSi 8 was found to be isotypic to the recently reported phase Rb 7 NaSi 8 . It crystallizes in the Rb 7 NaGe 8 structure type forming trigonal pyramidal Si 4 4-anions. Two unique environments of the cations are observed, a linear arrangement [Na(Si 4 ) 2 ]7-with short Na-Si distances of 3.0 Å and a Cs2 atom coordinated by six Si 4 4-anions with long Cs-Si distances of 4.2 Å. The bonding situation was investigated by a combined application of 29 Si, 23 Na, and 133 Cs solid-state NMR spectroscopy and quantum mechanical calculations of the NMR coupling parameters. In addition the electronic density of states (DOS),

A sequential CH functionalization strategy for the synthesis of the marine alkaloid dictyodendrin B is reported. Our synthesis begins from commercially available 4‐bromoindole and involves six direct functionalizations around the heteroarene core as part of a gram‐scale strategy towards the natural product.