Bifunctional Au–Fe3O4 nanoheterodimers were synthesized by thermally decomposing Fe­(III)­oleate on gold nanoparticles followed by functionalizing with tiron, 2,3-dihydroxybenzoic acid, or caffeic acid. These catechol derivatives are antioxidative and thus are predicted to function as superoxide scavengers. In particular, caffeic acid lost its antioxidant capacity, although it was covalently linked through its carboxyl moiety to the Fe3O4 surface. Tiron was shown to bind via its catechol group to the Au–Fe3O4 nanoheterodimers, and 2,3-dihydroxybenzoic was just physisorbed between the oleic acid surface structures. Caffeic-acid stabilized Au–Fe3O4 nanoheterodimers turned out to act as X-ray protector in healthy cells but as X-ray enhancing agents in cancer cells. Furthermore, these functionalized Au–Fe3O4 nanoheterodimers were found to inhibit the migratory capacity of the cancer cells.

Typically, intermetallic phases are obtained in solid‐state reactions or crystallization from melts, which are highly energy and time consuming. The polyol process takes advantage of low temperatures and short reaction times using easily obtainable starting materials. The formation mechanism of these intermetallic particles has received little attention so far, even though a deeper understanding should allow for better synthesis planning. In this study, we therefore investigated the formation of BiNi particles in ethylene glycol in a microwave‐assisted polyol process mechanistically. The coordination behavior in solution was analyzed using HPLC‐MS and UV‐Vis. Tracking the reaction with PXRD measurements, FT‐IR spectroscopy and HR‐TEM revealed a successive reduction of Bi3+ and Ni2+, leading to novel spherical core‐shell structure in a first reaction step. Bismuth particles are encased in a matrix of nickel nanoparticles of 2 nm to 6 nm in diameter and oxidation products of ethylene glycol. Step‐wise diffusion of nickel into the bismuth particle intermediately results in the bismuth‐rich compound Bi3Ni, which consecutively transforms into the BiNi phase as the reaction progresses. The impacts of the anion type, temperature and pH value were also investigated.

The new suboxide Bi4Ir2O was found as an intermediate in the formation of the intermetallic phase Bi2Ir by a microwave-assisted polyol process.

The study of Bi2Rh formation in a polyol process revealed a two-step mechanism. BiRh is formed by co-reduction of bismuth and rhodium cations and converted into Bi2Rh by Bi diffusion. Various starting materials and reaction parameters are examined.

The Front Cover shows the transformation of a Bi‐Ni core‐shell particle into a homogenous intermetallic BiNi particle. To understand the mechanism for the BiNi formation in the polyol process, various methods such as X‐ray and electron diffraction, HR‐TEM, mass spectrometry and FT‐IR spectroscopy were employed. In a microwave‐assisted one‐pot synthesis at first Bi‐particles emerge by reduction of a Bi‐salt. The reduction of the Ni‐salt most likely occurs on the surface of these particles, followed by a complete encasement of the Bi‐core (blue) with a shell of Ni‐particles (green). As the reaction continues, the Ni‐atoms diffuse into the Bi‐core until the homogeneous BiNi particle is attained. More information can be found in the Full Paper by Matthias Smuda et al.