Dalton Transactions

doi: 10.1039/c6dt90093cpmid: N/A

doi: 10.1039/C6DT90093Cpmid: N/A

doi: 10.1039/c6dt90094apmid: N/A

doi: 10.1039/C6DT90094Apmid: N/A

doi: 10.1039/c6dt90095jpmid: N/A

doi: 10.1039/C6DT90095Jpmid: N/A

Preishuber-Pflügl, Florian; Wilkening, Martin

doi: 10.1039/c6dt00944apmid: 27172256

The performance of new sensors or advanced electrochemical energy storage devices strongly depends on the active materials chosen to realize such systems. In particular, their morphology may greatly influence their overall macroscopic properties. Frequently, limitations in classical ways of chemical preparation routes hamper the development of materials with tailored properties. Fortunately, such hurdles can be overcome by mechanochemical synthesis. The versatility of mechanosynthesis allows the provision of compounds that are not available through common synthesis routes. The mechanical treatment of two or three starting materials in high-energy ball mills enables the synthesis not only of new compounds but also of nanocrystalline materials with unusual properties such as enhanced ion dynamics. Fast ion transport is of crucial importance in electrochemical energy storage. It is worth noting that mechanosynthesis also provides access to metastable phases that cannot be synthesized by conventional solid state synthesis. Ceramic synthesis routes often yield the thermally, i.e., thermodynamically, stable products rather than metastable compounds. In this perspective we report the mechanochemical synthesis of nanocrystalline fluorine ion conductors that serve as model substances to understand the relationship between local structures and ion dynamics. While ion transport properties were complementarily probed via conductivity spectroscopy and nuclear magnetic relaxation, local structures of the phases prepared were investigated by high-resolution 19F NMR spectroscopy carried out by fast magic angle spinning. The combination of nuclear and non-nuclear techniques also helped us to shed light on the mechanisms controlling mechanochemical reactions in general.

Banach, Ł.; Guńka, P. A.; Buchowicz, W.

doi: 10.1039/c5dt04663gpmid: 26853761

The general synthesis of [Ni(Cp)(X)(NHC)] complexes from a nickel halide, CpLi, and a carbene solution is reported. This procedure yields unprecedented complexes with ring-expanded NHC ligands (RE-NHC) of six- (1a, 1b), seven- (1c), and eight-membered (1d) heterocycles. The NMR spectra of 1a–1d are consistent with the hindered rotation of Ni–Ccarbene and N–CMes bonds, while X-ray analyses of 1b, 1c, and 1d reveal a pronounced trans influence of the RE-NHC ligands. Complexes 1a–1e are efficient pre-catalysts in Kumada–Tamao–Corriu coupling with the maximum efficiency observed for complexes bearing the six-membered NHC.

Zhou, Wen; Rath, Nigam P.; Mirica, Liviu M.

doi: 10.1039/c6dt00064apmid: 26845423

A Ni(ii) complex with two t-butylisocyanide ligands supported by a N3C− type tetradentate ligand was synthesized and characterized. Quantitative generation of the aromatic cyanation product, tBuN3C-CN, is observed by reacting this Ni(ii) complex with 1 equiv. of an oxidant. Reactivity studies suggest that this oxidatively-induced cyanation involves a heterolytic cleavage of the N–tBu bond and is mediated by Ni(iii).

Li, Jie; Wang, Taishan; Feng, Yongqiang; Zhang, Ying; Zhen, Mingming; Shu, Chunying; Jiang, Li; Wang, Yuqing; Wang, Chunru

doi: 10.1039/c6dt00223dpmid: 27064096

A new water-soluble gadolinium metallofullerenol was prepared through a solid–liquid reaction. It was characterized to have an enhanced effective magnetic moment, and improved T1-weighted relaxivity and magnetic resonance imaging performance in the liver. This material prepared by a facile method has wide application as a contrast agent and biological medicine.