The organonickel complexes are organometallic compounds containing a Ni−C σ-bond (σ-complexes). These species are very reactive and have been mainly characterized as the intermediates of catalytic processes of cross coupling and homocoupling involving organic and elementoorganic substrates such as organic halides, chlorophosphines, unsaturated hydrocarbons, etc. Thus, only a limited number of these complexes have been isolated and characterized as the free stable species. Although the organonickel complexes have been known since the 1960s, the chemistry of these species is currently at the beginning stages of development. The interest of the researchers in this class of compounds has significantly increased over the past decade, resulting in a plethora of scientific papers published on this topic. At the same time, electrochemical methods have become more and more popular in modern synthetic chemistry, due to easy access to high reactive intermediates, including organometallic species, which can be selectively generated in situ and used for subsequent synthetic processes. This review summarizes the elaborated electrochemical approaches for the preparation of organonickel complexes, including a discussion of the important role of the electrochemical cell construction and the influence of the electrode material nature on the electrochemical process. In order to give more insight into the importance of organonickel complexes in synthetic chemistry and introduce the reader to this problem of organometallic chemistry, focused on the development of new synthetic protocols for preparation of stable organonickel complexes, an overview of the most important catalytic processes proceeding with participation of these highly reactive intermediates and the main types of organonickel complexes are presented. However, in this review organonickel complexes will be limited by examples in which the organic fragment is singly bonded to the nickel center, because these species are responsible for the catalytic reactions.

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The development of modern chemistry is currently proceeding in several priority areas including investigations focused on the synthesis, stabilisation, and application of transition metal nanoparticles (NPs), which are widely used in physical, chemical, engineering, and biomedical processes. A special place among known transition metal NPs is occupied by cobalt nanoparticles, since they are used for highly important targets, such as creation of new catalysts, magnetic devices, composites, or carriers for drug delivery. The selective preparation of NPs is a difficult task that requires special conditions and has some limitations. In this minireview, we summarise the most successful and most efficient methods for obtaining Co NPs, including chemical and physical aspects of their preparation.

The imidazole-containing N 4 -tetradentate ligand N-(2-(1H-imidazol-2-yl)-3-(pyridin-2-yl)propyl)-2,6-diisopropylaniline (L2 H ) and its N-benzyl-protected variant (L2 Bn ) at the imidazole fragment have been synthesized and fully characterized. Both molecules contain an unresolved C sp3 stereogenic center. The coordination behavior of the newly prepared ligands towards group IV metal ions (M IV = Zr, Hf ) has been examined through multinuclear 1 H and 13 C{ 1 H} NMR spectroscopy and selected single-crystal X-ray structural analyses. The ability of the imidazole fragment to enter the metal coordination sphere as a neutral or a monoanionic system has also been investigated, unveiling quite original coordination modes as well as unexpected molecular architectures. When one N imidazole atom is blocked by a benzyl protecting group (L2 Bn ), the ligand reaction with M IV (NMe 2 ) 4 (M IV = Zr, Hf ) as metal precursor gives rise to discrete monometallic tris(dimethylamido) 5-coordinated [a]

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The Cover Feature shows the integration of various elaborate physical and chemical methods to prepare cobalt nanoparticles (CoNPs), which can be obtained in different forms depending on the used method. The application of modern analytical methods like TEM, SEM, XRD, EPR, etc. for determining the size, shape, and properties of the generated CoNPs is important for the creation of new practically useful materials based on CoNPs. More information can be found in the Minireview by A. F. Khusnuriyalova, M. Caporali, E. Hey‐Hawkins, O. G. Sinyashin, and D. G. Yakhvarov.

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