RESUMO
A bis(diphenyl)-phosphine functionalized ß-diketimine ligand (PNac-H) was applied for the synthesis of a subvalent Ni(I) complex [PNac-Ni]. Here, the Ni(I) center is stabilized by a tetradentate PNNP-type pocket, forming a square planar coordination sphere. Subsequently, the Ni(I) complex was investigated with regard to its reactivity and the activation of small molecules. The reductive potential of Ni(I) enabled an activation of different substrate classes, such as CH2 X2 (X=Br, I), I2 or Ph2 E2 (E=S, Se). The ligand's design allows a stabilization of the reactive Ni(I) species while at the same time enabling activation processes due to a hemilabile coordination behavior and accessible axial coordination sites. The activation products have been characterized by single crystal X-ray diffraction, NMR and IR spectroscopy as well as elemental analysis.
RESUMO
The positively charged and weakly polarizable s-block metals commonly do not usually have phosphine ligands in molecular complexes. Herein, we report mono- and dinuclear small diamidophosphine complexes of the alkaline-earth metals Mg, Ca, and Sr, which were prepared from simple precursors and a phosphine-functionalized diamine ligand N,N-bis(2-(diphenyl-phosphino)phenyl)ethane-1,2-diamine (PNHNHP). The alkaline-earth metal based complexes [(PNNP)Mg]2 and [(PNNP)M(thf)3 ] (M=Ca, Sr), exhibit unusual coordination spheres and show bright fluorescence, both in the solid state and in solution. For comparison, the even stronger luminescent Al and Zn complexes [(PNNP)Zn]2 and [(PNNP)AlCl] were prepared. Emission lifetimes in the nanosecond range and high photoluminescence quantum yields up to 93 % are observed at room temperature.