Linear Heterometallic Co₃Li₂ and Co₄Li₂ Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials

Abstract

New linear heterometallic Co3Li2 and Co4Li2 arrays have been assembled with the use of disiloxanediolate and silsesquioxane ligands. Treatment of anhydrous CoCl2 with in situ‐prepared (Ph2SiOLi)2O afforded (thf)Co[Co{μ‐(Ph2SiO)2O}{(μ‐Cl)2Li(thf)2}]2 (5) as dark blue prisms in 73 % yield, while the analogous reaction of CoCl2 with in situ‐prepared Cy7Si7O9(OLi)3 (Cy = cyclohexyl) gave royal blue [Co2(μ‐Cy7Si7O12)(μ‐OSiMe3)(μ‐Cl){Li(thf)2}2]2 (6) in 68 % yield. Both of the new compounds have been structurally characterized by X‐ray crystallography. Plasma treatment of 5 was found to activate the surface by creating –C–O, –C=O, and –COO functionalities. An initial study revealed promising formaldehyde adsorption properties for the plasma‐treated material 5a.

Heterometallic Europium Disiloxanediolates: Synthesis, Structural Diversity, and Photoluminescence Properties

“…The chemistry of well-defined metal siloxides (metallasiloxanes) comprising the M–O–Si functionality continues to attract considerable interest due to the diverse potential applications of that functionality . Not only are metal siloxides excellent molecular models for silica-supported heterogeneous metal catalysts but they also serve as useful precursors for new materials, nanoparticles, well-defined surface species, and homogeneous catalysts . Moreover, it is well-established that siloxide ligands can support highly reactive metal complexes in low oxidation states (e.g., Co(I), Ti(III), Sm(II), U(III), etc.)…”