Linear Heterometallic Co 3 Li 2 and Co 4 Li 2 Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials

New linear heterometallic Co 3 Li 2 and Co 4 Li 2 arrays have been assembled with the use of disiloxanediolate and silsesquioxane ligands. Treatment of anhydrous CoCl 2 with in situ‐prepared (Ph 2 SiOLi) 2 O afforded (thf)Co[Co{μ‐(Ph 2 SiO) 2 O}{(μ‐Cl) 2 Li(thf) 2 }] 2 ( 5 ) as dark blue prisms in 73 % yield, while the analogous reaction of CoCl 2 with in situ‐prepared Cy 7 Si 7 O 9 (OLi) 3 (Cy = cyclohexyl) gave royal blue [Co 2 (μ‐Cy 7 Si 7 O 12 )(μ‐OSiMe 3 )(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 .