A Self‐Assembled Heterometallic {Co₇–Ho₁} Nanocluster: <i>3d‐4f</i> Trimeric Keggin‐Type Silicotungstate [HoCo₇Si₃W₂₉O₁₀₈(OH)₅ (H₂O)₄]¹⁸^– and its Catalytic and Magnetic Applications

Abstract

A new self assembled Co 2+ and Ho 3+ ‐substituted polyoxometalate have been synthesized using a trilacunary Keggin‐type silicotungstate. The polyanion complex of the formula [HoCo 7 Si 3 W 29 O 108 (OH) 5 (H 2 O) 4 ] 18– (1) has a trimeric crystal structure which displayed an excellent catalytic and magnetic property. Here, we have carried out selective oxidation of various alcohol substrates such as derivatives of benzyl alcohol, cyclohexanol etc. to its corresponding aldehydes/ketones. The paramagnetic nature of the compound was seen from the magnetic study. However, antiferromagnetic interaction was observed between Co 2+ ‐Co 2+ or Co 2+ ‐Ho 3+ at a very low temperature. The compound was characterized by FT‐IR, UV/Visible spectroscopy, Single crystal X‐ray diffraction, X‐ray powder diffraction, high‐resolution electrospray ionization mass spectroscopy (HR‐ESI‐MS) and thermogravimetric analysis (TGA).