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Recent discoveries highlighted the activity and the intriguing mechanistic features of NbCl₅ as a molecular catalyst for the cycloaddition of CO₂ and epoxides under ambient conditions. This has inspired the preparation of novel silica-supported Nb species by reacting a molecular niobium precursor, [NbCl₅·OEt₂], with silica dehydroxylated at 700 °C (SiO_2-700) or at 200 °C (SiO_2-200) to generate diverse surface complexes. The product of the reaction between SiO_2-700 and [NbCl₅·OEt₂] was identified as a monopodal supported surface species, [SiONbCl₄·OEt₂] (1a). The reactions of SiO_2-200 with the niobium precursor, according to two different protocols, generated surface complexes 2a and 3a, presenting significant, but different, populations of the monopodal surface complex along with bipodal [(SiO)₂NbCl₃·OEt₂]. ⁹³Nb solid-state NMR spectra of 1a–3a and ³¹P solid-state NMR on their PMe₃ derivatives …