A series of thorium(IV)-imido complexes was synthesized and characterized. Extensive experimental and computational comparisons with the isostructural cerium(IV)-imido complexes revealed a notably more covalent bonding arrangement for the CeN bond compared with the more ionic ThN bond. The thorium-imido moieties were observed to be 3 orders of magnitude more basic than their cerium congeners. More generally, these results provide unique experimental evidence for the larger covalent character of 4f 0 5d 0 Ce(IV) multiple bonds compared to its 5f 0 6d 0 Th(IV) actinide congener.

Liquid‐like nanoparticle organic hybrid materials (NOHMs) consisting of a silica core with ionically grafted branched polyethyleneimine chains (referred to as NIPEI) are encapsulated within submicron‐scale polyacrylonitrile (PAN)/polymer‐derived‐ceramic electrospun fibers. The addition of a room‐temperature curable, liquid‐phase organopolysilazane (OPSZ) ceramic precursor to the PAN/NOHM solution enhances the internal dispersion of NOHMs and forms a thin ceramic sheath layer on the fiber exterior, shielding the hydrophilic NIPEI to produce near‐superhydrophobic non‐woven fiber mats with contact angles exceeding 140°. 60:40 loadings of NOHMs to PAN/OPSZ can be reliably achieved with low OPSZ percentages required, and up to 4:1 NOHM:polymer loadings are possible before losing hydrophobicity. These fibers demonstrate up to ≈2 mmol CO2 g−1 fiber capture capacities in a pure CO2 atmosphere through the nonwoven fibrous networks and the permeability of the OPSZ shell. The hybrid fibers additionally show enhanced capture kinetics under pure CO2 and 400 ppm CO2 conditions, indicating their promising application as a direct air capture platform.