Topochemical Oxidation of Ruddlesden–Popper Nickelates Reveals Distinct Structural Family: Oxygen-Intercalated Layered Perovskites - Dan Ferenc Segedin; Jinkwon Kim; Harrison LaBollita; Nicole K. Taylor; Kyeong-Yoon Baek; Suk Hyun Sung; Ari B. Turkiewicz; Grace A. Pan; Abigail Y. Jiang; Maria Bambrick-Santoyo; Tobias Schwaigert; Casey K. Kim; et al. (Journal of the American Chemical Society, 2026)