based on CpTiCl3. These copolymers have been characterized as for their composition, configuration, cross-linking (solubility and swelling),and polymorphism. The paper is mainly devoted to the influence of the chemical cross-linking on the formation, thermal transitions, and guest sorption of the nanoporous delta phase. Chemically cross-linked s-PS exhibiting a high degree of crystallinity of the nanoporous delta phase and the related high sorption ability can be achieved by copolymerizations with DVB content lower than 2 mol %. These cross-linked, and hence insoluble, nanoporous crystalline samples can be relevant for molecular separations, mainly in organic media.