reactants not only at their surface, but throughout the bulk. Hence, the development of new porous materials is closely linked to their application in adsorption processes and catalysis. Referring to a desirable design capability of these materials, metal organic frameworks (MOFs) arose and enabled the tailored engineering of the chemical and topological properties. While the thermodynamically controlled synthesis of the MOFs results in ordered and highly porous networks, the reversible coordination-bond formation between metal-containing units and organic linkers often effects a lack of chemical stability under application conditions. The introduction of covalent organic frameworks (COFs) addressed this issue and replaced coordinative through covalent bonding. The additional transition from inorganic to entirely organic building blocks extended the range of adjustable network properties and initiated the research field of porous organic polymers (POPs). Herein, hyper-crosslinked polymers (HCPs) are a prominent class of porous networks. HCPs already emerged in the early 1960s, where multitopic species were incorporated into polymers to provide crosslinking between the propagating chains. 9,10 Davankov established the porous network formation out of swollen polystyrene with crosslinkers like bischloromethylated derivatives of benzene or biphenyl, which are also capable to solely interconnect with itself. Based on these findings, Tan's group transferred the crosslinking concept to monomeric units and introduced a knitting strategy for diverse building blocks. In the knitting reaction, rigid aromatic monomers are interconnected by an external crosslinker via Friedel-Craftsalkylations or oxidative Scholl coupling in the presence of an acid. The porosity of the amorphous HCPs is derived by the extensive crosslinking in the solvated state, which prevents the collapse of the structure upon the removal of the porogen. This versatile approach merges several benefits: a cost-efficient and scalable one-pot-synthesis, high thermal and chemical stability of the network, a tailored design of the adjustable topology and the optional incorporation of specific chemical functionalities. Due to the controlled crafting of the microenvironment, stable and porous HCP networks enable an attractive approach for catalytic applications. Besides their usage as acid/base catalyst, photocatalyst or electrocatalyst, they can either act as supporting material with distinct hetero atoms for metal nanoparticles or function as macroligand for the immobilization of molecular metal species. In several reports bipyridine units , N-heterocyclic carbenes or aminocarbene ligands are connected via the external crosslinker formaldehyde dimethyl acetal (FDA) to a porous network, while using the co-monomer benzene. Furthermore, phosphine ligands, which are often involved in catalytically active transition metal complexes, are subject to various crosslinking attempts. Li et al. set the first example in 2012 by preparing an HCP out of triphenylphosphine (PPh3) for catalytic Suzuki-Miyaura coupling reactions. Their knitting strategy included the addition of the co-monomer benzene, the external crosslinker FDA and the presence of the Lewis acid iron chloride (FeCl3). This approach, where an aromatic co-monomer like benzene , biphenyl , 1,3,5-triphenylbenzene (TPB), pyrrole or thiophene is used for the crosslinking of aryl phosphines, was taken up by other groups, all of them applying FDA as external crosslinker and FeCl3 as Friedel-Crafts catalyst. Additionally, other bifunctional crosslinkers like 1,4-dimethoxybenzene , α,α′-dichloro-p-xylene or 4,4′bis(bromomethyl)biphenyl are chosen, omitting the supplementation with a co-monomer. The above crosslinking strategies mainly focus on the prototypical PPh3 or its monodentate derivatives, in addition bidentate diphosphines or PNP pincer ligands can function as macroligand for the immobilization of metal species. While the integration of transition metals is often realized by a post synthetic ligand exchange between the phosphine-based HCP and the metal precursor, the direct crosslinking of the entire metal phosphine complex is also feasible. Apart from this predominant knitting protocol, the acid catalyst for the HCP formation was varied and related to different crosslinking mechanisms. Li et al. suggested that the use of aluminum chloride (AlCl3) instead of FeCl3 induces a Scholl coupling between PPh3 and the co-monomer TPB. 17 trichloromethane caused high phosphorus contents. Additionally, this alternative crosslinking strategy, which is based on strong Friedel-Crafts catalysts like AlCl3 or SnCl4, was expanded through adding of α,α′-dihalide-p-xylenes as external crosslinkers. Collectively, these studies about phosphine-based HCPs outline the decisive feature of the chosen Friedel-Crafts catalysts and raise questions about the role of the aromatic co-monomers. In this work, we thus pay particular attention to the roles of the involved crosslinking reagents and investigate their influence on the chemical and topological properties of the HCPs. Based on the prototypical PPh3 ligand, we varied the Friedel-Crafts acid, the crosslinker unit and the degree of crosslinking and examined the catalytic properties of these ruthenium impregnated HCPs in the