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The crystallization chemistry of silica‐based zeolites in ionic liquids remains highly puzzling and interesting in the field of zeolite science. Herein, we report the successful ionothermal synthesis of germanosilicate zeolites. The ionothermal templating effect with respect to the structure, alkalinity and concentration of organic additives was comparatively studied. The results showed that a small amount of organic base could effectively aid the dissolution of silica source and facilitate the crystallization of germanosilicate zeolites with ionic liquid as template. Remarkably, STW and IRR structures constructed with double‐four‐ring (D4R) structure‐building units were ionothermally prepared using 1‐ethyl/butyl‐3‐methyl imidazolium and 1‐benzyl‐3‐methyl imidazolium ionic liquids as template, respectively. Ionothermal synthesis tailored with organic base showed suitable chemistry for the formation of germanium‐containing siliceous D4R units. This finding will be helpful for the rational exploration of novel extra‐large‐pore zeolitic structures. IRResistible: Germanosilicate zeolites were ionothermally prepared in the presence of organic base, which aided the dissolution of silica source and facilitated the crystallization of STW and IRR structures with ionic liquids of different structure as template. Ionothermal chemistry was effectively tailored by using an organic base, which exhibits a remarkable capability for the formation of germanium‐containing siliceous D4R units. [ABSTRACT FROM AUTHOR]

Abstract: The ionothermal synthesis of extra‐large‐pore aluminophosphate zeotype with −CLO topological structure, DNL‐1, was studied by using 1,6‐hexanediamine and several quaternary ammonium compounds with different types of cations and anions as co‐structure‐directing agents (co‐SDAs). The phase selectivity and crystallization process were investigated, and results showed that the crystallization of the −CLO and LTA structures correlated with the alkalinity and concentration, rather than with the structure of the co‐SDA. By combining solid/solution 13C NMR spectroscopy and other characterizations on DNL‐1 obtained with different co‐SDAs, it was demonstrated that the ionic‐liquid cation was unalterably occluded in the structure, whereas occlusion of the co‐SDA cation was not imperative. A plausible crystallization pathway was accordingly deduced, in which alkaline co‐SDA, which acted as an acidity regulator in the ionothermal system, could facilitate the formation of the double‐four‐ring (d4r) unit (Al4P4O20), and influence their subsequent assembly mode around ionic‐liquid cations, and thus, direct the crystallization of −CLO and LTA structures at different concentrations of co‐SDA. [ABSTRACT FROM AUTHOR]