Crystalline Inorganic Frameworks with 56-Ring, 64-Ring, and 72-Ring Channels

Abstract

The development of zeolite-like structures with extra-large pores (>12-membered rings, 12R) has been sporadic and is currently at 30R. In general, templating via molecules leads to crystalline frameworks, whereas the use of organized assemblies that permit much larger pores produces noncrystalline frameworks. Synthetic methods that generate crystallinity from both discrete templates and organized assemblies represent a viable design strategy for developing crystalline porous inorganic frameworks spanning the micro and meso regimes. We show that by integrating templating mechanisms for both zeolites and mesoporous silica in a single system, the channel size for gallium zincophosphites can be systematically tuned from 24R and 28R to 40R, 48R, 56R, 64R, and 72R. Although the materials have low thermal stability and retain their templating agents, single-activator doping of Mn(2+) can create white-light photoluminescence.

Selective anion exchange with nanogated isoreticular positive metal-organic frameworks

“…Here we are particularly interested in the separation of organic anions. Among reported MOFs, there are comparatively few permanently porous MOFs with positive framework (P-MOFs) 6,36,37 , whose rarity is also mirrored in other types of porous materials, including zeolites [38][39][40][41][42][43][44][45] . In addition, known P-MOFs often have low stability or small pore size that only permits the exchange of small inorganic anions 7,10 .…”

Construction of Mesoporous Frameworks with Vanadoborate Clusters

“…Müller et al [14] and Khan [15] introduced linkages between isolated cluster compounds to create porosity, while FØrey [16,17] proposed the scale chemistry method and predicted that the larger the structure building unit (SBU), the larger the pores. Very recently, Wang and coworkers [9] demonstrated that the channels in the phosphate framework can be successfully expanded by using templates with longer carbon chains. Of these three strategies, the first two are very successful with cluster-based building units, such as the germanates.…”

“…Compared to the metal-organic frameworks (MOFs), where the pore size can be expanded and designed in a more rational way through reticular chemistry [4,10] or modular chemistry, [11,12] the expansion of the pore size in the inorganic crystalline materials is much slower. Several strategies [9,13] have been proposed to circumvent this challenge. Müller et al [14] and Khan [15] introduced linkages between isolated cluster compounds to create porosity, while FØrey [16,17] proposed the scale chemistry method and predicted that the larger the structure building unit (SBU), the larger the pores.…”

“…[1][2][3][4] Mesoporous crystalline materials with a channel size above 2 nm are of special interest as the enlargement of the pores can enhance the diffusion of large organic molecules into the pores when the materials are used as catalysts or supports. However, there are only a few inorganic examples reported with such mesopores, such as ITQ-43[5] (a 28-ring germanium silicate), SU-M, [6] JLG-12 [7] (a 30-ring germanate), ITQ-37 [8] (a 30-ring germanium silicate), and NTHU-13, [9] a series of gallium zincophosphites with ring sizes from 24-ring to 72-ring. Compared to the metal-organic frameworks (MOFs), where the pore size can be expanded and designed in a more rational way through reticular chemistry [4,10] or modular chemistry, [11,12] the expansion of the pore size in the inorganic crystalline materials is much slower.…”

Organic–Inorganic Hybrid Zinc Phosphate with 28‐Ring Channels

“…[1][2][3] Many approaches toward the design and synthesis of inorganic frameworks have been explored; however, compounds containing extra-large channels are still limited. [2, 4,[6][7][8] In comparison with metal-organic frameworks (MOFs), the inorganic building units comprising various geometric polyhedra, flexible coordination behaviors, and assorted connectivities make the synthesis of inorganic frameworks with large pore sizes and channels difficult. One of the synthesis methods to prepare materials with open framework structures is the template-directed synthesis based on the charge density matching of the organic ammonium ions and the inorganic frameworks.…”