Cage-like structures synthesis

Effect of Addition of Sodium Ions to Tetramethylammonium Silicate Aqueous Solution. In zeolite synthesis, alkali metal cations are combined with organic quaternary ammonium ions to produce zeolites with different structures from the one produced with only the organic quaternary ammonium ion (2) It is then expected that other types of silicate species are formed in the silicate solutions when organic quaternary ammonium ions and alkali metal cations coexist. In such silicate aqueous solutions, however, alkali metal cations only act to suppress the ability of the organic quaternary ammonium ions to form selectively silicate species with cage-like structures (13,14,28,29). 

The supersilyl- Si(CMe3)3 and the hypersilylgroup Si(SiMe3)3 are exceptionally well suited to stabilize unusual structures that are otherwise prone to chemical attack. Here we report on the synthesis of some new cyclic and cage-like structures from elements of group 15 stabilized by the hypersilyl substituent. 

Fullerenes are carbon allotropes discovered in 1985 by Harold W. Kroto, Robert E Curl and Richard E. Smalley. These carbon nanostructures possess icosahedral symmetry and are sp hybridized. Fullerenes have a closed cage-like structure and are examples for zero-dimensional CNMs. Depending on the number of carbon atoms that a cluster possesses, these are named (contains 60 carbon atoms), C (contains 70 carbon atoms), Cg (contains 84 carbon atoms), etc. The unique morphology of these CNMs possess large surface area to volume ratio and is suitable for a wide variety of applications. Synthesis methods of fullerenes are well developed [7-9]. 

Tricyclic templates such as 246 have been used to obtain stereocontrol in the synthesis of important cyclopentanoic natural products [85]. Normally, the endo-face of a cage-like structure is strongly shielded, and all kinds of additions occur from the exo-side. Thus, cuprate addition to enone 246 selectively gives the exoadduct 247. If, however, an additional substituent is introduced onto the exo-face as in the ether 246b or the sulfide 246c, considerable amounts of the endo-adduct 248 are generated. For X= SPH, the endo-selectivity is completely reversed, yielding exclusively compound 248. 

Li Q, Walter EC, van der Veer WE, Murray BJ, Newberg JT, Bohannan EW, Switzer JA, Hemminger JC, Penner RM (2005) Molybdenum disulfide nanowires and nanoribbons by electrochemical/chemical synthesis. J Phys Chem B 109 3169-3182 Tenne R, Homyonfer M, Feldman Y (1998) Nanoparticles of layered compounds with hollow cage structures (inorganic fuUerene-like structures). Chem Mater 10 3225-3238 Shibahara T (1993) Syntheses of sulphur-bridged molybdenum and tungsten coordination compounds. Coord Chem Rev 123 73-147... 

J.R. Matos, M. Kruk, L.P. Mercuri, M. Jaroniec, L. Zhao, T. Kamiyama, O. Terasaki, T.J. Pinnavaia, and Y. Liu, Ordered Mesoporous Silica with Large Cage-like Pores Structural Identification and Pore Connectivity Design by Controlling the Synthesis Temperature and Time. J. Am. Chem. Soc., 2003, 125, 821-829. 

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