Silicates Cyclo

Table 5.9. Trapped noble gases in cyclo-silicate minerals and in other common crustal minerals...

Cyclo-silicates, especially beryl and cordierite, are known to have an abnormally large amount of 4He and 40Ar, which cannot be accounted for the in situ production from the radioactive decay of U, Th, and 40Ar. Lord Rayleigh (Strutt, 1908) first discovered that beryls contained excess 4He, which cannot be accounted for by in situ radiogenic 4He from U and Th. Subsequently, excesses of both 4He and 40Ar in all... 

E. M. Flanigen I would like to cite a recent reference on the Raman spectra of various silicates and aluminosilicates, W. P. Griffith, Raman Studies on Rock-Forming Minerals. Part I. Orthosilicates and Cyclo-silicates, J. Chem. Soc. (A) 1969, 1372. This author apparently experienced no difficulty in obtaining the Raman spectra with a He—Ne laser Raman. The particle size of the samples was not specified, but described as microcrystalline. ... 

Besides, it has been found3 that Silics possesses some antidiarrheal properties that are not related to sorption of microorganisms or their toxins. A Silics medicinal preparation retards secretion of water in isolated intestinal loops of rats in the case of its combined introduction with diarrhea mediators such as sodium desoxycholate, cyclo-adenosine 3 ,5 -monophosphate (c-AMP), and serotonin (Table 5). The decrease of water release into intestinal segment lumens seems to be related to the modifying action of the preparation on mucosa of bowels, because sorption of the stimulators themselves on Silics does not take place. The modifying action of the preparation on the small intestine mucosa is also attributed to the stimulation exerted by Silics on transport of glucose and electrolytes through bowel walls.3... 

Al-isopropoxide, Al-tert-butoxide, Al-phenoxide, Al-cyclo-hexoxide Al-anilide (CHgCOO)gTl Al-silicate Anhydrous silicate Clay, Kaolin, Super-filtrol, Montmorillo-nite. Zeolite Pumice... 

Subclasses also exist and the most useful ones are probably the neso-, soro-, cyclo-, ino-, phyllo-, and tecto-silicates which give some indication of the state of polymerization of SiOt tetrahedra into rings, chains, bands, sheets, networks, and so forth. 

Eddaoudi and coworkers developed a strategy for heterogenerization of porphyrin catalysts by impregnating free-base porphyrins into the pores of MOFs, and the catalytic function was realized by subsequent met-alation with active metal ions of Mn, Cu, Zn, and Co via postsynthesis. They proved that the H2RTMPyP platform was efficient in heterogeneous cyclohexane oxidation. Mn-RTMPyP oxidized cyclohexane to cyclo-hexanol/cyclohexanone in 91.5% yield with turnover number of 23.5, based on the amount of oxidant consumption, which is noticeably higher than other systems of supported metalloporphyrins on zeolites or mesoporous silicates. 

---