SPIROCYCLIC MOLECULES

At some point, in the year or so (1996-1997) I was a patent examiner, I searched the "shoes" for the history of patented spirocyclic molecules...I found some spirocyclic molecule patents going back to the 1940's about. Today I think you could go in to Chemical Abstracts and search their molecules' registry and probably find all spirocyclic miolecules, and within that set all the spiroconjugated molecules. I wonder how many such molecules are in the CAS molecule registry. Spirocyclic molecule chemistry probably has grown superexponentially since the 1940's...The Chemical Abstracts registry of molecules may have 1000's of spirocyclic molecular structures in its database...Wikipedia has an article on spirocyclic molecules in which it indicates that the chemist Adolf von Baeyer devised the first nomenclature for spirocyclic molecules back in 1900. Evidently spirocyclic molecules were known prior to 1900...MJB

SILICA POLYMORPHS & ZEOLITES

Each of the silica polymorphs could be turned in to their corresponding 2-,4-connected C allotropes by replacing the Si atoms with tetrahedral 4-connected C atoms and replacing the 2-connected O atoms with 2-connected acetylenic spacer groups thus. Also the zeolites could be dealt with in the same manner as the silica polymorphs, and the silica polymorphs and the numerous zeolites could have all 2-connected O linkages excised from the corresponding networks, and then one joins all corresponding 4-connected tetrahedral Si atoms etc. and one thus turns them in to tetrahedral C atoms...MJB