Tomoe Shimizu

Synthesis of zeolites from paper sludge ash and their ability to simultaneously remove NH4 + and PO4 3−

The objective of this study was to investigate the synthesis of zeolites from paper sludge ash, and to evaluate their applications for water purification to simultaneously remove NH4 + and PO4 3 − in aqueous solution. Paper sludge ash had a low abundance of Si and a significant Ca content, due to the presence of calcite that was used as paper filler. Na2SiO3 was added to the NaOH solution to increase Si content in order to synthesize zeolites with high cation exchange capacity. The original ash without addition of Si yielded hydroxysodalite with a cation exchange capacity of ca. 50 cmol/kg. Addition of Si to the solution yielded Na-P1 (zeolite-P) with a higher cation exchange capacity (ca. 120 cmol/kg). The observed concentrations of Si and Al in the solution during the reaction explain crystallizations of these two phases. The product with Na-P1 could simultaneously remove NH4 + and PO4 3 − from the solution between pH 4 and 9.

Removal of NaCl from seawater using natural zeolite

We attempted to develop a new process to remove NaCl content in seawater using natural zeolite. Na+ in seawater can be reduced by ion exchange of natural zeolite, and Cl− can be reduced by AgNO3 or calcined hydrotalcite. The two-step process, which comprised natural zeolite treatment and anion reduction treatment (AgNO3 or calcined hydrotalcite), was applied to remove NaCl from the seawater. The possibility of cultivation using the obtained solution for the growth test of radish sprouts was then examined. The latter did not grow in the seawater, the solution treated with natural zeolite, the solution treated with AgNO3 after zeolite treatment, and in the solution treated with natural zeolite after AgNO3 treatment, due to the high contents of Cl− and remaining in these solutions. Radish sprouts also did not grow in the solution treated with calcined hydrotalcite because of high pH and high content of Na+ in the solution. By combination of anion reduction treatment using calcined hydrotalcite and zeolite treatment, radish sprouts can be grown in the prepared solution.

Synthesis and structures of [2.n]metacyclophane-1,2-diones

McMurry cyclisation of 1,n-bis(5-formyl-2-methoxyphenyl)alkanes afforded dimethoxy[2.n]metacyclophan-1-enes and dimethoxy[2.n]metacyclophane-1,2-diols, in which latter one was converted to dimethoxy[2.n]metacyclophane-1,2-diones by Albright–Goldman oxidation.

Synthesis of 4,16-dimethoxy-1,2-dimethyl[2.4]metacyclophan-1-ene and 8,17-dimethoxy-1.2-dimethyl-10-thia[2.3.4](1,3,5)cyclophan-1-ene

McMurry cyclisation of 1,4-bis(3-acetyl-4-methoxyphenyl)butane afforded flexible 4,16-dimethoxy-1,2-dimethyl[2.4] metacyclophan-1-ene, which was converted to the corresponding triple bridged 8,17-dimethoxy-1,2-dimethyl-10-thia[2.3.4](1,3,5)cyclophan-1-ene. The conformational studies of these cyclophan-1-enes in solution are also described.

Synthesis and photoreactions of polymethyl substituted [2.2]metacyclophanes

Photo-oxygenation of 4,5,6,8,12,13,14,16-octamethyl[2.2]metacyclophane using a high-pressure mercury lamp produced a mixture of mono- and bis-endoperoxides in quantitative yield, while irradiation with sunlight in chloroform afforded 1,2,3,6,7,8-hexamethyl-trans-10b,10c-dimethyl-10b,10c-dihydropyrene in 20% yield.

Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

Various anti-9-substituted [3.3]MCP-2,11-diones are exclusively obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)benzenes and 2,6-bis[2-isocyano-2-(tolylsulfonyl)ethyl]-4-tert-butylbenzenes in dimethylformamide (DMF) with an excess of sodium hydride, from which the corresponding syn-[3.3]MCP are synthesised via anti-syn-isomerisation during the Wolff-Kishner reduction.

Synthesis of polymethyl substituted [2.2]metaparacyclophanes and their Lewis-acid induced isomerisation to [2.2]metacyclophanes

The preparation of polymethyl substituted [2.2]metaparacyclophanes using sulfur method and the X-ray structure determination of 4,5,6,8,12,13,15,16-octamethyl[2.2]metaparacyclophane are described. AlCl3-MeNO2-catalysed trans-tert-butylation of 5-tert-butyl-8,12,13,15,16-pentamethyl[2.2]metaparacyclophane in benzene led to isomerisation reaction to afford the strainless 8,12,13,14,16-pentamethyl[2.2]metacyclophane in 85% yield along with tert-butylbenzene.

Synthesis, structure and inclusion properties of distal -bis{[(5′-methyl-2,2′-bipyridyl)-5-yl]methoxy}tetrathiacalix[4]arene with 1,3- alternate conformation

distal-Tetrathiacalix[4]arene having [(5′-methyl-2,2′-bipyridyl)-5-yl]methoxy group with 1,3-alternate conformation was prepared, which shows strong Ag+ affinity and the high Ag+ selectivity. The conformational change of 2,2′-bipyridyl moiety from the original outward orientation of the ring nitrogen to the inside orientation toward the thiacalixarene cavity was observed in the process of Ag+ complexation.

Synthesis of 8-methyl[2.2]metacyclophanes and their charge-transfer complexes with tetracyanoethylene

The regioselective 1:1 charge-transfer band of 13-substituted 8-methyl[2.2]metacyclophanes with tetracyanoethylene in CH2Cl2, attributable to the 8-methyl substituted benzene-site complex, are observed in the field of 556–605 nm, which is strongly affected by π-electron density of the opposite aromatic ring.

Synthesis of 5-tert-butyl-8,12,14-trimethyl- and 5-tert-butyl-8,12,14,16-tetramethyl[2.2]metacyclophane and their treatment with Lewis acids in benzene

Treatment of 5-tert-butyl-8,12,14,16-tetramethyl[2.2]MCP with AlCl3-MeNO2 in benzene led to trans-tert-butylation to afford 8,12,14,16-tetramethyl[2.2]MCP in good yield along with tert-butylbenzene. On the other hand, the same treatment of 5-tert-butyl-8,12,14-trimethyl[2.2]MCP led to transannular cyclisation reaction and isomerisation reaction to afford the corresponding strainless 2-tert-butyl-3a,6,8-trimethyl-3,3a,4,5,9,10-hexahydropyrene in good yield.