Silicon-29 NMR Study of Alkali-Exchanged NaY Zeolites

High-resolution solid-state ²⁹Si NMR has been applied to the study of partially exchanged Li, K, and Cs NaY zeolites. The order of the ²⁹Si chemical shifts of dehydrated samples is Li, Na-Y < Na-Y < K, Na-Y. The correlation between the ²⁹Si chemical shift and the Li or K loading on Li, Na-Y or K, Na-Y was rationalized in terms of the interaction between the framework and the cations inside the small cages. Because of the restrictive migration of large Cs⁺ ions from the supercages to the small cages, the ²⁹Si chemical shift of Cs, Na-Y was found to be similar to that of Na-Y.     

DNA Interactions of a Dinuclear Ruthenium(II) Complex Bridged by 1,3-bis(1,10-phenanthroline[5,6-d]imidazol-2-yl)benzene

A novel dinuclear ruthenium(II) complex [(phen)₂Ru(mbpibH₂)Ru(phen)₂]⁴⁺ [phen = 1,10-phenanthroline; mbpibH₂ = 1,3-bis(1,10-phenanthroline[5,6-d]imidazol-2-yl)-benzene] has been synthesized and characterized. The DNA-binding behavior of this complex has been studied by spectroscopic and viscosity measurements. Results suggest that the dinuclear ruthenium(II) complex intercalates into DNA base pairs via its bridging moiety. It has also been found that the dinuclear ruthenium(II) complex displays the enantiopreferential DNA-binding after equilibrium dialysis.     

Initiation Mechanism of Polymerization of Acryl－amide by Ceric Ion／2－Benzoyl Acetanilide System

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Synthesis of dendritic polyamide with protected amino functional groups in the periphery

A homologous series of first-to third-generation dendritic polyamides 2a, 3, and 5 with tris(aminoethyl) amine (TREA) as the core and the protected amino functional groups at the periphery were synthesized via active ester route from “Schlüter” type dendron 1a. Their structures were characterized by ¹H-NMR and mass spectra. Based on the efficient synthesis of the first generation dendrimer 2a (yield 75%), the synthesis of second-generation dendrimer 3 was found to be more efficient via the convergent method (yield 69%), while the mixed strategy was applied efficiently for the synthesis of the higher generation dendrimer 5 (yield 37%). The overall yield for the third generation dendrimer 5 from Schlüter dendron is 12%. __________ Translated from Huaxue Tongbao (Chemistry), 2005, 68(12) (in Chinese)     

Hydrothermal synthesis and intercalation behavior of a layered titanium phosphate Ti2(H2PO4)(HPO4)(PO4)2 · 0.5C6N2H16, with an extended γ-phase intercalated into organic amine

With a hydrothermal technique, a layered titanium phosphate with the formula Ti₂(H₂PO₄)(HPO₄)(PO₄)₂ · 0.5C₆N₂H₁₆ (denoted TP-J2) has been prepared by treating the Ti/H₃PO₄/H₂O/1-methylpiperazine system directly. The as-synthesized products were characterized by powder X-ray diffraction, CP-MAS solid-state ³¹P NMR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA). The structure was solved by single-crystal X-ray diffraction analysis and it presents an extended γ-phase intercalated with organic amine. Crystal data: triclinic, , a = 8.106 (2) Å, b = 8.197 (2) Å, c = 11.658 (2) Å.  = 78.32 (3)°, β = 80.85 (3)°, γ = 77.90 (3)°, Z = 2. Additionally, the intercalation behavior of TP-J2 with n-alkyl monoamine (n = 2, 3, 4, 6, 8, 10 and 12) was investigated. Owing to the strong brønsted base, N,N′-dimethylpiperazine, resides in the interlayer, it presented unusual features of TP-J2 in contrast with that of γ-Tip.