ZSM－35、ZSM－5及丝光沸石中模板分子TMEDA质子化的研究

用（１３）Ｃ魔角固体核磁共振及化学分析研究处在高硅沸石ＺＳＭ－３５、ＺＳＭ－５及丝光沸石孔道中模板分子四甲基乙撑二胺（ＴＭＥＤＡ）的质子化。（１３）Ｃ核磁共振谱中δ＝３４～３７ｐｐｍ的共振峰可归属于单端质子化的模板分子。它们有序地分布在上述沸石的主孔道中。质子靠近－ＣＨ３基团，远离－Ｃ２Ｈ４－基团。     

模板分子TMEDA成CF—3及ZSM—39沸石笼中的位置及其与骨…

用ＸＲＤ、ＦＴＩＲ、ＴＧ－ＤＴＡ、＾１３Ｃ魔角固体核磁共振表征用四甲基乙基二胺（ＴＭＥＤＡ）为结构异向剂合成的高硅沸石ＣＦ－３及ＺＳＭ－３９．ＴＭＥＤＡ不同基团的＾１３Ｃ化学位移，共振峰相对强度在交叉极化（ＣＰ）及高功率去偶（ＨＰＤＥＣ）核磁共振谱中的变化，揭示出模板分子在尺寸不同的沸石笼中的位置、运动状态及其与骨架的相互作用。在ＺＳＭ－３９沸石中的ＴＭＥＤＡ分子，它的－Ｃ２Ｈ４－基团＾１３Ｃ共振     

ZSM—35,ZSM—5及丝光沸石中模板分子TMEDA质子化的研究

用＾１３Ｃ魔角固体核磁共振及化学分析研究处在高硅沸石ＺＳＭ－３５、ＺＳＭ－５及丝光沸石孔道中模板分子四甲基乙撑二胺（ＴＭＥＤＡ）的质子化。＾１３Ｃ核磁共振谱中δ＝３４～３７ｐｐｍ的共振峰可归属于单端质子化的模板分子。它们有序地分布在上述沸石的主孔道中。质子告近－ＣＨ３基团，远离－Ｃ２Ｈ４－基团。     

分子模拟及光谱法研究2-乙基-3-(3-硝基苯基)喹唑啉-4-酮与小牛胸腺DNA的相互作用

合成了2-乙基-3-(3-硝基苯基)喹唑啉-4-酮(ENPQO),用紫外光谱法、荧光光谱法、荧光偏振法、离子强度法及分子模拟法研究了ENPQO与小牛胸腺DNA(ct DNA)的相互作用。紫外光谱法显示ct DNA与ENPQO作用后,引起ENPQO紫外吸收光谱的增色效应;在以吖啶橙(AO)为荧光探针的实验中,随着ENPQO浓度的增加,ct DNA-AO体系的荧光被猝灭,其猝灭过程主要是静态猝灭,ENPQO对ct DNA-AO体系的荧光偏振基本无影响;不同浓度的Na Cl溶液未削弱ENPQO对ct DNA-AO的猝灭程度。以上结果均表明ENPQO与ct DNA之间的作用方式主要为沟槽结合。利用分子模拟对接技术预测了ENPQO与ct DNA的结合最优构象,与光谱实验结果一致。     

Single crystal growth,morphology, and structure of ZSM-39 and its variation CF-4

Single crystals of ZSM-39 and its variation CF-4 were crystallized with various habits. The crystals had a size up to 450 m and were hydrothermally grown over a period of 8 to 72 days from a gel system consisting of amine-alcohol-SiO₂–H₂O at 200°C. The amines used were MA (methylamine), TMEDA (N,N,N,N-tetramethylenediamine), TMAOH, TEAOH, isopropylamine,tert-butylamine, hexahydropyridine,n-propylamine, andN,N-dimethylethanolamine. The alcohols used were glycerine, ethylene glycol, and 1,3-propanediol. The highest quality crystals of ZSM-39 were grown in a system of MA–SiO₂–H₂O, and CF-4, in the MA-glycerine-SiO₂–H₂O system. The optical properties of these crystals were observed and crystal structures were measured from both powder and single crystal diffraction data.     

固相转晶合成含硼CF-2沸石过程中甲胺分子的状态变化

以¹³C MAS NMR与TG-DTG为主要手段,研究了多孔玻璃粉于蒸汽相中转变为含硼CF-2沸石过程中模板剂甲胺分子的状态变化.结果表明甲胺分子经历了三种状态变化:在反应初期,甲胺分子与多孔玻璃表面羟基形成弱相互作用;随着反应进行,一部分弱相互作用的甲胺分子转变为强相互作用的甲胺分子;强相互作用的甲胺分子与硅羟基、铝羟基、硼羟基共同形成CF-2沸石晶核,晶核长大成晶体,甲胺分子进入沸石孔道内,此时存在与多孔玻璃粉表面羟基弱相互作用、强相互作用以及处于沸石孔道内的三种甲胺分子.随着结晶度进一步升高,多孔玻璃表面弱相互作用与强相互作用的甲胺分子依次逐渐消失,最终全部进入CF-2沸石孔道内.孔道内有自由状态和质子化的甲胺分子.SEM照片从形貌上直观地表征了多孔玻璃向CF-2沸石的转变过程.     

The synthesis and properties of zeolite CF-3

The novel zeolite CF-3, with a high ratio of SiO₂/Al₂O₃ and a characteristic X-ray powder diffraction pattern, has been synthesized hydrothermally from a TMEDA-Na₂O–SiO₂–Al₂O₃–H₂O system at 200°C. The molar composition of CF-3 is (0.4–0.6)Na₂O·(1.5–6.3)TMEDA·Al₂O₃·(80–400)SiO₂·(0–17)H₂O·CF-3 is similar to ZSM-39 and melanophlogite, which have a clathrate-type structure.     

THF-FER沸石的系列研究—Ⅱ．模板剂分子THF的位置

用^13C HPDEC MAS NMR与热分析方法表征了在四氢呋喃（THF）-Na2O-SiO2- Al2O3-H2O体系中水热合成的高硅Na-THF-FER沸石、酸交换后的H-THF-FER沸石以及 吸附于Na-FER和H-FER沸石中的THF。结果证明，模板剂分子THF位于Na-THF-FER沸 石骨架的FER笼内，平衡骨架阳离子Na^+主要存在于十元环孔道；而吸附子FER沸石 中的THF仅处于十元环孔道中，合成样品中THF的化学位移与液态THF相比，向低场 移动，谱线明显变宽，表明THF分子与FER笼之间存在很强的相互作用。     

Synthesis of ZSM-5 Zeolite with Small Crystallite and its Application in Aromatiration of Propane

Recently.greatinterestswereputonthenano-sizedmaterials.ItwasfoundthatzeoliteZSM-5withsmallornano-sizedcrystallitecouldachieveexcellentcatalyticperformanceincertainreactions'-;.However,mostpublicationsconcerningthesynthesisofZSM-5withsmallcrystallitealwaysusethecostlyTPAOH/Brasorganictemplates.WereportedherefoemethodusingmuchcheaperethylamineastemplateandtheproductswereappliedtoaromatizationofpropaneinwhichthestabilityofcatalystwasimprovedwithoutusingcostlyPt'orPd'asstabilizer.Synthesisof…     

Analysis of β‐CH2 signals in the 13C NMR spectra of the methyl methacrylate–ethyl acrylate copolymer as a tool for microstructure determination

The incremental method of the chemical shift calculation in the ¹³C NMR spectra of the methyl methacrylate–ethyl acrylate copolymer, PMMA/EA, has been applied to the β‐CH₂ carbons. A positive simulation of the DEPT sub‐spectrum shows that it is possible to determine in this way the distribution of configurational‐compositional tetrads providing a tool for microstructure analysis of acrylic copolymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2147–2155, 2000     

Ligand π‐Radical Interaction with f‐Shell Unpaired Electrons in Phthalocyaninato–Lanthanoid Single‐Molecule Magnets: A Solution NMR Spectroscopic and DFT Study

The phthalocyaninato double‐decker complexes [M(obPc)₂]⁰ (M= Y^III, Tb^III, Dy^III; obPc=2,3,9,10,16,17,23,24‐octabutoxyphthalocyaninato), along with their reduced ([M(obPc)₂]^?[P(Ph)₄]⁺; M=Tb^III, Dy^III) and oxidized ([M(obPc)₂]⁺[SbCl₆]^? (M=Y^III, Tb^III) counterparts were studied with ¹H, ¹³C and 2D NMR. From the NMR data of the neutral (i.e., with one unpaired electron in the ligands) and anionic Tb^III complexes, along with the use of dispersion corrected DFT methods, it was possible to separate the metal‐centered and ligand‐centered contributions to the hyperfine NMR shift. These contributions to the ¹H and ¹³C hyperfine NMR shifts were further analyzed in terms of pseudocontact and Fermi contact shifts. Furthermore, from a combination of NMR data and DFT calculations, we have determined the spin multiplicity of the neutral complexes [M(obPc)₂]⁰ (M=Tb^III and Dy^III) at room temperature. From the NMR data of the cationic Tb^III complex, for which actually no experimental structure determination is available, we have analyzed the structural changes induced by oxidation from its neutral/anionic species and shown that the interligand distance decreases upon oxidation. The fast electron exchange process between the neutral and anionic Tb^III double‐decker complexes was also studied.     

Effects of polymorphic differences for sulfanilamide, as seen through 13C and 15N solid-state NMR, together with shielding calculations

We recorded both carbon-13 and nitrogen-15 NMR spectra of the three solid forms of sulfanilamide most commonly known. This study led to an interpretation of the solid-state effects seen in cross-polarization magic angle spinning spectra. Relaxation times for the different forms were measured. These show different behaviour for the three forms, arising from mobility variations. To obtain information on local environments, static spectra and spinning sideband manifolds were recorded and analysed for the 15N resonances, using isotopically enriched samples. Shielding asymmetries and anisotropies for the two nitrogen nuclei were obtained, showing very different behaviour for the two sites. Shielding calculations were carried out for both 13C and 15N nuclei, and the results are discussed in relation to the experimental values.     

Solid‐state cross‐polarization magic angle spinning 13C and 15N NMR characterization of Sepia melanin,Sepia melanin free acid and Human hair melanin in comparison with several model compounds

This paper presents the high‐resolution ¹³C and ¹⁵N cross‐polarization magic angle spinning (CP/MAS) NMR spectra of three natural melanin solids: Sepia officinalis melanin, Sepia officinalis melanin free acid (MFA) and Human hair melanin. The functional group characterization of Human hair melanin by NMR is the first to date and the ¹³C CP/MAS NMR spectra reported here show improved resolution of chemically inequivalent sites. The observed spectral regions of the solid melanin samples can be assigned to the postulated structural unit of the polymer chain of Sepia MFA derived from solution‐state NMR studies. To assist in the assignment of functional groups in the spectra, the solid‐state CP/MAS NMR spectra are compared with high‐resolution ¹³C and ¹⁵N CP/MAS spectra of four model compounds, L ‐dopa, dopamine, 2‐methoxycarbonyl‐3‐ethoxycarbonyl‐4‐methylpyrrole and ethyl 5,6‐dimethoxyindole‐2‐carboxylate. To aid further in the assignment of protonated and non‐protonated carbon atoms, CP contact time dependence and non‐quaternary carbon suppression (NQS) experiments were performed on the melanin samples. The ¹⁵N CP/MAS spectra of the melanin samples confirm the presence of indole and pyrrole units in the melanin polymer chain. The NMR peaks observed in all of the melanin samples are relatively broad, presumably owing to the presence of free radicals. Electron spin resonance (ESR) data shows that all three melanin samples contain localized free radicals (g = 2.007), with the Sepia melanin containing a 10‐fold higher free radical density than Human hair melanin. Copyright © 2003 John Wiley & Sons, Ltd.     

13C and 15N CP/MAS, 1H–15N SCT CP/MAS and FTIR spectroscopy as tools for qualitative detection of the presence of zwitterionic and non‐ionic forms of ansa‐macrolide 3‐formylrifamycin SV and its derivatives in solid state

¹³C, ¹⁵N CP/MAS, including ¹H–¹³C and ¹H–¹⁵N short contact time CP/MAS experiments, and FTIR methods were applied for detailed structural characterization of ansa‐macrolides as 3‐formylrifamycin SV (1) and its derivatives (2–6) in crystal and in powder forms. Although HPLC chromatograms for 2/CH₃OH and 2/CH₃CCl₃ were the same for rifampicin crystals dissolved in respective solvents, the UV–vis data recorded for them were different in 300–375 nm region. Detailed solid state ¹³C and ¹⁵N CP/MAS NMR and FTIR studies revealed that rifampicin (2), in contrast to 3‐formylrifamycin SV (1) and its amino derivatives (3–6), can occur in pure non‐ionic or zwitterionic forms in crystal and in pure these forms or a mixture of them in a powder. Multinuclear CP/MAS and FTIR studies demonstrated also that 3–6 derivatives were present exclusively in pure zwitterionic forms, both in powder and in crystal. On the basis of the solid state NMR and FTIR studies, two conformers of 3‐formylrifamycin SV were detected in powder form due to the different orientations of carbonyl group of amide moiety. The PM6 molecular modeling at the semi‐empirical level of theory, allowed visualization the most energetically favorable non‐ionic and zwitterionic forms of 1–6 antibiotics, strongly stabilized via intramolecular H‐bonds. FTIR studies indicated that the originally adopted forms of these type antibiotics in crystal or in powder are stable in standard laboratory conditions in time. The results presented point to the fact that because of a possible presence of two forms of rifampicin (compound 2), quantification of the content of this antibiotic in relevant pharmaceuticals needs caution. Copyright © 2013 John Wiley & Sons, Ltd.