Guest/Host Relationships in the Synthesis of the Novel Cage-Based Zeolites SSZ-35, SSZ-36, and SSZ-39
摘要:
Here, we report the synthesis and structure of three high-silica molecular sieves, SSZ-35, SSZ-36, and SSZ-39, that are prepared from a library of 37 different cyclic and polycyclic quaternized amine molecules that are used as structure-directing agents (SDAs). The size and shape of the quaternized amine molecules are purposely designed in order to obtain novel zeolite structures, and the synthesis of these molecules is presented. The selectivity for the three molecular sieve phases is found to depend on both the SDA and the degree of heteroatom lattice substitution of Al3+ or B3+ in the silicate framework. Molecular modeling is utilized to probe the effects of the nonbonded SDA/zeolite-framework interaction energy on the selectivity for the observed molecular sieve phase. The Rietveld refinement of the powder X-ray data confirms the structure of the SSZ-39 zeolite to be isomorphous with the aluminophosphate molecular sieve, SAPO-LS (AEI). The structure of SSZ-36 is found to possess a range of fault probabilities between the two-dimensional channel system, end-member polymorphs, ITQ-3 and RUB-13 (International Zeolite Association Codes ITE and RTH, respectively). The SSZ-35 structure is reported to contain a one-dimensional pore system possessing stacked cages circumscribed by alternating rings of 10 and 18 tetrahedral atoms (10- and 18-membered rings).
A study of the diels-alder reaction of 3-oxabicyclo[3.3.0]oct-1(5)-ene-2,4-dione with cyclopentadiene and some related dienes
作者:P. Camps、J. Castañé、M. Feliz、M. Figueredo
DOI:10.1016/s0040-4020(01)91277-3
日期:1984.1
stereoselectivity in the last reaction. Steric factors seem to be responsible for the absence of reaction between 2 and 4. The analysis of the 13C NMR spectra of these adducts and some derived compounds confirms the tentative configuration assignment carried out on the basis of PMR data. Also, the synthesis of dimethyl(1R,2S,6R,7S)-10-oxotricy-clo [5.2.1.02.6]decane2,6-decarboxylate, 1, from the endo-adduct
3-氧杂双环[3.3.0]辛-1-(5)烯-2,4-二酮2与环戊二烯3、5,5-二乙氧基环戊二烯4和6,6-二甲基富勒烯5的反应是研究过。的反应2倍3的产率的预期内切-adduct,而反应2和5给出的混合物中内切-和外切-adducts其比例是略微依赖于反应条件。在过渡态下导致外向的有吸引力的静电相互作用-加合物可以解释在最后的反应中没有内在立体选择性。立体因素似乎是造成2和4之间没有反应的原因。这些加合物和某些衍生化合物的13 C NMR光谱分析证实了基于PMR数据进行的暂定构型分配。另外,描述了由2和5的反应的内加成物合成二甲基(1R,2S,6R,7S)-10-氧合-闭[5.2.1.0 2.6 ]癸烷2,6-脱羧酯1。
An expeditious approach to highly functionalized angularly fused 5–5–n ring systems through ring opening–ring closing metathesis of norbornene derivatives
作者:Ritabrata Datta、Sritama Bose、Pipaliya B. Viththlbhai、Subrata Ghosh
DOI:10.1016/j.tetlet.2014.04.091
日期:2014.6
A new general route for the construction of angularly arrayed 5–5–n ring systems is described using tandem ring opening–ring closingmetathesis of appropriately designed norbornene derivatives as the key step.
1,4-Dimesylate embodied in strained polycyclic systems 2,7,10 undergoes facile reductive CC bond cleavage to bridged eight membered rings 4, 8, 11 while the less strained 14 gives reduced product 15.
Ghosh, Subrata; Sarkar, Subrata; Saha, Goutam, Journal of the Chemical Society. Perkin transactions I, 1993, # 19, p. 2281 - 2286
作者:Ghosh, Subrata、Sarkar, Subrata、Saha, Goutam
DOI:——
日期:——
Strain assisted carbon-carbon bond cleavage via carbon centred radical. A facile route to bridged eight membered rings
作者:Subrata Sarkar、Subrata Ghosh
DOI:10.1016/s0040-4039(00)60501-4
日期:1993.4
Tributyltin hydride reaction of the tricyclo[5.2.1.0(2, 6)]decenes 3, 11, 15 bearing the 1,4-halo carbonyl system has been shown to involve C-C bond cleavage as the major reaction path leading to bridged eight membered rings in contrast to reduction of the carbon-halogen bond in 7.