A Possible Infinite Number of Components in a Single Crystalline Phase: On the Isomorphism of Brivaracetam–Guest Molecules

2018 ◽  
Vol 18 (9) ◽  
pp. 4807-4810 ◽  
Author(s):  
Nicolas Couvrat ◽  
Morgane Sanselme ◽  
Yohann Cartigny ◽  
Frederic De Smet ◽  
Sandrine Rome ◽  
...  
2018 ◽  
Vol 768 ◽  
pp. 211-217 ◽  
Author(s):  
Rui Wang ◽  
Yu Kun Sun ◽  
Bao Jia Qi Jiang ◽  
Hui Yang ◽  
Xing Zhong Guo

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.


1992 ◽  
Vol 57 (4) ◽  
pp. 788-793 ◽  
Author(s):  
Falk Fischer ◽  
Marianne Hadan ◽  
Günter Fiedrich

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.


ChemCatChem ◽  
2013 ◽  
Vol 5 (10) ◽  
pp. 2869-2873 ◽  
Author(s):  
Chen Chen ◽  
Nakatani Kosuke ◽  
Toru Murayama ◽  
Wataru Ueda

2000 ◽  
Vol 122 (40) ◽  
pp. 9631-9637 ◽  
Author(s):  
Tetsuhiro Kodani ◽  
Kenji Matsuda ◽  
Taro Yamada ◽  
Seiya Kobatake ◽  
Masahiro Irie

2002 ◽  
Vol 389 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Lili Xu ◽  
Jiben Meng ◽  
Hui Wang ◽  
Ping Li ◽  
Teruki Sugiyama ◽  
...  

1992 ◽  
Vol 01 (04) ◽  
pp. 327-342
Author(s):  
TIM D. COCHRAN

We show that, in search of link invariants more discriminating than Milnor's [Formula: see text]-invariants, one is naturally led to consider seemingly pathological objects such as links with an infinite number of components and the join of an infinite number of circles (Hawaiian earrings space). We define an infinite homology boundary link, and show that any finite sublink of an infinite homology boundary link has vanishing Milnor's invariants. Moreover, all links known to have vanishing Milnor's invariants are finite sublinks of infinite homology boundary links. We show that the exterior of an infinite homology boundary link admits a map to the Hawaiian earrings space, and that this may be employed to get a factorization of K. E. Orr's omega-invariant through a rather simple space.


2003 ◽  
Vol 807 ◽  
Author(s):  
Neil C. Hyatt ◽  
Joseph A. Hriljac ◽  
Alia Choudhry ◽  
Laura Malpass ◽  
Gareth P. Sheppard ◽  
...  

ABSTRACTReactions of zeolite Na-A with AgI, and the sodium, copper and lead forms of zeolites A, LTA, X and Y with NaI, have been examined as possible starting routes to the long term immobilisation of iodine-129. Heating the salts in air, at 500°C, with the sodium forms of the zeolites leads to the formation of occlusion products, where the iodide salt migrates into the zeolite pores. Detailed studies of the Na-A / 5AgI complex indicate it has a uniform distribution of Na, Si, Al, Ag and I, and is thermally stable to ca. 750°C, where there is a substantial weight loss as iodine is released. In situ powder X-ray diffraction studies have been used to monitor the occlusion reaction at 400°C, and show that the occlusion product decomposes to produce a single crystalline phase at 800°C prior to further decomposition at 850°C to a mixture of nepheline and elemental silver.


2013 ◽  
Vol 62 (17) ◽  
pp. 176102
Author(s):  
Luo Yi ◽  
Zhao Guo-Ping ◽  
Yang Hai-Tao ◽  
Song Ning-Ning ◽  
Ren Xiao ◽  
...  

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