{"title":"Chirality in Porous Functional Materials","authors":"Shumaila Ashraf, Bo Wang","doi":"10.5772/INTECHOPEN.82288","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.82288","url":null,"abstract":"Recently crystalline porous functional materials have specifically captured the scientist’s attention, because of their high surface area coupled with many unique chemical and physical properties. These frameworks can be efficiently tailored to induce chirality for asymmetric catalysis and enantiomeric separation. Chirality can be introduced either through bottom up assembly or by post-synthetic modification. Compared to the traditional chiral catalysts, they are highly stereo-selective, reproducible and environmentally benign. They also have a great potential to be used as asymmetric photo-catalysts with the combination of photoactive group and chiral center in to one molecular architecture, providing the advantages of atomically economic structure design. On account of their high stability, large number of active sites, permanent porosity, easy recovery and reuse, they can be considered as excellent candidates to fabricate efficient and economical green chiral catalysts of com-mercial interest.","PeriodicalId":447319,"journal":{"name":"Chirality from Molecular Electronic States","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129624097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ageeva, E. Khramtsova, I. Magin, N. Polyakov, M. Miranda, T. Leshina
{"title":"Peculiarities of Electron Transfer in Chiral Linked Systems","authors":"A. Ageeva, E. Khramtsova, I. Magin, N. Polyakov, M. Miranda, T. Leshina","doi":"10.5772/INTECHOPEN.82684","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.82684","url":null,"abstract":"Electron transfer (ET) is one of the most universal reactions in chemistry and biology. Recent studies conducted on the examples of photoinduced ET (PET) in chiral linked systems (dyads) have shown several important features indicative for ET in chiral systems. The peculiarity of processes with PET in such systems is pri-marily the stereoselectivity; there is difference in ET rates and fluorescence quantum yields in dyad diastereomers. The next feature is the spin selectivity of back ET in the biradical-zwitterions (BZs) that are formed under the dyad diastereomer UV irradiation. This is the difference in the enhancement coefficients of chemically induced dynamic nuclear polarization (CIDNP) originated in BZs. The probable cause of this effect is the variation in the spin density values, resulting from difference in the spatial structure of BZ in (R,S)- and (S,S)-configurations. The latter, in turn, is due to the fact that these dyads react in the form of associates—dimers. The impact of dimerization on the effectiveness of ET in chiral systems is an example of the chiral catalysis. The study of ET in chiral linked systems reveals reasons for the various reactivities of chiral molecules, including the difference in therapeutic activity of drug enantiomers.","PeriodicalId":447319,"journal":{"name":"Chirality from Molecular Electronic States","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130072800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chirality and Circular Polarized Properties of Photochromic Polyaromatic Molecules","authors":"T. Sawada, Shingo Kubo, K. Nanamura","doi":"10.5772/INTECHOPEN.81880","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.81880","url":null,"abstract":"Dihydropyrenes (DHPs) are a particularly interesting class of photochromic polyaromatic molecules due to their negative photochromism in UV-Vis spectra . Asymmetric heterocyclic-[e]-annelated DHPs were prepared by new synthetic routes and their photochromism was studied. The optical resolution of heterocyclic-[e]-annelated DHPs was performed by chiral HPLC systems and their enantiomers indicate the photochromism for UV-Vis, and CD spectra. The absolute structures of the enantiomers were determined by using spectra predicted with time-dependent density functional theory. Photoswitchable circular dichroism properties of asymmetric heterocyclic-[e]-annelated DHPs have potential as the molecular device to control the circular polarized light.","PeriodicalId":447319,"journal":{"name":"Chirality from Molecular Electronic States","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124773090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Khakhalin Andrey Vladimirovich, Gradoboeva Olga Nikolaevna
{"title":"Chirality Properties of Modeling Water in Different Aqueous Systems","authors":"Khakhalin Andrey Vladimirovich, Gradoboeva Olga Nikolaevna","doi":"10.5772/INTECHOPEN.81770","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.81770","url":null,"abstract":"The research addresses the problem of chirality existence in modeling water with various impurity molecules using new numerical algorithm of chirality deter-mination. It is based on asymmetry analysis of molecular system composed of water molecules. The following molecular systems are investigated: (1) small water clusters such as (H 2 O) n , K + (H 2 O) m , and Na + (H 2 O) m (n = 4÷8, m = 5÷10) at temperature 1 K; (2) (H 2 O) n , K + (H 2 O) p , and Na + (H 2 O) p (n = 4÷9, p = 5÷8) at temperature 300 K; and (3) chiral biological molecules of L-valine, D-valine, L-glycerose, and D-glycerose and left or right water clusters (H 2 O) 4 with water molecule ’ s shell with thickness varied from 4 to 14 Å with a step of 2 Å. The systems (1), (2) are investigated by Monte Carlo method and the interaction is simulated with Poltev-Malenkov potentials. Systems (3) are initiated using Solvate software, and then aqueous systems are optimized by the conjugate gradient algorithm using the MMFF94 potential. It is revealed that there is no predominance of right-handed or lefthanded substructures in all studied configurations of water molecules. But in small aqueous systems (2), (3), the number of types of water structures, taking into account chirality, depends on the presence of impurity ion and its type.","PeriodicalId":447319,"journal":{"name":"Chirality from Molecular Electronic States","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131955344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Nonlinear Analysis of Chiral Medium","authors":"A. Volobuev","doi":"10.5772/INTECHOPEN.80067","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80067","url":null,"abstract":"The principle of calculation of a plate from a metamaterial with inductive type chiral inclusions is submitted. It is shown that distribution of an electromagnetic wave to such substance can be investigated with the help of introduction of a chiral parameter and on the basis of a detailed method of calculation. By comparison of two methods the dependence of chiral parameter from frequency of electromagnetic radiation falling on a plate is found. With the help of a detailed method the nonlinear equation for potential on the chiral plate is found. It is shown that this equation has solutions as solitary and standing waves but not running waves. The analysis of the received solutions of the nonlinear equation is carried out.","PeriodicalId":447319,"journal":{"name":"Chirality from Molecular Electronic States","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133479415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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