Mahsa Afshari, Hossein Fallah-Bagher-Shaidaei, Mohammad Nikpassand
{"title":"关于包含三个苯亚单位的 [13] 至 [33] 双链环烷的构象和芳香性的理论研究","authors":"Mahsa Afshari, Hossein Fallah-Bagher-Shaidaei, Mohammad Nikpassand","doi":"10.1007/s11224-024-02347-9","DOIUrl":null,"url":null,"abstract":"<div><p>In the present study, conformations and aromaticity of seventeen [1<sub>3</sub>], [2<sub>3</sub>] and [3<sub>3</sub>] double-stranded cyclophanes composed of three benzene moieties were investigated at <i>B3LYP</i> level of density functional theory. The stability of these conformers is different depending on the type of cycloalkane-like cycles formed by (CH<sub>2</sub>) <sub>n</sub> bridges and the peripheral benzene rings, and also the curvature of the latter. In [1<sub>3</sub>] cyclophane, this leads to only one conformer containing puckered cyclobutane-like cycle, at an angle of about 37<sup>◦</sup>. In comparison, in cyclophanes [2<sub>3</sub>] and [3<sub>3</sub>], the corresponding cycles are cyclohexane-like and cyclooctane-like, respectively. While conformer <b>2a</b> having TB-like cycles is the most stable member of the [2<sub>3</sub>] family, of eight ground-state conformers obtained for [3<sub>3</sub>], <b>3a</b> with two Chair-Chair-like and one Twist-Chair-like cycles is the most stable one, and <b>3h</b> with three Twist-Boat-like cycles being 6.5 kcal higher in energy than the former is the least stable member of series. In addition to the conformational analysis, the aromaticity of the series has been assessed using different indexes, including magnetic criteria nucleus-independent chemical shifts (NICS-based) at the cage and at the ring centers, HNMR chemical shift, Magnetic Susceptibility, HOMA and relative energy (RE).</p></div>","PeriodicalId":780,"journal":{"name":"Structural Chemistry","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Theoretical study on the conformation and aromaticity of [13] to [33] double-stranded cyclophanes encompassing three benzene subunits\",\"authors\":\"Mahsa Afshari, Hossein Fallah-Bagher-Shaidaei, Mohammad Nikpassand\",\"doi\":\"10.1007/s11224-024-02347-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In the present study, conformations and aromaticity of seventeen [1<sub>3</sub>], [2<sub>3</sub>] and [3<sub>3</sub>] double-stranded cyclophanes composed of three benzene moieties were investigated at <i>B3LYP</i> level of density functional theory. The stability of these conformers is different depending on the type of cycloalkane-like cycles formed by (CH<sub>2</sub>) <sub>n</sub> bridges and the peripheral benzene rings, and also the curvature of the latter. In [1<sub>3</sub>] cyclophane, this leads to only one conformer containing puckered cyclobutane-like cycle, at an angle of about 37<sup>◦</sup>. In comparison, in cyclophanes [2<sub>3</sub>] and [3<sub>3</sub>], the corresponding cycles are cyclohexane-like and cyclooctane-like, respectively. While conformer <b>2a</b> having TB-like cycles is the most stable member of the [2<sub>3</sub>] family, of eight ground-state conformers obtained for [3<sub>3</sub>], <b>3a</b> with two Chair-Chair-like and one Twist-Chair-like cycles is the most stable one, and <b>3h</b> with three Twist-Boat-like cycles being 6.5 kcal higher in energy than the former is the least stable member of series. In addition to the conformational analysis, the aromaticity of the series has been assessed using different indexes, including magnetic criteria nucleus-independent chemical shifts (NICS-based) at the cage and at the ring centers, HNMR chemical shift, Magnetic Susceptibility, HOMA and relative energy (RE).</p></div>\",\"PeriodicalId\":780,\"journal\":{\"name\":\"Structural Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2024-05-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Structural Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s11224-024-02347-9\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Structural Chemistry","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s11224-024-02347-9","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Theoretical study on the conformation and aromaticity of [13] to [33] double-stranded cyclophanes encompassing three benzene subunits
In the present study, conformations and aromaticity of seventeen [13], [23] and [33] double-stranded cyclophanes composed of three benzene moieties were investigated at B3LYP level of density functional theory. The stability of these conformers is different depending on the type of cycloalkane-like cycles formed by (CH2) n bridges and the peripheral benzene rings, and also the curvature of the latter. In [13] cyclophane, this leads to only one conformer containing puckered cyclobutane-like cycle, at an angle of about 37◦. In comparison, in cyclophanes [23] and [33], the corresponding cycles are cyclohexane-like and cyclooctane-like, respectively. While conformer 2a having TB-like cycles is the most stable member of the [23] family, of eight ground-state conformers obtained for [33], 3a with two Chair-Chair-like and one Twist-Chair-like cycles is the most stable one, and 3h with three Twist-Boat-like cycles being 6.5 kcal higher in energy than the former is the least stable member of series. In addition to the conformational analysis, the aromaticity of the series has been assessed using different indexes, including magnetic criteria nucleus-independent chemical shifts (NICS-based) at the cage and at the ring centers, HNMR chemical shift, Magnetic Susceptibility, HOMA and relative energy (RE).
期刊介绍:
Structural Chemistry is an international forum for the publication of peer-reviewed original research papers that cover the condensed and gaseous states of matter and involve numerous techniques for the determination of structure and energetics, their results, and the conclusions derived from these studies. The journal overcomes the unnatural separation in the current literature among the areas of structure determination, energetics, and applications, as well as builds a bridge to other chemical disciplines. Ist comprehensive coverage encompasses broad discussion of results, observation of relationships among various properties, and the description and application of structure and energy information in all domains of chemistry.
We welcome the broadest range of accounts of research in structural chemistry involving the discussion of methodologies and structures,experimental, theoretical, and computational, and their combinations. We encourage discussions of structural information collected for their chemicaland biological significance.