J. F. Kögel, D. A. Sorokin, A. Khvorost, M. Scott, K. Harms, D. Himmel, I. Krossing and J. Sundermeyer
{"title":"路易斯超强酸Al[N(C6F5)2]3及其高级同系物Ga[N(C6 F5)2]3-具有比SbF5更高的氟离子亲和力的金属酰胺的结构特征、理论研究和反应†","authors":"J. F. Kögel, D. A. Sorokin, A. Khvorost, M. Scott, K. Harms, D. Himmel, I. Krossing and J. Sundermeyer","doi":"10.1039/C7SC03988C","DOIUrl":null,"url":null,"abstract":"<p >Herein we present the synthesis of the two Lewis acids Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> (ALTA) and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> (GATA) <em>via</em> salt elimination reactions. The metal complexes were characterized by NMR-spectroscopic methods and X-ray diffraction analysis revealing the stabilization of the highly Lewis acidic metal centers by secondary metal–fluorine contacts. The Lewis acidic properties of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> are demonstrated by reactions with Lewis bases resulting in the formation of metallates accompanied by crucial structural changes. The two metallates [Cs(Tol)<small><sub>3</sub></small>]<small><sup>+</sup></small>[FAl(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> and [AsPh<small><sub>4</sub></small>]<small><sup>+</sup></small>[ClGa(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> contain interesting weakly coordinating anions. The reaction of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> with trityl fluoride yielded [CPh<small><sub>3</sub></small>]<small><sup>+</sup></small>[FAl(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> which could find application in the activation of metallocene polymerization catalysts. The qualitative Lewis acidity of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> was investigated by means of competition experiments for chloride ions in solution. DFT calculations yielded fluoride ion affinities in the gas phase (FIA) of 555 kJ mol<small><sup>−1</sup></small> for Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and 472 kJ mol<small><sup>−1</sup></small> for Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small>. Thus, Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> can be considered a Lewis superacid with a fluoride affinity higher than SbF<small><sub>5</sub></small> (493 kJ mol<small><sup>−1</sup></small>) whereas the FIA of the corresponding gallium complex is slightly below the threshold to Lewis superacidity.</p>","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":" 1","pages":" 245-253"},"PeriodicalIF":7.6000,"publicationDate":"2017-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1039/C7SC03988C","citationCount":"23","resultStr":"{\"title\":\"The Lewis superacid Al[N(C6F5)2]3 and its higher homolog Ga[N(C6F5)2]3 – structural features, theoretical investigation and reactions of a metal amide with higher fluoride ion affinity than SbF5†\",\"authors\":\"J. F. Kögel, D. A. Sorokin, A. Khvorost, M. Scott, K. Harms, D. Himmel, I. Krossing and J. Sundermeyer\",\"doi\":\"10.1039/C7SC03988C\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Herein we present the synthesis of the two Lewis acids Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> (ALTA) and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> (GATA) <em>via</em> salt elimination reactions. The metal complexes were characterized by NMR-spectroscopic methods and X-ray diffraction analysis revealing the stabilization of the highly Lewis acidic metal centers by secondary metal–fluorine contacts. The Lewis acidic properties of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> are demonstrated by reactions with Lewis bases resulting in the formation of metallates accompanied by crucial structural changes. The two metallates [Cs(Tol)<small><sub>3</sub></small>]<small><sup>+</sup></small>[FAl(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> and [AsPh<small><sub>4</sub></small>]<small><sup>+</sup></small>[ClGa(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> contain interesting weakly coordinating anions. The reaction of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> with trityl fluoride yielded [CPh<small><sub>3</sub></small>]<small><sup>+</sup></small>[FAl(N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>)<small><sub>3</sub></small>]<small><sup>−</sup></small> which could find application in the activation of metallocene polymerization catalysts. The qualitative Lewis acidity of Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> was investigated by means of competition experiments for chloride ions in solution. DFT calculations yielded fluoride ion affinities in the gas phase (FIA) of 555 kJ mol<small><sup>−1</sup></small> for Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> and 472 kJ mol<small><sup>−1</sup></small> for Ga[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small>. Thus, Al[N(C<small><sub>6</sub></small>F<small><sub>5</sub></small>)<small><sub>2</sub></small>]<small><sub>3</sub></small> can be considered a Lewis superacid with a fluoride affinity higher than SbF<small><sub>5</sub></small> (493 kJ mol<small><sup>−1</sup></small>) whereas the FIA of the corresponding gallium complex is slightly below the threshold to Lewis superacidity.</p>\",\"PeriodicalId\":9909,\"journal\":{\"name\":\"Chemical Science\",\"volume\":\" 1\",\"pages\":\" 245-253\"},\"PeriodicalIF\":7.6000,\"publicationDate\":\"2017-10-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1039/C7SC03988C\",\"citationCount\":\"23\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Science\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2018/sc/c7sc03988c\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Science","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2018/sc/c7sc03988c","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
The Lewis superacid Al[N(C6F5)2]3 and its higher homolog Ga[N(C6F5)2]3 – structural features, theoretical investigation and reactions of a metal amide with higher fluoride ion affinity than SbF5†
Herein we present the synthesis of the two Lewis acids Al[N(C6F5)2]3 (ALTA) and Ga[N(C6F5)2]3 (GATA) via salt elimination reactions. The metal complexes were characterized by NMR-spectroscopic methods and X-ray diffraction analysis revealing the stabilization of the highly Lewis acidic metal centers by secondary metal–fluorine contacts. The Lewis acidic properties of Al[N(C6F5)2]3 and Ga[N(C6F5)2]3 are demonstrated by reactions with Lewis bases resulting in the formation of metallates accompanied by crucial structural changes. The two metallates [Cs(Tol)3]+[FAl(N(C6F5)2)3]− and [AsPh4]+[ClGa(N(C6F5)2)3]− contain interesting weakly coordinating anions. The reaction of Al[N(C6F5)2]3 with trityl fluoride yielded [CPh3]+[FAl(N(C6F5)2)3]− which could find application in the activation of metallocene polymerization catalysts. The qualitative Lewis acidity of Al[N(C6F5)2]3 and Ga[N(C6F5)2]3 was investigated by means of competition experiments for chloride ions in solution. DFT calculations yielded fluoride ion affinities in the gas phase (FIA) of 555 kJ mol−1 for Al[N(C6F5)2]3 and 472 kJ mol−1 for Ga[N(C6F5)2]3. Thus, Al[N(C6F5)2]3 can be considered a Lewis superacid with a fluoride affinity higher than SbF5 (493 kJ mol−1) whereas the FIA of the corresponding gallium complex is slightly below the threshold to Lewis superacidity.
期刊介绍:
Chemical Science is a journal that encompasses various disciplines within the chemical sciences. Its scope includes publishing ground-breaking research with significant implications for its respective field, as well as appealing to a wider audience in related areas. To be considered for publication, articles must showcase innovative and original advances in their field of study and be presented in a manner that is understandable to scientists from diverse backgrounds. However, the journal generally does not publish highly specialized research.