Michael Morasch, Timothy Vilpas, Dr. Neha Patel, Johannes Maurer, Stefan Thum, Marcel A. Schmidt, Dr. Jens Langer, Prof. Dr. Sjoerd Harder
{"title":"低价锶的二氮活化","authors":"Michael Morasch, Timothy Vilpas, Dr. Neha Patel, Johannes Maurer, Stefan Thum, Marcel A. Schmidt, Dr. Jens Langer, Prof. Dr. Sjoerd Harder","doi":"10.1002/anie.202506989","DOIUrl":null,"url":null,"abstract":"<p>DFT calculations on β-diketiminate (BDI) complexes with the full series of alkaline-earth (Ae) metals show that (BDI)AeAe(BDI) complexes of the heavier Ae metals (Ca, Sr, Ba) have long weak Ae─Ae bonds that are prone to homolytic bond cleavage. However, isolation of (BDI)Sr(μ-N<sub>2</sub>)Sr(BDI) with a side-on bridging N<sub>2</sub><sup>2−</sup> dianion should thermodynamically be feasible. Attempts to stabilize such a complex with the super bulky BDI* ligand failed (BDI* = HC[(Me)C = N-DIPeP]<sub>2</sub>, DIPeP = 2,6-Et<sub>2</sub>CH-phenyl). First, N<sub>2</sub> fixation with a Sr complex was enabled by a heterobimetallic approach. Reduction of (<sup>DIPeP</sup>NN)Sr with potassium gave (<sup>DIPeP</sup>NN)<sub>2</sub>Sr<sub>2</sub>K<sub>2</sub>(N<sub>2</sub>) (<b>6</b>-Sr); <sup>DIPeP</sup>NN = <sup>DIPeP</sup>N-Si(Me)<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>Si(Me)<sub>2</sub>-N<sup>DIPeP</sup>. A similar Ca product was also isolated (<b>6</b>-Ca). Crystal structures reveal a N<sub>2</sub><sup>2−</sup> anion with side-on bonding to Ae<sup>2+</sup> and end-on coordination to K<sup>+</sup>. DFT calculations and Atoms-In-Molecules analyses show mainly ionic bonding. Both <b>6</b>-Ae complexes are synthons for hitherto unknown (BDI*)AeAe(BDI*) (Ae = Ca, Sr) and react by releasing N<sub>2</sub> and two electrons. Although surprisingly stable in benzene, the reduction of I<sub>2</sub> and H<sub>2</sub> is facile. Fast reaction with Teflon led to formation of crystalline [(<sup>DIPeP</sup>NN)SrKF]<sub>2</sub> (<b>7</b>), which is labile and decomposed to KF and (<sup>DIPeP</sup>NN)Sr. Latter reactivity underscores potential use of <b>6</b>-Ae complexes as very strong, hydrocarbon-soluble reducing agents.</p>","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"64 28","pages":""},"PeriodicalIF":16.9000,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.202506989","citationCount":"0","resultStr":"{\"title\":\"Dinitrogen Activation with Low-Valent Strontium\",\"authors\":\"Michael Morasch, Timothy Vilpas, Dr. Neha Patel, Johannes Maurer, Stefan Thum, Marcel A. Schmidt, Dr. Jens Langer, Prof. Dr. Sjoerd Harder\",\"doi\":\"10.1002/anie.202506989\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>DFT calculations on β-diketiminate (BDI) complexes with the full series of alkaline-earth (Ae) metals show that (BDI)AeAe(BDI) complexes of the heavier Ae metals (Ca, Sr, Ba) have long weak Ae─Ae bonds that are prone to homolytic bond cleavage. However, isolation of (BDI)Sr(μ-N<sub>2</sub>)Sr(BDI) with a side-on bridging N<sub>2</sub><sup>2−</sup> dianion should thermodynamically be feasible. Attempts to stabilize such a complex with the super bulky BDI* ligand failed (BDI* = HC[(Me)C = N-DIPeP]<sub>2</sub>, DIPeP = 2,6-Et<sub>2</sub>CH-phenyl). First, N<sub>2</sub> fixation with a Sr complex was enabled by a heterobimetallic approach. Reduction of (<sup>DIPeP</sup>NN)Sr with potassium gave (<sup>DIPeP</sup>NN)<sub>2</sub>Sr<sub>2</sub>K<sub>2</sub>(N<sub>2</sub>) (<b>6</b>-Sr); <sup>DIPeP</sup>NN = <sup>DIPeP</sup>N-Si(Me)<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>Si(Me)<sub>2</sub>-N<sup>DIPeP</sup>. A similar Ca product was also isolated (<b>6</b>-Ca). Crystal structures reveal a N<sub>2</sub><sup>2−</sup> anion with side-on bonding to Ae<sup>2+</sup> and end-on coordination to K<sup>+</sup>. DFT calculations and Atoms-In-Molecules analyses show mainly ionic bonding. Both <b>6</b>-Ae complexes are synthons for hitherto unknown (BDI*)AeAe(BDI*) (Ae = Ca, Sr) and react by releasing N<sub>2</sub> and two electrons. Although surprisingly stable in benzene, the reduction of I<sub>2</sub> and H<sub>2</sub> is facile. Fast reaction with Teflon led to formation of crystalline [(<sup>DIPeP</sup>NN)SrKF]<sub>2</sub> (<b>7</b>), which is labile and decomposed to KF and (<sup>DIPeP</sup>NN)Sr. Latter reactivity underscores potential use of <b>6</b>-Ae complexes as very strong, hydrocarbon-soluble reducing agents.</p>\",\"PeriodicalId\":125,\"journal\":{\"name\":\"Angewandte Chemie International Edition\",\"volume\":\"64 28\",\"pages\":\"\"},\"PeriodicalIF\":16.9000,\"publicationDate\":\"2025-05-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.202506989\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Angewandte Chemie International Edition\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/anie.202506989\",\"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":"Angewandte Chemie International Edition","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/anie.202506989","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
DFT calculations on β-diketiminate (BDI) complexes with the full series of alkaline-earth (Ae) metals show that (BDI)AeAe(BDI) complexes of the heavier Ae metals (Ca, Sr, Ba) have long weak Ae─Ae bonds that are prone to homolytic bond cleavage. However, isolation of (BDI)Sr(μ-N2)Sr(BDI) with a side-on bridging N22− dianion should thermodynamically be feasible. Attempts to stabilize such a complex with the super bulky BDI* ligand failed (BDI* = HC[(Me)C = N-DIPeP]2, DIPeP = 2,6-Et2CH-phenyl). First, N2 fixation with a Sr complex was enabled by a heterobimetallic approach. Reduction of (DIPePNN)Sr with potassium gave (DIPePNN)2Sr2K2(N2) (6-Sr); DIPePNN = DIPePN-Si(Me)2CH2CH2Si(Me)2-NDIPeP. A similar Ca product was also isolated (6-Ca). Crystal structures reveal a N22− anion with side-on bonding to Ae2+ and end-on coordination to K+. DFT calculations and Atoms-In-Molecules analyses show mainly ionic bonding. Both 6-Ae complexes are synthons for hitherto unknown (BDI*)AeAe(BDI*) (Ae = Ca, Sr) and react by releasing N2 and two electrons. Although surprisingly stable in benzene, the reduction of I2 and H2 is facile. Fast reaction with Teflon led to formation of crystalline [(DIPePNN)SrKF]2 (7), which is labile and decomposed to KF and (DIPePNN)Sr. Latter reactivity underscores potential use of 6-Ae complexes as very strong, hydrocarbon-soluble reducing agents.
期刊介绍：
Angewandte Chemie, a journal of the German Chemical Society (GDCh), maintains a leading position among scholarly journals in general chemistry with an impressive Impact Factor of 16.6 (2022 Journal Citation Reports, Clarivate, 2023). Published weekly in a reader-friendly format, it features new articles almost every day. Established in 1887, Angewandte Chemie is a prominent chemistry journal, offering a dynamic blend of Review-type articles, Highlights, Communications, and Research Articles on a weekly basis, making it unique in the field.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
