Precise control of the degree and regioselectivity of functionalization in nitro- and amino-functionalized di(trispyrazolylborato)iron(II) spin crossover complexes.
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| Title: | Precise control of the degree and regioselectivity of functionalization in nitro- and amino-functionalized di(trispyrazolylborato)iron(II) spin crossover complexes. |
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| Authors: | Ma, Chenyang1 (AUTHOR), Besson, Claire1 (AUTHOR) claire_besson@gwu.edu |
| Source: | Dalton Transactions: An International Journal of Inorganic Chemistry. 12/28/2021, Vol. 50 Issue 48, p18077-18088. 12p. |
| Subjects: | Spin crossover, Polar effects (Chemistry), Nanoelectromechanical systems, Iron, Exchange reactions, Alkyl group |
| Abstract: | Di(trispyrazolylborato)iron(II) ([Tp2Fe]) complexes represent one of the most robust classes of spin-crossover complexes. Their stability renders them particularly suitable for integration in nanoscale devices, e.g. as sensors or information storage units. While prior studies of the functionalization of those derivatives have been focused on the electronic and steric effects of alkyl and –CF3 groups in position 3, a pyrazole exchange reaction between nitropyrazole and either trispyrazolylborate or its iron complex allows the regioselective installation of nitro substituents in positions 3, 4 and 5 of the [Tp2Fe] complexes. The degree of substitution can be varied from 1 to 4 functionalized pyrazoles per complex. The amine-functionalized analogues are accessed by reduction of the nitro analogues under hydrogen transfer conditions. With the exception of di- and tetra-3-NO2 substituted complexes, all derivatives display spin crossover properties in the solid state, with transition temperatures ranging from 180 to 380 K and showing different degrees of abruptness but no hysteresis. The Slichter–Drickamer model was used to extract the empirical thermodynamic transition parameters, allowing a systematic investigation of the influence of stoichiometry, position, and electronic nature of the substitution on the magnetic properties of the complexes. The steric effects dominate for substitution in position 3 but the electronic effects are significant for the other positions. [ABSTRACT FROM AUTHOR] |
| Copyright of Dalton Transactions: An International Journal of Inorganic Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 154122675 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Precise control of the degree and regioselectivity of functionalization in nitro- and amino-functionalized di(trispyrazolylborato)iron(II) spin crossover complexes. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Ma%2C+Chenyang%22">Ma, Chenyang</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Besson%2C+Claire%22">Besson, Claire</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> claire_besson@gwu.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Dalton+Transactions%3A+An+International+Journal+of+Inorganic+Chemistry%22">Dalton Transactions: An International Journal of Inorganic Chemistry</searchLink>. 12/28/2021, Vol. 50 Issue 48, p18077-18088. 12p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Spin+crossover%22">Spin crossover</searchLink><br /><searchLink fieldCode="DE" term="%22Polar+effects+%28Chemistry%29%22">Polar effects (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Nanoelectromechanical+systems%22">Nanoelectromechanical systems</searchLink><br /><searchLink fieldCode="DE" term="%22Iron%22">Iron</searchLink><br /><searchLink fieldCode="DE" term="%22Exchange+reactions%22">Exchange reactions</searchLink><br /><searchLink fieldCode="DE" term="%22Alkyl+group%22">Alkyl group</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Di(trispyrazolylborato)iron(II) ([Tp2Fe]) complexes represent one of the most robust classes of spin-crossover complexes. Their stability renders them particularly suitable for integration in nanoscale devices, e.g. as sensors or information storage units. While prior studies of the functionalization of those derivatives have been focused on the electronic and steric effects of alkyl and –CF3 groups in position 3, a pyrazole exchange reaction between nitropyrazole and either trispyrazolylborate or its iron complex allows the regioselective installation of nitro substituents in positions 3, 4 and 5 of the [Tp2Fe] complexes. The degree of substitution can be varied from 1 to 4 functionalized pyrazoles per complex. The amine-functionalized analogues are accessed by reduction of the nitro analogues under hydrogen transfer conditions. With the exception of di- and tetra-3-NO2 substituted complexes, all derivatives display spin crossover properties in the solid state, with transition temperatures ranging from 180 to 380 K and showing different degrees of abruptness but no hysteresis. The Slichter–Drickamer model was used to extract the empirical thermodynamic transition parameters, allowing a systematic investigation of the influence of stoichiometry, position, and electronic nature of the substitution on the magnetic properties of the complexes. The steric effects dominate for substitution in position 3 but the electronic effects are significant for the other positions. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Dalton Transactions: An International Journal of Inorganic Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1039/d1dt03445f Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 18077 Subjects: – SubjectFull: Spin crossover Type: general – SubjectFull: Polar effects (Chemistry) Type: general – SubjectFull: Nanoelectromechanical systems Type: general – SubjectFull: Iron Type: general – SubjectFull: Exchange reactions Type: general – SubjectFull: Alkyl group Type: general Titles: – TitleFull: Precise control of the degree and regioselectivity of functionalization in nitro- and amino-functionalized di(trispyrazolylborato)iron(II) spin crossover complexes. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Ma, Chenyang – PersonEntity: Name: NameFull: Besson, Claire IsPartOfRelationships: – BibEntity: Dates: – D: 28 M: 12 Text: 12/28/2021 Type: published Y: 2021 Identifiers: – Type: issn-print Value: 14779226 Numbering: – Type: volume Value: 50 – Type: issue Value: 48 Titles: – TitleFull: Dalton Transactions: An International Journal of Inorganic Chemistry Type: main |
| ResultId | 1 |
