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Azasilicon-bridged heterocyclic arylamines: syntheses, structures and photophysical properties

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journal contribution
posted on 08.08.2018, 10:05 by Shifang Yuan, Lijing Wang, Chuanbing Huang, Chunxia Niu, Kai Xiang, Caihong Xu, Gregory A. Solan, Hongwei Ma, Wen-Hua Sun
The lithium κ1-enamides, Me2NSiMe2CHC(Ph)-{2,6-(R1)2-4-(R2)C6H2}NLi·3THF (R1 = iPr, R2 = H L1; R1 = Et, R2 = H L2; R1 = Me, R2 = H L3; R1 = R2 = Me L4; R1 = Et, R2 = Me L5), in the presence of titanium tetrachloride, undergo intermolecular rearrangement cyclization reactions resulting in 1,3-migration of the silicon groups and the elimination of dimethylamine affording five examples of bis-azasilicon-bridged heterocyclic arylamines, [{2,6-(R1)2-4-(R2)C6H2}N(Ph)CCSiMe2]2 (R1 = iPr, R2 = H D1; R1 = Et, R2 = H D2; R1 = Me, R2 = H D3; R1 = R2 = Me D4; R1 = Et, R2 = Me D5) in good yield, respectively. The molecular structures of D1–D5 show the two fused N–Si–C–C–C rings to be co-planar indicative of extended π-conjugation, while their photophysical properties reveal them to be green/blue emitting with high luminescence quantum yields (ΦF range: 75–99%). Furthermore, the compounds D serve as versatile reactants undergoing ring opening on hydrolysis to afford the saturated 1,4-diimines [{2,6-(R1)2-4-(R2)C6H2}N(Ph)C-CH2]2 (R1 = iPr, R2 = H E1; R1 = Et, R2 = H E2; R1 = Me, R2 = H E3; R1 = R2 = Me E4; R1 = Et, R2 = Me E5). Alternatively, D can be employed in a redox-promoted cascade reaction to afford the conjugated 1,4-diimines, (E)-[{2,6-(R1)2-4-(R2)C6H2}N[double bond, length as m-dash]C(Ph)CH]2 (R1 = iPr, R2 = H F1; R1 = Et, R2 = H F2; R1 = Me, R2 = H F3; R1 = R2 = Me F4; R1 = Et, R2 = Me F5). In addition to D1–D5, E1–E3, E5, F2 and F3 have been the subject of single crystal X-ray diffraction studies.

Funding

The authors thank the National Natural Science Foundation of China (No. 21101101 and U1362204) and Shanxi Province Natural Science Fund (No. 2012021007-1) for financial support. We also thank the Scientific Instrument Center of Shanxi University. GAS thanks the Chinese Academy of Sciences for a Visiting Fellowship.

History

Citation

New Journal of Chemistry, 2018, 42 (4), pp. 3102-3111 (10)

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Chemistry

Version

AM (Accepted Manuscript)

Published in

New Journal of Chemistry

Publisher

Royal Society of Chemistry

issn

1144-0546

eissn

1369-9261

Copyright date

2018

Available date

15/01/2019

Publisher version

http://pubs.rsc.org/en/Content/ArticleLanding/2018/NJ/C7NJ03876C#!divAbstract

Notes

Electronic supplementary information (ESI) available. CCDC 1576205–1576215 contain the supplementary crystallographic data for complexes D1–D5, E1–E3, E5, F2 and F3. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7nj03876c;The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.

Language

en