Selenoether macrocyclic chemistry—syntheses and properties of new potentially tridentate and hexadentate Se/O-donor macrocycles
| Autor: | Hayley L. Smith, Joanna M. Manning, Gillian Reid, Michael Webster, William Levason, Raju Ratnani, Manisha Nirwan |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Dalton Transactions. :3486 |
| ISSN: | 1477-9234 1477-9226 |
| DOI: | 10.1039/b718950h |
| Popis: | Treatment of O(CH2CH2SeCN)2 with Na in NH3(l), followed by dropwise addition of a thf solution of o-C6H4(CH2Br)2 at -40 degrees C leads to formation of three mixed Se/O-donor macrocycles which are separable by column chromatography, the [1 + 1] species L1, the [2 + 2] ring L2 and the [3 + 3] ring L3, of which L2 is by far the major species. Using the same starting materials, but in a high dilution cyclisation at room temperature with NaBH4 in thf/EtOH gives exclusively the [1 + 1] ring, L1. The saturated ring Se/O-donor macrocycles, L4 and L5 are obtained by simultaneous dropwise addition of solutions of O(CH2CH2SeCN)2 and Br(CH2)3Br to NaBH4 suspended in thf/EtOH. The small tridentate Se2O-donor ring, L4, is again the dominant product under these conditions (71%), although the more flexible precursors in this reaction also give rise to the larger Se4O2-donor ring, L5, as a by-product in 8% yield. These compounds are readily separated and purified by column chromatography (ethyl acetate:hexane, 1:19). The new macrocycles have been characterised by 1H, (13)C{1H} and (77)Se{1H} NMR spectroscopy and mass spectrometry, together with crystal structures of L1 and L2. Complexes of L1 and L2 with late transition metals (Pd(II), Pt(II), Cu(I) and Ag(I)) are also described. |
| Databáze: | OpenAIRE |
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