Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine
Reaction of the potentially bis-bidentate bridging ligand 3,6-bis(2-pyridyl)tetrazine (BPTZ) with various lanthanide complexes [Ln(tta)3(H2O)2] [Htta = thenoyl(trifluoro) acetone; Ln = La, Nd, Gd, Er, Yb] in aqueous ethanol afforded the mononuclear complexes [Ln(tta)3(BPTZ)] (Ln = La, Nd) or the din...
| Principais autores: | , , , , |
|---|---|
| Formato: | Journal article |
| Idioma: | English |
| Publicado em: |
2003
|
| _version_ | 1826271694684160000 |
|---|---|
| author | Shavaleev, N Pope, S Bell, Z Faulkner, S Ward, MD |
| author_facet | Shavaleev, N Pope, S Bell, Z Faulkner, S Ward, MD |
| author_sort | Shavaleev, N |
| collection | OXFORD |
| description | Reaction of the potentially bis-bidentate bridging ligand 3,6-bis(2-pyridyl)tetrazine (BPTZ) with various lanthanide complexes [Ln(tta)3(H2O)2] [Htta = thenoyl(trifluoro) acetone; Ln = La, Nd, Gd, Er, Yb] in aqueous ethanol afforded the mononuclear complexes [Ln(tta)3(BPTZ)] (Ln = La, Nd) or the dinuclear complexes [{Ln(tta)3}2(μ-BPTZ)] (Ln = Gd, Er, Yb) in which one or two, respectively, lanthanide tris-diketonate {Ln(tta)3} units are bound to the N,N-bidentate compartments of BPTZ. Crystal structures of the dinuclear complexes [{Yb(tta)3}2(μ-BPTZ)] ·CH2Cl2 and [{Gd(tta)3} 2(μ-BPTZ)]·2CH2Cl2 show that the metal centres have an approximately square-antiprismatic eight-coordinate geometry; there are close contacts above and below the plane of the BPTZ bridging ligand between peripheral trifluoromethyl groups from a tta ligand associated with each metal centre. It is not apparent why the larger lanthanides La and Nd only give a mononuclear complex whereas the smaller lanthanides Gd, Er and Yb give the dinuclear complex in each case. UV/Vis spectroscopic titrations of a solution of BPTZ in CH2Cl2 with increasing amounts of [Ln(tta)3(H2O)2] (Ln = La and Yb) show very similar behaviour, with stepwise binding constants K1 and K2 for association of the two {Ln(tta)3} units of ca. 106 M-1 and 105 M-1; allowing for the expected statistical factor of 4 there is an additional reduction in the value of K2 compared to K1 which may be associated with a steric interaction between the two {Ln(tta)3} units when the dinuclear complex forms. Steady-state and time-resolved luminescence studies on the complexes with Yb, Nd and Er, both in the solid state and CH 2Cl2 solution, show that near-IR luminescence on the microsecond timescale can be sensitised by irradiation either at 337 nm into the tta-based transition, or at 520 nm into the low-energy BPTZ-centred transition. © The Royal Society of Chemistry 2003. |
| first_indexed | 2024-03-06T22:00:43Z |
| format | Journal article |
| id | oxford-uuid:4e7cc96c-7dba-4d8e-a1cb-3515016a21a8 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:00:43Z |
| publishDate | 2003 |
| record_format | dspace |
| spelling | oxford-uuid:4e7cc96c-7dba-4d8e-a1cb-3515016a21a82022-03-26T16:01:27ZVisible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazineJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4e7cc96c-7dba-4d8e-a1cb-3515016a21a8EnglishSymplectic Elements at Oxford2003Shavaleev, NPope, SBell, ZFaulkner, SWard, MDReaction of the potentially bis-bidentate bridging ligand 3,6-bis(2-pyridyl)tetrazine (BPTZ) with various lanthanide complexes [Ln(tta)3(H2O)2] [Htta = thenoyl(trifluoro) acetone; Ln = La, Nd, Gd, Er, Yb] in aqueous ethanol afforded the mononuclear complexes [Ln(tta)3(BPTZ)] (Ln = La, Nd) or the dinuclear complexes [{Ln(tta)3}2(μ-BPTZ)] (Ln = Gd, Er, Yb) in which one or two, respectively, lanthanide tris-diketonate {Ln(tta)3} units are bound to the N,N-bidentate compartments of BPTZ. Crystal structures of the dinuclear complexes [{Yb(tta)3}2(μ-BPTZ)] ·CH2Cl2 and [{Gd(tta)3} 2(μ-BPTZ)]·2CH2Cl2 show that the metal centres have an approximately square-antiprismatic eight-coordinate geometry; there are close contacts above and below the plane of the BPTZ bridging ligand between peripheral trifluoromethyl groups from a tta ligand associated with each metal centre. It is not apparent why the larger lanthanides La and Nd only give a mononuclear complex whereas the smaller lanthanides Gd, Er and Yb give the dinuclear complex in each case. UV/Vis spectroscopic titrations of a solution of BPTZ in CH2Cl2 with increasing amounts of [Ln(tta)3(H2O)2] (Ln = La and Yb) show very similar behaviour, with stepwise binding constants K1 and K2 for association of the two {Ln(tta)3} units of ca. 106 M-1 and 105 M-1; allowing for the expected statistical factor of 4 there is an additional reduction in the value of K2 compared to K1 which may be associated with a steric interaction between the two {Ln(tta)3} units when the dinuclear complex forms. Steady-state and time-resolved luminescence studies on the complexes with Yb, Nd and Er, both in the solid state and CH 2Cl2 solution, show that near-IR luminescence on the microsecond timescale can be sensitised by irradiation either at 337 nm into the tta-based transition, or at 520 nm into the low-energy BPTZ-centred transition. © The Royal Society of Chemistry 2003. |
| spellingShingle | Shavaleev, N Pope, S Bell, Z Faulkner, S Ward, MD Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title | Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title_full | Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title_fullStr | Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title_full_unstemmed | Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title_short | Visible-light sensitisation of near-infrared luminescence from Yb(III), Nd(III) and Er(III) complexes of 3,6-bis(2-pyridyl)tetrazine |
| title_sort | visible light sensitisation of near infrared luminescence from yb iii nd iii and er iii complexes of 3 6 bis 2 pyridyl tetrazine |
| work_keys_str_mv | AT shavaleevn visiblelightsensitisationofnearinfraredluminescencefromybiiindiiianderiiicomplexesof36bis2pyridyltetrazine AT popes visiblelightsensitisationofnearinfraredluminescencefromybiiindiiianderiiicomplexesof36bis2pyridyltetrazine AT bellz visiblelightsensitisationofnearinfraredluminescencefromybiiindiiianderiiicomplexesof36bis2pyridyltetrazine AT faulkners visiblelightsensitisationofnearinfraredluminescencefromybiiindiiianderiiicomplexesof36bis2pyridyltetrazine AT wardmd visiblelightsensitisationofnearinfraredluminescencefromybiiindiiianderiiicomplexesof36bis2pyridyltetrazine |