File Download
There are no files associated with this item.
Links for fulltext
(May Require Subscription)
- Publisher Website: 10.1039/c2sc20038d
- Scopus: eid_2-s2.0-84864230192
- WOS: WOS:000304365000022
- Find via
Supplementary
- Citations:
- Appears in Collections:
Article: Ligand π-conjunction dictated intersystem crossing in phenyleneethynylene gold(I) complexes
Title | Ligand π-conjunction dictated intersystem crossing in phenyleneethynylene gold(I) complexes |
---|---|
Authors | |
Keywords | Combined method Comparative studies Delayed fluorescence Excited-state decay Excited-state dynamics |
Issue Date | 2012 |
Publisher | Royal Society of Chemistry. The Journal's web site is located at http://www.rsc.org/publishing/journals/sc/About.asp |
Citation | Chemical Science, 2012, v. 3 n. 6, p. 1883-1892 How to Cite? |
Abstract | The excited state dynamics of gold(i) complexes containing monomeric phenyleneethynylene (PE) or oligo (p- or m-PE) ligand, namely PhCCAu(PCy 3) (1a) and PhCC(C 6H 4-1,m-CC) 2Au(PCy 3) (m = 4, 2a; m = 3, 3a) were investigated by combined methods of femtosecond transient absorption (fs-TA), fs time-resolved fluorescence (fs-TRF) and nanosecond time-resolved emission (ns-TRE). Comparative study was also performed on the corresponding metal free p- and m-PE oligomers (2b and 3b) to allow for evaluating the effect of ligand π-conjugation and the effect of gold(i) on the overall dynamics and emission pathways of the gold(i)-PE complexes. The results reveal that, although the incorporation of heavy gold(i) into PE ligand is effective in promoting the spin-forbidden ligand centered S 1 1ππ* to T 1 3ππ* intersystem crossing (ISC), the exact ISC rate constant (k ISC) is largely controlled by π-conjugation of the PE ligand in the S 1 states of 1a-3a. Upon increasing π-conjugation as from 1a to 3a and to 2a, the k ISC decreases consecutively by ∼2 orders of magnitude from ∼1.2 × 10 12 s -1 in 1a to ∼2.6 × 10 10 and ∼1.6 × 10 8 s -1 in 3a and 2a, respectively. As a result, the prompt fluorescence (PF) from the initial S 1 1ππ* state is quenched to markedly different extent, with the lifetime (τ PF) ranging from ∼0.7 ps in 1a to ∼450 ps in 2a. Aside from PF, long-lived delayed fluorescence (DF, lifetime on microsecond timescale) formed due to triplet-triplet annihilation (TTA) has also been identified to contribute to the fluorescence of 2a and 3a but not 1a. The ligand dependent behavior of both the k ISC and DF provides a rationale to the varied efficiency and unusual composition of the emissions of 1a-3a. The findings present a compelling case that impacts the conventional scenario of ISC due to the heavy-atom effect in the excited state decay of transition-metal complexes; the photophysical parameters and the deactivation pattern derived in this work are useful information for understanding the structure-property relationship of transition-metal-PE complexes. © 2012 The Royal Society of Chemistry. |
Persistent Identifier | http://hdl.handle.net/10722/168660 |
ISSN | 2021 Impact Factor: 9.969 2020 SCImago Journal Rankings: 3.687 |
ISI Accession Number ID | |
References |
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Ma, C | en_US |
dc.contributor.author | Chan, CTL | en_US |
dc.contributor.author | Kwok, WM | en_US |
dc.contributor.author | Che, CM | en_US |
dc.date.accessioned | 2012-10-08T03:24:06Z | - |
dc.date.available | 2012-10-08T03:24:06Z | - |
dc.date.issued | 2012 | en_US |
dc.identifier.citation | Chemical Science, 2012, v. 3 n. 6, p. 1883-1892 | en_US |
dc.identifier.issn | 2041-6520 | en_US |
dc.identifier.uri | http://hdl.handle.net/10722/168660 | - |
dc.description.abstract | The excited state dynamics of gold(i) complexes containing monomeric phenyleneethynylene (PE) or oligo (p- or m-PE) ligand, namely PhCCAu(PCy 3) (1a) and PhCC(C 6H 4-1,m-CC) 2Au(PCy 3) (m = 4, 2a; m = 3, 3a) were investigated by combined methods of femtosecond transient absorption (fs-TA), fs time-resolved fluorescence (fs-TRF) and nanosecond time-resolved emission (ns-TRE). Comparative study was also performed on the corresponding metal free p- and m-PE oligomers (2b and 3b) to allow for evaluating the effect of ligand π-conjugation and the effect of gold(i) on the overall dynamics and emission pathways of the gold(i)-PE complexes. The results reveal that, although the incorporation of heavy gold(i) into PE ligand is effective in promoting the spin-forbidden ligand centered S 1 1ππ* to T 1 3ππ* intersystem crossing (ISC), the exact ISC rate constant (k ISC) is largely controlled by π-conjugation of the PE ligand in the S 1 states of 1a-3a. Upon increasing π-conjugation as from 1a to 3a and to 2a, the k ISC decreases consecutively by ∼2 orders of magnitude from ∼1.2 × 10 12 s -1 in 1a to ∼2.6 × 10 10 and ∼1.6 × 10 8 s -1 in 3a and 2a, respectively. As a result, the prompt fluorescence (PF) from the initial S 1 1ππ* state is quenched to markedly different extent, with the lifetime (τ PF) ranging from ∼0.7 ps in 1a to ∼450 ps in 2a. Aside from PF, long-lived delayed fluorescence (DF, lifetime on microsecond timescale) formed due to triplet-triplet annihilation (TTA) has also been identified to contribute to the fluorescence of 2a and 3a but not 1a. The ligand dependent behavior of both the k ISC and DF provides a rationale to the varied efficiency and unusual composition of the emissions of 1a-3a. The findings present a compelling case that impacts the conventional scenario of ISC due to the heavy-atom effect in the excited state decay of transition-metal complexes; the photophysical parameters and the deactivation pattern derived in this work are useful information for understanding the structure-property relationship of transition-metal-PE complexes. © 2012 The Royal Society of Chemistry. | en_US |
dc.language | eng | en_US |
dc.publisher | Royal Society of Chemistry. The Journal's web site is located at http://www.rsc.org/publishing/journals/sc/About.asp | en_US |
dc.relation.ispartof | Chemical Science | en_US |
dc.subject | Combined method | - |
dc.subject | Comparative studies | - |
dc.subject | Delayed fluorescence | - |
dc.subject | Excited-state decay | - |
dc.subject | Excited-state dynamics | - |
dc.title | Ligand π-conjunction dictated intersystem crossing in phenyleneethynylene gold(I) complexes | en_US |
dc.type | Article | en_US |
dc.identifier.email | Ma, C: macs@hkucc.hku.hk | en_US |
dc.identifier.email | Che, CM: cmche@hku.hk | en_US |
dc.identifier.authority | Ma, C=rp00758 | en_US |
dc.identifier.authority | Che, CM=rp00670 | en_US |
dc.description.nature | link_to_subscribed_fulltext | en_US |
dc.identifier.doi | 10.1039/c2sc20038d | en_US |
dc.identifier.scopus | eid_2-s2.0-84864230192 | en_US |
dc.identifier.hkuros | 205375 | - |
dc.relation.references | http://www.scopus.com/mlt/select.url?eid=2-s2.0-84864230192&selection=ref&src=s&origin=recordpage | en_US |
dc.identifier.volume | 3 | en_US |
dc.identifier.issue | 6 | en_US |
dc.identifier.spage | 1883 | en_US |
dc.identifier.epage | 1892 | en_US |
dc.identifier.isi | WOS:000304365000022 | - |
dc.publisher.place | United Kingdom | en_US |
dc.identifier.scopusauthorid | Che, CM=7102442791 | en_US |
dc.identifier.scopusauthorid | Kwok, WM=7103129332 | en_US |
dc.identifier.scopusauthorid | Chan, CTL=39960952700 | en_US |
dc.identifier.scopusauthorid | Ma, C=7402924979 | en_US |
dc.identifier.issnl | 2041-6520 | - |