Deactivating Unproductive Pathways in Multichromophoric Sensitizers

Sabatini, Randy P.; Zheng, Bo; Fu, Wen‐Fu; Mark, Daniel J.; Mark, Manfred J.; Hillenbrand, Emily Anne; Eisenberg, Richard; McCamant, David W.

doi:10.1021/jp508283d

Cited by 21 publications

(33 citation statements)

References 28 publications

(57 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result indicates that the complex at the ground state is more stabilized by polar solvents than that of the S 1 state. 39 Similar results were observed for Pt-3 and Pt-4.…”

Section: Steady State Uv−vis Absorption and Luminescencesupporting

confidence: 74%

“…37,38 On the other hand, it is important to control the vectorial energy transfer in these multichromophore complexes in order to efficiently funnel the photoexcitation energy. 39 However, complexes may show elusive photophysics, for example, short-lived intraligand triplet state ( 3 IL) was observed with PBI chromophore. 37,38,40 Recently, we prepared a series of visible light harvesting Pt(II) complexes with acetylide ligand based on coumarin 41 and Bodipy.…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Zhong

Karatay²,

Zhao

et al. 2015

Inorg. Chem.

View full text Add to dashboard Cite

Pt(II) dbbpy bisacetylide (dbbpy = 4,4'-di(tert-butyl)-2,2'-bipyridine) complex (Pt-1) with two different Bodipy ligands was prepared with the goal to attain broad-band visible light absorbing, efficient funneling of the photoexcitation energy (via resonance energy transfer, RET) to the energy acceptor and high triplet formation quantum yields. Construction of the above-mentioned molecular structural motif is challenging because two different arylacetylide ligands are incorporated in the complex; normally two homoleptic acetylide ligands were used for this kind of N(∧)N Pt(II) complexes. A reference complex with trans bis(tributylphosphine) Pt(II) bisacetylide protocol (Pt-4) was prepared for comparison of the photophysical properties. The two different Bodipy ligands in Pt-1 and Pt-4 constitute singlet/triplet energy donor/acceptor, as a result the harvested photoexcitation energy can be funneled to the triplet state confined on one of the two Bodipy ligands. The photophysical properties of the complexes were studied with steady state UV-vis absorption and luminescence spectroscopies, femto- and nanosecond transient absorption spectroscopies, cyclic voltammetry, as well as DFT/TDDFT calculations. Fluorescence/phosphorescence dual emission were observed for the complex. The ultrafast intramolecular singlet/triplet energy transfer in Pt-1 was confirmed by the transient absorption spectroscopy (kFRET = 2.6 × 10(11) s(-1), ΦFRET = 87.1%) followed by an intersystem crossing (kISC = 1.9 × 10(10) s(-1)), and the triplet state lifetime (τT) is 54.1 μs. The reference complex Pt-4 shows drastically different kinetics with kFRET = 6.9 × 10(10) s(-1), ΦFRET = 81.0%, kISC = 5.83 × 10(9) s(-1), and τT = 147.9 μs. Different singlet oxygen ((1)O2) quantum yields (ΦΔ = 75% and 70%) and triplet state quantum yields (ΦT = 91% and 69%, respectively) were observed for complexes Pt-1 and Pt-4.

show abstract

“…This result indicates that the complex at the ground state is more stabilized by polar solvents than that of the S 1 state. 39 Similar results were observed for Pt-3 and Pt-4.…”

Section: Steady State Uv−vis Absorption and Luminescencesupporting

confidence: 74%

Section: ■ Introductionmentioning

confidence: 99%

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Zhong

Karatay²,

Zhao

et al. 2015

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…From the TA result, a 2.3 ps time constant was assigned for the singlet energy transfer from the bodipy unit to the ZnP moiety, comparable to those (i.e., 0.51–0.73 ps) of the reported bodipy‐conjugated PtN 2 S 2 PSs. In the bodipy‐PtN 2 S 2 systems, the bodipy‐antenna was an effective energy‐transfer chromophore towards the PtN 2 S 2 charge‐transfer moiety, increasing the H 2 production efficiency . Accordingly, our dyad design should make a positive contribution towards H 2 generation compared to ZnP alone.…”

Section: Resultsmentioning

confidence: 99%

Panchromatic Sensitization with Zn^II Porphyrin‐Based Photosensitizers for Light‐Driven Hydrogen Production

Mark

Wang

et al. 2018

ChemSusChem

Self Cite

View full text Add to dashboard Cite

Three molecular photosensitizers (PSs) with carboxylic acid anchors for attachment to platinized titanium dioxide nanoparticles were studied for light-driven hydrogen production from a fully aqueous medium with ascorbic acid (AA) as the sacrificial electron donor. Two zinc(II) porphyrin (ZnP)-based PSs were used to examine the effect of panchromatic sensitization on the photocatalytic H generation. A dyad molecular design was used to construct a difluoro boron-dipyrromethene (bodipy)-conjugated ZnP PS (ZnP-dyad), whereas the other one featured an electron-donating diarylamino moiety (YD2-o-C8). To probe the use of the ZnP scaffold in this particular energy conversion process, an organic PS without the ZnP moiety (Bodipy-dye) was also synthesized for comparison. Ultrafast transient absorption spectroscopy was adopted to map out the energy transfer processes occurring in the dyad and to establish the bodipy-based antenna effect. In particular, the systems with YD2-o-C8 and ZnP-dyad achieved a remarkable initial activity for the production of H with an initial turnover frequency (TOF ) higher than 300 h under white light irradiation. The use of ZnP PSs in dye-sensitized photocatalysis for the H evolution reaction in this study indicated the importance of the panchromatic sensitization capability for the development of light absorbing PSs.

show abstract

“…The change is consistent with the LUMO for the 1 MMLL′CT absorption being bpy based and the COOMe and P(O)(OEt) 2 substituents being strongly electron withdrawing. For 1 with R = CH 2 (P(O)(OEt) 2 and for the phenanthroline dyad 5, there is little observable effect of the electron withdrawing ability of the phosphonate ester group (52).…”

Section: Resultsmentioning

confidence: 99%

Light-driven generation of hydrogen: New chromophore dyads for increased activity based on Bodipy dye and Pt(diimine)(dithiolate) complexes

Zheng

Sabatini

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

New dyads consisting of a strongly absorbing Bodipy (dipyrromethene-BF 2 ) dye and a platinum diimine dithiolate (PtN 2 S 2 ) charge transfer (CT) chromophore have been synthesized and studied in the context of the light-driven generation of H 2 from aqueous protons. In these dyads, the Bodipy dye is bonded directly to the benzenedithiolate ligand of the PtN 2 S 2 CT chromophore. Each of the new dyads contains either a bipyridine (bpy) or phenanthroline (phen) diimine with an attached functional group that is used for binding directly to TiO 2 nanoparticles, allowing rapid electron photoinjection into the semiconductor. The absorption spectra and cyclic voltammograms of the dyads show that the spectroscopic and electrochemical properties of the dyads are the sum of the individual chromophores (Bodipy and the PtN 2 S 2 moieties), indicating little electronic coupling between them. Connection to TiO 2 nanoparticles is carried out by sonication leading to in situ attachment to TiO 2 without prior hydrolysis of the ester linking groups to acids. For H 2 generation studies, the TiO 2 particles are platinized (Pt-TiO 2 ) so that the light absorber (the dyad), the electron conduit (TiO 2 ), and the catalyst (attached colloidal Pt) are fully integrated. It is found that upon 530 nm irradiation in a H 2 O solution (pH 4) with ascorbic acid as an electron donor, the dyad linked to Pt-TiO 2 via a phosphonate or carboxylate attachment shows excellent light-driven H 2 production with substantial longevity, in which one particular dyad [4(bpyP)] exhibits the highest activity, generating ∼40,000 turnover numbers of H 2 over 12 d (with respect to dye).photochemistry | solar energy conversion | hydrogen | spectroscopy | synthesis W ater splitting into hydrogen and oxygen is the key energystoring reaction of artificial photosynthesis (AP) and one of the most promising long-term strategies for carbon-free energy on a potentially global scale (1). As a redox reaction, water splitting has been studied primarily in terms of its two halfreactions, the reduction of aqueous protons to H 2 and the oxidation of water to O 2 (2-13). Whereas some of these studies date back more than 30 y (14-22), recent progress on each halfreaction has been notable, particularly with regard to catalyst development and mechanistic understanding of each transformation (6,(23)(24)(25)(26)(27)(28)(29). In this paper, we focus on efforts dealing with the lightdriven generation of H 2 , which in its simplest form requires a light absorber or photosensitizer (PS) for electron-hole creation, a means or pathway for charge separation and electron transfer, an aqueous proton source, a catalyst for collecting electrons and protons and promoting their conversion to H 2 , and an ultimate source of electrons in the form of an electron donor.Dating from the earliest work on the light-driven generation of H 2 , the photosensitizer has most often been a Ru(II) complex with 2,2′-bipyridine (bpy) and/or related heterocyclic ligands having a long-lived triplet metal-to-ligand ...

show abstract

Deactivating Unproductive Pathways in Multichromophoric Sensitizers

Cited by 21 publications

References 28 publications

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Panchromatic Sensitization with Zn^II Porphyrin‐Based Photosensitizers for Light‐Driven Hydrogen Production

Light-driven generation of hydrogen: New chromophore dyads for increased activity based on Bodipy dye and Pt(diimine)(dithiolate) complexes

Contact Info

Product

Resources

About

Deactivating Unproductive Pathways in Multichromophoric Sensitizers

Cited by 21 publications

References 28 publications

Broad-Band N∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Broad-Band N∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Panchromatic Sensitization with ZnII Porphyrin‐Based Photosensitizers for Light‐Driven Hydrogen Production

Light-driven generation of hydrogen: New chromophore dyads for increased activity based on Bodipy dye and Pt(diimine)(dithiolate) complexes

Contact Info

Product

Resources

About

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Broad-Band N^∧N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

Panchromatic Sensitization with Zn^II Porphyrin‐Based Photosensitizers for Light‐Driven Hydrogen Production