7 research outputs found
The d(10) route to dye-sensitized solar cells: step-wise assembly of zinc(II) photosensitizers on TiO2 surfaces
Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl2, and subsequent capping with a chromophore functionalized 2,2`:6`,2 ``-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication
Oligoazobenzenes - Switching in a New Dimension
A new synthesis of cyclotrisazobenzene with different substituents was developed with yields of up to 30%. Solid-state structures of cyclotrisazobenzene as well as the tert-butyl derivative were obtained. Also, the photochromic properties and the complexation behaviour with alkali metal ions of this class of molecules were investigated
Alkyl chain-functionalized hole-transporting domains in zinc(II) dye-sensitized solar cells
FTO/TiO2 electrodes have been functionalized with {Zn(tpyanchor)(tpyancillary)}2+ dyes (tpy = 2,2′:6′,2″-terpyridine) using a stepwise method to sequentially introduce (i) the anchoring ligand tpyanchor (either a dicarboxylic acid or a diphosphonic acid), (ii) Zn2+ ions, and (iii) chromophoric ancillary (4-([2,2′:6′,2″-terpyridin]-4′-yl)-N,N-bis(4-alkoxyphenyl)aniline ligands. A comparison of unmasked and fully masked DSSCs containing representative dyes shows a significant drop in photon-to-current efficiency upon masking. Solid-state absorption spectra of the dye-functionalized electrodes confirm that the intensity of absorption decreases with the steric demands of the ancillary ligand. DSSC measurements show that the {Zn(tpyanchor)(tpyancillary)}2+ dyes give poor photon-to-current efficiencies, values of the short circuit current density (JSC) and the external quantum efficiency (EQE) spectra are consistent with very poor electron injection. Introducing longer alkoxy chains in place of methoxy substituents in the hole-transporting domains in tpyancillary is beneficial, resulting in increased JSC and VOC, although values remain low despite the 'push–pull' design of the sensitizers
2,2':6',2''-terpyridine substituted in the 4'-position by the solubilizing and sterically demanding tert-butyl group : a surprisingly new ligand
We describe the synthesis and characterization of 4′-tert-butyl-2,2′:6′,2′′-terpyridine (4′-tButpy, 1), a convergent tpy ligand that exhibits both a sterically demanding and solubilizing 4′-substituent. In the solid state, molecules of 1 pack with alternating tpy and tert-butyl domains, and the bulky alkyl substituents prevent the molecules from engaging in the face-to-face π-interactions which are typical of simple tpy ligands. Instead, the predominant packing forces involve CH⋯N hydrogen bonds and weak CH⋯π contacts. The syntheses of the homoleptic complexes [M(1)2][PF6]2 (M = Fe, Co, Zn and Ru) and the heteroleptic [Ru(tpy)(1)][PF6]2 are described. The complexes have been fully characterized in solution, including the 1H NMR spectroscopic characterization of the paramagnetic [Co(1)2][PF6]2. Cyclic voltammetric data are consistent with the tert-butyl substituent being slightly electron releasing. The single crystal structures of [Zn(1)2][PF6]2 and [Ru(1)2][PF6]2 have been determined; the compounds are essentially isomorphous. The packing of the cations is such that the tert-butyl substituents are accommodated in pockets between the tpy domains of adjacent cations, and as a consequence, the {M(tpy)2}-embrace that is a ubiquitous feature of many related structures is not observed
The d10 route to dye-sensitized solar cells: step-wise assembly of zinc(ii) photosensitizers on TiO2 surfaces
Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl2, and subsequent capping with a chromophore functionalized 2,2`:6`,2 ``-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication
Mycophenolate and azathioprine efficacy in interstitial lung disease: a systematic review and meta-analysis
Objectives Mycophenolate mofetil (MMF) and azathioprine (AZA) are immunomodulatory treatments in interstitial lung disease (ILD). This systematic review aimed to evaluate the efficacy of MMF or AZA on pulmonary function in ILD.Design Population included any ILD diagnosis, intervention included MMF or AZA treatment, outcome was delta change from baseline in per cent predicted forced vital capacity (%FVC) and gas transfer (diffusion lung capacity of carbon monoxide, %DLco). The primary endpoint compared outcomes relative to placebo comparator, the secondary endpoint assessed outcomes in treated groups only.Eligibility criteria Randomised controlled trials (RCTs) and prospective observational studies were included. No language restrictions were applied. Retrospective studies and studies with high-dose concomitant steroids were excluded.Data synthesis The systematic search was performed on 9 May. Meta-analyses according to drug and outcome were specified with random effects, I2 evaluated heterogeneity and Grading of Recommendations, Assessment, Development and Evaluation evaluated certainty of evidence. Primary endpoint analysis was restricted to RCT design, secondary endpoint included subgroup analysis according to prospective observational or RCT design.Results A total of 2831 publications were screened, 12 were suitable for quantitative synthesis. Three MMF RCTs were included with no significant effect on the primary endpoints (%FVC 2.94, 95% CI −4.00 to 9.88, I2=79.3%; %DLco −2.03, 95% CI −4.38 to 0.32, I2=0.0%). An overall 2.03% change from baseline in %FVC (95% CI 0.65 to 3.42, I2=0.0%) was observed in MMF, and RCT subgroup summary estimated a 4.42% change from baseline in %DLCO (95% CI 2.05 to 6.79, I2=0.0%). AZA studies were limited. All estimates were considered very low certainty evidence.Conclusions There were limited RCTs of MMF or AZA and their benefit in ILD was of very low certainty. MMF may support preservation of pulmonary function, yet confidence in the effect was weak. To support high certainty evidence, RCTs should be designed to directly assess MMF efficacy in ILD.PROSPERO registration number CRD42023423223