Prediction of Strong Solvatochromism in a Molecular Photocatalyst

Based on quantum chemical calculations, we predict strong solvatochromism in a light-driven molecular photocatalyst for hydrogen generation, that is we show that the electronic and optical properties of the photocatalyst strongly depend on the solvent it is dissolved in. Our calculations in particular indicate a solvent-dependent relocation of the highest occupied molecular orbital (HOMO). Ground-state density functional theory and linear response time-dependent density functional theory calculations were applied in order to investigate the influence of implicit solvents on the structural, electronic and optical properties of a molecular photocatalyst. Only at high dielectric constants of the solvent, is the HOMO located at the metal center of the photosensitizer, whereas at low dielectric constants the HOMO is centered at the metal atom of the catalytically active complex. We elucidate the electronic origins of this strong solvatochromic effect and sketch the consequences of these insights for the use of photocatalysts in different environments

Structure of Diethyl-Phosphonic Acid Anchoring Group Affects the Charge-Separated State on an Iridium(III) Complex Functionalized NiO Surface

Cyclometalated Iridium(III) complexes, i. e. [Ir(C N)2(dppz)][PF6], bearing either two or four -CH2PO(OH)2 anchoring groups (IrP2dppz or IrP4dppz) are explored as photosensitizers for p-type dye sensitized solar cell (DSSC). The synthetic route is described and the iridium(III) complexes are characterized with respect to their electrochemical and photophysical properties. The modified anchoring ligand geometry exploited in this work not only alters the electronic nature of the complex (that is by destabilizing the LUMO energetically) but more importantly improves the grafting ability of the complex towards the NiO surface. The photoinduced long-lived charge separated state (CSS) at the NiO|IrPxdppz interface is of a different nature comparing the two complexes. For IrP2dppz and IrP4dppz the electron density of the CSS dominantly resides on the dppz and the C N ligand, respectively. The stability of the CSS can be correlated to the solar cell performance in NiO-based p-DSSCs, which yield conversion efficiencies which are among the highest in the class of iridium(III) complexes developed for p-DSSCs. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

Structure of diethyl‐phosphonic acid anchoring group affects the charge‐separated state on an iridium(III) complex functionalized NiO surface

Abstract Cyclometalated Iridium(III) complexes, i. e . [Ir(C N) 2 (dppz)][PF 6 ], bearing either two or four ‐CH 2 PO(OH) 2 anchoring groups ( IrP 2 dppz or IrP 4 dppz ) are explored as photosensitizers for p‐type dye sensitized solar cell (DSSC). The synthetic route is described and the iridium(III) complexes are characterized with respect to their electrochemical and photophysical properties. The modified anchoring ligand geometry exploited in this work not only alters the electronic nature of the complex (that is by destabilizing the LUMO energetically) but more importantly improves the grafting ability of the complex towards the NiO surface. The photoinduced long‐lived charge separated state (CSS) at the NiO|IrP x dppz interface is of a different nature comparing the two complexes. For IrP 2 dppz and IrP 4 dppz the electron density of the CSS dominantly resides on the dppz and the C N ligand, respectively. The stability of the CSS can be correlated to the solar cell performance in NiO‐based p‐DSSCs, which yield conversion efficiencies which are among the highest in the class of iridium(III) complexes developed for p‐DSSCs

Plasmonic Titania Photocatalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape

Plasmonic titania photocatalysts were prepared by titania modification with gold by photodeposition. It was found that for smaller amount of deposited gold (≤0.1 wt%), anatase presence and large surface area were beneficial for efficient hydrogen evolution during methanol dehydrogenation. After testing twelve amounts of deposited gold on large rutile titania, the existence of three optima for 0.5, 2 and >6 wt% of gold was found during acetic acid degradation. Under visible light irradiation, in the case of small gold NPs deposited on fine anatase titania, the dependence of photoactivity on gold amount was parabolic, and large gold amount (2 wt%), observable as an intensively coloured powder, caused photoactivity decrease. While for large gold NPs deposited on large rutile titania, the dependence represented cascade increase, due to change of size and shape of deposited gold with its amount increase. It has been thought that spherical/hemispherical shape of gold NPs, in comparison with rod-like ones, is beneficial for higher level of photoactivity under visible light irradiation. For all tested systems and regardless of deposited amount of gold, each rutile Au/TiO2 photocatalyst of large gold and titania NPs exhibited much higher photoactivity than anatase Au/TiO2 of small gold and titania NPs

Automated dissection of permanent effects of hippocampal or prefrontal lesions on performance at spatial, working memory and circadian timing tasks of C57BL/6 mice in IntelliCage

Peer reviewe

Link to glow - iEDDA conjugation of a Ruthenium(II) tetrazine complex leading to dihydropyrazine and pyrazine complexes with improved 1O2 formation ability

The synthesis and photophysical properties of the Ru-polypyridyl type complex [(tbbpy)2Ru(bptz)]2+ (Ru-bptz, tbbpy: 4,4’-di-tert-butyl-2,2’-bipyridine, bptz: 2,6-dipyrido-1,2,4,5-tetrazine), and the complexes [(tbbpy)2Ru(L)]2+ formed by inverse electron demand Diels Alder reaction (iEDDA) of Ru-bptz with with alkenes and alkynes, where L is 3,6-dipyrido-2,5-dihydropyridazine (bpdhpn) or 3,6-dipyrido-pyridazine (bppn) are described. A combination of steady-state and time-resolved spectroscopy complemented by the computation of state-specific absorption properties by means of time-dependent density functional theory reveals that the intense visible absorption band stems from Ru → tbbpy and Ru → L metal-to-ligand charge-transfer (MLCT) excitations. The studies show that lowest-lying L-centered MLCT states (3MLCTL) show comparably low emission quantum yields (3–9%) and lifetimes (90–150 ns). This correlates with the singlet oxygen generation ability, following the trend: Ru-bppn > Ru-bpdhpn > Ru-bptz

Pyrimidoquinazolinophenanthroline Opens Next Chapter in Design of Bridging Ligands for Artificial Photosynthesis **

The synthesis and detailed characterization of a new Ru polypyridine complex containing a heteroditopic bridging ligand with previously unexplored metal‐metal distances is presented. Due to the twisted geometry of the novel ligand, the resultant division of the ligand in two distinct subunits leads to steady state as well as excited state properties of the corresponding mononuclear Ru(II) polypyridine complex resembling those of prototype [Ru(bpy) 3 ] 2+ (bpy=2,2'‐bipyridine). The localization of the initially optically excited and the nature of the long‐lived excited states on the Ru‐facing ligand spheres is evaluated by resonance Raman and fs‐TA spectroscopy, respectively, and supported by DFT and TDDFT calculations. Coordination of a second metal (Zn or Rh) to the available bis‐pyrimidyl‐like coordination sphere strongly influences the frontier orbitals, apparent by, for example, luminescence quenching. Thus, the new bridging ligand motif offers electronic properties, which can be adjusted by the nature of the second metal center. Using the heterodinuclear Ru−Rh complex, visible light‐driven reduction of NAD + to NADH was achieved, highlighting the potential of this system for photocatalytic applications

Prosthetic Joint Infection in Mega-Arthroplasty Following Shoulder, Hip and Knee Malignancy—A Prospective Follow-Up Study

Introduction: The risk of prosthetic joint infection (PJI) in mega-prosthesis for malignancy is increased compared with non-tumor cases. While several studies describe PJI in tumor-related arthroplasty, prospective studies comparing infection characteristics among different joints are limited. The present study analyzes mega-arthroplasty for hip, knee, and shoulder malignancy and compares the epidemiology, diagnosis, microbe spectrum, treatments, and outcomes between the different entities. Methods: The retrospective inclusion criteria were as follows: (1) mega-arthroplasty (2) in the hip, knee, or shoulder joint and a total femur arthroplasty (3) following a malignant bone tumor or metastasis (4) between 1996 and 2019. All included patients were prospectively followed and invited for a renewed hospital examination, and their PJI characteristics (if identified) were analyzed using both retrospective as well as newly gained prospective data. A PJI was defined according to the Infectious Disease Society of America (IDSA) and re-infection was defined according to the modified Delphi Consensus criteria. Results: In total, 83 cases of tumor mega-arthroplasty at a mean follow-up of 3.9 years could be included (32 knee, 30 hip, and 19 shoulder cases and 2 cases of total femur arthroplasty). In total, 14 PJIs were identified, with chondrosarcoma in 6 and osteosarcoma in 3 being the leading tumor entities. Knee arthroplasty demonstrated a significantly higher rate of PJI (p = 0.027) compared with hips (28.1% vs. 6.7%), while no significant difference could be found between the knee and shoulder (10.5%) (p = 0.134) or among shoulder and hip cases (p = 0.631). The average time of PJI following primary implantation was 141.4 months in knee patients, 64.6 in hip patients, and 8.2 months in shoulder patients. Age at the time of the primary PJI, as well as the time of the first PJI, did not show significant differences among the groups. Thirteen of the fourteen patients with PJI had a primary bone tumor. Statistical analysis showed a significant difference in the disadvantage of primary bone tumors (p = 0.11). While the overall cancer-related mortality in the knee PJI group (10%) was low, it was 50% in the hip and 100% in the shoulder group. Conclusion: The risk of PJI in knee tumor arthroplasty is significantly increased compared with hips, while cancer-related mortality is significantly higher in hip PJI cases. At the same time, mega-prostheses appear to be associated with a higher risk of infection due to a primary bone tumor compared with metastases. The study confirms existing knowledge concerning PJI in tumor arthroplasty, while, being one of the few studies to compare three different joints concerning PJI characteristics

Regioselective functionalization of tetrabromophenanthroline-ruthenium complexes

Structural, photophysical and -chemical characterisation and reactivity of a novel polypyridyl ruthenium complex based on 3,5,6,8-tetra-bromophenanthroline are discussed. Signal storage at a molecular level is great challenge for chemistry.1 The possibility of connecting different functionalities selectively to one ligand of a metal complex may open the route towards higher integrated molecular units capable of processing various external stimuli in a predesignated order. The implementation of this concept demands ligands with a multitude of potential connecting groups which can selectively be transformed.2 3-bromo- and 3,8-dibromophenanthrolines have proved useful for the preparation of mononuclear3 and multiheteronuclear complexes.4 These systems have found applications ranging from DNA photoprobes5 to metalloligands in catalysis.6 A very useful feature of this bromophenanthroline ruthenium complexes is their susceptibility towards nucleophilic aromatic substitution which is very well established

Surgical Margins in Soft Tissue Sarcoma Management and Corresponding Local and Systemic Recurrence Rates: A Retrospective Study Covering 11 Years and 169 Patients in a Single Institution

Soft tissue sarcomas (STSs) are a diverse group of rare malignant soft tissue tumors with a high disease burden. Treatment protocols are complex and, to this day, a precise recommendation for the surgical margin width is lacking. The present study aims to analyze the width of the surgical margins in STS resection specimens and analyze them for local and systemic disease-free survival as well as for most frequent histologic STS subtypes. A total of 169 consecutive patients diagnosed and treated in curative intent in our institution following a primary and localized STS of the extremities or trunk from January 2010 to December 2020 were included in this study regardless of age. Our data reveal that low-grade STSs are best controlled locally by a surgical margin >= 2 mm and in this way also preventing distant metastases effectively. Local recurrence-free survival and metastasis-free survival in high-grade STS were improved by intact muscle fascia or periosteum at the margin when compared only to soft tissue. However, the outcome was independent of the surgical margin width, suggesting a close but negative margin may be safe in high-grade STS subtypes with less invasive growth patterns when combined with adjunct radiochemotherapy