Dynamics of reduced perylene bisimide cyclophane redox species by ultrafast spectroelectrochemistry.

Charged molecules play essential roles in many natural and artificial functional processes, ranging from photosynthesis to photovoltaics to chemical reactions and more. It is often difficult to identify the optical dynamic properties of relevant redox species because they cannot be easily prepared, their spectra overlap, or they evolve on a femtosecond timescale. Here, we address these challenges by combining spectroelectrochemistry, ultrafast transient absorption spectroscopy, and suitable data analysis. We illustrate the method with the various redox species of a cyclophane composed of two perylene bisimide subunits. While singular-value decomposition is a well-established tool in the analysis of time-dependent spectra of a single molecular species, we here use it additionally to separate transient maps of individual redox species. This is relevant because at any specific applied electrochemical potential, several redox species coexist in the ensemble, and our procedure allows disentangling their spectroscopic response. In the second step, global analysis is then employed to retrieve the excited-state lifetimes and decay-associated difference spectra. Our approach is generally suitable for unraveling ultrafast dynamics in materials featuring charge-transfer processes.

Size Determination of Organic Cages by Diffusion NMR Spectroscopy.

Reliable structure elucidation of covalent organic cage compounds remains challenging as routine analysis might leave ambiguities. Diffusion-ordered NMR spectroscopy (DOSY) allows insight into the molecular size and mass of the species present in solution, but a systematic evaluation of the diffusion behavior for cage assemblies is rarely considered. Here we report the synthesis of four series of covalent organic cages based on tribenzotriquinacenes and diboronic acids with varying geometry and exohedral substituents. We provide a guideline for the consistent measurement of diffusion coefficients from 1 H-DOSY NMR spectroscopy, which was utilized to study the diffusion behavior for the whole set of cages and selected examples from the literature. For structurally similar cages, a linear correlation between the solvodynamic volume and the molecular mass allows precise size determination. For more complex systems, multiple parameters, such as window size or rigid exohedral functionalization. further modulate cage diffusion in solution.

Intersystem crossing of perylene bisimide neutral, radical anion, and dianion derivatives compared via ultrafast spectroelectrochemistry.

Perylene bisimides are widely studied due to their various applications. Most research is carried out on neutral molecules but charged species are essential in the context of organic electronics and photovoltaics. In this study, we carry out ultrafast transient absorption spectroelectrochemistry and coherent two-dimensional electronic spectroelectrochemistry on three different neutral perylene bisimide derivatives as well as their singly and doubly reduced species. We compare an unsubstituted, flat parent perylene bisimide with two twisted ones that introduce spin-orbit coupling, leading to enhanced intersystem crossing. The internal conversion from higher excited states to the lowest electronically excited state occurs in the picosecond regime with lifetimes significantly shorter for the charged species compared to the neutral ones. Coherent oscillations of the transients for the flat dianion of parent perylene bisimide indicate the occurrence of Fermi resonance. The corresponding vibrational coupling and the superposition of the participating vibrational modes may lead to an enhanced charge separation and triplet formation.

A prospective case-control validation of procalcitonin as a biomarker diagnosing pacemaker and implantable cardioverter-defibrillator pocket infection.

BACKGROUND: The diagnosis of device infections, especially pocket infections, is challenging and relies primarily on clinical presentation. The prospective DIRT (Device associated Infections Role of new diagnostic Tools) study identified procalcitonin (PCT) as the most promising biomarker among other 14 biomarkers to aid the diagnosis of pocket infection. It also identified an optimized cut-off value of 0.05 ng/ml for a localized generator pocket infection. AIMS: The present study aims to validate the proposed PCT cut-off value of 0.05 ng/ml for the diagnosis of pocket infection in an independent cohort. METHODS: We prospectively enrolled 81 patients with pocket infections and 81 controls matched for age and renal function presenting for elective device exchange or lead revision. Patients with concomitant infectious or inflammatory diseases, end-stage renal failure, current active malignancy, or receiving immunosuppressive therapy were excluded. RESULTS: An elevated PCT over 0.05 ng/ml was found in 68% (n = 55) of pocket infections and 24% (n = 19) of controls, corresponding to a sensitivity of 68% and a specificity of 77% for diagnosing a pocket infection. In receiver operating characteristic (ROC) analysis, PCT showed an area under the curve of 0.75 (95% confidence interval, 0.68-0.83; P < 0.001). Sensitivity remained high with antibiotic pretreatment (65% compared to 69% without pretreatment) and in cases with minimal inflammatory signs (67% compared to 70% with extensive inflammation). CONCLUSION: Our study validates the cut-off value of 0.05 ng/ml PCT for diagnosis of a pocket infection, even in patients pre-treated with antibiotics or with minimal clinical signs of inflammation.

Patient Characteristics, Procedural Characteristics, and Outcomes in Patients Having Lead Extraction in a High-Volume Center.

The rate of transvenous lead extraction (TLE) is increasing, with an increasing rate of complex devices being implanted. TLE is now a routine part of cardiac device management and up-to-date data on the safety and efficacy of TLE with modern tools and techniques is essential to management decisions regarding noninfectious indications for lead extraction. We present a contemporary, prospective review of TLE at our high-volume cardiac center. All patients who underwent TLE from June 2016 to June 2019 were enrolled in our local database, and baseline clinical data, procedural information, and outcome data were collected. In total, 561 leads were explanted (n = 153) or extracted (n = 408) from 341 patients over the study period. Patients were predominantly male (71%), with a mean age of 65 ± 17 years. The most common indication for lead removal was lead failure (45.2%, n = 154), followed by infection of the pocket or device (29.3%, n = 100). In total, complete success was achieved in 96.4% (n = 541) leads, clinical success in a further 2.1% (n = 12), and failure only in 1.4% (n = 8). There was an overall complication rate of 0.9% (3/341) for major complications and 1.5% (5/341) for minor complications. There were no deaths. In conclusion, our data suggest that there are ongoing improvements in the safety profile and success rates of lead extraction undertaken by experienced operators. The major complication rate now is <1%.