Post-Synthetic Modification of Aerogels Made of Covalent Cross-linked Metal-Organic Polyhedra

Aerogels are porous ultralight materials known for their high porosity, wide range of pore sizes, low density, and good macroscopic mechanical properties, all of which make them promising candidates for shaped adsorbents, catalysts, and insulators, among other applications. Here, this work reports a new approach that enables both the formation of modular aerogels, via dynamic covalent chemistry, and their post-synthetic modification, via coordination chemistry. To demonstrate this strategy, this work first polymerizes porous amino-functionalized Rh(II)-based metal-organic polyhedra (MOPs) with aldehydes, which afforded robust imine-gel networks that is then converted into aerogels. Next, this work functionalizes these aerogels through the coordination of ligands on the axial site of Rh(II) paddlewheels of the MOP. Interestingly, in this chemistry, the local changes in the coordination site of the MOPs are transferred to the overall aerogel, thereby altering its macroscopic physicochemical properties. Importantly, this feature enables the synthesis of optimized adsorbents tailored to specific guests, as this work demonstrates through a series of experiments using ligands of different electrostatic and hydrophobic charactersThis work was supported by the Spanish MINECO (project RTI2018-095622-B-I00, PID2019-106268GB-C32, and TED2021-129886B-C42)), and the Catalan AGAUR (project 2021 SGR 00458). It was also funded by the CERCA program/Generalitat de Catalunya. ICN2 is supported by the Severo Ochoa Centres of Excellence program, Grant CEX2021-001214-S, funded by MCIN/AEI/10.13039.501100011033. A.C.S. is indebted to the Ramón y Cajal Program (RYC2020-029749-I Fellowship) and the Europa Excelencia grant (EUR2021-121997). K.R. gratefully acknowledges the support of the National Science Centre (NCN), Poland (Grants no. 2020/36/C/ST4/00534

3D printing of covalent organic frameworks: a microfluidic-based system to manufacture binder-free macroscopic monoliths

Covalent organic frameworks (COFs) have witnessed outstanding developments in the past 15 years, particularly in optimizing their pore structures, linkages, and variety of monomers used in their synthesis. Yet, a significant challenge remains unaddressed: the processability of COFs into macroscopic architectures with arbitrary shapes, as they are typically obtained as unprocessable powders. This study presents a novel strategy to address this issue by developing a 3D printable ink comprising a colloidal water suspension of COF nanoparticles. A microfluidic device is engineered that provides precise control over the gelation process of the COF-based ink, allowing for a layer-by-layer fabrication. As a result, the direct production of large-scale binder-free COF architectures from digital designs is achieved at room temperature and atmospheric pressure while eliminating the use of toxic organic solventsThis work had been supported by the Spanish MINECO (PID2019- 106268GB-C32, PID2022-138908NB-C31, TED2021-129886B-C42, PDC2022-133498-I00, and PID2020-116612RB-C33). The authors acknowledge the service from the MiNa Laboratory at IMN and funding from CM (project S2018/NMT-4291 TEC2SPACE), MINECO (project CSIC13-4E-1794) and EU (FEDER, FSE). F.Z. acknowledges financial support from the Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D (CEX2018- 000805-M). S.P., J.P.-L., and F. Z. also acknowledge support from the European Innovation Council under grant Agreement 101047081 (EVA). The authors acknowledge the support from the “(MAD2D-CM)-UAM” project funded by Comunidad de Madrid, by the Recovery, Transformation and Resilience Plan, and by NextGenerationEU from the European Unio

Oxygen reduction using a metal-free naphthalene diimide-based covalent organic framework electrocatalyst

A novel naphthalene diimide-based covalent organic framework (NDI-COF) has been synthesized and successfully exfoliated into COF nanosheets (CONs). Electrochemical measurements reveal that the naphthalene diimide units incorporated into NDI-CONs act as efficient electrocatalyst for oxygen reduction in alkaline media, showing its potential for the development of metal-free fuel cellsFinancial support from the Spanish Government (projects MAT2016-77608-C3-1-P, MAT2016-77608-C3-2-P, CTQ2017-84309-C2-1-R, MAT2017-85089-C2-1-R, FJCI-2017-33536 and RYC-2015-17730), the UCM (INV.GR.00.1819.10759) and the Madrid Regional Government (TRANSNANOAVANSENS-CM (S2018/NMT-4349)) is acknowledge

Riesgo quirúrgico tras resección pulmonar anatómica en cirugía torácica. Modelo predictivo a partir de una base de datos nacional multicéntrica

Introduction: the aim of this study was to develop a surgical risk prediction model in patients undergoing anatomic lung resections from the registry of the Spanish Video-Assisted Thoracic Surgery Group (GEVATS). Methods: data were collected from 3,533 patients undergoing anatomic lung resection for any diagnosis between December 20, 2016 and March 20, 2018. We defined a combined outcome variable: death or Clavien Dindo grade IV complication at 90 days after surgery. Univariate and multivariate analyses were performed by logistic regression. Internal validation of the model was performed using resampling techniques. Results: the incidence of the outcome variable was 4.29% (95% CI 3.6-4.9). The variables remaining in the final logistic model were: age, sex, previous lung cancer resection, dyspnea (mMRC), right pneumonectomy, and ppo DLCO. The performance parameters of the model adjusted by resampling were: C-statistic 0.712 (95% CI 0.648-0.750), Brier score 0.042 and bootstrap shrinkage 0.854. Conclusions: the risk prediction model obtained from the GEVATS database is a simple, valid, and reliable model that is a useful tool for establishing the risk of a patient undergoing anatomic lung resection

Covalent organic frameworks based on electroactive naphthalenediimide as active electrocatalysts toward oxygen reduction reaction

Developing organic electrocatalysts toward the oxygen reduction reaction (ORR) that avoid heteroatom doping processes and high-temperature carbonization is of great significance for the maturing of fuel cell applications. Herein, a series of two-dimensional imide-based covalent organic framework (COFs) electrocatalysts toward the ORR is reported. The hydrodynamic electrochemical study reveals that 3.5 electrons are exchanged during the ORR indicating that the process catalyzed by these COFs has a clear preference for the 4-electron reduction pathway. The COFs contain conjugated electroactive napthalenediimide (NDI) moieties that provides the active sites for the electrocatalysis and promotes the formation of COFs with face-to-face π-π stacked structures to provide intrinsic porosity and large surface areas. These COFs can be essentially considered as an organized pattern of active sites embedded in the pore walls of the COF. The choice of suitable comonomers with variable distortions from planarity offers the possibility of obtaining these electroactive COFs with similar redox ability but different degrees of porosity and interlaminar spacing. This work evidences a new insight into developing novel families of electrocatalysts from COFs. Structure and stacking fashion of the COF-systems are investigated on the basis of DFT calculations, as well as the photoabsorption spectra of the representative molecular entities and a proof-of-concept rationalization of the intermediate steps of the ORR mechanismThis work was financially supported by MICINN (PID2019-106268GB-C33; RED2018-102412-T; PID2020-116728RB-I00), Comunidad de Madrid (P2018/NMT-4349 TRANSNANOAVANSENS Program; SI3/PJI/2021-00341) and the UCM (INV.GR.00.1819.10759). The support provided by Álvaro Fuentes Benavides for the artwork of the graphical abstract is also acknowledged. MMF acknowledges Comunidad de Madrid for a predoctoral contrac

β-Ketoenamine-linked covalent organic frameworks synthesized via gel-to-gel monomer exchange reaction: From aerogel monoliths to electrodes for supercapacitors

Covalent organic frameworks (COFs) possess intrinsic nanoscale pores,limiting mass transport and impacting their utility in many applications, suchas catalysis, supercapacitors, and gas storage, demanding efficient diffusionthroughout the material. Hierarchical porous structures, integrating largermacropores with inherent micro-/meso-pores, facilitate rapid mass transport.Recently, the fabrication of aerogel monoliths is reported exclusively fromimine-linked COFs, offering flexibility in aerogel composition. However,challenges in synthesizing robust -ketoenamine-based COFs withcomparable surface areas prompted innovative synthetic approaches.Leveraging the dynamic nature of COF bonds, in this work efficient monomerexchange from imine to partially -ketoenamine-linked COFs within the gelphase is demonstrated. These aerogels can be transformed into electrodesusing the compression technique. The new flexible electrodes-based-ketoenamine-linked COF composites with C super P exhibit superiordurability and redox activity. Through supercapacitor assembly, the-ketoenamine-linked COF electrodes outperform their imine-basedcounterparts, showcasing enhanced capacitance (88 mF cm−2 ) and stability athigh current densities (2.0 mA cm−2 ). These findings underscore the promiseof -ketoenamine-linked COFs for pseudocapacitor energy storageapplicationsPDC2022-133498-I00, TED2021-129886B-C42, PID2019-106268GB-C32, PID2022-38908NB-C31, MAT2016-77608-C3-1-P, PCI2018-093081, RTI2018-095622-B-I0