6 research outputs found
Controllable Synthesis of Covalent Porphyrinic Cages with Varying Sizes via Template-Directed Imine Condensation Reactions
Covalent
porphyrinic cages (CPCs) have been a target of interest
for years. In this paper, we report the design and synthesis of two
CPCs in which the cofacial porphyrins have a distance of 7.66 and
11.96 Ã… via template-directed imine condensation reactions and
through the selective choice of templating linker and diamine length
Controllable Synthesis of Covalent Porphyrinic Cages with Varying Sizes via Template-Directed Imine Condensation Reactions
Covalent
porphyrinic cages (CPCs) have been a target of interest
for years. In this paper, we report the design and synthesis of two
CPCs in which the cofacial porphyrins have a distance of 7.66 and
11.96 Ã… via template-directed imine condensation reactions and
through the selective choice of templating linker and diamine length
A Pyrene-Based, Fluorescent Three-Dimensional Covalent Organic Framework
The targeted synthesis of 3D COFs
has been considered challenging,
especially adopting new topologies and bearing photoelectric units.
Herein, for the first time, we report the synthesis and characterization
of a novel 3D pyrene-based COF (3D-Py-COF), by selectively choosing
the geometry of the precursors and the connection patterns. Based
on X-ray diffraction measurement and detailed simulations, 3D-Py-COF
is proposed to adopt a two-fold interpenetrated <b>pts</b> topology,
which has never been reported before. In addition, 3D-Py-COF has a
narrow pore size distribution and high surface area and also features
selective absorption of CO<sub>2</sub> over N<sub>2</sub>. Interestingly,
due to the existence of isolated pyrene units in the 3D framework,
3D-Py-COF is the first fluorescent 3D COF and can be used in explosive
detection. Our results not only show it is possible to rationally
design and synthesize 3D COFs with other topologies but also demonstrate
that the incorporation of photoelectric units into 3D COFs can allow
the resulting materials with interesting properties
3D Porphyrin-Based Covalent Organic Frameworks
The design and synthesis
of three-dimensional covalent organic
frameworks (3D COFs) bearing photoelectric units have been considered
as a big challenge. Herein, for the first time, we reported the targeted
synthesis of two 3D porphyrin-based COFs (3D-Por-COF and 3D-CuPor-COF),
starting from tetrahedral (3D-<i>T</i><sub>d</sub>) and
square (2D-<i>C</i><sub>4</sub>) building blocks connected
through [4 + 4] imine condensation reactions. On the basis of structural
characterizations, 3D-Por-COF and 3D-CuPor-COF are microporous materials
with high surface areas, and are proposed to adopt a 2-fold interpenetrated <b>pts</b> topology with <i>Pmc</i>2<sub>1</sub> space
group. Interestingly, both 3D COFs are photosensitive and can be used
as heterogeneous catalyst for generating singlet oxygen under photoirradiation.
However, 3D-Por-COF shows enhanced photocatalytic activity compared
with 3D-CuPor-COF, indicating the properties of 3D porphyrin-based
COFs can be tuned by metalation of porphyrin rings. The results reported
here will greatly inspire us to design and synthesize 3D COFs bearing
other metalloporphyrins for interesting applications (e.g., catalysis)
in the future
data_sheet_2_Role of Hepatic Deposited Immunoglobulin G in the Pathogenesis of Liver Damage in Systemic Lupus Erythematosus.PDF
<p>The onset of hepatic disorders in patients with systemic lupus erythematosus (SLE) is frequent; however, the etiology and liver pathogenesis of SLE remain unknown. In the present study, the role of hepatic deposited immunoglobulin G (IgG) in SLE-derived liver damage was investigated. From a retrospective analysis of the medical records of 404 patients with lupus and from experimental studies on mice models, we found that liver dysfunction is common in SLE and liver damage with IgG deposition spontaneously develops in lupus-prone mice. Liver injury was recreated in mice by injecting IgG from lupus serum intrahepatically. The inflammation intensity in the liver decreased with IgG depletion and the lupus IgG-induced liver inflammation in FcγRIII-deficient mice was comparatively low; while, inflammation was increased in FcγRIIb-deficient mice. Macrophages, Kupffer cells, natural killer cells, and their products, but not lymphocytes, are required for the initiation of SLE-associated liver inflammation. Blocking IgG signaling using a spleen tyrosine kinase (Syk) inhibitor suppressed the liver damage. Our findings provided evidence of spontaneously established liver damage in SLE. They also suggested that hepatic-deposited lupus IgG is an important pathological factor in the development of liver injury and that hepatic inflammation is regulated by the Syk signaling pathway. Thus, Syk inhibition might promote the development of a therapeutic strategy to control liver damage in patients with SLE.</p
Electronic Tuning of Active Sites in Bifunctional Covalent Organic Frameworks for Photoassisted CO<sub>2</sub> Electrocatalytic Full Reaction
Realizing simultaneously energy-efficiency improvement
and green
economic implementation remains a daunting challenge in addressing
the low-efficiency issues of CO2 electroreduction to meet
the sustainable development strategy. Here, we propose a series of
porphyrin-based COFs (TTCOF-M, M = Co, Ni, and Cu) as model catalysts to study the hybrid CO2 electrocatalytic
full reaction for the first time, during which the catalysts can simultaneously
accomplish photoassisted CO2 electroreduction and 4-nitrophenol
(4-NP) mineralization. As model catalysts, the effects of various
parameters have been intensively studied from typical tandem electro-reactions
to extended photoassisted ones. Specifically, TTCOF-Co can achieve the cathodic reduction efficiency increasing from 90
to 96% (−0.7 V) after illumination and simultaneously 5 times
shortened reaction time with a 4-NP degradation efficiency of ∼99%.
Notably, the 4-NP mineralization rate is calculated to be ∼93.51%
with ∼30.27 mmol/g/h CO2 production rate, and a
rarely investigated mechanism relating to the 4-NP electro-degradation
has been intensively studied