Facile Synthesis of Nitrogen-Doped Nanographenes with Joined Nonhexagons via a Ring Expansion Strategy

Synthetic methodology is considered a holy grail in both organic chemistry and materials science. Over the past few decades, researchers have explored graphene-type molecules (or nanographenes) through classic Scholl oxidative cyclodehydrogenation. Despite the successes achieved with various nanographenes, the development of new methods to synthesize these highly desired molecules lags behind. Herein, we developed a facile and effective method to produce a series of nanographenes bearing nitrogen (N)-doped pentagon-heptagon pairs in acceptable yields. Modification of the heptagonal ring endowed the resultant nanographenes with tunable physicochemical properties; for instance, M9 exhibited both aggregation-caused quenching and aggregation-induced emission behavior. Most strikingly, novel nanographenes containing N-doped pentagon-octagon pairs were also obtained using the same synthetic strategy, demonstrating the superior versatility and efficiency of the proposed ring expansion method.     

Densely Packed CO2 Aids Charge,Spin, and Lattice Ordering Partially Fluctuated in a Porous Metal–Organic Framework Magnet

Partial charge fluctuations in the charge-ordered state of a material, often triggered by structural disorders and/or defects, can significantly alter its physical characteristics, such as magnetic long-range ordering. However, it is difficult to post-chemically fix such accidental partial fluctuations to reconstruct a uniform charge-ordered state. Herein, we report CO₂-aided charge ordering demonstrated in a CO₂-post-captured layered magnet, [{Ru₂(o-ClPhCO₂)₄}₂{TCNQ(OMe)₂}] ⋅ CO₂ ( 1⊃CO₂ ; o-ClPhCO₂⁻=ortho-chlorobenzoate; TNCQ(OMe)₂=2,5-dimethoxy-7,7,8,8-tetracyanoquinodimethane). Pristine porous layered magnet 1 had a partially charge-fluctuated ordered state, which provided ferrimagnetic ordering at T_C=65 K. Upon loading CO₂, 1 adsorbed one mole of CO₂, forming 1⊃CO₂ , and raising T_C to 100 K. This was because of the vanishing charge fluctuations without significantly changing the framework structure. This research illustrates the post-accessible host–guest chemistry delicately combined with charge, spin, and lattice ordering in a spongy magnet. Furthermore, it highlights how this innovative approach opens up new possibilities for technology and nanoscale magnetism manipulation.     

Spinel lithium titanate anode/polyether sulfone nanocomposite synthesized by pulsed laser ablation method for optoelectronic applications

Nowadays, to increase the usage of energy storage applications like electric cars or stationary storage, the cost of these manufacturers must be reduced. Our present study focuses on an alternate electrode production approach to suit the needs of today's lithium ion battery’s cost efficiency by using an eco-friendly method, the pulsed laser ablation method in liquid media technique, which was used for the first time to synthesize spinel lithium titanate anode, Li₄Ti₅O₁₂ nanoparticles (LTO NPs), and incorporate them with polyether sulfone (PES) in just one step to form a PES/LTO nanocomposite. The evidence from XRD showed that the nanocomposite film is formed as a crystalline phase from a cubic spinel structure corresponding to LTO, with crystalline sizes around 9.4 nm. Furthermore, SEM revealed a semi-spherical distribution of LTO NPs throughout the PES matrix. Also, the elemental analysis provides the elemental peaks for C, S, Ti, and O, and no other elemental peaks do, confirming their purity. Moreover, the FT-IR investigation affirmed the interaction between PES and LTO NPs via the sulfone group with the breakage of the sulfur and oxygen double bond and the formation of a new link between SOLa and SOTi that may be responsible for the emergence of this band. Also, the absorption study confirmed the formation of localized states between occupied and unoccupied molecular orbital bands is made feasible by the chemical linkages between PES chains and LTO NPs. As a result of the dielectric investigation, LTO NPs are a good choice for usage as dopants to enhance the electrical characteristics of PES polymer. Overall, the PES/LTO nanocomposite films' improved dielectric and optical properties make them appropriate for energy storage applications.