Chemical Fixation of CO2 and Other Heterogeneous Catalytic Studies by Employing a Layered Cu‐Porphyrin Prepared Through Single‐Crystal to Single‐Crystal Exchange of a Zn Analogue

A solvothermal reaction of Zn(NO₃)₂ ? 6 H₂O, tetra‐(4‐pyridyl)porphyrin (H₂TPyP), and 4,4′‐oxybis(benzoic acid) (H₂OBA) resulted in a new two‐dimensional Zn‐ porphyrin metal–organic framework compound, [Zn₂(C₄₀H₂₄N₈)_0.5(C₁₄H₈O₅)(DMA)](DMA)(H₂O)₆ ( 1 ; DMA=N,N‐dimethylacetamide). The Zn^II ions present in 1 could be exchanged by using a solution of Cu(NO₃)₂ ? 3 H₂O in DMA at room temperature to give [Cu₂(C₄₀H₂₄N₈)_0.5(C₁₄H₈O₅)(DMA)](DMA)(H₂O)₃ ( Cu∈1 ). The extra‐framework solvent molecules have been shown to be reversibly removed or exchanged without collapse of the framework. Solvent‐free Cu∈1 was explored as an active heterogeneous catalyst towards three different organic reactions: 1) the chemical fixation of CO₂ into cyclic carbonate at room temperature and 1 atm; 2) the nitroaldol reaction under solvent‐free conditions, and 3) the three‐component coupling of aminopyridine, benzaldehyde, and aryl alkynes followed by 5‐exo‐dig cyclization to produce the important pharmacophore imidazopyridine.     

Chemical Stimulus‐responsive Folding and Unfolding of a Dendrimeric Assembly

A dendrimeric trimer undergoes folding and unfolding in response to a chemical stimulus. The trimer of interest contains a central dendrimer with a butadiyne‐linked zinc porphyrin dimer ((ZnP)₂) core, in addition to two terminal dendrimers with zinc porphyrin (ZnP) cores. The obtained absorption spectra indicate that the unfolded form is the exclusive conformer in chloroform, while the addition of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in chloroform leads to transformation from the unfolded to the folded structure containing two DABCO units per trimer; the folded structure originates from the cross‐linking of (ZnP)₂ and ZnP with DABCO. Moreover, the addition of excess DABCO promotes the generation of the unfolded structure containing four DABCO units.     

Photooxidation of a Twisted Isoquinolinone

Understanding the oxidation mechanism and positions of twistacenes and twistheteroacenes under ambient conditions is very important because such knowledge can guide us to design and synthesize novel, larger stable analogues. Herein, we demonstrated for the first time that a twisted isoquinolinone can decompose under oxygen and light at room temperature. The as‐decomposed product 1 was fully characterized through conventional methods as well as single‐crystal structure analysis. Moreover, the physical properties of the as‐obtained product were carefully investigated and the possible formation mechanism was proposed.     

High Crystalline Prussian White Nanocubes as a Promising Cathode for Sodium‐ion Batteries

Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room‐temperature sodium‐ion batteries (SIBs). Herein, we report high crystalline and Na‐rich Prussian white Na₂CoFe(CN)₆ nanocubes synthesized by an optimized and facile co‐precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na₂CoFe(CN)₆ nanocubes exhibited an initial capacity of 151 mA h g^?1, which is close to its theoretical capacity (170 mA h g^?1). Meanwhile, the Na₂CoFe(CN)₆ cathode demonstrated an outstanding long‐term cycle performance, retaining 78 % of its initial capacity after 500 cycles. Furthermore, the Na₂CoFe(CN)₆ Prussian white nanocubes also achieved a superior rate capability (115 mA h g^?1 at 400 mA g^?1, 92 mA h g^?1 at 800 mA g^?1). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na ions through large channels in the open‐framework. Most noteworthy, the as‐prepared Na₂CoFe(CN)₆ nanocubes are not only low‐cost in raw materials but also contain a rich sodium content (1.87 Na ions per lattice unit cell), which will be favorable for full cell fabrication and large‐scale electric storage applications.     

Synthesis of Functionalized (η5‐Indenyl)rhodium(III) Complexes and Their Application to C−H Bond Functionalization

It has been established that reductive complexation of functionalized benzofulvenes, which are readily prepared from commercially available indene and 2‐methylindene, with RhCl₃ in ethanol affords the corresponding indenyl–rhodium(III) dichlorides bearing substituents at the 1‐ (H or CO₂Et), 2‐ (H or Me), and 3‐ [CH₂Ph or CH₂(2‐MeOC₆H₄)] positions. The indenyl–rhodium(III) complexes bearing one ethoxycarbonyl group showed higher thermal stability and regioselectivity than our previously reported Cp^ERh^III complex toward the oxidative [3+2] annulation of acetanilides with internal alkynes.     

Synthesis of a Near‐Infrared BODIPY Dye for Bioimaging and Photothermal Therapy

The development of robust photothermal agents for near‐infrared (NIR) imaging is a great challenge. Herein, we report the design and synthesis of a new photothermal agent, based on the aza‐boron‐dipyrromethene framework (azaBDP). This compound possessed excellent photostability and high photothermal‐conversion efficiency (50 %) under NIR laser irradiation. When the photothermal properties of this compound were utilized for tumor inhibition, stable long‐term fluorescence was observed in living animals. Photothermal treatment efficiently suppressed tumor growth, as evidenced by in vitro and in vivo experiments. Furthermore, NIR emission could be detected by using an imaging system and therapeutic self‐monitoring was achieved by using NIR imaging.     

Bifunctional Fluorescent Probe for Sequential Sensing of Thiols and Primary Aliphatic Amines in Distinct Fluorescence Channels

Thiols and primary aliphatic amines (PAA) are ubiquitous and extremely important species in biological systems. They perform significant interplaying roles in complex biological events. A single fluorescent probe differentiating both thiols and PAA can contribute to understanding the intrinsic inter‐relationship of thiols and PAA in biological processes. Herein, we rationally constructed the first fluorescent probe that can respond to thiols and PAA in different fluorescence channels. The probe exhibited a high selectivity and sensitivity to thiols and PAA. In addition, it displayed sequential sensing ability when the thiols and PAA coexisted. The application experiments indicated that the probe can be used for sensing thiols and PAA in human blood serum. Moreover, the fluorescence imaging of endogenous thiols and PAA as well as antihypertensive drugs captopril and amlodipine in living cells were successfully conducted.     

Dianionic Titanyl and Vanadyl (Cation+)2[MIVO(Pc4−)]2− Phthalocyanine Salts Containing Pc4− Macrocycles

In this study, the titanyl and vanadyl phthalocyanine (Pc) salts (Bu₄N⁺)₂[M^IVO(Pc^4?)]^2? (M=Ti, V) and (Bu₃MeP⁺)₂[M^IVO(Pc^4?)]^2? (M=Ti, V) with [M^IVO(Pc^4?)]^2? dianions were synthesized and characterized. Reduction of M^IVO(Pc^2?) carried out with an excess of sodium fluorenone ketyl in the presence of Bu₄N⁺ or Bu₃MeP⁺ is exclusive to the phthalocyanine centers, forming Pc^4? species. During reduction, the metal +4 charge did not change, implying that Pc is an non‐innocent ligand. The Pc negative charge increase caused the C?N(pyr) bonds to elongate and the C?N(imine) bonds to alternate, thus increasing the distortion of Pc. Jahn–Teller effects are significant in the [eg(π*)]² dianion ground state and can additionally distort the Pc macrocycles. Blueshifts of the Soret and Q‐bands were observed in the UV/Vis/NIR when M^IVO(Pc^2?) was reduced to [M^IVO(Pc ^{. 3?})] ^{. ?} and [M^IVO(Pc^4?)]^2?. From magnetic measurements, [Ti^IVO(Pc^4?)]^2? was found to be diamagnetic and (Bu₄N⁺)₂[V^IVO(Pc^4?)]^2? and (Bu₃MeP⁺)₂[V^IVO(Pc^4?)]^2? were found to have magnetic moments of 1.72–1.78 μ_B corresponding to an S=1/2 spin state owing to V^IV electron spin. As a result, two latter salts show EPR signals with V^IV hyperfine coupling.     

Boron‐Based Catalysts for C−C Bond‐Formation Reactions

Because the construction of the C?C bond is one of the most significant reactions in organic chemistry, the development of an efficient strategy has attracted much attention throughout the synthetic community. Among various protocols to form C?C bonds, organoboron compounds are not just limited to stoichiometric reagents, but have also made great achievements as catalysts because of the easy modification of the electronic and steric impacts on the boron center. This review presents recent developments of boron‐based catalysts applied in the field of C?C bond‐formation reactions, which are classified into four kinds on the basis of the type of boron catalyst: 1) highly Lewis acidic borane, B(C₆F₅)₃; 2) organoboron acids, RB(OH)₂, and their ester derivatives; 3) borenium ions, (R₂BL)X; and 4) other miscellaneous kinds.     

Alkylation‐, Heating‐, and Doping‐Induced Emission Enhancement of a Polyaromatic Tube in the Solid State

A polyaromatic tube with a subnanometer‐sized cavity was efficiently prepared on a gram‐scale through the stereo‐controlled cyclotrimerization of a diphenylanthracene derivative as a key step. The facile exterior alkylation of the polyaromatic framework leads to a moderately fluorescent tube (R=‐OC₁₀H₂₁; Φ_F=20 %) in the solid state. The emission intensity of the solid‐state alkyl‐substituted tube is remarkably enhanced upon heating (up to 1.6 times, Φ_F=31 %) as well as doping with fluorescent dyes (up to 4.2 times, Φ_F=83 %) through efficient energy transfer.