Fabricating ultrathin two-dimensional (2D) covalent organic framework (COF) nanosheets (NSs) in large scale and high yield still remains a great challenge. This limits the exploration of the unique functionalities and wide range of application potentials of such materials. Herein, we develop a scalable general bottom-up approach to facilely synthesize ultrathin (<2.1 nm) imine-based 2D COF NSs (including COF-366 NSs, COF-367 NSs, COF-367-Co NSs, TAPB-PDA COF NSs, and TAPB-BPDA COF NSs) in large scale (>100 mg) and high yield (>55%), via an imine-exchange synthesis strategy through adding large excess amounts of 2,4,6-trimethylbenzaldehyde into the reaction system under solvothermal conditions. Impressively, visualization of the periodic pore lattice for COF-367 NSs by a scanning tunneling microscope (STM) clearly discloses the ultrathin 2D COF nature. In particular, the ultrathin COF-367-Co NSs isolated are subject to the heterogeneous photocatalyst for CO2-to-CO conversion, showing excellent efficiency with a CO production rate as high as 10 162 μmol g–1 h–1 and a selectivity of ca. 78% in aqueous media under visible-light irradiation, far superior to corresponding bulk materials and comparable with the thus far reported state-of-the-art visible-light driven heterocatalysts.

Hydrogen-bonded organic framework (HOF)-based catalysts still remain unreported thus far due to their relatively weak stability. In the present work, a robust porous HOF (HOF-19) with a Brunauer–Emmett–Teller surface area of 685 m2 g–1 was reticulated from a cagelike building block, amino-substituted bis­(tetraoxacalix[2]­arene[2]­triazine), depending on the hydrogen bonding with the help of π–π interactions. The postsynthetic metalation of HOF-19 with palladium acetate afforded a palladium­(II)-containing heterogeneous catalyst with porous hydrogen-bonded structure retained, which exhibits excellent catalytic performance for the Suzuki–Miyaura coupling reaction with the high isolation yields (96–98%), prominent stability, and good selectivity. More importantly, by simple recrystallization, the catalytic activity of deactivated species can be recovered from the isolation yield 46% to 92% for 4-bromobenzonitrile conversion at the same conditions, revealing the great application potentials of HOF-based catalysts.

The imine condensation reaction of 5,5'-(benzo[c]- [1,2,5]thiadiazole-4,7-diyl)diisophthalaldehyde with cyclohexanediamine resulted in as hape-persistent multifunctional tubular organic cage (MTC1). It exhibits selective fluorescence sensing towards divalent Pd ions with avery lowdetection limit (38 ppb), suggesting effective complexation between these two species.S ubsequent reduction of MTC1 and Pd(OAc) 2 with NaBH 4 afforded acage-supported catalyst with well-dispersed ultrafine Pd nanoparticles (NPs) in anarrowsizedistribution (1.9 AE 0.4 nm), denoted as Pd@MTC1-1/5. Suchu ltrafine Pd NPs in Pd@MTC1-1/5, in cooperation with photocatalytically active MTC1, enable efficient sequential reactions involving visible light-induced aerobic hydroxylation of 4-nitrophenylboronic acid to 4-nitrophenol and the following hydride reduction with NaBH 4 .T his is the first example of am ultifunctional organic cage capable of sensing,d irecting nanoparticle growth, and catalyzing sequential reactions.

The investigation on the catalytic properties of porous organic cages is still in an initial stage. Herein, the reaction of cyclohexanediamine with 5,15-di[3',5'-diformyl(1,1'-biphenyl)]porphyrin affords a porphyrin tubular organic cage, PTC-1(2H). Transient absorption spectroscopy in solution reveals much prolonged triplet lifetime of PTC-1(2H) relative to monomer reference, illustrating the unique photophysical behavior of cagelike photosensitizer. The long triplet lifetime ensures high-efficiency singlet oxygen evolution according to homogeneous photo-bleach experiment, electron spin-resonance spectroscopy, and aerobic photooxidation of benzylamine. Furthermore, microporous supramolecular framework of PTC-1 (2H) is able to promote the heterogeneous photo-oxidation of various primary amines with conversion efficiency above 99% under visible light irradiation. These results indicate the great application potentials of porous organic cages in heterogeneous phase.

Covalent organic frameworks (COFs) are promising crystalline materials for photocatalytic solar-to hydrogen-energy conversion due to the tunable chemical structures and energy band gaps. Herein, we report a chemical modification strategy for improving the photocatalytic activity of COFs. A benzene-1,3,5-tricarbaldehyde (BT)-and benzothiadiazole derivative-based twodimensional donor−acceptor (D-A) COF, denoted as BT-COF, were fabricated and further modified by using an alternative electron-donating unit, 2-hydroxybenzene-1,3,5-tricarbaldehyde (HBT), to the polycondensation reaction, yielding HBT-COF with an enhanced internal D-A effect and hydrophilicity. Interestingly, the photocatalytic H 2 production rate of HBT-COF reaches 19.00 μmol h −1 , which is 5 times higher than that of BT-COF (3.40 μmol h −1 ) under visible light irradiation. The increase in photocatalytic activity of HBT-COF is rationally attributed to finely tuned energy levels and improved wettability, which in turn leads to broadened visible light absorption, efficient photoinduced charge separation and transfer, and enhanced interactions between the COF catalyst and reaction substrates. The present results demonstrate that a subtle structural modification can significantly modulate the band structure and interfacial property, thus providing a feasible strategy for the optimization of COFbased photocatalytic systems.

The catch of ribbonfish Trichiurus lepturus in the coastal waters of south-western Taiwan has significantly declined in recent years. To examine the effects of exploitation on the feeding habits of ribbonfish, 1570 specimens were collected on a monthly basis during March 2002-March 2003 from the landings by trawlers operating in the coastal waters of south-western Taiwan. The size of the ribbonfish ranged from 83-298 mm preanal length (PL), with a peak at 201-250 mm PL. Although they fed on shrimps and squid, fishes including Benthosema pterotum, Bregmaceros lanceolatus and Encrasicholina heteroloba were their main food items. In particular, B. pterotum was the most important food all year except during summer. No evidence of cannibalism was found in this study. No differences between day and night were found in the feeding activity of T. lepturus. However, B. pterotum and Acetes intermedius were the most important prey in the daytime, whereas B. lanceolatus, B. pterotum and E. heteroloba were at night. Feeding activity and the number of food items increased with increasing size of ribbonfish. Their feeding intensity in February to June, the main spawning season, was significantly greater than in other months. Changes in the food and feeding habits of this species before and after the recent period of heavy exploitation are discussed in detail in this study.

We synthesized a rare (3,12)-connected zirconium metal–organic framework with a sky topology showing efficient iodine adsorption and pH sensing capacity.

Bulky and strong electron-donating dibutylamino groups were incorporated onto the peripheral positions of one of the two phthalocyanine ligands in the bis(phthalocyaninato) terbium complex, resulting in the isolation of heteroleptic double-decker (Pc)Tb{Pc[N(CH)]} {Pc = phthalocyaninate; Pc[N(CH)] = 2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyaninate} with the nature of an unsymmetrical molecular structure, a square-antiprismatic coordination geometry, an intensified coordination field strength, and the presence of organic radical-f interaction. As a total result of all these factors, this sandwich-type tetrapyrrole lanthanide single-ion magnet (SIM) exhibits an overall enhanced magnetic performance including a high blocking temperature (T) of 30 K and large effective spin-reversal energy barrier of U = 939 K, rendering it the best sandwich-type tetrapyrrole lanthanide SIM reported thus far.