Effectively increasing the length of N‐heteroacenes is highly desirable because such materials could have great potential applications in organic optoelectronics. In this review we summarize the recent progress in the construction of larger N‐heteroacenes based on the use of phenazinediamine and its analogues as building blocks to react with different kinds of ortho‐diketones (or tetraketones) or ortho‐dihalides through condensation or coupling reactions. In addition, the potential applications of the corresponding N‐heteroacenes are also presented.

No abstract

To improve the humidity resistance and water absorption capacity of the superabsorbent polymer (SAP), a biodegradable cellulosecontaining polymer was successfully assembled through inverse suspension polymerization, using cellulose, acrylic acid, and acrylamide as monomers, Span-80 as dispersant, and potassium persulfate as initiator. The impact of conditions such as reaction temperature, ratio of oil to water, degree of neutralization, amount of cellulose, and cross-linking agents on the properties of the polymer were evaluated. The results showed that the as-prepared superabsorbent polymer exhibited the best water (859 g/g) and salt water (72.48 g/g) absorption rate, when the reaction temperature was 70 ∘ C, monomer ratio was 1 : 10, neutralization degree was 75%, and oil-water ratio was 3 : 1. Moreover, the humidity resistance of the polymer could be enhanced significantly by adding different cross-linking reagents such as epoxy chloropropane or diethylene glycol.

In this paper, two pyridazine‐heterocycles‐containing azaacenes 9,12‐diphenylphenanthro[4,5‐fgh]phthalazine (DPPA) and 2,9‐di‐tert‐butyl‐4,7,11,14‐tetraphenylpyridazino[4′,5′:9,10]phenanthro[4,5‐fgh]phthalazine (TPPA) have been synthesized and fully characterized. The single crystal analysis of TPPA showed that TPPA molecule exhibits a twisted structure with the dihedral angel of 27° between pyrene and pyridazine unit, which suppresses the π‐π stackings in the solid state. The two‐photon absorption properties of DPPA and TPPA were investigated, respectively, by using the femtosecond Z‐scan technique. The results showed that both DPPA and TPPA showed moderate two‐photon absorption cross‐section values, and the larger one was found to be 454 GM with TPPA. Obviously, the introduction of pyridazine ring into the skeleton of acenes forming a A−D‐A structure could lead to a much larger two‐photon absorption coefficient and two‐photon absorption cross section.

Catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) over high-performance and stable metal nanoparticle catalyst is highly desirable. This study experimentally demonstrated that graphdiyne (GDY), an all-carbon two-dimensional material composed of two hybrid carbon atoms (sp and sp 2 ), can uniformly disperse copper nanoparticles through simple microwave reduction and has excellent 4-NP reduction ability.Cu/GDY shows an extraordinary reaction rate constant of 0.9984 min À 1 , Moreover, the catalytic activity is maintained almost intact within five cycles. These encouraging results demonstrated that the unique pores and electronic structure of GDY enhance the stability of anchored metal nanoparticles and have great potential to degrade 4-NP as a promising support for copper nanoparticles.