4-Sulfocalix[4]arene/Cucurbit[7]uril-Based Supramolecular Assemblies through the Outer Surface Interactions of Cucurbit[n]uril.

Upon mixing of aqueous solutions of the freely soluble building blocks cucurbit[7]uril (Q[7]) and 4-sulfocalix[4]arene (SC[4]A), white microcrystals instantly separate in near-quantitative yield. The driving force for this assembly is suggested to be the outer-surface interaction of the Q[n]. Dynamic light scattering, scanning electron microscopy, and NMR (diffusion-ordered NMR spectroscopy) analyses have confirmed the supramolecular aggregation of Q[7] and SC[4]A. Titration 1H NMR spectroscopy and isothermal titration calorimetry have shown that the interaction ratio of Q[7] and SC[4]A is close to 3:1. Moreover, the Q[7]/SC[4]A-based supramolecular assembly can accommodate molecules of some volatile compounds or luminescent dyes. Thus, this work offers a simple and highly efficient means of preparing adsorbent or solid fluorescent materials.

Multiple Efficient Fluorescence Emission from Cucurbit[10]uril-[Cd4Cl16]8--Based Pillared Diamond Porous Supramolecular Frameworks.

Cucurbit[10]uril (Q[10] or CB[10]), with the largest rigid cavity (ca. 1.0 nm) yet characterized in the cucurbiturils family, and indeed among all artificial macrocyclic receptors to date, has been successfully exploited to construct a novel Q[10]-[Cd4Cl16]8--based pillared diamond porous supramolecular framework. Single-crystal X-ray diffraction analysis revealed that the three-dimensional open-nanotube-type porous framework is constructed from free Q[10] molecules and [Cd4Cl16]8- cluster anions through the outer surface interactions of Q[10]. Notably, the Q[10]-based porous framework host can accommodate guest dyes, such as rhodamine B (G1), pyrenemethanamine hydrochloride (G2), and bathocuproine hydrochloride (G3), to form solid materials with efficient red-green-blue (RGB) fluorescence. This work not only exemplifies a facile approach for the construction of macrocycle-based porous frameworks but also offers a simple, lower cost, yet still highly efficient means of preparing multi-emitting, including white-light-emitting, solid luminescent materials.

[Effects of long-term tillage measurements on soil aggregate characteristic and microbial diversity].

Soil aggregate stability and microbial diversity play important roles in nutrient recycling in soil-crop systems. This study investigated the impacts of different soil tillage systems on soil aggregation and soil microbial diversity based on a 15-year long-term experiment on loess soil in Henan Province of China. Treatments included reduced tillage (RT), no-tillage (NT), sub-soiling with mulch (SM), wheat-peanut two crops (TC), and conventional tillage (CT). Soil aggregates were separated by wet sieving method, and soil microbial (bacterial, archaeal and fungal) diversity was examined by using the techniques of denaturing gradient gel electrophoresis (PCR-DGGE) analysis. The results showed that water-stable macroaggregates concent (R0.25) and the mean mass diameter (MWD) in the surface soil significantly increased under NT, SM and TC, R0.25 increased by 21.5%, 29.5% and 69.2%, and MWD increased by 18.0%, 12.2% and 50.4%, respectively, as compared with CT. Tillage practices caused changes in bacterial, archaeal and fungal community compositions. With NT, SM and TC, the bacterial, archaeal and fungal Shannon indices increased by 0.3%, 0.3%, and 0.6%, and 20.2%, 40.5%, and 49.1%, and 23.7%, 19.5%, and 25.8%, respectively, as compared with CT. Both bacterial and archaeal Shannon indices were significantly correlated with the indices of R0.25 and MWD, while the fungal Shannon index was not significantly correlated with these two indices. In conclusion, conservation tillage, including NT and SM, and crop rotation, including TC, improved soil aggregation and soil microbial diversity.

[Effects of tillage pattern on the flag leaf senescence and grain yield of winter wheat under dry farming].

A field experiment was conducted to study the effects of different tillage patterns, i.e., deep plowing once, no-tillage, subsoiling, and conventional tillage, on the flag leaf senescence and grain yield of winter wheat, as well as the soil moisture and nutrient status under dry farming. No-tillage and subsoiling increased the SOD and POD activities and the chlorophyll and soluble protein contents, decreased the MDA and O2(-.) contents, and postponed the senescence of flag leaf. Under non-tillage and subsoiling, the moisture content in 0-40 cm soil layer at anthesis and grain-filling stages was decreased by 4.13% and 6.23% and by 5.50% and 9.27%, respectively, and the contents of alkali-hydrolysable N, available P, and available K in this soil layer also increased significantly, compared with those under conventional tillage. Deep plowing once decreased the moisture content and increased the nutrients contents in 0-40 cm soil layer, but the decrement and increment were not significant. The post-anthesis biomass, post-anthesis dry matter translocation rate, and grain yield under no-tillage and subsoiling were 4.34% and 4.76%, 15.56% and 13.51%, and 10.22% and 9.26% higher than those under conventional tillage, respectively. It could be concluded that no-tillage and subsoiling provided better soil conditions for the post-anthesis growth of winter wheat, under which, the flag leaf senescence postponed, post-anthesis dry matter accumulation and translocation accelerated, and grain yield increased significantly, being the feasible tillage practices in dry farming winter wheat areas.