X-ray analysis on the nanogram to microgram scale using porous complexes

• Yasuhide Inokuma,
• Shota Yoshioka,
• Junko Ariyoshi,
• Tatsuhiko Arai,
• Yuki Hitora,
• Kentaro Takada,
• Shigeki Matsunaga,
• Kari Rissanen
• & Makoto Fujita

X-ray single-crystal diffraction (SCD) analysis has the intrinsic limitation that the target molecules must be obtained as single crystals. Here we report a protocol for SCD analysis that does not require the crystallization of the sample. In our method, tiny crystals of porous complexes are soaked in a solution of the target, such that the complexes can absorb the target molecules. Crystallographic analysis clearly determines the absorbed guest structures along with the host frameworks. Because the SCD analysis is carried out on only one tiny crystal of the complex, the required sample mass is of the nanogram–microgram order. We demonstrate that as little as about 80 nanograms of a sample is enough for the SCD analysis. In combination with high-performance liquid chromatography, our protocol allows the direct characterization of multiple fractions, establishing a prototypical means of liquid chromatography SCD analysis. Furthermore, we unambiguously determined the structure of a scarce marine natural product using only 5 micrograms of the compound.

Not something related to our work, but still a super cool analysis technique. I look forward to seeing what can be done with this idea.

Force Sensors: Hybrid Mechanoresponsive Polymer Wires Under Force Activation (Adv. Mater. 12/2013)

 Hongbin Feng¹,Jin Lu¹,Jinghong Li^1,*,Francis Tsow²,Erica Forzani²,Nongjian Tao^2,*

Force activation is triggered in a stretched polymer wire with color changes produced as the molecules undergo structural and conformational changes. Nongjian Tao, Jinghong Li, and co-workers show on page 1729 that the hybrid mechanosensitive polymer wire can function as a micro- and nanoscale force sensor.

Biocompatible, Functional Spheres Based on Oxidative Coupling Assembly of Green Tea Polyphenols

Zhenhua Chen †‡, Caihong Wang †, Junze Chen †, and Xudong Li *†

Green luminescent, monodisperse, smooth, porous and hollow spheres were simply prepared by Cu2+ and temperature mediated oxidative coupling assembly of green tea polyphenols in water. These polymeric tea polyphenol spheres are GSH responsive, acid resistant but alkali-responsive, ideally used as platform for controlled delivery of functional guests.

Nanocontainer-Based Anticorrosive Coatings: Effect of the Container Size on the Self-Healing Performance

1. Dimitriya Borisova^1,*, 
2. Dilek Akçakayıran¹,
3. Matthias Schenderlein¹, 
4. Helmuth Möhwald¹,
5. Dmitry G. Shchukin^1,2

Organic coatings based on inhibitor loaded inorganic containers for smart corrosion inhibition are presented. The overall coating performance is strongly influenced by the containers as well as their inhibitor capacity, compatibility with the coating matrix, and size. The important effect of container size is described for the first time in this work by investigating two types of mesoporous silica containers of different diameters: 80 and 700 nm. The coating physical properties (thickness and adhesion) are comparable for both container types. In contrast, the coating barrier properties are strongly influenced by the container size as assessed with electrochemical impedance spectroscopy (EIS). The incorporation of bigger containers reduces the coating resistance by a factor of two. Surprisingly, despite the similar amounts (20 wt%) of loaded inhibitor (2-mercaptobenzothiazole), different active inhibition ability is detected with the scanning vibrating electrode technique (SVET). Therefore, it is found that coatings with smaller containers exhibit better self-healing performance.

Interesting article for anyone working on nanocontainers and self-healing.