A unique superparamagnetic‐like behavior and a large “positive magneto‐LC effect” were observed in the solid phases and the hexagonal columnar (Colh) liquid crystalline (LC) phase, respectively, of novel achiral non‐π‐delocalized nitroxide diradical compounds (R,S)‐1, which showed polymorphism in the solid phases (solids I and II). The SQUID magnetization measurement revealed that (1) (R,S)‐1 containing a small amount of racemic diastereomers (R*,R*)‐1 possessed an unusual and large temperature‐independent magnetic susceptibility (χTIM>0) component in the original nanocrystalline solid I that was responsible for the observed superparamagnetic‐like behavior under low magnetic fields and did not arise from the contamination by extrinsic magnetic metal or metal ion impurities, besides ordinary temperature‐dependent paramagnetic susceptibility (χpara>0) and temperature‐independent diamagnetic susceptibility (χdia<0) components, (2) a large increase in molar magnetic susceptibility (χM) (positive magneto‐LC effect) that occurred at the solid I‐to‐liquid crystal transition upon heating was preserved as an additional χTIM increase in the resulting polymorphic nanocrystalline solid II by cooling, and (3) such unique magnetic phenomena were induced by thermal processing for (R,S)‐1 or by adding a small amount of (R*,R*)‐1 to (R,S)‐1 as the impurity.

Highly concentrated dissolved silicate was detected in pore water from anoxic-reducing sediment in Lake Nakaumi, a brackish lake. Silicate concentration also simultaneously increased with total hydrogen sulfide concentration during the summer. Generally, dissolved silicate is readily adsorbed onto ferric hydroxide and precipitates in an oxidative environment. In this study, we focused on the behavior of ferric hydroxide adsorbing silicate in sediment and determined that hydrogen sulfide was the main cause of dissolved silicate elution from ferric hydroxide adsorbing silicate because the hydrogen sulfide produced via microbiological processes in the anoxic-reducing environment was reducible for other metal oxides. According to laboratory experiments, silicate was released from ferric hydroxide by reacting with sodium sulfide, causing increasing elution of dissolved silicate from anoxic-reducing sediments with increasing concentration of sodium sulfide in the solutions. This result shows that hydrogen sulfide is very crucial for silicate release under a reducing environment. Therefore, in Lake Nakaumi, silicate would be released from the bottom after ferric hydroxide adsorbing silicate reacted with hydrogen sulfide in a summer reductive environment.

Invited for this month's cover are the collaborating groups of Dr. Yoshiaki Uchida from Osaka University, Japan, Prof. Rui Tamura and Prof. Masahito Sugiyama from Kyoto University, Japan and Dr. Dmitrii G. Mazhukin from Novosibirsk State University, Russia. The cover picture depicts a contrast between localized spins and conductive ions in the newly‐synthesized ionic liquid crystalline (ILC) nitroxide radicals. The ILC droplet of the new compounds is magnetically manipulable. More information can be found in the Full Paper by Yoshiaki Uchida, Rui Tamura, and co‐workers.

Nanomolar concentrations of NH2OH in natural water sources were determined using an Fe 3+ oxidation method. A pH of 2.35-2.50 was used, which was adjusted by adding a chloroacetate buffer. Equal amounts (1.0 mL) of the chloroacetate solution and ferric chloride solution were added to the water sample (70 mL) to oxidize NH2OH to N2O. The resulting N2O in the sample water was then quantified by headspace analysis using a gas chromatograph with an electroncapture detector (ECD), where a limit of detection of 0.2 μgN L -1 (14 nmol L -1 ) was achieved.This method was successfully applied to samples of freshwater, brackish water, and seawater, and despite the various salinities no interfering substances were observed. Furthermore, NH2OH was successfully detected in samples collected from the Hii River and Lakes Shinji and Nakaumi (Shimane Prefecture, Japan). In addition, the proposed method was also applicable to samples rich in organic substance derived from phytoplankton.