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A Hypo helmet is a fabric hood soaked with an aqueous solution of two sodium salts for the detoxication of chlorine that was developed during the First World War. Herein, we report on a lecture, developed for non-chemistry majors that used the Hypo helmet to highlight the physical and chemical properties of chlorine. The lecture consisted of the following three components: (1) a brief introduction to the First World War (the Chemists’ War), (2) video demonstrations of the generation of chlorine by mixing bleaching powder and hydrochloric acid and the detoxication of chlorine using a dummy Hypo helmet, and (3) students’ written impressions of the lecture. The students’ written impressions revealed two things: the lecture on chlorine and the Hypo helmet was well received, and most of the students (71 %, N = 82) did not know that chlorine was used as a poisonous gas during the First World War.

Commercially available molecular models are elaborately made but generally expensive, which hinders their distribution to all classroom students. Aiming at developing an affordable molecular model, we developed a structure model kit consisting of inexpensive electronic components including transistors and colored light-emitting diodes (LEDs) with a total cost of ca. 2 USD. The structure model kit was designed for building a family of environmental pollutant molecules known as dioxins, in which transistor, white LED, red LED, and yellow LED components are used to represent sp2 carbon, hydrogen, oxygen, and chlorine atoms, respectively. Herein, we report an activity directed to nonchemistry majors studying environmental science and electronic engineering to help them gain insight into the molecular structure of dioxins using the newly developed structure model kit. The activity was well received by many students, some of whom came to understand the relationship between the structure and nomenclature of dioxins, mainly 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (2,3,7,8-TCDD) and its isomers.

Catalytic converters (automotive catalysts) and the chemical reactions they catalyze appear in general and introductory chemistry textbooks. Although the detailed mechanisms of the chemical reactions that occur in catalytic converters have been clearly revealed via recent developments in surface and computational chemistry research, the description and illustration of the catalysis are still ambiguous in textbooks. In this paper, we describe an extracurricular lecture whereby a handmade teaching aid was employed to illustrate the basic principle of the catalytic oxidation of carbon monoxide over platinum surface, which is an essential reaction occurring in catalytic converters. The teaching aid, constructed combining easily available materials, can illustrate the positions and motions of the molecules on the platinum surface during catalytic oxidation. The lecture was favorably received by non-chemistry majors and high school students. Despite the difficulty of the topic, the audience displayed a relatively high level of understanding.

Structure model sets for inorganic compounds are generally expensive; their distribution to all students in a class is therefore usually impractical. We have therefore developed a structure model set to illustrate inorganic compounds. The set is constructed with inexpensive materials: ping-pong balls, and snap buttons. The structure model set can be used to illustrate isomerism in coordination compounds and periodic structures of ceramic perovskites. A hands-on activity using the structure model set was developed for high school students and was well-received by them. Despite the concepts being slightly advanced for them, the students’ retention of the knowledge gained through the activity was tested a week after they completed the activity and was found to be relatively high, demonstrating the usefulness of the activity based on the structure model set.

Teachers are developing unique teaching aids to attract students to the field of chemistry. Ideal teaching aids are tools that students can enjoy utilizing, reutilizing, and which can be constructed without employing special tools. LEGO®-based teaching aids satisfy all these requirements. Chemistry teachers have employed bricks to illustrate basic chemical concepts. Moreover, LEGO-based chemistry teaching aids have been vigorously reported by Campbell and coworkers since the late 1990s and are still being persistently reported by several groups. The focus of this review is the applications of LEGO bricks in teaching chemistry. This review describes LEGO-based teaching aids that are easily constructed and may be beneficial to readers, in terms of creating new teaching aids. Since LEGO bricks possess varieties of shapes and colors, they can be employed to design various teaching aids, including periodic tables, molecular models, polymer structure models, and frameworks for handmade measuring instruments. The polymeric structure models are generally difficult to build with typical ball-and-stick type molecular models; however, they can be easily built, employing LEGO bricks. The bricks are suitable for the construction of handmade measuring instruments because of their versatility and computer interface, as well as their non-requirement of special tools.

The present article details a quiz-style lesson for teaching three introductory chemistry concepts: the cleavage of rock salt as well as the oxidation and malleability of metals, through the history of chosen world cultural heritage sites, including the Wieliczka Salt Mine, the Statue of Liberty, and the Golden Pavilion in Kyoto. The described lesson comprises three questions aimed at promoting critical thinking. The responses to the designed questions were made by the students working in groups. While revealing the correct answers, three simple demonstrations were conducted to entice the students and to enhance their understanding of the discussed chemical concepts. The lesson was favorably received by the students and helped them to relate relevant chemical concepts to real-world situations.

Buckminsterfullerene (C[subscript 60]), along with diamond and graphite, appears in many chemistry textbooks as an example of an allotrope of carbon. This communication describes a hands-on activity to explore the characteristic structure of C[subscript 60] through the construction of a structural model using transistors and plastic tubes (heat-shrink and silicone). Transistors resemble sp[superscript 2] carbons when their three electrodes are spread 120° in relation to each other. The heat-shrink tube is suitable for connecting thin electrodes of transistors. By connecting 60 transistors using 90 precut plastic tubes, a C[subscript 60] model can be built that costs about 2.1 USD. This activity was carried out with nonchemistry majors using a remote lecture system. The participants enjoyed constructing their C[subscript 60] models and were challenged to estimate the diameter of an actual C[subscript 60] molecule using the models that they had built.

A unique demonstration with ball-rolling mechanisms has been developed to illustrate the basic principles of mass analyzers as components of mass spectrometers. Three ball-rolling mechanisms mimicking the currently used mass analyzers (i.e., a quadrupole mass filter, a magnetic sector, and a time-of- flight) have been constructed. Each mechanism was designed to separate balls with three different weights (representing three ionized analytes with different weights) in an attempt to imitate the separation process employed by real mass analyzers. This demonstration helped students understand the basic principles of mass analyzers.

We describe an activity that is suitable for high school students and makes use of plastic bottles. This activity allows students to familiarize themselves with gas chemistry by introducing technologies that were applied in old submarine systems. Plastic bottles, which are representative of submarines, are used as reaction vessels. Three simple experiments regarding gas chemistry are carried out in the plastic bottles: (1) a carbon dioxide absorption reaction using soda lime, which mimics an air-cleaning canister; (2) a chlorine and hydrogen evolution reaction by the electrolysis of brine, which highlights the accidental generation of gases by lead batteries on board submarines; and (3) a catalytic hydrogen peroxide decomposition that exists in submarine propulsion system. To introduce an antisonar countermeasure system outside the submarine, a fourth experiment on hydrogen generation by the reaction of calcium hydride and water is also conducted.

Catalysis with transition-metal complexes is a part of the inorganic chemistry curriculum and a challenging topic for upper-level undergraduate and graduate students. A hands-on teaching aid has been developed for use during conventional lectures to help students understand these catalytic reactions. A unique method of illustrating the coordination polymerization of propylene with interlocking building blocks is described. Three metallocene block models mimicking real catalysts recognize top and bottom faces of a prochiral propylene monomer block model and subsequently provide three polypropylene structures with different tacticity. The monomer recognition processes of the metallocene block models are based on steric hindrance, similar to those of the real catalysts. (Contains 4 figures.)

Research has been conducted on the coordination polymers with redox activity. The construction of these polymers via the use of ferrocene-based bidentate ligands is described.

Research has been conducted on metal-centered ferrocene compounds. The authors report that these compounds have been designed via the use of 5-ferrocenylpyrimidine and ferrocenylpyrazine, and that when combined with transition metal salts they produce structurally diverse mixed-metal polynuclear complexes.

The structure, electronic properties and inclusion phenomena of the self-assembled coordination polymers have attracted special interest. The complexation of 4-PDS with M(hfac)(sub 2) (M = Cu, Mn), affording simple N-coordinated 1:1 polymer complexes 4-PDS.Cu(hfac)(sub 2) and 4-PDS.Mn(hfac)(sub 2) are described.