In this two-session experiment for an organic chemistry lab, students prepare a macrocyclic host compound--namely, a pillar[5]arene--by means of a templated 1,4-dimethoxybenzene/formaldehyde cyclo-oligomerization (session 1), and then, they explore its molecular recognition properties toward the 1,8-diaminooctane guest with the aid of [superscript…

High-resolution mass spectrometry (HRMS) is an analytical technique that is typically used by mass spectrometry experts. However, with recent advancements, it is becoming more accessible to students in organic chemistry laboratories. Still, a significant knowledge gap exists between these experts and students. A straightforward laboratory…

Electrophilic aromatic substitution reactions are common in the organic chemistry laboratory. These reactions, while ubiquitous, use corrosive reagents and halogenated or hydrophobic solvents that produce expensive and hazardous waste streams. The carboxylation of phenols (Kolbe-Schmitt reaction), although aqueous, typically involves conditions…

This laboratory experiment consists of the synthesis of two series of alkaline-earth titanates (calcium-strontium and strontium-barium)to corroborate Vegard's law by obtaining their X-ray diffraction patterns and plotting the lattice parameter versus mole fraction of both cations. This experiment allows students to understand the key concepts in…

For solid solutions with the same arrangement of atoms, the size of a unit cell depends on the size of the atoms in the unit cell. The distance between nuclei also helps determine how strongly electrons are held, which changes the band gap energy. Samples of semiconductor CH[subscript 3]NH[subscript3]Pb(I[subscript…

Dilute guarana´ ("Paullinia cupana") powder aqueous extract is a soft drink that contains three structurally related methylxanthines (MXs), caffeine (CF), theobromine (TB), and theophylline (TP); CF is present in a large excess. Literature data show that values of [lambda][subscript max] and [epsilon][subscript max] of these three MXs…

An understanding of basic organic chemical reactivity is key for many biosciences students. The reactivities of different carbonyl groups affect their function in many biomolecules. A practical class, the two-step synthesis of paracetamol, has been devised to illustrate the electrophilic reactivities of carbonyls, which was covered in the…

An absorption line at 900 nm has been observed in Perspex. Samples of 1 and 2 cm thickness were used and the integrated absorption (line width times peak absorption) of the line was proportionate to the thickness. Facilities for lowering the sample temperature were not available and therefore both measurements were carried out at room temperature.…

Iodonium zwitterions are hypervalent iodine compounds in which the iodine center binds to two substituents and carries a positive formal charge which is compensated by a negative charge within the same molecule. Under thermodynamic conditions, iodonium zwitterion sallow concerted nucleophilic aromatic substitutions to be performed, followed by…

Is the reductionist approach to teaching chemical principles in the laboratory adequate for students to make effective evaluations? In this work, using the example of sunscreens, students first assessed the analytical chemistry parameters of the active ingredients, later comparing and contrasting them with organic chemistry information for…

The mental models students have after engaging in an activity designed to teach infrared (IR) spectroscopy without reliance on IR absorption tables, were characterized. Qualitative analysis of semi-structured interviews, through open coding, allowed the classification of the mental models as Molecules as Dynamic (MAD), Bonds as Dynamic (BAD),…

The abstract nature of physical chemistry and spectroscopy makes the subject difficult to comprehend for many students. However, bridging arts and science has the potential to provide innovative learning methods and to facilitate the understanding of abstract concepts. Herein, we present a high-school project based on the conversion of selected…

The attractive photophysical properties of luminescent nanoparticles have prompted numerous studies on their synthesis and biological applications. Due to the complexity of components, sizes, morphologies, and strong light scattering of the nanoparticles the absorption spectrum alone is not enough for characterising and analysing the real…

Nuclear magnetic resonance (NMR) spectroscopy has become a cornerstone tool for studying a variety of molecular features in advanced chemistry laboratories. In this experiment, students prepare a pyrrole-[beta]-amide via a one-pot, three-step synthesis and use NMR spectroscopy to confirm its molecular structure. In addition, variable temperature…

The use of symmetry is widespread in chemistry, as it is used for predictions of the number of allowed and forbidden absorptions in electronic, vibrational, and rotational spectroscopies; for predictions of the combination of atomic orbitals to produce molecular orbitals; and in many other chemical applications. One critical step in these…