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…

The NMR spectrometer is a commonly used spectroscopic instrument that records resonance frequencies of nuclei present in molecular systems. While the NMR frequencies fall within the radio frequency regime for a given molecular system, they are presented in terms of chemical shifts in the audio frequency regime, thereby having the versatility to be…

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…

Benzoin, an [alpha]-hydroxy ketone, is stereoselectively reduced by sodium borohydride to yield hydrobenzoin, the stereochemistry of which is determined by acetalization and analysis of the derivative by NMR spectroscopy. This classical experiment has been enhanced by modern spectroscopic and computational analysis to enable students to…

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…

A straightforward protocol for the preparation of the colorful and air-stable diphenyl ditelluride is described. In one laboratory session, students isolate their product and characterize it via melting point determination, mass spectrometry, and NMR spectroscopy ([superscript 1]H, [superscript 13]C­{[superscript 1]H}, and [superscript…

Chemistry undergraduate curricula typically place Nuclear Magnetic Resonance (NMR) lectures under either Organic Chemistry or Spectroscopy courses, aiming for students to acquire basic knowledge for the determination of the structure of simple organic compounds. On the other hand, regarding laboratory practice, NMR is frequently disregarded by…

Infrared spectroscopy (IR) is a staple structural elucidation and characterization technique because of its ability to identify functional groups and its ease of use. Interestingly, it allows the capture of electronic effects via their influence on the bond strength of "probes", such as the carbonyl group and also offers a wealth of…

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.…

An operationally simple, reliable synthesis of ethynylated acenes suitable for an upper-division undergraduate organic chemistry laboratory course has been developed. This experiment requires students to synthesize two acene derivatives and can be completed in 6-8 laboratory sessions (3 h each); a shorter experiment could be realized in the…

A structured series of activities has been designed and implemented to promote analysis and data reporting skills for second-year organic chemistry students. Student report sheets were developed to assist students in reporting necessary data for their compounds. A series of rubrics have been utilized by students to promote metacognition and by…