Isotope effects are widely used in infrared analyses of a range of chemical systems. Water molecules with three active modes are one of the most studied for testing the applicability of theoretical models. Whereas the IR spectrum of free gaseous water is very complex due to the accompanying rotational spectral features, the ATR-FTIR spectrum of a…

A laboratory experiment has been designed for teaching laboratories aimed at training students in the basics of spectroscopy in junior and senior level undergraduate chemistry courses. Despite the ubiquity of light-based tools in modern science, students often find it difficult to comprehend light and light-matter interactions. A portable…

The self-association of caffeine in solution, driven by the hydrophobic effect, is a simple example of molecular aggregation. It obeys an isodesmic association model in which each successive binding occurs with the same equilibrium constant. Here, we describe an activity for chemistry students that explores this phenomenon using nuclear magnetic…

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…

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…

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…

The contemporary Human activity utilizes huge volumes of digital data to solve efficiently multiple socio-economic, scientific and technical problems. Now the big data analysis is mainly oriented to the socioeconomic sphere with a goal to lift the profit. The science and technology to penetrate deeper in the nature of objects and systems under…