Virtual FTIR spectrometer and 3D visual display for a course in molecular spectroscopy

Abstract

The use of a visual 3D display and a virtual spectrometer for the teaching of a course in molecular spectroscopy presents new possibilities. All the movements of the molecules are shown along with their relations with their characteristic spectra. The virtual laboratory simulates a true commercial spectrometer as well as a software of recognition. All the students simultaneously follow the laboratory under conditions very close to the reality of a modern industrial laboratory. SummaryTeaching a course in molecular spectroscopy is not an easy task. First, we must use concepts of molecular symmetry to relate the observed spectra to the quantum properties of the molecules, such as the creation or the modification of an electric dipole moment or the quantified energy levels. The visualization of these 3D symmetry properties is not easy, and the use of sticks and ball models has become complicated and obsolete today. Second FTIR spectroscopy now involves very expensive equipment and signal analysers. Teaching laboratories often lack the number of spectrometers required for teaching large groups of students, and, even less, the expensive software to analyze and recognize the spectra. The result is that the students are not trained with modern apparatus and under the conditions normally met in their future work place. Sometimes they are also obliged to apply concepts in the laboratory, which they will learn only later in class. The development of the information and communications technology (ICT) enables us to conceive the teaching of such courses differently. The first problem is easily solved by developing a 3D visual display with the six degrees of freedom which describe the translation and the rotation of the whole molecule. Moreover, the 3N minus six (or five for linear molecule) degrees of freedom of a N atoms molecule can also be illustrated, showing all the movement of the atoms. So we can simulate the normal modes of vibration of a molecule or of a group and correlate them with their spectra. We have done this with the Java 3D language, and using the spectra from the National Institute of Standards and Technology (NIST) site. Several molecules were simulated, so that all the symmetry operations are presented, as well as some normal modes of vibration of This paper is freely available as a resource for the optics and photonics education community.

FTIR-SIS: A Fourier Transform Infrared Scientific Instrument Simulator

“…Shortly following the advent of the microprocessor and widespread incorporation of them in microcomputers (i.e., personal computers), a number of SISs were developed, including NMR, − IR, − UV–Vis, , X-ray fluorescence, ESR, and HPLC simulators, some of which have a command line interface, while others have a visual interface that was designed to resemble that of the real instrument. Changes in computer technology over the years have necessitated the continued development of interactive software for the teaching of chemistry, and accordingly, a number of SISs with more modern visual interfaces have since been developed for HPLC, , NMR spectroscopy, , Raman spectroscopy, fluorescence spectroscopy, UV–Vis spectroscopy, and FTIR spectroscopy …”

“…An article describing the previously developed FTIR-SIS (referred to as a virtual FTIR spectrometer) was published in 2005, where it was mentioned that spectra were utilized from a variety of sources (e.g., the National Institute of Standards and Technology (NIST) Web site) in order to simulate the spectra of a wide variety of molecules (using the Java 3D application programming interface (API)) . It seems that the focus was on providing students with an opportunity to learn (1) how to operate an FTIR spectrometer in an autonomous setting, enabling them to operate a real spectrometer, and (2) how peaks in vibrationally resolved spectra correlate with the normal modes of the molecule .…”