Synthesis Of Polythene Lab Report

Phosgene was first synthesized by the Cornish chemist John Davy in 1812. This reaction was performed by exposing a mixture of carbon monoxide and chlorine gas to sunlight. The name was derived from the Greek: phos, and gene; meaning light and birth respectively. Gradually, phosgene became important in the chemical industry, finding its way into the dye industry in the 1800s. Today it has many industrial applications such as the formation of isocyanates, precursors to polyurethanes and for forming polycarbonates, both used heavily in many materials manufacturing. Aside from its industrial applications, phosgene is still used sparingly in the laboratory despite the many substitutes that have been developed. Its uses range from producing acid

The HOMO is the highest energy orbital that has electrons occupying it, and the LUMO is the next resultant linear combination of the atomic orbitals that is empty. The transitional energy between these two orbitals can be measured as well, often through UV-Visible spectrum spectroscopy. [2] Lastly, the enthalpy of phosgene's reaction with water, which likely contributes to its toxicity was also investigated and calculated. All of these results and calculations will be discussed in detail throughout the report. All calculations and simulations for our experiment were performed utilizing Spartan Student v7.2.7 software through different 2 computational methods (Hartree-Fock and EDF2) and 2 corresponding basis sets (6-31G*and 6-311+G**). In terms of accuracy, EDF2 (which is based on Electron Density Functional Theory) was the more accurate of the two, and the reasoning for this is simple. Hartree-Fock has to make many approximations for its calculation because it is based on wavefunctions rather that electron density functions like EDF2 that take into account electron-electron interactions. Hartree-Fock mostly ignores these interactions by producing a system wavefunction from many separate 1 electron spin wavefunctions. This method is normally a basis point for more advanced

The only adsorption that is relatively accurate is the peak at about 1800 that should correspond to the stretching vibrations of the carbonyl carbon-oxygen bond. Hartree-Fock method analysis did not allow for corrected IR values either, contributing to its inaccuracy. As is expected, the EDF2 model outperformed the HF model in terms of accuracy and 6-31G* was a less rigorous and precise basis than 6-311+G. These values are not satisfactory for this molecule in comparison to expected values, but that does not mean Spartan will fail for all molecules, but at the very least, it seems to be inadequate for phosgene. The very low wavenumber region of the spectrum (sometimes called the "fingerprint region") is the most inaccurate area, but with good reason. This region usually corresponds to the more complex molecular oscillations, so it is not surprising that Spartan had more trouble correctly predicting