Quantum Mechanical Investigation of the Oxidative Cleavage of the C–C Backbone Bonds in Polyethylene Model Molecules

Recalcitrant plastic waste has caused serious global ecological problems. There is an urgent need to develop environmentally friendly and efficient methods for degrading the highly stable carbon skeleton structure of plastics. To that end, we used a quantum mechanical calculation to thoroughly investigate the oxidative scission of the carbon-carbon (C–C) backbone in polyethylene (PE). Here, we studied the reaction path of C–C bond oxidation via hydroxyl radical in PE. The flexible force constants and fuzzy bond orders of the C–C bonds were calculated in the presence of one or more carbocations in the same PE carbon chain. By comparison, the strength of the C–C bond decreased when carbocation density increased. However, the higher the density of carbocations, the higher the total energy of the molecule and the more difficult it was to be generated. The results revealed that PE oxidized to alcohol and other products, such as carboxylic acid, aldehyde and ketone, etc. Moreover, the presence of carbocations was seen to promote the cleavage of C–C backbones in the absence of oxygen.

First Fruits

Anderson thrives in graduate school where he begins a career-long friendly rivalry with Walter Kohn. He consciously chooses not to work with superstar theorist Julian Schwinger and pursues a PhD supervised by John Van Vleck. His thesis problem is a quantum mechanical calculation of the microwave absorption spectrum of small molecules. His social time is spent almost exclusively with non-physics graduate students, including the mathematician-comedic songwriter Tom Lehrer. He meets Joyce Gothwaite during a vacation trip home and only a short time passes before they marry in Boston and she becomes pregnant. Daughter Susan is born and Anderson completes his thesis work quickly. Money is tight.

Can Local Electric Field be a Descriptor of Catalytic Activity? A Case Study on Chorismate Mutase

The current theoretical perception of enzymatic activity is highly reliant on the determination of activation energy of the reactions which is often calculated using a computational demanding quantum mechanical calculation....

Comparison of Electrostatic Potential Obtained From Different Atomic Point Charges Calculation Methods for a Large Set of Molecules

The Electrostatic Potential is of great importance in chemical reactivity since it is closely related to many of molecular properties. Despite the fact that there are significant improvements in the quantum mechanical calculation methods, the atom centered partial charge approximation keeps hold of its importance in the field of estimating electrostatic potential as an inexpensive alternative to the ab initio method. However, even today, there is no universally accepted the best method for computing a partial atomic charge. Here, we compared the electrostatic potential obtained from different atomic point charges calculation methods for a large set of molecules. To this end, the large Grimme set of molecules was used. Some of the molecules in the set naturally failed in estimating the electrostatic potential. This failure, therefore, was investigated in depth. The Iterative Hirshfeld method can be preferable for electrostatic potential field generation.