| This dissertation contains three parts as described in three individual chapters (Chapter 2, 3 and 4). The extensive background for all three parts is outlined in Chapter 1. The first part of this dissertation is on possibly dangerous reactions in air conditioning systems. The consequences of R-40 (chloromethane) being used as a refrigerant in AC system were evaluated. Al containing materials can react with R-40 to produce explosive TMA (trimethylaluminum). However, these reactions require strict conditions such as addition of Mg under high temperature and high R-40 pressure. Most C=O bond containing chemicals including polyester refrigerant lubricants can react with TMA by stabilizing the methyl groups on C=O bonds, thus decreasing the methane release and the risk of explosion. The second part focuses on synthesis and evaluation of heterogeneous catalysts for olefin oxidation using atmosphere oxygen. Reduction of AgNO3 by ethylene glycol in presence of PVP and MCM-41 resulted in nanosized silver particles on the surface and in the channels of MCM-41. The composite material was characterized by TEM, XRD, TGA and BET surface area analyzer. The catalytic properties of the material on oxidation of various olefins was evaluated by GC-MS. A free radical mechanism was proposed and well explained the catalysis. Hexamer vanadium complexes [(V3(micro 3-O)O2)(micro2-O2P(CH 2C6H5)2)6]2(micro 2-N1,N2-di(pyridin-4-yl)oxalamide) consisting two vanadium trimeric complexes bridged by micro2- N1,N2-di(pyridin-4-yl)oxalamide was synthesized by reacting VO(acac)2 with dibenzylphosphinic acid and micro2-N1,N2-di(pyridin-4-yl)oxalamide. Using 4,4'-bipyridine instead of micro2-N 1,N2-di(pyridin-4-yl)oxalamide only resulted in the formation of trimeric (V3(micro3-O)O 2)(micro2-O2P(CH2C6H 5)2)6(4,4'-bipyridine) presumely due to shorter bridge length and higher steric hindrance. The two complexes were characterized by FTIR, 1H NMR, TGA and single crystal X-ray diffraction measurements. |
