Electronic structure of thiophenes and phtalocyanines

The results of x-ray fluorescence measurements of thiophenes @regioregular poly ~3-hexylthiophene ~P3HT!and a,v-dihexylquaterthiophene ~DHa4T!# and phtalocyanines @copper phtalocyanine ~CuPc! and copperhexadecafluorophtalocyanine (F16CuPc)# are presented. Experimental carbon, nitrogen, fluorine Ka and sulphur,copper L2,3 x-ray emission spectra are compared with ultraviolet photoemission spectroscopy spectra anddeMon density-functional theory calculations of model molecules. We find that the carbon Ka emission isalmost identical for P3HT and DHa4T. This indicates that the electronic structure of the p system is notaffected by the presence of the side group. The ratio of emission intensities of the Cu L2 to Cu L3 intensitiesis found to be smaller by a factor of 2 for CuPc and F16CuPc than it is for pure metal. This demonstrates thestrong covalency in phalocyanines