Structural preparative studies of some phenyl derivatives of Group IVa elements

The infrared spectra of a number of aryl tin and aryl lead compounds have been examined in the 2-50mu. region. The infrared spectra (2.15mu.) of these derivatives are the spectra of mono-substituted benzene derivatives. The spectra in the far infrared region (15-50 mu) have been found to be distinctive and can be used for the qualitative identification of these compounds. Frequency assignments are made and the spectra are discussed in terms of structural features of the organometallis, derivatives. There seems to be no evidence to support the possible existence of Ph3Sn+ and Ph3Pb+ cations in any of the derivatives examined. The derivatives with strong electro-negative groups, i.e. fluorides, fluoroborates, perchlorates, hexafluoroarsenates, hexafluoroantimonates, nitrates are considered a predominently covalent in character with polymeric structures involving five co-ordinate tin or lead atoms. A number of new compound have been prepared during the course of this work. Conductivity measurements have been made on nitromethane solutions of hexaphenylditin and hexaphenyldilead at varying temperatures. It has been conclusively shown that there is no heterolytic dissociation of these compounds. The far infrared spectra (15-50 mu) of a range of aryl compounds of Group IVA, VA, VIA and VIIA elements have been studied. Frequency assignments are made for the stronger bands. Most of the vibrational frequencies occurring in this region sensitive t the substituent atom attached to the benzene ring. Some new salts of the triphenylmetnea carbonium ion have been prepared and their infrared spectra examined. The carbonium ion dyestuffs (malachite green, brilliant green and crystal violet) form ionic derivatives with fluoro-boratec perchlorate and heteropoly acid anions. The solution spectra of these derivatives have been examined in the visible region (400-700 mu.) and the spectra are discussed in terms of aggregation of the dyestuff cations in solution. Many new crystalline compounds have been prepared with fluoroborete, perchlorate and heteropoly acid anions and the infrared and reflectance spectra discussed. The cyanide, cyanates, thiocyanate, metaborate and sulphide derivatives of the dyestuffs have been found to be covalent with a true tetrahedral arrangement about the central carbon atom. The dyestuffs give orange-red solutions in strong acids. The colour is due to the formation of new species by protonatior of the nitrogen atoms of the dyestuff cations. Many new salts containing these protonated species with anions derived from heteropoly and Lewis acids have been prepared and examined spectroscopically. The dyestuffs also form complexes with Lewis acids (SnCl4, SbCl5) in non-aqueous solvents. The successive addition of SbCl5 has been studied and a number of new colplexes have been prepared with crystal violet