Synthesis and characterization of new bi-functional monomers based on germarylene or silarylene units: 4,4 '-(R1R2-silylene)bis(phenyl chloroformates) and 4,4 '-(R1R2-germylene)bis(phenyl chloroformates)

Foll owing the reaction route between a diphenol and phosgene/toluene, solution in basic medium, six new bis(chloroformates) containing germarylene or silarylene units were synthesized with good yield. The variation on the structure is due to the nature of the groups bonded to the heteroatom. Therefore, combinations of Me, Et and Ph groups were used. 4,4'-(Diethylsilyiene)bis(phenyl chloroformate), 4,4'-(ethylmethylsilylene)bis(pheny1 chloroformate) and 4,4'-(diethylgermylene)bis(phenyI chloroformate) were obtained as a slightly yellow oil, while 4,4'(diphenylsilylene)bis(phenyl chloroformate), 4,4'-(methylphenylsilylene)bis(phenyI chloroformate) and 4,4'-(diphenylgermylene)bis(phenyI chloroformate) were obtained as a white solid. The new bi-functional monomers were characterized by FT-IR, Si-29-, C-13- and H-1-NMR spectroscopy and elemental analysis. The T-m, of the products in general was higher in samples containing germanium as the central atom, compared to those containing silicon.