We have studied the c-polarized optical phonons of high quality single crystals of La{sub 2{minus}x}Sr{sub x}CuO{sub 4} with doping concentrations ranging from the underdoped to the overdoped regime (x=0.1,0.12,0.15,0.18,0.2) at temperatures between 10 and 300 K. We discuss the dependence of all observed phonon modes on temperature as well as on doping. We find no indication for a coupling of the zone-center phonons to the electronic continuum, either in the normal or in the superconducting state. {copyright} {ital 1997} {ital The American Physical Society}