Absorption L-lines of iron ions are observed, in spectra of Seyfert 1 galaxies by the new generation of X-ray satellites: Chandra and XMM-Newton. Lines associated to Fe 23+ to Fe16+ have been already observed in emission, in the solar corona and in laboratory. Whereas, those corresponding to Fe 15+ to Fe6+ have not been observed as emission lines, the upper level of the transition decaying preferentially by autoionization. Many atomic data are available for the first ion set. For the second set, some data have been recently published for n=2 to n’=3 transitions. We have recalculated them using another theoretical approach and have extended them to n’=4.