The smallest distortion is shown by 1,4-AMC cation, which is the aliphatic analogue of 1,4-XDA, suggesting a conjugate ring provide more rigid structural constranits. 17 the stretching and bending modes of the Pb-Br cages in the lower energy part and the libration of the organic cations partially bound to the Pb-Br framework. At first, we observe for all the investigated samples well defined Raman fingerprints thus confirming a high crystal quality. In addition the data pointed out that the Raman yields from (1,3-PDA)PbBr4, (1,4-PDA)PbBr4 are markedly lower with respect to that from (1,4-XDA)PbBr4. This is particularly clear for the mode observed for 1,4-XDA at 78.5 cm -1 probably associated to the stretching motion of Pb-Br unit. For (1,3-PDA)PbBr4 , (1,4-PDA)PbBr4 weaker bands are observed at 88 cm -1 . This behaviour is consistent with the greater distortion affecting the two short diammonium cations with respect to 1,4-XDA. In the region 130-250 cm -1 we observe, in comparison with the octahedral Raman yield, a small Raman activity decrease for 1,4-PDA and 1,4-XDA with respect to 1,3-PDA. Even if a detailed mode attribution is required this could be due to the smaller NH3 + penetration characterizing 1,3-PDA sample.