Enhanced UV stability of 2D perovskites (HO(CH2)(4)NH3)(2)(MA)(n-1)PbnI3n+1 due to hydrogen bonding

2D organic-inorganic lead iodide perovskites (HO(CH2)(4)NH3)(2)(MA)(n-1)PbnI3n+1 (n = 1, 2, 3, and 4) were prepared and showed enhanced UV stability due to the additional inner hydrogen bonds between adjacent spacer cations, compared with the counterpart (CH3(CH2)(3)NH3)(2)PbI4 without the additional inner hydrogen bonds. The hydrogen bonds were formed between the hydroxyl groups of the organic spacer cations BA-OH+ and were demonstrated by the H-1 NMR chemical shift of the active hydrogen of the spacer's hydroxyl groups. The 2D (HO(CH2)(4)NH3)(2)(MA)(n-1)PbnI3n+1 perovskites remained stable after 10 days of UV radiation, while the (CH3(CH2)(3)NH3)(2)PbI4 perovskites decomposed after 3 days of UV radiation, as indicated by the XRD results.