Zur Kenntnis von Strontiumhydroxidchlorid und Strontiumhydroxidbromid - Darstellung, Kristallstrukturen, IR- und Raman-Spektren

Aqua oxyhydroxycarbonate second phases at the surface of Ba/Sr‐based proton conducting perovskites: a source of confusion in the understanding of proton conduction

“…f'. As expected, very narrow peaks are observed at ~3600 cm −1 which shift after deuteration. The vibrational wavenumber of free OH ‐ ion is expected to be about the mean value of the symmetric and the antisymmetric stretching wavenumbers of gaseous water molecules, i.e.…”

“…Previous X‐ray and IR/Raman combined study pointed out that Ba and Sr‐based hydroxides form different allotropic phases and hence exhibit different vibrational signatures with peaks at 3606/3481 (Sr) and 3596/3360 (Ba) cm −1 . The example of Sr/Ba hydroxide halides shows that two different phases with high (~3610 cm −1 ) and lower (3543/3492 cm −1 doublet) wavenumber positions may exist as a function of the thermal history. Thus two alternate assumptions can be made: the first suggesting an incomplete drying of some previous hydroxides and the second postulating the presence of phases with different structures.…”

“…Usually hydroxyl groups show very sharp IR and Raman stretching modes detected at ~3550–3600 cm −1 because they form vibrators isolated both from the electrical and mechanical point of view . However, the vibrational signature of some hydroxides – this is the case of some earth alkali ones – is much more complex due to the formation of strong H‐bond with water molecules that shifts down the wavenumber and broadens the bands. Consequently, the dynamic disorder and high protonic diffusion are measured for some (hydr)oxides, in their both solid and molten states, that is at the origin of many confusions in the determination of conducting properties .…”

“…Consequently, the dynamic disorder and high protonic diffusion are measured for some (hydr)oxides, in their both solid and molten states, that is at the origin of many confusions in the determination of conducting properties . Comprehensive studies of Ba, Sr, Ca, Mg, … ‐based hydroxides were conducted by Lutz and co‐workers . They pointed out that contrary to the magnesium and calcium hydroxide, which exist in an anhydrous form only, the alkaline earth element hydroxides show polymorphism and form several different hydrates.…”

Synthesis and Characterization of the Manganese Hydroxide Halides Mn(OH)X (X = Br, I) and Crystal Structure of trans‐MnBr2·4H2O

“…Many divalent metal hydroxide halides of the type M (OH) X ( M = Mg, Ca, Ba, Sr, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Sn, Sr; X = Cl, Br, I) are known so far . The most prominent group of this class is constituted by the hydroxide chlorides.…”