What is Present in Concentrated Hydrobromic Acid?

Most of the time I spent in my research was to answer this question. One would think this would be easy, since it is easy to precipitate oxobromomolybdate(V) compounds from concentrated hydrobromic acid solution by adding a suitable cation. Unfortunately, different cations precipitate a total of four different oxomolybdate(V) structures. These structures are shown below with the chemical formulas of the oxobromomolybdate(V) compounds I prepared. Most of these compounds were precipitated from concentrated(>12M) hydrobromic acid solutions. QuinolineH)2 MoObr5 and (dipyridylH)2 MoObr5 were separated from 6M hydrobromic acid solutions.

Type I Compounds: (MoOBr5)2-
(NH4)2 MoOBr5
(anilineH)2 MoOBr5
(quinolineH)2 MoOBr5
(dipyridylH2) MoOBr5

Type II Compounds: (MoOBr4 - H2O) 1-
(CH3)4N MoOBr4 - H2O
(CH3)3phenN MoOBr4 - H2O

Type III Compound: (MoOBr4 1-)
(C4H9)4N MoOBr4

Type IV Compounds: (MoOBr4) 1-
pyridineH MoOBr4
quinolineH MoOBr4