Protactinium(V) bromide

Protactinium(V) bromide  Names

IUPAC name

Protactinium(V) bromide

Identifiers

CAS Number

* 15608-38-5 Y

3D model (JSmol)

* Interactive image

SMILES

* [Pa](Br)(Br)(Br)(Br)Br

Properties

Chemical formula

| PaBr5
Molar mass | 630.556 g mol−1
Appearance  | red solid
Density | 4.98 g/cm3
Structure

Crystal structure

| monoclinic[1][2]

Space group

| P21/c , No. 14
Related compounds

Other anions

| Protactinium(V) fluoride
Protactinium(V) chloride
Protactinium(V) iodide

Other cations

| Praseodymium(III) bromide
Thorium(IV) bromide
Uranium(IV) bromide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Infobox references

Chemical compound

Protactinium(V) bromide is an inorganic compound. It is a halide of protactinium, consisting of protactinium and bromine. It is radioactive and has a chemical formula of PaBr5, which is a red crystal of the monoclinic crystal system.[2][1]

## Preparation[edit]

Protactinium(V) bromide can be obtained by reacting protactinium(V) chloride with boron tribromide at 500 to 550 °C.[3]

3PaCl5 \+ 5BBr3 → 3PaBr5 \+ 5BCl3

It can also be obtained by reacting protactinium(V) oxide with aluminum bromide at 400 °C.[4]

## Physical properties[edit]

Protactinium(V) bromide is an orange-red, crystalline, extremely moisture-sensitive solid that reacts violently with water and ammonia, but is persistent in absolutely dry air. It is insoluble in isopentane, dichloromethane and benzene, and in anhydrous acetonitrile is dissolves to form PaBr5•4CH3CN. It comes in several modifications. Below 400 °C as an α-modification and above 400 °C as a β-modification. The α-form has a monoclinic crystal structure of the space group P21/c (No. 14) and lattice parameters a = 1296 pm, b = 1282 pm, c = 992 pm, β = 108° and the β-form also has monoclinic crystal structure with space group P21/n (No. 14, position 2) and lattice parameters a = 838.5 pm, b = 1120.5 pm, c = 895.0 pm, β = 91.1°.[3] The β form exists as a dimer. At 400 °C in a vacuum, protactinium(V) bromide sublimes.[5] A γ-form, which has a β-uranium(V) chloride-type crystal structure, has also been detected.[6]

## References[edit]

1. ^ a b Brown, D.; Petcher, T. J.; Smith, A. J. (1968). "Crystal Structures of some Protactinium Bromides". Nature. 217 (5130): 737. Bibcode:1968Natur.217..737B. doi:10.1038/217737a0. S2CID 4264482.
2. ^ a b Brown, D.; Petcher, T. J.; Smith, A. J. (1969). "The crystal structure of β-protactinium pentabromide". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 25 (2): 178. doi:10.1107/S0567740869007357.
3. ^ a b Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 1177.
4. ^ Advances in Inorganic Chemistry and Radiochemistry (in German), Academic Press, 1970, p. 31
5. ^ D. Brown, T. J. Petcher, A. J. Smith: The crystal structure of β-protactinium pentabromide. In: Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 25, S. 178–182, doi:10.1107/S0567740869007357.
6. ^ D. Brown: The polymorphism of protactinium pentabromide. In: Inorganic and Nuclear Chemistry Letters. 15, 1979, S. 219–223, doi:10.1016/0020-1650(79)80132-4.

* v
* t
* e

Protactinium compounds

Pa(II)|

* PaO

Pa(III)|

* PaH3

Pa(IV)|

* PaO2
* PaCl4
* PaBr4
* Pa(C8H8)2

Pa(V)|

* Pa2O5
* PaF5
* PaCl5
* PaBr5
* PaI5

* v
* t
* e

Salts and covalent derivatives of the bromide ion

| HBr |  |  |  | He

|
|
|
|

LiBr | BeBr2 | BBr3
+BO3 | CBr4
+C | NBr3
BrN3
NH4Br
+N | Br2O
BrO2
Br2O3
Br2O5 | BrF
BrF3
BrF5 | Ne
NaBr | MgBr2 | AlBr
AlBr3 | SiBr4 | PBr3
PBr5
PBr7
+P | S2Br2
SBr2 | BrCl | Ar
KBr | CaBr2
|  | ScBr3 | TiBr2
TiBr3
TiBr4 | VBr2
VBr3 | CrBr2
CrBr3 | MnBr2 | FeBr2
FeBr3 | CoBr2 | NiBr2
NiBr42− | CuBr
CuBr2 | ZnBr2 | GaBr3 | GeBr2
GeBr4 | AsBr3
+As
+AsO3 | SeBr2
SeBr4 | Br2 | Kr
RbBr | SrBr2 |  | YBr3 | ZrBr3
ZrBr4 | NbBr5 | MoBr2
MoBr3
MoBr4 | TcBr4 | RuBr3 | RhBr3 | PdBr2 | AgBr | CdBr2 | InBr
InBr3 | SnBr2
SnBr4 | SbBr3
+Sb | Te2Br
TeBr4
+Te | IBr
IBr3 | XeBr2
CsBr | BaBr2 | *  | LuBr3 | HfBr4 | TaBr5 | WBr5
WBr6 | ReBr3 | OsBr3
OsBr4 | IrBr3
IrBr
4 | PtBr2 | AuBr
AuBr3 | Hg2Br2
HgBr2 | TlBr | PbBr2 | BiBr3 | PoBr2 | AtBr | Rn
Fr  | RaBr2 | **  | Lr  | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og

*  | LaBr3 | CeBr3 | PrBr3 | NdBr2,
NdBr3 | PmBr3 | SmBr2,
SmBr3 | EuBr2,
EuBr3 | GdBr3 | TbBr3 | DyBr3 | HoBr3 | ErBr3 | TmBr2,
TmBr3 | YbBr3
**  | AcBr3 | ThBr4 | PaBr5 | UBr4
UBr5 | NpBr4 | PuBr3 | AmBr2
AmBr3 | CmBr3 | BkBr3 | CfBr3 | EsBr3 | Fm  | Md  | No
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template