:Pentaborane(11)

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|Section1={{Chembox Identifiers

| CASNo = 18433-84-6

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII = 79Z6OH65UV

| UNII_Ref = {{fdacite|correct|FDA}}

| PubChem =

| ChemSpiderID = 34987102

| EINECS = 242-307-4

| SMILES = [BH3]1[BH2]2[BH]13[BH2]2[BH3]3

| StdInChI = 1S/B5H11/c1-3-4-2-5(1,3)4/h5H,3-4H2,1-2H3

| StdInChIKey = OPSKXWPMAKCNOG-UHFFFAOYSA-N

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|Section2={{Chembox Properties

| B=5 | H=11

| Appearance =

| Density =

| MeltingPtC = -123

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| BoilingPtC = 63

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|Section3={{Chembox Hazards

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Pentaborane(11) is inorganic compound with the chemical formula B5H11. It is an obscure boron hydride cluster, especially relative to the heavily studied pentaborane(9) (B5H9). With two more hydrogen atoms than nido-pentaborane(9), pentaborane(11) is classified as an arachno- cluster.{{Greenwood&Earnshaw2nd}}

Synthesis

Like many boron hydride clusters, pentaborane(11) was originally obtained from the pyrolysis of diborane. A more systematic synthesis entails treatment of [B4H9] with boron tribromide. The Lewis acid abstracts hydride to give unstable B4H8, the precursor to B5H11:{{cite journal|title=New, Systematic Syntheses of Boron Hydrides via Hydride ion Abstraction Reactions: Preparation of B2H6, B4H10, B5H11, and B10H14|last1=Toft |first1=Mark A. |last2=Leach |first2=J. B. |last3=Himpsl |first3=Francis L. |last4=Shore |first4=Sheldon G. |journal=Inorganic Chemistry|year=1982|volume=21|issue=5|pages=1952–7|doi=10.1021/ic00135a048 }}

:[B4H9] + BBr3 → B4H8 + HBBr3

:2 B4H8 → B5H11 + "B3H5"

References

{{reflist}}

{{Boron compounds}}

{{Hydrides by group}}

Category:Boranes