Pentaamine(dinitrogen)­ruthenium(II) chloride
Names
IUPAC name
pentaamminedinitrogenruthenium (II) chloride
Identifiers
3D model (JSmol)
  • InChI=1S/2ClH.N2.5H3N.Ru/c;;1-2;;;;;;/h2*1H;;5*1H3;/q;;;;;;;;+2/p-2
    Key: VLZPOOHIDLPMKN-UHFFFAOYSA-L
  • [Cl-].N#[N+][Ru-4]([NH3+])([NH3+])([NH3+])([NH3+])[NH3+].[Cl-]
Properties
H15N7Cl2Ru
Molar mass 285.14 g/mol
Appearance colorless solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pentaamine(nitrogen)ruthenium(II) chloride is an inorganic compound with the formula [Ru(NH3)5(N2)]Cl2. It is a nearly white solid, but its solutions are yellow. The cationic complex is of historic significance as the first compound with N2 bound to a metal center.[1][2] [Ru(NH3)5(N2)]2+ adopts an octahedral structure with C4v symmetry.[3]

Preparation and properties

Pentaamine(nitrogen)ruthenium(II) chloride is synthesized in an aqueous solution from pentaamminechlororuthenium(III) chloride, sodium azide, and methanesulfonic acid:[4]

[Ru(NH3)5Cl]Cl2 + NaN3 → [Ru(NH3)5N2]Cl2 + ...

If it is to be used in situ, the cation can be made more conveniently from ruthenium(III) chloride and hydrazine hydrate:[4]

RuCl3 + 4 N2H4 → [Ru(NH3)5N2]2+ + ...

This N2 complex is stable in aqueous solution and has a relatively low ligand exchange rate with water. Being a d6 complex, the Ru-N bond is stabilized by the pi backbonding, the donation of metal d-electrons into the N2 π* orbitals.[5] The related metal ammine complex [Os(NH3)5(N2)]2+ is also known.

Reactions

The dinitrogen ligand is not reduced by aqueous sodium borohydride.[6] Nearly all known reactions of this compound are displacement reactions. Pentaamine(halogen)ruthenium(II) halides can be synthesized by treating [Ru(NH3)5N2]2+ with halide sources:[4]

[Ru(NH3)5N2]2+ + X → [Ru(NH3)5X]+ + N2

[Ru(NH3)5N2]2+ forms the symmetrically bridging symmetrical dinitrogen complex [(NH3)5Ru-NN-Ru(NH3)5]4+.[7][8]

References

  1. ^ Allen, A. D.; Senoff, C. V. (1965). "Nitrogenopentammineruthenium(II) Complexes". Chemical Communications (24): 621. doi:10.1039/C19650000621.
  2. ^ Senoff, Caesar V. (1990). "The Discovery of [Ru(NH3)5N2]2+: A Case of Serendipity and the Scientific Method". Journal of Chemical Education. 67 (5): 368. Bibcode:1990JChEd..67..368S. doi:10.1021/ed067p368.
  3. ^ Fergusson, J. E.; Love, J. L.; Robinson, Ward T. (1972). "Crystal and Molecular Structure of Dinitrogenpentaammineosmium(II) chloride, [Os(NH3)5N2]Cl2, and Related Ruthenium Complexes". Inorganic Chemistry. 11 (7): 1662–1666. doi:10.1021/ic50113a042.
  4. ^ a b c Allen, A. D., Bottomley, F., Harris, R. O., Reinsalu, V. P., Senoff, C. V. "Pentaammine(Nitrogen)Ruthenium(II) Salts and Other Ammines of Ruthenium" Inorganic Syntheses, 2007, volume 12, pp. 2-8. doi:10.1002/9780470132432.ch1
  5. ^ Taube, H. "Chemistry of Ruthenium(II) and Osmium(II) Ammines" Pure and Applied Chemistry, 1979, volume 51, p. 901–12. doi:10.1351/pac197951040901
  6. ^ J. Chatt, R. L. Richards, J. F. Fergusson and J. L. Love, "The reduction of nitrogen complexes" Chem. Commun. 1968, 1522. doi:10.1039/C19680001522
  7. ^ Harrison, D. F.; Weissberger, E.; Taube, H. (1968). "Binuclear Ion Containing Nitrogen as a Bridging Group". Science. 159 (3812): 320–322. Bibcode:1968Sci...159..320H. doi:10.1126/science.159.3812.320. PMID 5634502. S2CID 39569679.
  8. ^ Chatt, J. (1970). "Molecular Nitrogen as a Ligand". Pure and Applied Chemistry. 24 (2): 425–442. doi:10.1351/pac197024020425.