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. [Ru(NH3)5(N2)]2+ adopts an octahedral structure with C4v symmetry.
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:5
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.6 The related metal ammine complex [Os(NH3)5(N2)]2+ is also known.
Reactions
The dinitrogen ligand is not reduced by aqueous sodium borohydride.7 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:8
[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+.910
References
Allen, A. D.; Senoff, C. V. (1965). "Nitrogenopentammineruthenium(II) Complexes". Chemical Communications (24): 621. doi:10.1039/C19650000621. /wiki/Doi_(identifier) ↩
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. /wiki/Bibcode_(identifier) ↩
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. /wiki/Doi_(identifier) ↩
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 /wiki/Doi_(identifier) ↩
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 /wiki/Doi_(identifier) ↩
Taube, H. "Chemistry of Ruthenium(II) and Osmium(II) Ammines" Pure and Applied Chemistry, 1979, volume 51, p. 901–12. doi:10.1351/pac197951040901 /wiki/Doi_(identifier) ↩
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 /wiki/Doi_(identifier) ↩
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 /wiki/Doi_(identifier) ↩
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. /wiki/Bibcode_(identifier) ↩
Chatt, J. (1970). "Molecular Nitrogen as a Ligand". Pure and Applied Chemistry. 24 (2): 425–442. doi:10.1351/pac197024020425. /wiki/Doi_(identifier) ↩