Alkene and alkyne reactivity toward a bisruthenium(II) μ2-dinitrogen complex containing the "pincer" ligand 2,6-bis[(dimethylamino)methyl]pyridine (NN′N). The X-ray crystal structures of [Ru(=C=CHPh)-Cl2(NN′N)] and [Ru(=C=CHPh)(OTf)(NN′N)(PPh3)][OTf] (OTf = trifluoromethane sulfonate)