94089-99-3Relevant academic research and scientific papers
Syntheses, molecular structures, and properties of two polar diruthenium(II,III) complexes of 2-hydroxypyridine and 2-anilinopyridine
Chakravarty, Akhil R.,Cotton, F. Albert,Tocher, Derek A.
, p. 172 - 177 (2008/10/08)
The compounds Ru2Cl(hp)4(Hhp) (8) and Ru2Cl(PhNpy)4 (9) were prepared by reactions of Ru2Cl(CH3COO)4 with Hhp (2-hydroxypyridine) and PhNHpy (2-anilinopyridine) at 120 and 140°C, respectively. These air-stable compounds have been characterized by analytical and spectroscopic data, and their structures have been determined by X-ray crystallography. Compound 8 crystallizes in the space group C2/c with a = 32.619 (7) A?, b = 10.664 (2) A?, c = 15.099 (4) A?, β = 106.18 (2)°, V = 5044 (2) A?3, and Z = 8. Compound 9 belongs to the space group C2/c with a = 23.529 (9) A?, b = 9.599 (5) A?, c = 21.475 (11) A?, β = 126.26 (3)°, V = 3910 (4) A?3, and Z = 4. Each compound has a totally polar arrangement of the four bridging ligands (i.e., all four are oriented in the same direction) across the diruthenium centers. The metal oxidation states in both the complexes are formally +2 and +3, giving an average value of +2.5. The Ru-Ru distances in 8 and 9 are 2.286 (1) and 2.275 (3) A?, respectively. In 8, one ruthenium atom is coordinated by all four nitrogen atoms of the bridging ligands and one chlorine atom, while the other ruthenium atom is bonded to five oxygen atoms of five ligands. The axial ligands are a chlorine atom and an Hhp molecule. The Hhp hydrogen atom is bonded to the pyridine nitrogen and is used in hydrogen-bond formation to one of the bridging oxygen atoms. In 9, one ruthenium atom is bonded to all four pyridine nitrogen atoms (Npy) and an axial chlorine atom, while the other ruthenium atom has all four amine nitrogen atoms (Nam) in its coordination sphere with no axial ligand. The four Ph groups on the amine nitrogen atoms oriented toward the axial site block the axial position. In 8, the Ru-Cl and average Ru-N distances are 2.558 (2) and 2.117 A?, respectively. The average Ru-O distance in the bridging ligands is 1.992 A?. The axial Ru-O bond length is 2.299 (5) A?. In 9, the Ru-Cl, average Ru-Npy, and average Ru-Nam bond lengths are 2.437 (7), 2.104, and 2.026 A?, respectively. Electronic spectra of compounds 8 and 9 show bands at 480 nm (ε 4690 M-1 cm-1) and 368 nm in CH3CN for 8 and at 764 nm (6910) and 415 nm (5770) in CH2Cl2 for 9. Compound 8 has a magnetic moment of 4.61 μB in the solid state at 297 K, and 9 has a magnetic moment of 3.94 μB in CH2Cl2 at 308 K.
