Regioisomerism displayed by the 6-chloro-2-oxopyrodinate complexes of Ru2(4+) and Ru2(5+)

Article abstract of DOI:10.1016/0020-1693(95)04609-D

Three new compounds containing either the Ru2(4+) or the Ru2(5+) core surrounded by four chp(1-) ligands (where chp(1-) represents the anion of2-hydroxy-6-chloropyridine) have been prepared and structurally characterized. 2,2-trans-[Ru2(chp)4] (1) was obtained by reaction of Ru2(O2CCH3)4Cl with molten Hchp (via the unisolated intermediate 0,4-[Ru2(chp)4Cl]). It crystallizes in space group Pbca (No. 61) with a=16.073(5), b=18.603(5), c=15.594(2)?, V=4663(2)?**3, Z=8. The Ru-Ru distance is 2.248(1)? 0,4-[Ru-2(chp)4(THF)]*THF (2) was obtained by reduction of 0,4-[Ru2(chp)4Cl] with zinc. It forms monoclinic crystals in space groupP21/c (No. 14) with a=13.616(2), b=12.820(3), c=18.673(2)?, β=97.39(4)°, V=3233(1)?**3, Z=4. The Ru-Ru distance is 2.261(1)? The compound {0,4-[Ru2(chp)4]}2(BF4)2 (3) was obtained from 0,4-[Ru2(chp)4Cl] by removal of Cl(1-) with Ag(CH3CN)4BF4. It crystallizes in space group P1- (No. 2) with a=12.995(3), b=13.459(3), c=10.640(3)?,α=106.54(2), β=93.48(2), γ=65.78(2)°, V=1623.5(7)?**3, Z=1. The Ru-Ru distance is 2.254(1)?