Preparation of hydride complexes of ruthenium with bidentate phosphite ligands

Hydride complex RuH2(PFFP)2 (1) [PFFP = (CF3CH2O)2PN(CH3)N(CH3)P(OCH2CF3)2] was prepared by allowing the compound RuCl4(bpy) · H2O (bpy = 1,2-bipyridine) to react first with the phosphite PFFP and then with NaBH4. Chloro-complex RuCl2(PFFP)2 (2) was also prepared, either by reacting RuCl4(bpy) · H2O with PFFP and zinc dust or by substituting triphenylphosphine with PFFP in the precursor complex RuCl2(PPh3)3. Hydride derivative RuH2(POOP)2 (3) (POOP = Ph2POCH2CH2OPPh2) was prepared by reacting compound RuCl3(AsPh3)2(CH3OH) first with the phosphite POOP and then with NaBH4. Depending on experimental conditions, treatment of carbonylated solutions of RuCl3 · 3H2O with POOP yields either the cis- or trans-RuCl2(CO)(PHPh2)(POOP) (4) derivative. Reaction of both cis- and trans-4 with LiAlH4 in thf affords dihydride complex RuH2(CO)(PHPh2)(POOP) (5). Chloro-complex all-trans-RuCl2(CO)2(PPh2OMe)2 (6) was obtained by reacting carbonylated solutions of RuCl3 · 3H2O in methanol with POOP. Treatment of chloro-complex 6 with NaBH4 in ethanol yielded hydride derivative all-trans-RuH2(CO)2(PPh2OMe)2 (7). The complexes were characterised spectroscopically and the X-ray crystal structures of complexes 1, 3, cis-4 and 6 were determined.