Preparation of hydride complexes of ruthenium with bidentate phosphite ligands

Abstract

Hydride complex RuH 2(PFFP) 2 ( 1) [PFFP = (CF 3CH 2O) 2PN(CH 3)N(CH 3)P(OCH 2CF 3) 2] was prepared by allowing the compound RuCl 4(bpy) · H 2O (bpy = 1,2-bipyridine) to react first with the phosphite PFFP and then with NaBH 4. Chloro-complex RuCl 2(PFFP) 2 ( 2) was also prepared, either by reacting RuCl 4(bpy) · H 2O with PFFP and zinc dust or by substituting triphenylphosphine with PFFP in the precursor complex RuCl 2(PPh 3) 3. Hydride derivative RuH 2(POOP) 2 ( 3) (POOP = Ph 2POCH 2CH 2OPPh 2) was prepared by reacting compound RuCl 3(AsPh 3) 2(CH 3OH) first with the phosphite POOP and then with NaBH 4. Depending on experimental conditions, treatment of carbonylated solutions of RuCl 3 · 3H 2O with POOP yields either the cis- or trans-RuCl 2(CO)(PHPh 2)(POOP) ( 4) derivative. Reaction of both cis- and trans- 4 with LiAlH 4 in thf affords dihydride complex RuH 2(CO)(PHPh 2)(POOP) ( 5). Chloro-complex all- trans-RuCl 2(CO) 2(PPh 2OMe) 2 ( 6) was obtained by reacting carbonylated solutions of RuCl 3 · 3H 2O in methanol with POOP. Treatment of chloro-complex 6 with NaBH 4 in ethanol yielded hydride derivative all- trans-RuH 2(CO) 2(PPh 2OMe) 2 ( 7). The complexes were characterised spectroscopically and the X-ray crystal structures of complexes 1, 3, cis- 4 and 6 were determined.