“…All the chemicals were purchased from Sigma–Aldrich, Alfa Aesar, SD Fine and Spectrochem. 6,6′‐dihydroxy‐2,2′‐bipyridine, 6,6′‐dimethoxy‐2,2′‐bipyridine, [RuHCl(CO)(PPh 3 ) 3 ], [RuCl 2 (PPh 3 ) 3 ], [(2,2′‐bipyridine)Ru(H)(CO)(PPh 3 ) 2 ]Cl ( 1 a ) and [(2,2′‐bipyridine)RuCl 2 (PPh 3 ) 2 ] ( 2 a ) were synthesised according to previously reported literature procedures. 1 H, 13 C and 31 P NMR spectra were recorded on Jeol 400 and 500 MHz spectrometer.…”