(4'-Ethynyl-2,2':6',2''-terpyridine)(2,2':6',2''-terpyridine)­ruthenium(II) bis­(hexa­fluoridophosphate) acetonitrile disolvate

The title heteroleptic bis­-terpyridine complex, [Ru(C₁₅H₁₁N₃)(C₁₇H₁₁N₃)](PF₆)₂·2CH₃CN, crystallized from an acetonitrile solution as a salt containing two hexa­fluoridophosphate counter-ions and two acetonitrile solvent mol­ecules. The Ru^II atom has a distorted octa­hedral geometry due to the restricted bite angle [157.7 (3)°] of the two mer-arranged N,N',N''-tridendate ligands, viz. 2,2':6',2''-terpyridine (tpy) and 4'-ethynyl-2,2':6',2''-terpyridine (tpy'), which are essentially perpendicular to each other, with a dihedral angle of 87.75 (12)° between their terpyridyl planes. The rod-like acetyl­ene group lies in the same plane as its adjacent terpyridyl moiety, with a maximum deviation of only 0.071 (11) Å from coplanarity with the pyridine rings. The mean Ru-N bond length involving the outer N atoms trans to each other is 2.069 (6) Å at tpy and 2.070 (6) Å at tpy'. The Ru-N bond length involving the central N atom is 1.964 (6) Å at tpy and 1.967 (6) Å at tpy'. Two of the three counter anions were refined as half-occupied.

(2,2′-Bi­pyridine)­chlorido­[diethyl (2,2′:6′,2′′-terpyridin-4-yl)phospho­nate]ruthenium(II) hexa­fluorido­phosphate aceto­nitrile/water solvate

The cationic complex in the title compound, [RuCl(C₁₀H₈N₂)(C₁₉H₂₀N₃O₃P)]PF₆·0.83CH₃CN·0.17H₂O, is a water-oxidation precatalyst functionalized for TiO₂ attachment via terpyridine phospho­nate. The The Ru^II atom in the complex has a distorted octa­hedral geometry due to the restricted bite angle [159.50 (18)°] of the terpyridyl ligand. The dihedral angle between the least-squares planes of the terpyridyl and bipyridyl moieties is 86.04 (14)°. The mean Ru—N bond length for bi­pyridine is 2.064 (5) Å, with the bond opposite to Ru—Cl being 0.068 Å shorter. For the substituted terpyridine, the mean Ru—N distance involving the outer N atoms trans to each other is 2.057 (6) Å, whereas the bond length involving the central N atom is 1.944 (5) Å. The Ru—Cl distance is 2.4073 (15) Å. The P atom of the phospho­nate group lies in the same plane as its adjacent pyridyl ring, with the ordinary character of the bond between P and C_tpy [1.801 (6) Å] allowing for free rotation of the terpyridine substituent around the P—C_tpy axis. The aceto­nitrile solvent mol­ecule was refined to be disordered with two water mol­ecules; occupancies for the acetontrile and water mol­ecules were 0.831 (9) and 0.169 (9), respectively. Also disordered was the PF₆⁻ counter-ion (over three positions) and one of the eth­oxy substituents (with two positions). The crystal structure shows significant intra- and inter­molecular H...X contacts, especially some involving the Cl⁻ ligand.