Crystal structure and near-infrared emission of <i>trans</i> -dichlorido(dimethoxyphenylphosphine)[4,4′,4′′-tris(methoxycarbonyl)-2,2′:6′,2′′-terpyridine]ruthenium(II) monohydrate

In the title compound, [RuCl₂(C₂₁H₁₇N₃O₆)(C₈H₁₁O₂P)]·H₂O, the Ru^II atom is coordinated by three N atoms of a meridionally bound 4,4',4''-tris-(meth-oxy-carbon-yl)-2,2':6',2''-terpyridine ligand, a phosphinite P donor and two chloride ligands in a distorted octa-hedral geometry. The Ru-N distances lie in the range 1.996 (2)-2.078 (2) Å, with a Ru-P distance of 2.2879 (9) Å and Ru-Cl distances of 2.3713 (8) and 2.4191 (8) Å; the N-Ru-N bite angles are 78.59 (9) and 79.10 (9)°, with an N-Ru-N angle of 157.30 (9)° within the terpyridine chelate. The methyl ester groups adopt conformations that minimize steric inter-actions with the phosphinite phenyl ring and provide potential anchoring sites in the corresponding carb-oxy-lic acid dye. In the crystal, pairs of complex mol-ecules are linked into discrete hydrogen-bonded dimers by the water mol-ecule of crystallization: one H atom forms an O-H⋯O contact to a methyl carbonyl O atom [H⋯O = 2.17 Å] and the other H atom forms an O-H⋯Cl contact to a <i>trans</i> chloride ligand of a neighbouring complex [H⋯Cl = 2.40 Å].