Abstract: | A new ruthenium(II) complex [Ru(NO2)4(CO)(H2O)]Cl2 · 2H2O has been prepared and characterized structurally. The compound crystallizes in monoclinic space group C2 /m, with the unit cell parameters a = 12.913(2), b = 14.605(2), c = 7.4494(1)Å, ß =121.49(2)°; V = 1198.0(3)Å3, Z = 4, Dc = 2.429 Mgm—3; μ = 1.83 mm—1; R = 0.0455, wR = 0.1552. The complex contains four neutral NO2 ligands. The ruthenium atom is six‐coordinated to four nitrogen atoms of nitrogen dioxide, one carbon atom from carbon monoxide and one oxygen atom from water molecule, forming slightly distorted octahedral coordination. The preparation procedure has been discussed. |