Reactions of [Ru(bpy)(CO)2Cl2] in Acidic Media: Formation and Structural Characterization of [Ru(bpy)Cl3NO], [Ru2N(bpy)2Cl5(H2O)], and (H5O2)[Ru2N(bpy)2Cl6]

Article abstract of DOI:10.1021/ic00115a021

Reactions of [Ru(bpy)(CO)2Cl2] in concentrated HCl/HNO3 solutions at high temperatures were studied. In acidic solutions carbonyl groups are lost and replaced by chlorine and nitrosyl, nitrido or water ligands. Formation of [Ru(bpy)Cl3(NO)] and (Ru2N(bpy)2Cl5(H2O)] was time-dependent; with shorter reaction times ( <6 h, 240°C) solid crystalline fac(Cl)-[Ru(bpy)Cl3(NO)] (1a) and mer(Cl)-[Ru(bpy)Cl3(NO)] (1b) were formed, and with longer reaction times a new crystalline nitrido-bridged complex[Ru2N(bpy)2Cl5(H2O)] (2) was produced, most probably via a nitrosyl intermediate. Both 1 and 2 are practically insoluble and highly stable. However, the reaction of [Ru(bpy)(CO)2Cl2] in HCl/HNO3 solution with small amounts of [Ru(bpy)Cl3(NO)] added gave in low yield another nitrido-bridged product, (H5O2)[Ru2N(bpy)2Cl6] (3). The role of added [Ru(bpy)Cl3(NO)] in this reaction is unclear, and it is possible that (3) may also form directly from pure [Ru(bpy)(CO)2Cl2]. Crystal structures of fac(Cl)-[Ru(bpy)Cl3(NO)], mer(Cl)-[Ru(bpy)Cl3(NO)], [Ru2N(bpy)2Cl5(H2O)], and (H5O2)[Ru2N(bpy)2Cl6] showed that the ruthenium atoms are octahedrally coordinated in all complexes. Crystal data: 1a, monoclinic, space group P21/c, a = 6.798(3) ?, b = 11.993(4) ?, c = 16.760(8) ?, β =98.89(3)°, Z = 4; 1b, monoclinic. space group Pn, a = 8.175(2) ?, b = 6.733(2) ?, c = 12.594(5) ?, β = 105.06(3)°, Z = 2; 2, monoclinic, space group P21/n, a = 10.133(5) ?, b = 15.042(6) ?, c = 16.506(8) ?, β = 104.86(4)°, Z = 4; 3,triclinic. space group P1-, a = 10.281(3) ?, b = 10.776(3) ?, c= 12.527(5) ?, α = 90.78(3)°, β = 98.31(3)°, γ = 100.91(2)°, Z = 2.