Reactions of tetra-µ-carboxylato-diruthenium(II,II) compounds. X-Ray crystal structures of Ru2(µ-O2CCF3)4(thf)2, Ru2(µ-O2CR)4(NO)2(R = Et or CF3), and {Na3[Ru2(µ-O2CO)4]·6H2O}n

Abstract

Improved procedures for the synthesis of the diruthenium(II) carboxylates, Ru₂(µ-O₂CR)₄L₂, and substitutions of either the bridged carboxylate or axial ligands (L) are described. Among new bridged compounds are the trifluoroacetate, Ru₂(µ-O₂CCF₃)₄, the carbonate, {Na₃[Ru₂(µ-O₂CO)₄]·6H₂O}_n, and the triazenide, Ru₂(µ-N₃Ph₂)₄; adducts of the triazenide include the nitrosyl, Ru₂(µ-N₃Ph₂)₄(NO)₂, the isocyanide, Ru₂(µ-N₃Ph₂)₄(Bu^tNC), and the carbonyl Ru₂(µ-N₃Ph₂)₄(CO)₂. Reactions of the carboxylates with donors such as isocyanides, pyridine (py), phosphines, or CO leads in some cases to bridge cleavage and products such as trans-Ru(O₂CR)₂(py)₄ or Ru(O₂CR)₂(PPh₃)₂(R = Me or CF₃), while the reactions with NO yield the diamagnetic adducts Ru₂(µ-O₂CR)₄(NO)₂. Infrared, n.m.r., e.s.r., and electronic spectra are recorded together with cyclic voltammetric studies. The X-ray crystal structures of the dimers Ru₂(µ-O₂CCF₃)₄(thf)₂(thf = tetrahydrofuran) and Ru₂(µ-O₂CR)₄(NO)₂(R = Et or CF₃), and the polymer {Na₃[Ru₂(µ-O₂CO)₄]·6H₂O}_n are reported.