Dinuclear ruthenium(II) carbonyl complexes bridged by a C(O)CH2C5H3NCH2 group: synthesis, characterization and crystal structures

Abstract

The reaction of [Ru₃(CO)₁₂] with 2,6-bis(chloromethyl)pyridine (ClCH₂C₅H₃NCH₂Cl) gave the scarcely soluble complex 1, [Ru₂Cl₂{C(O)CH₂C₅H₃NCH₂}(CO)₄]. Further reactions of 1 with MeOH and PPh₃ under appropriate conditions afforded organic-soluble complexes [Ru₂(µ-Cl){µ-C(O)CH₂C₅H₃NCH₂-C,N,C′}Cl(CO)₄(MeOH)₂] 2 and [Ru₂(µ-Cl){µ-C(O)CH₂C₅H₃NCH₂-C,N,C′}Cl(CO)_n(PPh₃)_m] (n = 4, m = 1 3; n = 3, m = 2 4), respectively. Complexes 2–4 were characterized by ¹H, ¹³C and ³¹P (for 3 and 4) NMR spectroscopy and by single-crystal structure determinations. These complexes are dinuclear and two Ru atoms are doubly connected by a chlorine atom and a C(O)CH₂C₅H₃NCH₂ group. Each of the metal atoms in 2 has a distorted octahedral co-ordination, while in 3 and 4 one metal atom adopts a distorted octahedral geometry and the other pseudo-octahedral; the latter geometry is completed by a Ru· · ·Cl secondary bonding interaction [2.855(2) in 3; 2.941(2) Å in 4].