TY - JOUR
T1 - Redox-dependent isomerization of organometallic RuII/Ru III compounds containing the hydrotris(methimazolyl)borate ligand
T2 - An electrochemical square scheme mechanism
AU - Kuan, Seah Ling
AU - Leong, Weng Kee
AU - Goh, Lai Yoong
AU - Webster, Richard D.
PY - 2005/9/12
Y1 - 2005/9/12
N2 - [Cp*RuIII{HB(mt)3}]X (1A(X); X = Cl, PF 6) and [Cp*RuII{HB(mt)3}] (2A) (Cp* = η5-C5-Me5, mt = N-methyl-2- mercaptoimidazol-1-yl) were synthesized by the reactions of K[HB(mt) 3] with [Cp*RuIIICl2]2 and [Cp*RuII(OMe)]2, respectively. 1A and 2A exist in the solid state in k3-S,S′,S″ coordination, so that the sulfur atom in each mt group coordinates to the central Ru ion, producing the normal tripodal geometry of the [HB(mt)3] ligand. However, both compounds undergo an isomerization reaction in solution, where the sulfur on one mt group is displaced in favor of coordination to the hydrogen bonded to the boron (an agostic B-H-Ru interaction), resulting in k3-H,S,S′ coordination about the Ru (K3-H,S,S′ forms of [Cp*Ru III{HB(mt)3}] and [Cp*RuII{HB(mt) 3}] are designated 1B and 2B, respectively). The rate and equilibrium constants associated with the reactions 1A ⇄ 2A ⇄ 2B ⇄ 1B ⇄ 1A have been determined by theoretical digital simulation comparisons of experimental 1H NMR spectroscopic and cyclic voltammetric data over a range of temperatures.
AB - [Cp*RuIII{HB(mt)3}]X (1A(X); X = Cl, PF 6) and [Cp*RuII{HB(mt)3}] (2A) (Cp* = η5-C5-Me5, mt = N-methyl-2- mercaptoimidazol-1-yl) were synthesized by the reactions of K[HB(mt) 3] with [Cp*RuIIICl2]2 and [Cp*RuII(OMe)]2, respectively. 1A and 2A exist in the solid state in k3-S,S′,S″ coordination, so that the sulfur atom in each mt group coordinates to the central Ru ion, producing the normal tripodal geometry of the [HB(mt)3] ligand. However, both compounds undergo an isomerization reaction in solution, where the sulfur on one mt group is displaced in favor of coordination to the hydrogen bonded to the boron (an agostic B-H-Ru interaction), resulting in k3-H,S,S′ coordination about the Ru (K3-H,S,S′ forms of [Cp*Ru III{HB(mt)3}] and [Cp*RuII{HB(mt) 3}] are designated 1B and 2B, respectively). The rate and equilibrium constants associated with the reactions 1A ⇄ 2A ⇄ 2B ⇄ 1B ⇄ 1A have been determined by theoretical digital simulation comparisons of experimental 1H NMR spectroscopic and cyclic voltammetric data over a range of temperatures.
UR - http://www.scopus.com/inward/record.url?scp=25444439864&partnerID=8YFLogxK
U2 - 10.1021/om050432o
DO - 10.1021/om050432o
M3 - Article
SN - 0276-7333
VL - 24
SP - 4639
EP - 4648
JO - Organometallics
JF - Organometallics
IS - 19
ER -