Appearance brown solid | ||
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Pentamethylcyclopentadienyl ruthenium dichloride is an organoruthenium chemistry with the formula [(C5(CH3)5)RuCl2]2, commonly abbreviated [Cp*RuCl2]2. This brown paramagnetic solid is a reagent in organometallic chemistry. It is an unusual example of a compound that exists as isomers that differ in the intermetallic separation, a difference that is manifested in a number of physical properties.
Preparation, structure, reactions
The compound has C2h symmetry. Each metal is pseudo-octahedral. Two isomers are observed in the unit cell, one with an Ru-Ru bond (2.93 Å) and one with a long internuclear distance of 3.75Å. The former isomer is thought to be diamagnetic, and the latter is magnetic.
It is prepared by the reaction of hydrated ruthenium trichloride with pentamethylcyclopentadiene.
2 Cp*H + 2 RuCl3(H2O)3 → [Cp*RuCl2]2 + 2 HCl + 6 H2OThe reaction is accompanied by formation of decamethylruthenocene.
Pentamethylcyclopentadienyl ruthenium dichloride can reduced to the diamagnetic tetramer of Ru(II):
2 [Cp*RuCl2]2 + 2 Zn → [Cp*RuCl]4 + 2 ZnCl2Methoxide also can be used to produce a related diruthenium(II) derivative, which is also diamagnetic:
[Cp*RuCl2]2 + 3 NaOCH3 + HOCH3 → [Cp*RuOCH3]2] + 3 NaCl + CH2O + HCl