Chiral tetraphenylcyclopentadienyl complexes of ruthenium and palladium; crystal structure of [Ru(η5-C5Ph4R1*)(CO)2Br](R1*= menthyl)

Abstract

The compound (–)-bromomenthyltetraphenylcyclopentadiene has been synthesised. It reacts with [Ru₃(CO)₁₂] to give [Ru(η⁵-C₅Ph₄R¹*)(CO)₃]Br (R¹*= menthyl) which on heating yields [Ru(η⁵-C₅Ph₄R¹*)(CO)₂Br]1. Alternatively complex 1 may be prepared by treating bromoform with [Ru(η⁵-C₅Ph₄R¹*)(CO)₂H], generated from [Ru₃(CO)₁₂] and C₅Ph₄R¹*H. A crystal structure of complex 1 shows that the crystals are monoclinic, space group P2₁(C₂², no. 4), Z= 4, with a= 13.783(4), b= 17.799(5), c= 14.974(3)Å, β= 107.05(2)°, U= 3512.0 Å^3., the structure has been refined to R 0.0777 for 3931 unique reflections in the range 3.5 < 2θ < 45°(Mo-K_α radiation). The corresponding complex [Pd(η⁵-C₅Ph₄R²*)(η³-C₃H₅)](R²*= neomenthyl)2 has been synthesised by the reaction of Li[C₅Ph₄R²*] with [{Pd(η³-C₃H₅)Cl}₂].