Synthesis, molecular and crystal structure of tetraruthenium butterfly arene clusters

Abstract

A series of Ru₄ butterfly cluster complexes have been synthesized and investigated by spectroscopic and diffraction methods. The solid-state structure of [Ru₄(CO)₁₂(µ₄-η² : η²-C₆H₈)]1 and of the two isomers of [Ru₄(CO)₉(µ₄-η² : η²-C₆H₈)(η⁶-C₆H₆)] with the benzene ring located on the butterfly hinge (2) or on the wingtip (3), have been characterized. The three complexes are monoclinic, 1: space group P2₁/c, a= 9.779(8), b= 22.163(14), c= 10.069(6)Å, β= 90.23(9)°, Z= 4; 2: space group Cc, a= 10.010(3), b= 15.532(4), c= 15.384(4)Å, β= 93.50(2)°, Z= 4; 3: space group P2₁/c, a= 16.655(3), b= 15.709(3), c= 17.831(4)Å, β= 91.44(3)°, Z= 8. The molecular structures of the complexes have been investigated in relation with the respective crystal structure and, in the case of 2, compared with the polymorphic modification described previously.