title: Bis(2,4,7-trimethylindenyl)cobalt(II) and rac-2,2',4,4',7,7'-hexamethyl-1,1'-biindene.
abstract: The crystal and molecular structures of bis(eta(5)-2,4,7-trimethylindenyl)cobalt(II), [Co(C(12)H(13))(2)], (I), and rac-2,2',4,4',7,7'-hexamethyl-1,1'-biindene, C(24)H(26), (II), are reported. In the crystal structure of (I), the Co atom lies on an inversion centre and the structure represents the first example of a bis(indenyl)cobalt complex exhibiting an eclipsed indenyl conformation. The (1R,1'R) and (1S,1'S) enantiomers of the three possible stereoisomers of (II), which form as by-products in the synthesis of (I), cocrystallize in the monoclinic space group P2(1)/c. In the unit cell of (II), alternating (1R,1'R) and (1S,1'S) enantiomers pack in non-bonded rows along the a axis, with the planes of the indenyl groups parallel to each other and separated by 3.62 and 3.69 A.
authors.affiliation: Department of Chemistry, Stellenbosch University, Private Bag X1, Matieland 7600, South Africa.
authors.forename: O
authors.initials: O
authors.lastname: Stenzel
authors.forename: M W
authors.initials: MW
authors.lastname: Esterhuysen
authors.forename: H G
authors.initials: HG
authors.lastname: Raubenheimer