The X-ray Structures of [Fe(CO)3(η4-6-exo-(PAr3)cyclohepta-2,4-dien-1-one][BF4] (Ar = m-C6H4CH3 or p-C6H4F)

Abstract The structures of [Fe(CO) 3 (η 4 -6- exo -(tri- m -tolylphosphine)cyclohepta-2,4-dien-1-one][BF 4 ] [tetragonal, a = 35.6005(7), b = 35.6005(7), c = 10.5456(3), space group I4 1 /a] and [Fe(CO) 3 (η 4 -6- exo -(tri- p -fluorophenylphosphine)cyclohepta-2,4-dien-1-one][BF 4 ] [triclinic, a = 9.8852(3), b = 10.0996(4), c = 16.0526(4), α = 99.813(3), β = 94.164(2), g = 102.911(3) space group P-1] have been determined. Both structures contain a disordered CH 2 Cl 2 molecule. The tetrafluoroborate ion in [Fe(CO) 3 (η 4 -6- exo -(tri- m -tolylphosphine)cyclohepta-2,4-dien-1-one][BF 4 ] is also disordered. There are no close contacts indicative of hydrogen bonding within either structure, but there is π - π stacking observed for [Fe(CO) 3 (η 4 -6- exo -(tri- m -tolylphosphine)cyclohepta-2,4-dien-1-one][BF 4 ]. Graphical Abstract