title: Bond length and bond multiplicity: sigma-bond prevents short pi-bonds.
abstract: Analysis of model compounds such as Fe2(CO)6, C2 and HBBH shows that pi-bonds left to themselves are shorter than sigma-bonds; in many ways sigma-bonds prevent pi-bonds from adopting their optimal shorter distances.
authors.affiliation: School of Chemistry, University of Hyderabad, Hyderabad 500 046, India. jemmis@ipc.iisc.ernet.in
authors.forename: Eluvathingal D
authors.initials: ED
authors.lastname: Jemmis
authors.forename: Biswarup
authors.initials: B
authors.lastname: Pathak
authors.forename: R Bruce
authors.initials: RB
authors.lastname: King
authors.forename: Henry F
authors.initials: HF
authors.lastname: Schaefer