Analogous to CN,BO[1] has recently emerged as an interesting new concept(boronyl)in cluster science.[2] Herein we predict three new boron boronyl clusters,the perfectly planar B6O4-(D2h,2B3u),B6O4 2-(D2h,1Ag)and B6O4(C2v,1A1),which are established as the global-minimum at DFT and CCSD(T)levels.D2h B6O4 2-/-possess an ethylene-like structure which can be formulated as B2(BO)4 2-/-featuring a B=B double bond as the core with four boronyl groups attached terminally,closely resembling ethylene in structure and chemical bonding and obtainable from the latter via isovalent BO/H substitution.[3] Detailed canonical molecular orbital(CMO)analyses also reveal that both C2H4 and B6O4 2-/-possess one 2c-2e σ-bond and one localized 2c-2e π-bond which are analogous in nature(Fig.1).Neutral B6O4 features a hexgonal B4O2 ring with two terminal BO(η1-BO)and possesses three delocalized 6c-2e π-bonds covering the hexagonal ring,which can be viewed as a boron anlogy of benzene(Fig.2).Furthermore,we simulated the photoelectron spectroscopy of the B6O4-to facilitate its future experimental characterization.Our investigation provides new examples for the BO/H isolobal analogy,electron transmutation from B to C(in B2(BO)4 2-/-),and enriches the chemistry of boron.