Photochemically mediated alkyne metalation in the donor–acceptor complexes Ru2(CO)6(μ-PP) [where PP=bpcd, (Z)-Ph2PCHCHPPh2]. X-ray diffraction structure of the zwitterionic compound Ru2(CO)6[μ-(Z)-MeO2CCCCO2Me](μ-bpcd) - Simon Bott (Inorganica Chimica Acta, 2000)