The nature of the active species in photocatalytic metathesis reaction was investigated. The formation of Wittig-type addition products with benzaldehyde indicates that catalytically active carbene is the product of olefin and tungsten hexacarbonyl under reaction conditions.
BOZKURT, Çetin and İMAMOĞLU, Yavuz (1997) "Catalytically Active Intermediates in Photochemical Metathesis," Turkish Journal of Chemistry: Vol. 21: No. 3, Article 12. Available at: https://journals.tubitak.gov.tr/chem/vol21/iss3/12