Group 10 metal germylene complexes of general formula (R3P)(2)MGeQ(2) are f
ound to be highly photosensitive. Ambient fluoresent lighting causes comple
te decomposition of nickel germylene species in less than one minute in the
presence of germylene traps. The formation of metallacycle (Et3P)(2)Pt(mu-
eta(2)-H2CO)Ge[N-(SiMe3)(2)](2) and the photochemical cycloreversion reacti
on are also reported.