Valence isomerization of a 1,3-diphosphacyclobutane-2,4-diyl: Photochemical ring closure to 2,4-diphosphabicyclo[1.1.0]butane and its thermal ring opening to gauche-1,4-diphosphabutadiene
E. Niecke et al., Valence isomerization of a 1,3-diphosphacyclobutane-2,4-diyl: Photochemical ring closure to 2,4-diphosphabicyclo[1.1.0]butane and its thermal ring opening to gauche-1,4-diphosphabutadiene, ANGEW CHEM, 38(20), 1999, pp. 3028-3031