1,2-Diphosphetes with Unusual Structures – A Quantum Chemical Investigation of Bonding Properties⋆

On the Stabilisation of a Singlet Nitrene by the Phosphaniminato and Related Imine-Type Substituents, a Quantum Chemical Investigation

“…It is worth noting the peculiar role of the phosphaniminato ligand which has also recently been shown to stabilise the singlet of phosphanylcarbenes 38. Imine‐type functional groups are also predicted to lengthen the strained P−P bond in 1,2‐diphosphacyclobutene 39…”

Electronic Structure of the 2.4-Diphosphacyclobutane-diyl-1.3 and Substituted Derivatives

“…Other structures of the family of valence isomers are the diphosphacyclobutane and the diphosphabutadiene. They have been discussed earlier; , hence these will not be included in the present considerations. The phosphino-carbene has been postulated as an intermediate in the reaction of 1 to the bicyclobutane valence isomer .…”

Chemical Shift Tensors of Directly Bonded Phosphorus Nuclei in Unsaturated Four-Membered Rings. Solid-State 31P NMR and Theoretical Study of Trans- and Cis-Substituted Diphosphetes

“…We must also consider the effect of substituting hydrogen atoms for tert -butyl groups on the unsaturated ring carbons. Recent theoretical calculations on diphosphetes suggest that such substitutions do not have a significant effect on the molecular structure about the phosphorus atoms . Nevertheless, the necessary simplicity of our model makes a rigorous comparison of experimental and calculated results difficult.…”