Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Diphosphenes
Diphosphene is a type of organophosphorus compound that has a phosphorus–phosphorus double bond, denoted by R-P=P-R'. These compounds are not common, but their properties have theoretical importance.
Normally, compounds with the empirical formula RP exist as rings. However, like other multiple bonds between heavy main-group elements, P=P double bonds can be stabilized by large steric hindrance. In general, diphosphenes react like alkenes.
In 1877, Köhler and Michaelis claimed what would have been the first isolated diphosphene (PhP=PPh), The structure of Köhler and Michaelis' product was later revised. and X-ray crystallographic analysis proved that this "diphosphene" only had P-P single bonds and was in fact primarily a four-membered ring of the form (PPh)4. The isolation of phosphorus ylide and phosphaalkenes suggested that compounds with P=P bonds could be made.
Yoshifuji et al's isolated a sterically-hindered diphosphene in 1981. That compound's P-P bond distance is 2.034 Å, which is much shorter than the average bond length in (C6H5P)5 (2.217 Å) and (C6H5P)6 (2.237 Å) and indicates double-bond character.
Following Maasaka Yoshifuji and his coworkers' 1981 preparation of bis(2,4,6-tri-tert-butylphenyl)diphosphene, most disphosphene syntheses involve dehalogenation of bulkyl aryldichlorophosphine (ArPCl2). Mg is a typical dehalogenation reagent:
Such a synthesis works also for trisalkylsilylphosphines, or N-heterocyclic boro-phosphines.
Examples of di-vinyl-substituted diphosphenes arise via a ring opening/dimerization process from kinetically unstable 2H-phosphirenes. However, the conjugation caused the compounds to exhibit reactivity closer to a phosphinidene.
Cyclic voltammetry and UV/Vis spectra indicate that boryl-substituted diphosphenes have lower LUMO level and larger HOMO–LUMO gap than aryl-substituted diphosphenes.
Hub AI
Diphosphenes AI simulator
(@Diphosphenes_simulator)
Diphosphenes
Diphosphene is a type of organophosphorus compound that has a phosphorus–phosphorus double bond, denoted by R-P=P-R'. These compounds are not common, but their properties have theoretical importance.
Normally, compounds with the empirical formula RP exist as rings. However, like other multiple bonds between heavy main-group elements, P=P double bonds can be stabilized by large steric hindrance. In general, diphosphenes react like alkenes.
In 1877, Köhler and Michaelis claimed what would have been the first isolated diphosphene (PhP=PPh), The structure of Köhler and Michaelis' product was later revised. and X-ray crystallographic analysis proved that this "diphosphene" only had P-P single bonds and was in fact primarily a four-membered ring of the form (PPh)4. The isolation of phosphorus ylide and phosphaalkenes suggested that compounds with P=P bonds could be made.
Yoshifuji et al's isolated a sterically-hindered diphosphene in 1981. That compound's P-P bond distance is 2.034 Å, which is much shorter than the average bond length in (C6H5P)5 (2.217 Å) and (C6H5P)6 (2.237 Å) and indicates double-bond character.
Following Maasaka Yoshifuji and his coworkers' 1981 preparation of bis(2,4,6-tri-tert-butylphenyl)diphosphene, most disphosphene syntheses involve dehalogenation of bulkyl aryldichlorophosphine (ArPCl2). Mg is a typical dehalogenation reagent:
Such a synthesis works also for trisalkylsilylphosphines, or N-heterocyclic boro-phosphines.
Examples of di-vinyl-substituted diphosphenes arise via a ring opening/dimerization process from kinetically unstable 2H-phosphirenes. However, the conjugation caused the compounds to exhibit reactivity closer to a phosphinidene.
Cyclic voltammetry and UV/Vis spectra indicate that boryl-substituted diphosphenes have lower LUMO level and larger HOMO–LUMO gap than aryl-substituted diphosphenes.