AI Article Synopsis

  • The study details the synthesis and characterization of three 1,2-diphosphonium dications using a naphthalene backbone, highlighting the methods used to achieve good yields and purity of these dications.
  • The research includes a comparison of meso and rac forms obtained through specific alkylation techniques and emphasizes the diastereospecific nature of the reactions involving different methylating agents.
  • Additionally, the findings discuss the structural parameters and stabilization factors of the new dications, incorporating computational analyses to assess the energy implications of substituents on the naphthalene framework.

Article Abstract

Syntheses and full characterisation data (including single crystal diffraction) of three 1,2-diphosphonium dicationic species with the naphthalene-1,8-diyl (Nap) backbone are reported. The oxidation of Nap[P(NMe(2))(2)](2) with P(2)I(4) to its 1,2-dication was achieved. meso- and rac-forms of "all carbon" 1,2-diphosphonium dications were obtained in good yields and purity by double alkylation of the parent diphosphine (1,2-diphenyl-1,2-diphosphaacenaphthene) with methyl triflate or trimethyloxonium tetrafluoroborate. Each methylating reagent produces one of the rac- or meso-forms of the dication diastereospecifically. Structural parameters of the new dications are discussed with respect to other phosphorus 1,2-dications. DFT (B3LYP) computations revealed the significant role of the naphthalene backbone in stabilisation of the dicationic motif and helped to assess the energy cost of the steric clash of a variety of groups attached to the peri-positions of naphthalene. The synthesis and single crystal X-ray data of the extremely crowded Nap[P(Se)(OiPr)(2)](2) are discussed, and are contrasted with the unsuccessful synthesis of Nap(PtBu(2))(2) from NapLi(2) and ClPtBu(2).

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http://dx.doi.org/10.1002/chem.201002259DOI Listing

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