Study Of Three-electron σ-bond Radicals Containing Sulfur Group Element

This thesis summarizes the development and research status,potential application value and future research prospects of three-electronσ-bond radicals.In this thesis,we designed,synthesized and characterized a series of new homonuclear and heteronuclear three-electronσ-bond radical cations and diradical dications.Combining with experiments and theoretical calculations,this thesis provides three-electronσ-bond complexes in the field of basic chemistry new research directions and ideas.The main work of this paper is summarized as follows:I.Based on the naphthalene ring as the bridging skeleton,compounds 1-4 with groups15 and 16 elements as the central oxidizing atom were designed and synthesized.By using the oxidants:NOSb F₆ and NO[Al（OR_F）₄]（OR_F=OC（CF₃）₃）,compounds 1-4were oxidized to obtain the complexes 1^+··[Al（OR_F）₄]^--4^+··[Al（OR_F）₄]^-,and were subjected to Electron Paramagnetic Resonance（EPR）spectroscopy.By fitting the spectrum and DFT theoretical calculation,the existence of heteronuclear three-electronσ-bond is proved.Among them,2^+··[Al（OR_F）₄]^-has the maximum hyperfine coupling constant a(³¹P)among persistent and stable arylphosphorus radicals,and4^+··[Al（OR_F）₄]^-has the maximum hyperfine coupling constant a(⁷⁵As)in persistent and stable arsenic radicals.Ⅱ.Based on the naphthalene ring as the bridge skeleton,the neutral compounds 5-7with 16 group elements as the central atom were designed and synthesized.They were respectively oxidized twice by NO[Al（OR_F）₄].The dication 5²⁺·2[Al（OR_F）₄]^-、6^2+···2[Al（OR_F）₄]^-and 7²⁺·2[Al（OR_F）₄]^-were synthesized and separated.By using low-temperature crystallization technology,the crystal structures were obtained.For further discussion,through Ultraviolet-visible absorption（UV-vis）spectroscopy test,Superconducting Quantum Interferometer（SQUID）magnetic measurement system test and EPR test.Combined with DFT theoretical calculations,it is proved that the ground state of 5²⁺·2[Al（OR_F）₄]^-and 7²⁺·2[Al（OR_F）₄]^-is a closed-shell singlet state,6^2+···2[Al（OR_F）₄]^-’s ground state is the open shell singlet state.6^2+···2[Al（OR_F）₄]^-also became the first three-electron sigma bond double radical compound.