Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteris...Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteristics and customizing optical properties.In this work,we achieved the precise synthesis of isostructural alloy clusters R/S-Ag_(3)Cu([Ag_(3)Cu(tppm)(R/S-IPTT)]ClO_(4),R/S-IPTT=R/S-4-isopropylthiazolidine-2-thiolate,tppm=tris(diphenylphosphino)methane)in high yield(89%-91%)through selective doping of a Cu(Ⅰ)atom into chiral homometallic cluster enantiomers R/S-Ag_(4)([Ag_(4)(tppm)(R/S-IPTT)]ClO_(4)).In stark contrast to R/S-Ag_(4)(Φ_(em)<0.5%)that displays weak circularly polarized luminescence(CPL)with phosphorescence characteristic,R/S-Ag_(3)Cu(Φ_(em)≈70%)demonstrates strong CPL properties featured with thermally activated delay fluorescence(TADF)at ambient temperature.The selective substitution of the apical Ag(Ⅰ)atom in Ag_(4)triangular pyramid with a Cu(Ⅰ)atom not only gives rise to beyond 100-fold boosting of photoluminescence quantum yield(PLQY),but also leads to more pronounced optically chiral activity of alloy clusters in excited states in view of the larger photoluminescence dissymmetry factors(g_(PL))of R/S-Ag_(3)Cu(-3.5×10^(-3)/3.4×10^(-3))than that of R/S-Ag_(4)(-2.7×10^(-3)/2.6×10^(-3)).Furthermore,compared with chiral homometallic clusters R/S-Cu_(4)([Cu_(4)(tppm)(R/S-IPTT)]ClO_(4))with the same TADF characteristic at ambient temperature,R/S-Ag_(3)Cu manifests 1.7-fold PLQY and 6-fold g_(PL)due to faster reverse intersystem crossing(RISC)and more effective coupling of electric and magnetic transition moments in alloy clusters.This work not only presents a typical example of selective heterometal doping to modulate excited-state properties of isostructural metal clusters,but also gets deeper insight into the doping chemistry of dissimilar metals at the molecular level.展开更多
In this work,a diphosphine chelator,2-Ph_(2)PC_(6)H_(4)PH_(2),containing both primary and tertiary phosphine donors,was used to create highly stable silver(I)nanoclusters through a dynamic ligand metathesis reaction.T...In this work,a diphosphine chelator,2-Ph_(2)PC_(6)H_(4)PH_(2),containing both primary and tertiary phosphine donors,was used to create highly stable silver(I)nanoclusters through a dynamic ligand metathesis reaction.Taking advantage of thiolate-silver coordination polymers as synthetic precursors,we developed a viable synthetic approach to access Ag34 nanoclusters through dual proton and ligand exchange successfully.Owing to the stronger coordination ability of the bifunctional 2-Ph_(2)PC_(6)H_(4)PH_(2)ligand,substitution results in the formation of thermodynamically stable Ag34 nanoclusters linked by fifteen 2-Ph_(2)PC_(6)H_(4)P^(2-)chelators.Notably,thiolates as structural templates rather than protective ligands play a crucial role in directing nanocluster construction.The Ag34 nanoclusters manifest highly efficient near-infrared photoluminescence peaked at ca.800 nm with over 24%of quantum yield in fluid CH_(2)Cl_(2)solution,arising mostly from ligand-to-metal charge transfer(^(3)LMCT)and cluster-centered(^(3)CC)triplet states.Solution-processable near-infrared organic light-emitting diodes(NIR-OLEDs)achieved high-efficiency nearinfrared electroluminescence with an external quantum efficiency(EQE)of 10.2%.The unique synthetic approach can be extended to other metal systems,thereby expanding both the structural diversity and application potential of metal nanoclusters.展开更多
基金supported by the National Natural Science Foundation of China(92061202,21531008,22175181)the Fujian Province Science and Technology Project Program(2022H0041)the Self-deployment Project Research Program of Haixi Institute,Chinese Academy of Sciences(CXZX-2022-GH11)。
文摘Precise heterometal doping or substitution of specific metal sites in isostructural metal clusters remains a formidable synthetic challenge,despite its transformative potential for modulating excited-state characteristics and customizing optical properties.In this work,we achieved the precise synthesis of isostructural alloy clusters R/S-Ag_(3)Cu([Ag_(3)Cu(tppm)(R/S-IPTT)]ClO_(4),R/S-IPTT=R/S-4-isopropylthiazolidine-2-thiolate,tppm=tris(diphenylphosphino)methane)in high yield(89%-91%)through selective doping of a Cu(Ⅰ)atom into chiral homometallic cluster enantiomers R/S-Ag_(4)([Ag_(4)(tppm)(R/S-IPTT)]ClO_(4)).In stark contrast to R/S-Ag_(4)(Φ_(em)<0.5%)that displays weak circularly polarized luminescence(CPL)with phosphorescence characteristic,R/S-Ag_(3)Cu(Φ_(em)≈70%)demonstrates strong CPL properties featured with thermally activated delay fluorescence(TADF)at ambient temperature.The selective substitution of the apical Ag(Ⅰ)atom in Ag_(4)triangular pyramid with a Cu(Ⅰ)atom not only gives rise to beyond 100-fold boosting of photoluminescence quantum yield(PLQY),but also leads to more pronounced optically chiral activity of alloy clusters in excited states in view of the larger photoluminescence dissymmetry factors(g_(PL))of R/S-Ag_(3)Cu(-3.5×10^(-3)/3.4×10^(-3))than that of R/S-Ag_(4)(-2.7×10^(-3)/2.6×10^(-3)).Furthermore,compared with chiral homometallic clusters R/S-Cu_(4)([Cu_(4)(tppm)(R/S-IPTT)]ClO_(4))with the same TADF characteristic at ambient temperature,R/S-Ag_(3)Cu manifests 1.7-fold PLQY and 6-fold g_(PL)due to faster reverse intersystem crossing(RISC)and more effective coupling of electric and magnetic transition moments in alloy clusters.This work not only presents a typical example of selective heterometal doping to modulate excited-state properties of isostructural metal clusters,but also gets deeper insight into the doping chemistry of dissimilar metals at the molecular level.
基金supported by the National Natural Science Foundation of China(Grants 92061202 and 21531008)the Fujian Province Science and Technology Project Program(Grant 2022H0041)the Self-deployment Project Research Program of Haixi Institute,Chinese Academy of Sciences(Grant CXZX-2022-GH11).
文摘In this work,a diphosphine chelator,2-Ph_(2)PC_(6)H_(4)PH_(2),containing both primary and tertiary phosphine donors,was used to create highly stable silver(I)nanoclusters through a dynamic ligand metathesis reaction.Taking advantage of thiolate-silver coordination polymers as synthetic precursors,we developed a viable synthetic approach to access Ag34 nanoclusters through dual proton and ligand exchange successfully.Owing to the stronger coordination ability of the bifunctional 2-Ph_(2)PC_(6)H_(4)PH_(2)ligand,substitution results in the formation of thermodynamically stable Ag34 nanoclusters linked by fifteen 2-Ph_(2)PC_(6)H_(4)P^(2-)chelators.Notably,thiolates as structural templates rather than protective ligands play a crucial role in directing nanocluster construction.The Ag34 nanoclusters manifest highly efficient near-infrared photoluminescence peaked at ca.800 nm with over 24%of quantum yield in fluid CH_(2)Cl_(2)solution,arising mostly from ligand-to-metal charge transfer(^(3)LMCT)and cluster-centered(^(3)CC)triplet states.Solution-processable near-infrared organic light-emitting diodes(NIR-OLEDs)achieved high-efficiency nearinfrared electroluminescence with an external quantum efficiency(EQE)of 10.2%.The unique synthetic approach can be extended to other metal systems,thereby expanding both the structural diversity and application potential of metal nanoclusters.
