Herein we present a structure–property relationship study of thirteen cationic iridium(III)complexes of the form of[Ir(C^N)2(P^P)]PF6 in both solution and the solid state through systematic evaluation of six bisphosp...Herein we present a structure–property relationship study of thirteen cationic iridium(III)complexes of the form of[Ir(C^N)2(P^P)]PF6 in both solution and the solid state through systematic evaluation of six bisphosphine(P^P)ligands(xantphos,dpephos,dppe,Dppe,nixantphos and isopropxantphos).展开更多
Four new fluorescent sensors(1-4)based on the 4-amino-1,8-naphthalimide fluorophores(Naps)have been synthesized based on the classical fluorophore-spacer-receptor model.These four compounds all gave rise to emission b...Four new fluorescent sensors(1-4)based on the 4-amino-1,8-naphthalimide fluorophores(Naps)have been synthesized based on the classical fluorophore-spacer-receptor model.These four compounds all gave rise to emission bands centred at ca.535 nm,which were found to be highly pH dependent,the emission being‘switched on’in acidic media,while being quenched due to PET from the amino moieties to the excited state of the Nap at more alkaline pH.The luminescent pH dependence for these probes was found to be highly dependent on the substitution on the imide site,as well as the polyamine chain attached to the position 4-amino moiety.In the case of sensor 2 the presence of the 4-amino-aniline dominated the pH dependent quenching.Nevertheless,at higher pH,PET quenching was also found to occur from the polyamine site.Hence,2 is better described as a receptor1-spacer1-fluorophore-spacer2-receptor2 system,where the dominant PET process is due to(normally less favourable)‘directional’PET quenching from the 4-amino-aniline unit to the Nap site.Similar trends and pH fluorescence dependences were also seen for 3 and 4.These compounds were also tested for their imaging potential and toxicity against HeLa cells(using DRAQ5 as nuclear stain which does now show pH dependent changes in acidic and neutral pH)and the results demonstrated that these compounds have reduced cellular viability at moderately high concentrations(with IC50 values between ca.8-30μmol?L^?1),but were found to be suitable for intracellular pH determination at 1μmol?L^?1 concentrations,where no real toxicity was observed.This allowed us to employ these as lysosomal probes at sub-toxic concentrations,where the Nap based emission was found to be pH depended,mirroring that seen in aqueous solution for 1-4,with the main fluorescence changes occurring within acidic to neutral pH.展开更多
基金the University of St Andrews for financial support.We thank Johnson Matthey and Umicore AG for the gift of materials and Cihang Yu for the preparation of isopropxantphos.We thank Dr Nail Shavaleev for the synthesis of NMS25.IDWS and AKB acknowledge support from EPSRC(EP/J01771X)We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services.This work has been supported by the Spanish Ministry of Economy and Competitiveness(MINECO)MAT2014–55200.
文摘Herein we present a structure–property relationship study of thirteen cationic iridium(III)complexes of the form of[Ir(C^N)2(P^P)]PF6 in both solution and the solid state through systematic evaluation of six bisphosphine(P^P)ligands(xantphos,dpephos,dppe,Dppe,nixantphos and isopropxantphos).
基金Science Foundation Ireland(SFI PI Award 13/IA/1865 to TG)and TCD for financial supportthe Ministerio of Economia y Competitividad of Spain and The Irish Research Council(IRC)for the funding of postdoctoral fellowships to MMC and AFH(GOIPD/2018/162),respectively.
文摘Four new fluorescent sensors(1-4)based on the 4-amino-1,8-naphthalimide fluorophores(Naps)have been synthesized based on the classical fluorophore-spacer-receptor model.These four compounds all gave rise to emission bands centred at ca.535 nm,which were found to be highly pH dependent,the emission being‘switched on’in acidic media,while being quenched due to PET from the amino moieties to the excited state of the Nap at more alkaline pH.The luminescent pH dependence for these probes was found to be highly dependent on the substitution on the imide site,as well as the polyamine chain attached to the position 4-amino moiety.In the case of sensor 2 the presence of the 4-amino-aniline dominated the pH dependent quenching.Nevertheless,at higher pH,PET quenching was also found to occur from the polyamine site.Hence,2 is better described as a receptor1-spacer1-fluorophore-spacer2-receptor2 system,where the dominant PET process is due to(normally less favourable)‘directional’PET quenching from the 4-amino-aniline unit to the Nap site.Similar trends and pH fluorescence dependences were also seen for 3 and 4.These compounds were also tested for their imaging potential and toxicity against HeLa cells(using DRAQ5 as nuclear stain which does now show pH dependent changes in acidic and neutral pH)and the results demonstrated that these compounds have reduced cellular viability at moderately high concentrations(with IC50 values between ca.8-30μmol?L^?1),but were found to be suitable for intracellular pH determination at 1μmol?L^?1 concentrations,where no real toxicity was observed.This allowed us to employ these as lysosomal probes at sub-toxic concentrations,where the Nap based emission was found to be pH depended,mirroring that seen in aqueous solution for 1-4,with the main fluorescence changes occurring within acidic to neutral pH.
