Template-oriented multi-component synthesis method has been proven to be an exceedingly reasonable and excellent method for the synthesis of giant two-dimensional(2D)and three-dimensional(3D)supramolecules,but designi...Template-oriented multi-component synthesis method has been proven to be an exceedingly reasonable and excellent method for the synthesis of giant two-dimensional(2D)and three-dimensional(3D)supramolecules,but designing and constructing heteroleptic and controllable self-assembly without unexpected by-products remains a challenge.Here we report two discrete trefoil-shaped metallacycle S1 and metallacage s2 by heteroleptic self-assembly using one hexaphenylbenzene core ligand and two capping ligands.The 2D trefoil-shaped metallacycle S1 could resemble the emblem of the classic'Mitsubishi motif.The use of template-oriented ligand and bent spacer ligand promotes the quantitative formation of the desired 3D trefoil-shaped metallacage S2.The formed metallacage S2 possesses a molecular weight up to 36 kDa,diameter 6.6 nm and height 3.0 nm.All supramolecular coordination complexes were fully characterized by NMR spectroscopy(^(1)H NMR,2D COSY,2D NOESY,2D DOSY),high-resolution electrospray ionization mass sectrometry ESI-MS.ESI-TWIM-MS,TEM and AFM.展开更多
A typical metal complex has a central metal surrounded by multiple ligands,which greatly affect the properties of the whole complex.Although heteroleptic complexes often exhibit substantially different behaviors from ...A typical metal complex has a central metal surrounded by multiple ligands,which greatly affect the properties of the whole complex.Although heteroleptic complexes often exhibit substantially different behaviors from homoleptic complexes,systematic studies to explain their origins have been rare.Of special importance is to understand why the heteroleptic metal complex shows a more complicated excited state relaxation dynamics than the homoleptic metal complex.To address this issue,we investigated the excited state relaxation dynamics of a heteroleptic Ir(Ⅲ)complex,fac-Ir(ppy)_(2)(ppz),and two homoleptic Ir(Ⅲ)complexes,fac-Ir(ppy)_(3) and fac-Ir(ppz)_(3),using femtosecond X-ray transient absorption(fs-XTA)spectroscopy,ultrafast optical transient absorption(TA)spectroscopy,and DFT/TDDFT calculation.The data show that the ultrafast relaxation dynamics of∼450 fs,which is significantly faster than those of previous Ir(Ⅲ)complexes with other ligands,is observed only in fac-Ir(ppy)_(2)(ppz)but not in the homoleptic Ir(Ⅲ)complexes.Such dynamics observed for only heteroleptic Ir(Ⅲ)complexes must originate from the heteroleptic character,and naturally,the inter-ligand energy transfer between two different types of ligands has been suggested to explain the fast dynamics.Both fs-XTA and TA data,however,favor the assignment of the ultrafast dynamics of∼450 fs to the internal conversion(IC)process from the ppz-localized ^(3)MLCT to the ppy-localized ^(3)MLCT.The DFT/TDDFT calculations support that the abnormally fast IC for fac-Ir(ppy)_(2)(ppz)is due to a large nonadiabatic coupling and the small energy gap between the two states.展开更多
For the purpose of engineering magnetic anisotropy,chiral binaphthyl substituents with slight electron-withdrawing ability and dibutylamino substituents with intense electron-donating nature are incoporated onto the p...For the purpose of engineering magnetic anisotropy,chiral binaphthyl substituents with slight electron-withdrawing ability and dibutylamino substituents with intense electron-donating nature are incoporated onto the periphery of each phthalocyanine ligand in the bis(phthalocyaninato)terbium double-decker compound,resulting in the chiral heteroleptic bis(phthalocyaninato)terbium complex(R)/(S)-[Pc(OBNP)_(4)]Tb{Pc[N(C_(4)H_(9))_(2)]_(8)}(R/S-1){Pc(OBNP)_(4)={tetrakis(dinaphtho[1,2-e:1′,2′-g]-1,4-dioxocine)[2,3-b;2′,3′-k;2″,3″-t;2″′,3″′-c′]phthalocyanine};Pc[N(C_(4)H_(9))_(2)]_(8)=[2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyanine]}.Magnetic studies reveal the typical single-ion magnet(SIM)nature of this chiral bis(phthalocyaninato)terbium double-decker with spin reversal energy barrier of 638 K.A butterfly-shaped magnetic hysteresis loop was observed at even 25 K for R-1 under the sweep rate of 500 Oe s^(-1).The performance of this SIM is well rationalized on the basis of theoretical analysis of the electrostatic potential according to calculations using the density functional theory method.展开更多
Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they w...Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they were investigated for their ability to activate ammonia through N-H bond scission.By combining synthetic modifications of the ancillary ligand framework and computational analyses,detailed insights into the mechanism of NH_(3) activation by these systems were obtained,highlighting an activation pathway at tin without a change in oxidation state.Additionally,an observed by-product during these studies underscores the non-innocence of a lithium salt in the synthesis of the stannylene starting materials,providing access to a novel lithium stannylenoid.展开更多
A substituted pyridazine was used to construct a family of mononuclear heteroleptic complexes[Ln(tta)_(3)(dppn)],Ln=Pr-Lu;Htta=thenoyltrifluoroacetone;dppn=3,6-di(2-pyridyl)pyridazine.All the complexes obtained were c...A substituted pyridazine was used to construct a family of mononuclear heteroleptic complexes[Ln(tta)_(3)(dppn)],Ln=Pr-Lu;Htta=thenoyltrifluoroacetone;dppn=3,6-di(2-pyridyl)pyridazine.All the complexes obtained were characterized by CHN elemental analysis,NMR spectroscopy,ESI mass spectrometry,FTIR spectroscopy and single crystal X-ray analysis.The photophysical properties of lanthanide complexes were carefully investigated,and the dppn ligand was found to act as a chromophore centre to sensitize metal-centred emission of the Nd,Sm,Eu,and Yb complexes under UV excitation.It has been shown that a powder sample of the Eu complex can contain two isomers with somewhat different symmetries of the environment of the metallocentre.The mechanism for the emission of luminescent Nd,Sm,Eu,and Yb complexes was investigated by TDDFT calculations and the results confirmed the conclusion made on the basis of experimental data regarding the likely pathway of energy transfer from the chromophore centre to the emissive level of Ln(III).展开更多
Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followe...Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followed for the preparation of a neutral Sac[(bipy-OH)Cu(Trop)Sac],2,selectively isolated in its blue anhydrous 2a and green mono-hydrated 2b crystalline solid-state forms.The structural characterization of 2 has revealed that the Sac ion is bound to the Cu(Ⅱ)centre through one of the oxygen atoms of the sulphonyl group.展开更多
Two bis-heteroleptic ruthenium(II)complexes,1[PF_(6)]_(2)and 2[PF_(6)]_(2)of 4,7-dihydroxy-1,10-phenanthroline,have been developed for the highly selective‘light-up’detection of nerve agent simulant and organopho sp...Two bis-heteroleptic ruthenium(II)complexes,1[PF_(6)]_(2)and 2[PF_(6)]_(2)of 4,7-dihydroxy-1,10-phenanthroline,have been developed for the highly selective‘light-up’detection of nerve agent simulant and organopho sphate pesticide in aqueous solution.Both the complexes,1[PF_(6)]_(2)and 2[PF_(6)]_(2),were fully characterized by spectroscopic means and single-crystal X-ray diffraction studies.Compounds 1[PF_(6)]_(2)and 2[PF_(6)]_(2)show a selective turn-on luminescence response in the presence of nerve agent stimulant DCP over other com petitive nerve agent surrogates,acylating agents,HCl and pulmonary agent like phosgene.The detection of DCP was achieved via a nucleophilic attack of two hydroxyl groups of the 4,7-dihydroxy-1,10-phen anthroline ligand with DCP by forming bulkier phosphotriester and corresponding PL enhancement.The detection limit implies that 1[PF_(6)]_(2)and 2[PF_(6)]_(2)are able to detect DCP at the micromolar level.1 H NMR titration,31 P NMR and ESI-MS analysis collectively support the binding mechanism of phenolic hydroxyl groups of the ligand L with the PvO center of DCP.Triplet state TD-DFT calculations endorsed that the weak and strong red luminescence of 1 and 1-(DCP)2 originated from the non-emissive 3MC and emissive 3MLCT states,respectively.Also,probes 1[PF_(6)]_(2)and 2[PF_(6)]_(2)have been used for the highly selective luminescence detection of an organophosphate pesticide,dichlorvos,over the market available other organophosphorus pesticides(paraoxon-ethyl,parathion-ethyl,profenofos,and dimethoate).Furthermore,a test paper strip coated with complex 1 was fabricated to detect DCP in the vapor phase and dichlorvos in solution.Finally,probe 1 was successfully applied in biological studies to visualize DCP as well as dichlorvos in catfish brain tissue.展开更多
Supramolecular self-assembly is a promising tool to develop multifunctional theranostic agents and has recently entered the field of radiochemistry.In this work,lantern-shaped[Pd_(2)L_(4)]^(4+)metallacages featuring a...Supramolecular self-assembly is a promising tool to develop multifunctional theranostic agents and has recently entered the field of radiochemistry.In this work,lantern-shaped[Pd_(2)L_(4)]^(4+)metallacages featuring a blood–brain barrier-penetrating peptide were designed for dual-modality imaging.Two silicon-based fluoride acceptors were incorporated in the cage ligand for radiolabeling with fluorine-18,an isotope used in positron emission tomography(PET).Ligands(L1,L2)and the respective homoleptic cages(C1hom[Pd_(2)(L1)_(4)]^(4+),C2hom[Pd_(2)(L2)_(4)]^(4+))were fully characterized by NMR spectroscopy,liquid chromatography and high-resolution electrospray mass spectrometry(HR-ESI-MS).Cage stability was assessed in different solvents and concentrations by HPLC.^(18)F-labelled cages were obtained by radiolabeling the ligands preassembly under mild conditions within four hours via[19F]-to-[^(18)F]isotopic exchange.The high lipophilicity of the ligands was also assessed in vitro(log DpH_(7.4))and in ovo,using the chick chorioallantoic membrane(CAM)model.Furthermore,formation of host–vip complexes between the metallacages and perrhenate(ReO_(4)^(-)),the‘cold’surrogate of radioactive^(99m)TcO_(4)-(used for single photon computed tomography,SPECT),could be detected by mass spectrometry,although the adduct did not sustain chromatographic separation.To improve stability of the supramolecular system,heteroleptic cages of general formula[Pd_(2)(L)m(L0)_(n)]^(4+)(m=1,2,n=4-m)were synthesized by statistical self-assembly and separated by liquid chromatography in good yield.Overall,this study demonstrates the feasible adaptation of supramolecular principles to achieve innovative theranostic agents.展开更多
The effective incorporation of well-defined coordination spheres,multiple types of ligands(heteroleptic),and specific assembly modes in a given structure enables the fabrication of simplified coordinative supramolecul...The effective incorporation of well-defined coordination spheres,multiple types of ligands(heteroleptic),and specific assembly modes in a given structure enables the fabrication of simplified coordinative supramolecular bio-mimics.Herein,we report the fabrication of a unique racemic macrocycle via association of metallosupramolecular helicates.展开更多
Two families of cyclopentadienyl(Cp)/carboranyl heteroleptic sandwiched organolanthanide complexes,namely[Ln{η^(5):σ-Me_(2)C(C_(5)H_(4))(C_(2)B_(10)H_(10))}_(2)][Li(DME)_(3)](1Ln,Ln=Tb,Dy,Ho,Er)and[2-THF-2'-(μ^...Two families of cyclopentadienyl(Cp)/carboranyl heteroleptic sandwiched organolanthanide complexes,namely[Ln{η^(5):σ-Me_(2)C(C_(5)H_(4))(C_(2)B_(10)H_(10))}_(2)][Li(DME)_(3)](1Ln,Ln=Tb,Dy,Ho,Er)and[2-THF-2'-(μ^(2)-Cl)Li(THF)_"(3)-2,2'-Ln(nido-1,7-C_(2)B_(9)H_(11))Cp*](2Dy),were synthesized.Family of 1Ln has been proposed based on the mixing-ligands idea by linking Cp and nido-dicarborllide.However,the carborane cage of[Me_(2)C(C_(5)H_(4))(C_(2)B_(10)H_(10))]_(2)−deprotons and forms a mono-C−anion rather than deboron to form dicarborllide dianion.Hence,the family of 1Ln features a dysprosocenium skeleton with extra two coordination of C−anions of carborllides.Such coordination geometry is more like a tetrahedron if abstracting the centroids of two coordinated Cp rings.In this cubic-type geometry,no significant magnetic axiality is presented;only 1Dy and 1Tb show field-induced slow magnetic relaxation behavior below 10 K.Inspired by 1Ln,the free pentamethylcyclopentadienyl(Cp^(*−))and nido-dicarborllide ligands are used to sandwich central Dy3+ion,achieving heteroleptic complex 2Dy.The bending angle by linking the centroid of Cp^(*−),Dy^(3+)and C_(2)B_(3)^(2−)in 2Dy is increased to 132.8(1)°.As such,the effective energy barrier for magnetic reversal(Ueff)and magnetic blocking temperature TB(ZFC)are both increased(Ueff=616(10)K;TB=6 K).The effort of further enhancing Ueff and TB in such heteroleptic organolanthanide sandwiches should rely on keeping increasing the ligand axiality.展开更多
The size complementarity between a host and a vip is a critical prerequisite for selective molecular recognition.Numerous artificial host systems have been designed to achieve size-selective recognition and chemical...The size complementarity between a host and a vip is a critical prerequisite for selective molecular recognition.Numerous artificial host systems have been designed to achieve size-selective recognition and chemical transformations.However,the inherent challenge lies in the fixed selectivity governed by a size-exclusion mechanism dictated by the host's structure.Modulating the selectivity necessitates structural modifications of hosts.Examples of host systems with modifiable sizeselectivity are rare.In this study,we present an approach to modulating vip-selectivity via endo-functionalization of supramolecular cavities.Heteroleptic Pd_(2)A_(3)B-cages are constructed with a Pd_(2)A_(3)precursor or directly from palladium ions and relevant ligands.Furthermore,the simultaneous and selective formation of multiple hetero-cages was achieved by simply mixing PdIIand the free ligands in a one-pot reaction.The fidelity of the assembly process relies on cooperative steric control at the periphery and within the cavity of the hetero-cages,respectively.The central steric group also functions as the endohedral moiety.Variations of the endohedral groups facilitate facile and modular derivatization of the microenvironment within the cages,enabling the fine-tuning of vip binding affinities as evidenced by titration experiments.This strategy offers a new solution for the development of customized host structures.展开更多
Nonlinear optical(NLO)materials enable direct second-harmonic generation(SHG)of coherent ultraviolet(UV)light,yet achieving phase matching(PM)in systems dominated by non-π-conjugated units remains a critical bottlene...Nonlinear optical(NLO)materials enable direct second-harmonic generation(SHG)of coherent ultraviolet(UV)light,yet achieving phase matching(PM)in systems dominated by non-π-conjugated units remains a critical bottleneck.Herein,we present the first rare-earth nitrate sulfamate,La(SO_(3)NH_(2))_(2)NO_(3)·H_(2)O,designed through synergistic anion engineering by integrating La^(3+)withπ-conjugated[NO_(3)]units and heteroleptic tetrahedra[SO_(3)NH_(2)].This crystal achieves a short PM wavelength(258 nm)and UV cutoff edge(234 nm),a large SHG response(1×KH_(2)PO_(4)),and a record birefringence(0.077@546 nm),overcoming the transparency-anisotropy-SHG response trade-offs in inorganic sulfamate-based materials.The results demonstrate that the heteroleptic tetrahedra[SO_(3)NH_(2)]play a key role in modulating the band gap of La(SO_(3)NH_(2))_(2)NO_(3)·H_(2)O,while the(d-p)πinteraction between the La and[NO_(3)]units further enhances optical anisotropy.Our work establishes synergistic anion engineering as a paradigm for developing high-performance UV NLO materials through a rational combination of heteroleptic tetrahedra andπ-conjugated motifs.展开更多
The evaluation of N’-(1-(2-pyridyl)ethylidene)nicotinohydrazide(HL)as a linker for the Pb^(II)tagged extended structures is described.The reaction of Pb(ClO_(4))_(2)or Pb(OAc)_(2)with HL in MeOH at 60℃and room tempe...The evaluation of N’-(1-(2-pyridyl)ethylidene)nicotinohydrazide(HL)as a linker for the Pb^(II)tagged extended structures is described.The reaction of Pb(ClO_(4))_(2)or Pb(OAc)_(2)with HL in MeOH at 60℃and room temperature,respectively,leads to heteroleptic complexes{[PbL]ClO_(4)}n·nH_(2)O and[PbL(OAc)]_(2),while the same reaction of Pb(ClO_(4))_(2)with HL at 60℃in the presence of two equivalents of NaOAc or NaNO_(2)leads to heteroleptic complexes{[Pb(HL)(OAc)]ClO_(4)}_(n)and[PbL(NO_(2))]n,respectively.Using Pb(NO_(3))_(2)as a source of Pb^(II)in the same reaction with HL and two equivalents of NaN_(3)or NaNCS at room temperature yields[PbLN_(3)]_(n)and[Pb_(2)(HL)_(2)(NO_(3))_(2)(NCS)_(2)],respectively.The room temperature reaction of Pb(NO_(3))_(2)with HL in the presence of two equivalents of NaClO_(4)leads to the transformation of the parent ligand to its perchlorate salt[H_(2)L]ClO_(4).In all the obtained Pb^(II)structures,HL or its deprotonated form L acts both as a chelating and a bridging ligand.The nature of the inorganic anion also influences the final structure.In all complexes the Pb^(II)center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151°to 232°.The sterically available Pb^(II)ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes.As a result of tetrel bonding,the structures of all the six compounds can be extended to a higher dimensional framework,which is further stabilized byπ…πstacking interactions between the aromatic rings.The DFT based charge and energy decomposition(ETS-NOCV)calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.展开更多
Ruthenium polypyridyl complexes are known for their excellent photophysical properties and rich electrochemical behavior.Thus,developing complexes with multifunctional behavior showing potential applications in multip...Ruthenium polypyridyl complexes are known for their excellent photophysical properties and rich electrochemical behavior.Thus,developing complexes with multifunctional behavior showing potential applications in multiple fields is of great importance.Herein,we report a new aggregation-induced emission(AIE)active bis-heteroleptic ruthenium(Ⅱ)complex(Ru-4)of 4,7-diamino 1,10-phenanthroline along with a series of other bis-heteroleptic Ru(Ⅱ)polypyridyl complexes(Ru-1,Ru-2 and Ru-3)containing 4,7-disubstituted 1,10-phenanthroline and two homoleptic complexes(Ru-5 and Ru-6)of 2,2’-bipyridine and 1,10-phenanthroline.展开更多
Aryl-substituted sodium 1,2-diphosphacyclopentadienides Na(P_(2)C_(3)R_(3))(R=Ph,4-Me-C_(6)H_(4),4-Cl-C_(6)H_(4))(1a-c)react with[FeCp(η^(6)-C_(6)H_(5)CH_(3))][PF6]to give heteroleptic 3,4,5-triaryl-1,2-diphosphaferr...Aryl-substituted sodium 1,2-diphosphacyclopentadienides Na(P_(2)C_(3)R_(3))(R=Ph,4-Me-C_(6)H_(4),4-Cl-C_(6)H_(4))(1a-c)react with[FeCp(η^(6)-C_(6)H_(5)CH_(3))][PF6]to give heteroleptic 3,4,5-triaryl-1,2-diphosphaferrocenes[FeCp(η^(5)-P_(2)C_(3)R_(3))](2a-c)in 71-78%yield.The structures of 2a-c were confirmed by NMR,UV-Vis spectroscopy and X-ray structure analysis,and supported by DFT calculations.Electrochemical studies of 2a-c in CH3CN demonstrate a pronounced reversible one-electron oxidation,while in the solid state,all 3,4,5-triaryl-1,2-diphosphaferrocenes show fully reversible oxidation and reduction waves,which indicates the stability of the oxidized form.Regardless of the substituent(R=Ph,4-Me-C_(6)H_(4),4-Cl-C_(6)H_(4)),the studied 1,2-diphosphaferrocenes have similar oxidation and reduction potentials.展开更多
Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 ...Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 K and 28 K,respectively,providing an alternative method towards enhancing the magnetic behavior.展开更多
A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with ...A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with a phenylsulfonyl group(–SO_(2)Ph)substituted at different positions,new unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes have been successfully synthesized.Their photophysical,electrochemical and electroluminescence(EL)behaviors have been fully characterized.In addition,both time-dependent functional theory(TD-DFT)and natural transition orbital(NTO)theoretical results have been obtained to gain insight into the optoelectronic behaviors of these unsymmetric Ir(Ⅲ)complexes with OBA units.The NTO results indicate that the features of the lowest triplet excited states(T_(1))can be delicately tuned by combination between the OBA-based cyclometalating ligand and another ppy-type ligand with the–SO_(2)Ph group.Importantly,these unsymmetric Ir(Ⅲ)complexes can exhibit very high phosphorescence quantum yield(Φ_(p))higher than 0.90 due to the highly rigid OBA unit which can effectively restrain non-radiative processes.In addition,an electron injection/transporting(EI/ET)ability can be conferred to these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes by both OBA and–SO_(2)Ph moieties.Taking advantage of these merits,organic light-emitting diodes(OLEDs)based on these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes can show a high maximum external quantum efficiency(ηext)of 12.8%,a current efficiency(η_(L))of 51.1 cd A^(−1),and a power efficiency(η_(P))of 40.5 lm W^(−1) for a yellowish-green device,while EL efficiencies for red devices are 6.8%,13.9 cd A^(−1),and 12.8 lm W^(−1),respectively.All these results indicate the good potential of the rigid OBA unit in developing functional phosphorescent emitters.展开更多
A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye...A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye. As such, a great deal of atten- tion has been focused on sensitizers with the general formula Ru（ancillary-ligand）（anchoring-ligand）（NCS）2, among which important examples are Ru（4,4＇-bis（5-hexylthiophen-2-yl）-2,2＇-bipyridine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （C101） and Ru（N-（4-butoxyphenyl）-N-2-pyridinyl-2-pyridinamine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （J13）. In order to simulate experimental conditions with different pH values, the photosensitizing processes of these sensitizers pos- sessing different degrees of deprotonation （2I-I, lit to OH） have been explored theoretically in this work. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of all the complexes in acetonitrile solution are also predicted at the TDDFT （B3LYP） level. The calculated results show that the ancillary ligand contributes to the molecular or- bital （MO） energy levels and absorption transitions. It is intriguing to observe that the introduction of a thiophene group into the ancillary ligand leads directly to the increased energy of the absorption transitions in the 380-450 nm region. The calcula- tions reveal that although deprotonation destabilizes the overall frontier MOs of the chromophores, it tends to exert a greater influence on the unoccupied orbitals than on the occupied orbitals. Consequently, an obvious blue shift was observed for the absorptions and emissions in going from 21-1, 1H to OH. Finally, the optimal degree of deprotonation for C101 and J13 has al- so been evaluated, which is expected to lead to further improvements in the performance of dye-sensitized solar cells （DSSCs） coated with such sensitizers.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22101060 for M.C.,and 21971257 for P.w.)the Guangdong Natural Science Foundation(No.2022A1515012187 to M.C.)the Science and Technology Research Project of Guangzhou(Nos.202201020201 for M.C.and 202102010432 for ZJ..Science and technology support plan of Guizhou Province[2019]2860 for W.L.The authors gratefully acknowledge the Center for Advanced Research in CSU for the NMR measurements.
文摘Template-oriented multi-component synthesis method has been proven to be an exceedingly reasonable and excellent method for the synthesis of giant two-dimensional(2D)and three-dimensional(3D)supramolecules,but designing and constructing heteroleptic and controllable self-assembly without unexpected by-products remains a challenge.Here we report two discrete trefoil-shaped metallacycle S1 and metallacage s2 by heteroleptic self-assembly using one hexaphenylbenzene core ligand and two capping ligands.The 2D trefoil-shaped metallacycle S1 could resemble the emblem of the classic'Mitsubishi motif.The use of template-oriented ligand and bent spacer ligand promotes the quantitative formation of the desired 3D trefoil-shaped metallacage S2.The formed metallacage S2 possesses a molecular weight up to 36 kDa,diameter 6.6 nm and height 3.0 nm.All supramolecular coordination complexes were fully characterized by NMR spectroscopy(^(1)H NMR,2D COSY,2D NOESY,2D DOSY),high-resolution electrospray ionization mass sectrometry ESI-MS.ESI-TWIM-MS,TEM and AFM.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(NRF-2017R1C1B1010736,NRF-2020R1C1C1009007 and NRF-2020R1I1A3054352)The fs-XTA experiments were performed at beamline XSS of PAL-XFEL(proposal no.2018-2nd-XSS-012)supported by the Institute for Basic Science(IBS-R004).
文摘A typical metal complex has a central metal surrounded by multiple ligands,which greatly affect the properties of the whole complex.Although heteroleptic complexes often exhibit substantially different behaviors from homoleptic complexes,systematic studies to explain their origins have been rare.Of special importance is to understand why the heteroleptic metal complex shows a more complicated excited state relaxation dynamics than the homoleptic metal complex.To address this issue,we investigated the excited state relaxation dynamics of a heteroleptic Ir(Ⅲ)complex,fac-Ir(ppy)_(2)(ppz),and two homoleptic Ir(Ⅲ)complexes,fac-Ir(ppy)_(3) and fac-Ir(ppz)_(3),using femtosecond X-ray transient absorption(fs-XTA)spectroscopy,ultrafast optical transient absorption(TA)spectroscopy,and DFT/TDDFT calculation.The data show that the ultrafast relaxation dynamics of∼450 fs,which is significantly faster than those of previous Ir(Ⅲ)complexes with other ligands,is observed only in fac-Ir(ppy)_(2)(ppz)but not in the homoleptic Ir(Ⅲ)complexes.Such dynamics observed for only heteroleptic Ir(Ⅲ)complexes must originate from the heteroleptic character,and naturally,the inter-ligand energy transfer between two different types of ligands has been suggested to explain the fast dynamics.Both fs-XTA and TA data,however,favor the assignment of the ultrafast dynamics of∼450 fs to the internal conversion(IC)process from the ppz-localized ^(3)MLCT to the ppy-localized ^(3)MLCT.The DFT/TDDFT calculations support that the abnormally fast IC for fac-Ir(ppy)_(2)(ppz)is due to a large nonadiabatic coupling and the small energy gap between the two states.
基金Financial support from National Natural Science Foundation of China(No.21401009,21631003,21671017,and 21671024)Fundamental Research Funds for the Central Universities(No.FRF-BD-17-016A)Beijing Municipal Commission of Education,and University of Science and Technology Beijing is gratefully acknowledged.
文摘For the purpose of engineering magnetic anisotropy,chiral binaphthyl substituents with slight electron-withdrawing ability and dibutylamino substituents with intense electron-donating nature are incoporated onto the periphery of each phthalocyanine ligand in the bis(phthalocyaninato)terbium double-decker compound,resulting in the chiral heteroleptic bis(phthalocyaninato)terbium complex(R)/(S)-[Pc(OBNP)_(4)]Tb{Pc[N(C_(4)H_(9))_(2)]_(8)}(R/S-1){Pc(OBNP)_(4)={tetrakis(dinaphtho[1,2-e:1′,2′-g]-1,4-dioxocine)[2,3-b;2′,3′-k;2″,3″-t;2″′,3″′-c′]phthalocyanine};Pc[N(C_(4)H_(9))_(2)]_(8)=[2,3,9,10,16,17,23,24-octakis(dibutylamino)phthalocyanine]}.Magnetic studies reveal the typical single-ion magnet(SIM)nature of this chiral bis(phthalocyaninato)terbium double-decker with spin reversal energy barrier of 638 K.A butterfly-shaped magnetic hysteresis loop was observed at even 25 K for R-1 under the sweep rate of 500 Oe s^(-1).The performance of this SIM is well rationalized on the basis of theoretical analysis of the electrostatic potential according to calculations using the density functional theory method.
文摘Heteroleptic stannylenes,featuring pendant hemilabile iminophosphorane functionalities and kinetically stabilizing terphenyl ligands,were synthesized straightforwardly through formal C-H activation.Subsequently,they were investigated for their ability to activate ammonia through N-H bond scission.By combining synthetic modifications of the ancillary ligand framework and computational analyses,detailed insights into the mechanism of NH_(3) activation by these systems were obtained,highlighting an activation pathway at tin without a change in oxidation state.Additionally,an observed by-product during these studies underscores the non-innocence of a lithium salt in the synthesis of the stannylene starting materials,providing access to a novel lithium stannylenoid.
文摘A substituted pyridazine was used to construct a family of mononuclear heteroleptic complexes[Ln(tta)_(3)(dppn)],Ln=Pr-Lu;Htta=thenoyltrifluoroacetone;dppn=3,6-di(2-pyridyl)pyridazine.All the complexes obtained were characterized by CHN elemental analysis,NMR spectroscopy,ESI mass spectrometry,FTIR spectroscopy and single crystal X-ray analysis.The photophysical properties of lanthanide complexes were carefully investigated,and the dppn ligand was found to act as a chromophore centre to sensitize metal-centred emission of the Nd,Sm,Eu,and Yb complexes under UV excitation.It has been shown that a powder sample of the Eu complex can contain two isomers with somewhat different symmetries of the environment of the metallocentre.The mechanism for the emission of luminescent Nd,Sm,Eu,and Yb complexes was investigated by TDDFT calculations and the results confirmed the conclusion made on the basis of experimental data regarding the likely pathway of energy transfer from the chromophore centre to the emissive level of Ln(III).
基金support was received from the Ministero dell’Universitàe della Ricerca(MUR),for F.S.POR Calabria FESR-FSE 2014/2020-Linea(B)Azione 10.5.12。
文摘Heteroleptic Cu(Ⅱ)compounds containing 4,4’-bis(hydroxymethyl)-2,2’-bipyridine(bipy-OH),tropolonate(Trop)and saccharinate(Sac)have been synthesized and characterized.Different synthetic procedures have been followed for the preparation of a neutral Sac[(bipy-OH)Cu(Trop)Sac],2,selectively isolated in its blue anhydrous 2a and green mono-hydrated 2b crystalline solid-state forms.The structural characterization of 2 has revealed that the Sac ion is bound to the Cu(Ⅱ)centre through one of the oxygen atoms of the sulphonyl group.
基金supported by DST,India(No.SB/FT/CS-115/2012)DST-SPLICE,India(DST/CCP/HICAB/SN-Meghalaya/178/2018(G)).
文摘Two bis-heteroleptic ruthenium(II)complexes,1[PF_(6)]_(2)and 2[PF_(6)]_(2)of 4,7-dihydroxy-1,10-phenanthroline,have been developed for the highly selective‘light-up’detection of nerve agent simulant and organopho sphate pesticide in aqueous solution.Both the complexes,1[PF_(6)]_(2)and 2[PF_(6)]_(2),were fully characterized by spectroscopic means and single-crystal X-ray diffraction studies.Compounds 1[PF_(6)]_(2)and 2[PF_(6)]_(2)show a selective turn-on luminescence response in the presence of nerve agent stimulant DCP over other com petitive nerve agent surrogates,acylating agents,HCl and pulmonary agent like phosgene.The detection of DCP was achieved via a nucleophilic attack of two hydroxyl groups of the 4,7-dihydroxy-1,10-phen anthroline ligand with DCP by forming bulkier phosphotriester and corresponding PL enhancement.The detection limit implies that 1[PF_(6)]_(2)and 2[PF_(6)]_(2)are able to detect DCP at the micromolar level.1 H NMR titration,31 P NMR and ESI-MS analysis collectively support the binding mechanism of phenolic hydroxyl groups of the ligand L with the PvO center of DCP.Triplet state TD-DFT calculations endorsed that the weak and strong red luminescence of 1 and 1-(DCP)2 originated from the non-emissive 3MC and emissive 3MLCT states,respectively.Also,probes 1[PF_(6)]_(2)and 2[PF_(6)]_(2)have been used for the highly selective luminescence detection of an organophosphate pesticide,dichlorvos,over the market available other organophosphorus pesticides(paraoxon-ethyl,parathion-ethyl,profenofos,and dimethoate).Furthermore,a test paper strip coated with complex 1 was fabricated to detect DCP in the vapor phase and dichlorvos in solution.Finally,probe 1 was successfully applied in biological studies to visualize DCP as well as dichlorvos in catfish brain tissue.
基金funding from EU Horizon Europe Research and Innovation program,EIC Pathfinder Open network“SMARTdrugs”(grant agreement ID:101129886)Funding for T.H.W.was provided by UK Research and Innovation(UKRI)under the UK Government’s Horizon Europe funding guarantee(grant no.10091247)to T.H.W.+1 种基金arising from the above mentioned EIC Pathfinder grant.The TUM International Graduate School of Science and Engineering(IGSSE)is kindly acknowledged for financial support(International Project Team:Supramolecular Organometallic and Coordination Complexes for Medical Applications,SOCoMED)This research has also received funding from the European Union’s Horizon H2020 Research and Innovation under the Marie Skłodowska-Curie grant agreement no.945416 through the PhD fellowship of IK.
文摘Supramolecular self-assembly is a promising tool to develop multifunctional theranostic agents and has recently entered the field of radiochemistry.In this work,lantern-shaped[Pd_(2)L_(4)]^(4+)metallacages featuring a blood–brain barrier-penetrating peptide were designed for dual-modality imaging.Two silicon-based fluoride acceptors were incorporated in the cage ligand for radiolabeling with fluorine-18,an isotope used in positron emission tomography(PET).Ligands(L1,L2)and the respective homoleptic cages(C1hom[Pd_(2)(L1)_(4)]^(4+),C2hom[Pd_(2)(L2)_(4)]^(4+))were fully characterized by NMR spectroscopy,liquid chromatography and high-resolution electrospray mass spectrometry(HR-ESI-MS).Cage stability was assessed in different solvents and concentrations by HPLC.^(18)F-labelled cages were obtained by radiolabeling the ligands preassembly under mild conditions within four hours via[19F]-to-[^(18)F]isotopic exchange.The high lipophilicity of the ligands was also assessed in vitro(log DpH_(7.4))and in ovo,using the chick chorioallantoic membrane(CAM)model.Furthermore,formation of host–vip complexes between the metallacages and perrhenate(ReO_(4)^(-)),the‘cold’surrogate of radioactive^(99m)TcO_(4)-(used for single photon computed tomography,SPECT),could be detected by mass spectrometry,although the adduct did not sustain chromatographic separation.To improve stability of the supramolecular system,heteroleptic cages of general formula[Pd_(2)(L)m(L0)_(n)]^(4+)(m=1,2,n=4-m)were synthesized by statistical self-assembly and separated by liquid chromatography in good yield.Overall,this study demonstrates the feasible adaptation of supramolecular principles to achieve innovative theranostic agents.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government Ministry of Science and ICT(MSICT)(NRF-2015R1A4A1041631,NRF-2016R1A2B4009281,and NRF-2018R1A6A3A01013041)Experiments at PLS-II were supported in part by MSICT and POSTECH(2019-1st-2D-009 and 2019-2nd-2D-015)Magnetic measurements were performed using facilities at IBS Center for Correlated Electron Systems,Seoul National UniversityThis research was also supported by the Korea Basic Science Institute under the R&D program(Project No.D39701)supervised by the Ministry of Science and ICT.
文摘The effective incorporation of well-defined coordination spheres,multiple types of ligands(heteroleptic),and specific assembly modes in a given structure enables the fabrication of simplified coordinative supramolecular bio-mimics.Herein,we report the fabrication of a unique racemic macrocycle via association of metallosupramolecular helicates.
基金the assistance of the project supported by the National Natural Science Foundation of China(22375157,22401227)the Programme of Introducing Talents of Discipline to Universities(B23025)+3 种基金State Key Laboratory of Electrical Insulation and Power Equipment(EIPE23402,EIPE23405)the China Postdoctoral Science Foundation(2023M742783,GZB20240599)"Medical-Engineering Cross Project of the First Affiliated Hospital of XJTU(QYJCo2)"Shaanxi Postdoctoral Science Foundation(2023BSHYDZZ12)and the"Scientists+Engineers"Team Building Project of Qin Chuang Yuan(2022KXJ-088).
文摘Two families of cyclopentadienyl(Cp)/carboranyl heteroleptic sandwiched organolanthanide complexes,namely[Ln{η^(5):σ-Me_(2)C(C_(5)H_(4))(C_(2)B_(10)H_(10))}_(2)][Li(DME)_(3)](1Ln,Ln=Tb,Dy,Ho,Er)and[2-THF-2'-(μ^(2)-Cl)Li(THF)_"(3)-2,2'-Ln(nido-1,7-C_(2)B_(9)H_(11))Cp*](2Dy),were synthesized.Family of 1Ln has been proposed based on the mixing-ligands idea by linking Cp and nido-dicarborllide.However,the carborane cage of[Me_(2)C(C_(5)H_(4))(C_(2)B_(10)H_(10))]_(2)−deprotons and forms a mono-C−anion rather than deboron to form dicarborllide dianion.Hence,the family of 1Ln features a dysprosocenium skeleton with extra two coordination of C−anions of carborllides.Such coordination geometry is more like a tetrahedron if abstracting the centroids of two coordinated Cp rings.In this cubic-type geometry,no significant magnetic axiality is presented;only 1Dy and 1Tb show field-induced slow magnetic relaxation behavior below 10 K.Inspired by 1Ln,the free pentamethylcyclopentadienyl(Cp^(*−))and nido-dicarborllide ligands are used to sandwich central Dy3+ion,achieving heteroleptic complex 2Dy.The bending angle by linking the centroid of Cp^(*−),Dy^(3+)and C_(2)B_(3)^(2−)in 2Dy is increased to 132.8(1)°.As such,the effective energy barrier for magnetic reversal(Ueff)and magnetic blocking temperature TB(ZFC)are both increased(Ueff=616(10)K;TB=6 K).The effort of further enhancing Ueff and TB in such heteroleptic organolanthanide sandwiches should rely on keeping increasing the ligand axiality.
基金supported by the National Natural Science Foundation of China(22171192)the“1000-Youth Talents Program”,the Science&Technology Department of Sichuan Province(2022ZYD0050)the Fundamental Research Funds for the Central Universities。
文摘The size complementarity between a host and a vip is a critical prerequisite for selective molecular recognition.Numerous artificial host systems have been designed to achieve size-selective recognition and chemical transformations.However,the inherent challenge lies in the fixed selectivity governed by a size-exclusion mechanism dictated by the host's structure.Modulating the selectivity necessitates structural modifications of hosts.Examples of host systems with modifiable sizeselectivity are rare.In this study,we present an approach to modulating vip-selectivity via endo-functionalization of supramolecular cavities.Heteroleptic Pd_(2)A_(3)B-cages are constructed with a Pd_(2)A_(3)precursor or directly from palladium ions and relevant ligands.Furthermore,the simultaneous and selective formation of multiple hetero-cages was achieved by simply mixing PdIIand the free ligands in a one-pot reaction.The fidelity of the assembly process relies on cooperative steric control at the periphery and within the cavity of the hetero-cages,respectively.The central steric group also functions as the endohedral moiety.Variations of the endohedral groups facilitate facile and modular derivatization of the microenvironment within the cages,enabling the fine-tuning of vip binding affinities as evidenced by titration experiments.This strategy offers a new solution for the development of customized host structures.
基金supported by the National Key Research and Development Program of China(2021YFB3601502)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(ZDBS-LY-SLH035)+3 种基金the National Natural Science Foundation of China(22193044,22335007,22361132544)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0880000)the Tianshan Basic Research Talents(2022TSYCJU0001)the CAS Project for Young Scientists in Basic Research(YSBR-024)。
文摘Nonlinear optical(NLO)materials enable direct second-harmonic generation(SHG)of coherent ultraviolet(UV)light,yet achieving phase matching(PM)in systems dominated by non-π-conjugated units remains a critical bottleneck.Herein,we present the first rare-earth nitrate sulfamate,La(SO_(3)NH_(2))_(2)NO_(3)·H_(2)O,designed through synergistic anion engineering by integrating La^(3+)withπ-conjugated[NO_(3)]units and heteroleptic tetrahedra[SO_(3)NH_(2)].This crystal achieves a short PM wavelength(258 nm)and UV cutoff edge(234 nm),a large SHG response(1×KH_(2)PO_(4)),and a record birefringence(0.077@546 nm),overcoming the transparency-anisotropy-SHG response trade-offs in inorganic sulfamate-based materials.The results demonstrate that the heteroleptic tetrahedra[SO_(3)NH_(2)]play a key role in modulating the band gap of La(SO_(3)NH_(2))_(2)NO_(3)·H_(2)O,while the(d-p)πinteraction between the La and[NO_(3)]units further enhances optical anisotropy.Our work establishes synergistic anion engineering as a paradigm for developing high-performance UV NLO materials through a rational combination of heteroleptic tetrahedra andπ-conjugated motifs.
基金the PL-Grid Infrastructure and resources provided by the ACC Cyfronet AGH(Cracow,Poland).
文摘The evaluation of N’-(1-(2-pyridyl)ethylidene)nicotinohydrazide(HL)as a linker for the Pb^(II)tagged extended structures is described.The reaction of Pb(ClO_(4))_(2)or Pb(OAc)_(2)with HL in MeOH at 60℃and room temperature,respectively,leads to heteroleptic complexes{[PbL]ClO_(4)}n·nH_(2)O and[PbL(OAc)]_(2),while the same reaction of Pb(ClO_(4))_(2)with HL at 60℃in the presence of two equivalents of NaOAc or NaNO_(2)leads to heteroleptic complexes{[Pb(HL)(OAc)]ClO_(4)}_(n)and[PbL(NO_(2))]n,respectively.Using Pb(NO_(3))_(2)as a source of Pb^(II)in the same reaction with HL and two equivalents of NaN_(3)or NaNCS at room temperature yields[PbLN_(3)]_(n)and[Pb_(2)(HL)_(2)(NO_(3))_(2)(NCS)_(2)],respectively.The room temperature reaction of Pb(NO_(3))_(2)with HL in the presence of two equivalents of NaClO_(4)leads to the transformation of the parent ligand to its perchlorate salt[H_(2)L]ClO_(4).In all the obtained Pb^(II)structures,HL or its deprotonated form L acts both as a chelating and a bridging ligand.The nature of the inorganic anion also influences the final structure.In all complexes the Pb^(II)center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151°to 232°.The sterically available Pb^(II)ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes.As a result of tetrel bonding,the structures of all the six compounds can be extended to a higher dimensional framework,which is further stabilized byπ…πstacking interactions between the aromatic rings.The DFT based charge and energy decomposition(ETS-NOCV)calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.
文摘Ruthenium polypyridyl complexes are known for their excellent photophysical properties and rich electrochemical behavior.Thus,developing complexes with multifunctional behavior showing potential applications in multiple fields is of great importance.Herein,we report a new aggregation-induced emission(AIE)active bis-heteroleptic ruthenium(Ⅱ)complex(Ru-4)of 4,7-diamino 1,10-phenanthroline along with a series of other bis-heteroleptic Ru(Ⅱ)polypyridyl complexes(Ru-1,Ru-2 and Ru-3)containing 4,7-disubstituted 1,10-phenanthroline and two homoleptic complexes(Ru-5 and Ru-6)of 2,2’-bipyridine and 1,10-phenanthroline.
基金funded by the grant of the Russian Science Foundation,grant number 21-73-10204The authors gratefully acknowledge the Assigned Spectral-Analytical Center of FRC Kazan Scientific Center of RAS(NMR,X-ray,electrochemical measurements)and the scholarship program of the German Academic Exchange Service(DAAD,X-ray structure determination of 2b)Y.S.G.is grateful for the support of the Ministry of Science and Higher Education of the Russia Federation.
文摘Aryl-substituted sodium 1,2-diphosphacyclopentadienides Na(P_(2)C_(3)R_(3))(R=Ph,4-Me-C_(6)H_(4),4-Cl-C_(6)H_(4))(1a-c)react with[FeCp(η^(6)-C_(6)H_(5)CH_(3))][PF6]to give heteroleptic 3,4,5-triaryl-1,2-diphosphaferrocenes[FeCp(η^(5)-P_(2)C_(3)R_(3))](2a-c)in 71-78%yield.The structures of 2a-c were confirmed by NMR,UV-Vis spectroscopy and X-ray structure analysis,and supported by DFT calculations.Electrochemical studies of 2a-c in CH3CN demonstrate a pronounced reversible one-electron oxidation,while in the solid state,all 3,4,5-triaryl-1,2-diphosphaferrocenes show fully reversible oxidation and reduction waves,which indicates the stability of the oxidized form.Regardless of the substituent(R=Ph,4-Me-C_(6)H_(4),4-Cl-C_(6)H_(4)),the studied 1,2-diphosphaferrocenes have similar oxidation and reduction potentials.
基金the National Key Basic Research Program of China(Grant No.2013CB933402)the Natural Science Foundation of China(No.21290174,21631003,and 21401009)the China Scholarship Council,University of Science and Technology Beijing is gratefully acknowledged.
文摘Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 K and 28 K,respectively,providing an alternative method towards enhancing the magnetic behavior.
基金supported by the National Natural Science Foundation of China(21572176,21875179,21602170 and 51803163)the Natural Science Foundation of Shaanxi Province(2019JZ-29 and 2019JQ-188)+3 种基金the China Postdoctoral Science Foundation(2016M600778)the Shaanxi Province Postdoctoral Science Foundation(2017BSHEDZZ03)the Fundamental Research Funds for the Central Universities(xjj2017099,xjj2016061 and cxtd2015003)the Key Laboratory Construction Program of Xi’an Municipal Bureau of Science and Technology(201805056ZD7CG40).
文摘A series of 2-phenylpyridine(ppy)-type cyclometalating ligands containing rigid 5,9-dioxa-13bboranaphtho[3,2,1-de]anthracene(OBA)units have been developed.Together with different ppy-type cyclometalating ligands with a phenylsulfonyl group(–SO_(2)Ph)substituted at different positions,new unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes have been successfully synthesized.Their photophysical,electrochemical and electroluminescence(EL)behaviors have been fully characterized.In addition,both time-dependent functional theory(TD-DFT)and natural transition orbital(NTO)theoretical results have been obtained to gain insight into the optoelectronic behaviors of these unsymmetric Ir(Ⅲ)complexes with OBA units.The NTO results indicate that the features of the lowest triplet excited states(T_(1))can be delicately tuned by combination between the OBA-based cyclometalating ligand and another ppy-type ligand with the–SO_(2)Ph group.Importantly,these unsymmetric Ir(Ⅲ)complexes can exhibit very high phosphorescence quantum yield(Φ_(p))higher than 0.90 due to the highly rigid OBA unit which can effectively restrain non-radiative processes.In addition,an electron injection/transporting(EI/ET)ability can be conferred to these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes by both OBA and–SO_(2)Ph moieties.Taking advantage of these merits,organic light-emitting diodes(OLEDs)based on these unsymmetric heteroleptic cyclometalated Ir(Ⅲ)complexes can show a high maximum external quantum efficiency(ηext)of 12.8%,a current efficiency(η_(L))of 51.1 cd A^(−1),and a power efficiency(η_(P))of 40.5 lm W^(−1) for a yellowish-green device,while EL efficiencies for red devices are 6.8%,13.9 cd A^(−1),and 12.8 lm W^(−1),respectively.All these results indicate the good potential of the rigid OBA unit in developing functional phosphorescent emitters.
基金supported by the National Natural Science Foundation of China (20703015,20973076,and 21003057)Program for New Century Excellent Talents in Heilongjiang Provincial University of China (1154-NCET-010)
文摘A variety of heteroleptic ruthenium sensitizers have been engineered and synthesized because of their higher light-harvesting efficiency and lower charge-recombination possibility than the well known homoleptic N3 dye. As such, a great deal of atten- tion has been focused on sensitizers with the general formula Ru（ancillary-ligand）（anchoring-ligand）（NCS）2, among which important examples are Ru（4,4＇-bis（5-hexylthiophen-2-yl）-2,2＇-bipyridine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （C101） and Ru（N-（4-butoxyphenyl）-N-2-pyridinyl-2-pyridinamine）（4,4＇-carboxylic acid-4＇-2,2＇-bipyridine）（NCS）2 （J13）. In order to simulate experimental conditions with different pH values, the photosensitizing processes of these sensitizers pos- sessing different degrees of deprotonation （2I-I, lit to OH） have been explored theoretically in this work. Their ground/excited state geometries, electronic structures and spectroscopic properties are first calculated using density functional theory （DFT） and time-dependent DFT （TDDFT）. The absorption and emission spectra of all the complexes in acetonitrile solution are also predicted at the TDDFT （B3LYP） level. The calculated results show that the ancillary ligand contributes to the molecular or- bital （MO） energy levels and absorption transitions. It is intriguing to observe that the introduction of a thiophene group into the ancillary ligand leads directly to the increased energy of the absorption transitions in the 380-450 nm region. The calcula- tions reveal that although deprotonation destabilizes the overall frontier MOs of the chromophores, it tends to exert a greater influence on the unoccupied orbitals than on the occupied orbitals. Consequently, an obvious blue shift was observed for the absorptions and emissions in going from 21-1, 1H to OH. Finally, the optimal degree of deprotonation for C101 and J13 has al- so been evaluated, which is expected to lead to further improvements in the performance of dye-sensitized solar cells （DSSCs） coated with such sensitizers.
