Metallophilicity-Induced Clusterization: Single-Component White-Light Clusteroluminescence with Stimulus Response

Open AccessCCS ChemistryCOMMUNICATION5 Aug 2022Metallophilicity-Induced Clusterization: Single-Component White-Light Clusteroluminescence with Stimulus Response Xueqian Zhao†, Parvej Alam†, Jianyu Zhang, Shiyun Lin, Qian Peng, Jun Guodong Liang, Sijie Chen, Jing Herman H. Y. Sung, Jacky W. Lam, Ian D. Williams, Xinggui Gu, Zheng Zhao and Ben Zhong Tang Zhao† Department of Chemistry Hong Kong Branch Chinese National Engineering Research Center for Tissue Restoration Reconstruction, The University Science Technology, Clear Water Bay, Kowloon, 999077 †X. P. Alam contributed equally to this work.Google Scholar More articles by author , Alam† Zhang Google Lin MOE Key Laboratory Organic OptoElectronics Molecular Engineering, Chemistry, Tsinghua University, Beijing 100084 Peng CAS Solids, Institute Sciences, Academy 100190 School Materials Chemical Anhui Jianzhu Hefei 230601 Liang PCFM GDHPPC Labs, Sun Yat-sen Guangzhou 510275 Chen Ming Wai Lau Centre Reparative Medicine, Karolinska Institutet, Sung Lam Williams Gu *Corresponding authors: E-mail Address: [email protected] Advanced Innovation Soft Matter College State Resource 100029 Shenzhen Aggregate Kong, Shenzhen, Guangdong 518172 Aggregation-Induced Emission, SCUT-HKUST Joint Institute, Luminescent Devices, South China 510640 AIE Development District, Huangpu, 510530 https://doi.org/10.31635/ccschem.021.202101392 SectionsSupplemental MaterialAboutAbstractPDF ToolsAdd favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail showing metallophilic interactions continue attract considerable theoretical experimental attention largely because their unusual unanticipated photophysical behavior as well unique stimuli-responsive in an aggregate or solid state. Metallophilic are mostly found between metals either identical (d10–d10) different (s2–d8, d8–d10) configurations. Among various interactions, aurophilic (Au?Au) well-known widely reported. In study, a new phosphorescent gold(I) complex, [(CF3Ph)3PAuC?CPh] (TPPGPA) was crystal structure TPPGPA demonstrated the formation trimers caused intermolecular interactions. These trimeric crystals showed efficient nearly pure white-light emission Commission Internationale de L’Eclairage 1931 chromaticity coordinates (0.33, 0.34) at ambient conditions. Moreover, displayed fascinating mechanochromic thermochromic luminescence properties crystalline application temperature-responsive illumination also successfully demonstrated. molecular packing temperature-dependent modulation were subtly taken functional relationship correlation wavelength intensity. It is anticipated that present results will provide insights into design strategy construction intelligent complex-based luminescent materials. Download figure PowerPoint Introduction Interactions atoms molecules contribute cohesion chemical biological systems play fundamentally important role assembly recognition processes.1 For example, observed receptor–ligand, DNA–protein, antigen–antibody, sugar–lectin, RNA–ribosome, so on.2 Thus, study non-covalent profound significance. Unlike other extensively studied nonmetallic such hydrogen bonding,3 dipole–dipole interactions,4 ??? interactions,5 hydrophobic effects,6 generally induced orbital hybridization, dispersion, relativistic effects metal-containing systems.7 suggested be critical structural assembly,8,9 catalysis,10 luminescence,11–13 sensing applications.14 However, metal nature poorly understood overall interaction not equivalent interaction.15 last decade, research on especially clusters16,17 complexes,18,19 has attracted substantial interest precise alteration these Therefore, very attractive topic comprehensively understand structure–activity relationship. On hand, some cases, cluster state brings isolated molecules. many non-conjugated organic proteins, enzymes, starch, cellulose emissive solution but become after formation. Recently, turn-on been attributed phenomenon termed clusteroluminescence.20 Similarly, clusters complexes exhibit no emit strongly state.19,21 may which crucial role. all aurophilicity exists field centers have [5d10] closed-shell electronic configuration introduce only weak van der Waals forces.22–24 (7–12 kcal/mol) endow gold force comparable even stronger than bonds can readily regulated tune properties.25,26 interesting phenomena triggered discovered state, transition from fluorescence phosphorescence,27 conversion dark bright emission,28 extension color visible infrared region,29 on.30,31 it foreseeable metallophilic-induced clusterization (MIC) specific functionalities find wide applications fields increasingly anti-counterfeiting,32 materials,33,34 high-tech devices.35–38 Correspondingly, mechanisms MIC significant instructive guide future development more luminogens.22,24,39 few systematic studies conducted far, where specifically crystallographic evidence aurophilicity-regulated emissions (I) remains unexplored. Precise control stacking one vital approaches access issue, heavily relies ideal prototype molecule achieve regulation along keen insight matters aurophilicity.40–44 addition, several reports published covering entire region; however, white-emitting scarce.30,45,46 Herein, trinuclear alkynylgold(I) (TPPGPA), synthesized one-pot synthetic protocol.47 This simple easily complex aggregation-induced (AIE)48–50 characteristics. exhibited both due compact conglobate robust motions co-governed thermal equilibrium triplet charge-transfer monomer explained distinct dual phosphorescence room temperature (RT). Because distinctive conformations properties, we set out determine changes investigate possible Finally, material polymer matrix studied. Its further coating blue-light lamp. Results Discussion facilely reacting amounts phenylacetylene chloro[tris(4-trifluoromethylphenyl)phosphine]gold(I) high yield 75%.51,52 characterized standard spectroscopic techniques 1H, 13C, 19F, 31P NMR spectroscopies ( Supporting Information Figures S1–S4), high-resolution mass spectrometry, elemental analysis. To obtain information, X-ray diffraction (XRD) analysis single performed. optical first investigated degassed dichloromethane (DCM) solution. UV–vis absorption spectra broad band spanning 250 300 nm, tentatively assigned mixture spin-allowed ligand-to-metal (1LMCT) ligand-centered (1LC) ?–?* Figure S5). Such assignment good accordance interpretation time-dependent density theory (TDDFT). As shown Table S1, DFT indicated maximum located 288 nm S0 ? S4 transition, mainly 1LC 1LMCT states oscillator strength 0.4419. photoluminescence (PL) spectrum recorded RT (293 K) frozen (77 concentrations 10?5 10?3 M. concentration-independent 293 K. conditions, three narrow concentration-dependent peaks 423, 443, 464 1a 1b. spread 400 500 vibrational monomer. According mechanism restriction intramolecular motion (RIM),53 non-emissive DCM motions, allowed excited decay non-radiatively. PL dimethylformamide (DMF)/water mixtures evaluate aggregation effect light process. 1c 1d, increasing water fraction (fw) DMF/water 0% 40% exerted change At fw ? 50%, became stronger, peak appeared ?490 signaling aggregates. aggregates could revealed dynamic scattering (DLS) measurements average hydrodynamic diameter 210 80% S6. intensity = 80%, being ?20 times higher DMF. newly monomeric quantum (QY) still low (QY < 1%), suggesting Au?Au 1 | (a b) 77 inset (a) shows TPPGPA. (c) fractions (fw). (d) A plot relative (?AIE I/I0) versus composition TPPGPA, I0 0%, concentration 10 ?M, ?ex 365 nm. Inset: photographs content presence UV irradiation hand-held Interestingly, conditions including maxima bands centered 475 578 relatively QY 15.5%. associated (CIE) quite close 0.33) white defined CIE demonstrates component (Figures 2a 2b).54 mechanism, prepared analyzed single-crystal RT. 2c S7, unit cell motifs triclinic system. cell, structures shorter 2.95 3.15 Å. values sum two Van Waals’ radii (3.32 Å), indicating strong among atoms.55 Additionally, trimer experienced staggered conformation respect tris(4-(trifluoromethyl)phenyl)phosphine group minimize hindrance free energy. driving intriguing intrinsic reveal arrangements packing, mechanical grinding performed precisely tuned altering Au–Au 2d, (?max nm) converted greenish-yellow 515 powder grinding. Powder XRD (PXRD) arrangements, is, ordered disordered crystalline-to-amorphous, responsible S8a. depicted S8b presented detailed changes. short-wavelength red-shifted 40 nm), while long-wavelength disappeared value decreased 15.5% 1%. Presumably, trimer, disassembled increase possibility having external stimuli. suggests origin contributions 2 image 360 (b) 50% probability ellipsoids. Hydrogen omitted clarity. PXRD patterns amorphous states, sample under before (e) Electron cloud distributions (gas state) (solid-state) ground TD-DFT B3LYP/(6-31G**+LANL2DZ) level schematic illustration anisotropic pressure ignited our examine its piezochromic isotropic pressure. Diamond anvil (DAC) equipment perform high-pressure experiments, generate hydrostatic dozens gigapascals (GPa) S9, thoroughly shift red-shift within about 2.18 GPa. variable chromism modeled gradually varying intra-/inter-molecular distance gold–gold pressures. noticeable affected applied pressure, indicates crystals. crystals, lifetime maxima, ?max 488 580 carried temperatures ranging 297 Independent temperature, monoexponentially microsecond obtained wavelengths S10). When K, increased 6.9 9.5 ?s 10.8 17.6 ?s, respectively. decreasing nonradiative rate usually occurs lower temperatures. measurement ruled thermally activated delayed emitting excitation monitoring S11. ?360 self-governed came closely spaced states. Hence, lowest ascribe gain TDDFT calculations based clusters. frontier orbitals gas picked 2e. case monomer, highest occupied (HOMO) composed delocalized phenylethynyl little atom; unoccupied (LUMO) tris[para-(trifluoromethyl)phenyl]phosphine (Figure 2e S12). HOMO over minor neighboring Au(I) centers. LUMO electron densities group. Considering calculations, lowest-energy transitions described predominantly LMCT small ligand-to-ligand (LLCT) S14 S2). ligand-to-metal–metal (LMMCT) proposed Based above discussion, rational After relaxation S1 fast intersystem crossing occurred T1 T1?. metal-perturbed 3??* intracomplex (3LLCT) character. Meanwhile, metallophilicity-induced endowed low-lying energy (T?) intercomplex CT 3LMMCT nature.56 suggest originates lying mixed (3LMMCT)/(3LMCT). sensitive offered opportunity regulating mode Furthermore, gap calculated 3.77 3.31 eV, respectively S13). difference (?E 0.46 eV) species spaced. current indicate levels ?1.73 ?1.98 eV contrast, ?5.50 ?5.29 Destabilization stabilization typically S14).25,57 regulate level, temperature-variable 100 details refined given 3a Tables S3–S11, there existed phase transitions. coefficients expansion a, b, c axes large equal 53.3 × 10?6 K?1, 121.5 72.1 respectively, coefficient cubical 236.3 K?1. S15. worth mentioning (?) expands elevated falls range 0 K?1 20 positive lattice system, orders magnitude those seen materials.58,59 Besides, maintained same (134.6 K?1). speculate parameters structure. stimulus induce subtle responses 3 Plots volume (black line) distances (red (average). during cooling process interval time min cycle cooling–heating heating processes, (f) position short- I0,S I0,L ?S band, ?L band. verify exact connection 77-297 K systematically conducted. 3b, temperature. 585 (297 603 remained unchanged whole redshift Stokes (?ex (?em 10,303.24 cm?1 distortion often metal–metal 10,813.51 cm?1, supports should mentioned reversible 3c Sup