Synthesis and characterization of Pt1Ag13 and Pd1Ag13 nanoclustersPt1Ag13 and Pd1Ag13 were successfully synthesized using a convenient one-pot synthetic method, as described in the Methods. The overall structure is shown in Fig. 1a, b. The chemical compositions of Pt1Ag13 and Pd1Ag13 were confirmed by electrospray ionization mass spectrometry (ESI-MS) in the positive ion mode. In the ESI-MS spectrum of Pt1Ag13, a strong signal was observed at m/z 4761.07 (Fig. 1c), corresponding to the [Pt1Ag13(PFBT)6(TPP)7Cs]+ species (calculated at m/z 4761.06). Similarly, the ESI-MS spectrum of Pd1Ag13 exhibited a prominent peak at m/z 4673.03, which was assigned to [Pd1Ag13(PFBT)6(TPP)7Cs]+ (calculated at m/z 4673.00) (Fig. 1d). These assignments were supported by the excellent correlation between the experimental and simulated isotopic patterns, indicating that both NCs were charge-neutral. The thermogravimetric measurements (Supplementary Figs. 1, 2) showed a weight loss of 65.21% for Pt1Ag13 and 66.45% for Pd1Ag13, respectively, which aligned with the theoretical ligand contents of 65.48% for Pt1Ag13 and 66.75% for Pd1Ag13, respectively. X-ray photoelectron spectroscopy confirmed the presence of Pt and Ag in Pt1Ag13 and Pd and Ag in Pd1Ag13. Pt and Pd exhibited nearly zero valence states at the centers of Pt1Ag13 or Pd1Ag13 (Supplementary Figs. 3–6). The Ag 3d5/2 peak at 368.4 eV suggests that the Ag valence state is close to that of Ag(I) (Supplementary Fig. 7). Inductively coupled plasma-atomic emission spectroscopy and energy-dispersive spectrometry (Supplementary Figs. 8, 9 and Supplementary Table 1) were performed to identify the composition and purity of the NCs. Moreover, Pt1Ag13 and Pd1Ag13 exhibited an odd number of valence electrons (13–6 = 7), similar to previously reported Ag23 and Ag34 NCs41,42. The presence of an unpaired electron was further evidenced by a solid-state electron paramagnetic resonance analysis, which showed a strong signal at g = 2.003, with one local maximum and one local minimum (Supplementary Figs. 10, 11).Fig. 1: X-ray structure and ESI-MS results of Pt1Ag13 and Pd1Ag13.a, b Ball-and-stick representation of Pt1Ag13 (a) and Pd1Ag13 (b). c, d ESI-MS results of Pt1Ag13 (c) and Pd1Ag13 (d) nanoclusters. Insets: experimental (in black) and simulated (in red) isotope patterns. e Sequence from inside to outside showing M1Ag11 (M = Pt, Pd) kernel, P ligands, M1Ag11@5 P, two Ag1S3P1 motifs, and M1Ag11@5 P@(Ag1S3P1) frame. For clarity, the H atoms are omitted. Color labels: blue, Pt or Pd; yellow, Pt; green, Pd; sky blue, Ag; red, S; magenta, P; orange, F; gray, C.Single-crystal X-ray crystallography revealed that Pt1Ag13 and Pd1Ag13 adopt the P−1 space group (Supplementary Figs. 12, 13 and Supplementary Tables 2, 3). Both NCs comprised a crown-like M1Ag11 kernel with Pt or Pd atoms in the center surrounded by five PPh3 ligands and two Ag(SR)3(PPh3) motifs (Fig. 1e). Compared to the icosahedral M13 kernel of Pt1Ag14 reported by Huang et al. 43. the loss of one vertex Ag atom in the crown-like M12 kernel caused structural distortion with five neighboring non-coplanar Ag atoms, changing the Ag-Ag-Ag bond angle (Supplementary Fig. 14). Most metal NCs with M13 as the kernel contained complete surface shells and closed electronic configurations. However, it was extremely rare for vacant atomic positions to form on the standard M13 core. Therefore, Pt1Ag13 and Pd1Ag13 not only had open-shell electronic configurations, but also open geometric cores. By contrast, we found that the subtle difference between the kernel bond lengths in Pt1Ag13 and Pd1Ag13 was observed. The Pt-Ag length (on average, 2.747 Å) was slightly longer than the Pd-Ag length (on average, 2.742 Å), while the Ag-Ag lengths in the kernel of the Pt1Ag13 (on average, 2.886 Å) were slightly shorter than those of the Pd1Ag13 (on average, 2.892 Å) (Supplementary Fig. 15). Additionally, five Ag atoms located at the waist of the M12 kernel were bounded to five PPh3 ligands, whereas the either side six Ag atoms were connected to six S atoms from two Ag(SR)3(PPh3) motifs. Only one type of Agk-S-Ags mode was observed for Pt1Ag13 and Pd1Ag13 (Supplementary Fig. 16). The Ag-S lengths (on average, 2.550 Å) of Pt1Ag13 were almost identical to that of Pd1Ag13 (on average, 2.549 Å), while the Ag-P lengths (on average, 2.461 Å) of Pt1Ag13 was slightly shorter than that of Pd1Ag13 (on average, 2.469 Å), suggesting a slightly more compact shell structure of the former (Supplementary Fig. 15). Subtle differences in bond lengths may arise from the different behaviors of Pt and Pd nucleation.Dual emission of Pt1Ag13 and Pd1Ag13 nanoclustersThe ultraviolet-visible (UV-vis) absorption spectra of Pt1Ag13 and Pd1Ag13 are shown in Fig. 2a and Supplementary Fig. 17, respectively. Specifically, three prominent absorption peaks centered at 390, 470, and 600 nm are observed for Pt1Ag13. For Pd1Ag13, three significant peaks are observed at 420, 497, and 680 nm. This red shift of Pd1Ag13 compared with that of Pt1Ag13 in optical absorption may be attributed to their different electronic structures, which is consistent with the previous investigations on [PtAg24(SR)18]2− and [PdAg24(SR)18]2− (SR = 2,4-dichlorobenzenethiol) NCs44. The PL spectra revealed the presence of DE in both NCs, as shown in Fig. 2a and Supplementary Fig. 18. Specifically, Pt1Ag13 in 2-Me-THF solution exhibited one visible peak centered at 660 nm and one NIR peak centered at 825 nm, with photoluminescent quantum yield (PLQY) determined to be 1.49%. Similarly, the Pd1Ag13 in 2-Me-THF solution shows DE centered at 748 and 830 nm, respectively, with the PLQY measured to be 0.07%. The difference in the PLQY between the two NCs may be caused by different electron affinity of Pt or Pd (i.e., the capability to attracting electron)45,46. The stronger electron affinity of Pt may lead to enhanced charge transfer abilities, resulting in higher PLQY in Pt1Ag13.Fig. 2: Optical Properties of Pt1Ag13.a Ultraviolet-visible absorption and photoluminescence (PL) spectra of Pt1Ag13 in 2-Me-THF. Abs: absorption, Em: emission. b PL I and PL II decay curves of Pt1Ag13 at 390 nm excitation. Ex: excitation. c PL excitation (PLE) spectrum of Pt1Ag13 at PL I and PL II wavelengths. d Three-dimensional (3D) consecutive PLE/PL map of Pt1Ag13. λex: excitation wavelength, λem: emission wavelength. e PL intensity of PL I and PL II of Pt1Ag13 in 2-Me-THF at different excitation wavelengths. f The percentage of lifetime τ1 and τ2 of PL I and PL II in Pt1Ag13 excited at 390, 425, 470, and 505 nm, respectively.The dynamics of the DE in Pt1Ag13 and Pd1Ag13 were investigated by time-correlated single-photon counting. The average lifetimes of Pt1Ag13 were calculated to be approximately 1.148 and 1.886 μs, respectively, according to the fitting results of the decays of PL I and PL II, indicating that PL I and PL II may exhibit phosphorescence (Fig. 2b, Supplementary Fig. 19 and Supplementary Table 4). In addition, the PL I and PL II intensities were simultaneously enhanced under an N2 atmosphere and reduced under an O2 atmosphere (Supplementary Figs. 20–22). Furthermore, the peak at 415 nm corresponding to the characteristic absorption of 1,3-diphenylisobenzofuran in solution containing Pt1Ag13 decreased rapidly, confirming the presence of singlet oxygen (Supplementary Fig. 23). These findings indicated that PL I and PL II of Pt1Ag13 exhibit phosphorescence. Similar results were observed for Pd1Ag13, with average lifetimes of approximately 1.034 μs and 1.509 μs for PL I and PL II respectively, both exhibiting phosphorescent characteristics. (Supplementary Figs. 24–28 and Supplementary Table 5).We performed PL excitation (PLE) and wavelength-dependent PL analyzes to reveal the origin of DE in Pt1Ag13 and Pd1Ag13. The PLE spectra of Pt1Ag13 in 2-Me-THF for PL I and PL II were primarily located at 390, 425, 470, and 505 nm, with a new peak emerging at 600 nm upon PL II excitation (Fig. 2c). The maximum excitation peaks for PL I and PL II were different and located at 390 and 470 nm, respectively. The PLE spectra were not aligned with their absorption spectra, conversely to previously reported NCs, such as [Pt1Ag30(S-Adm)14(Bdpm)4Cl5]3+ (Bdpm = N, N-bis-(diphenylphosphino)methylamine) and Au2Cu6(S-Adm)6(TPP)2, where the PLE and absorption spectra were similar31,47. Hence, neither PL band was excited by the Pt1Ag11-core-based HOMO-LUMO transition.Notably, the three-dimensional (3D) PL/PLE spectra showed a distinct difference between PL I and PL II of Pt1Ag13 (Fig. 2d). The PL I intensity exhibited dynamic fluctuations at different excitation wavelengths ranging from 310 to 630 nm, with the strongest emission observed at an excitation wavelength of 390 nm. Interestingly, no PL I emission was observed under 600 nm excitation. In contrast, PL II displayed a prominent peak emission under excitation at 470 nm, which diverged significantly from that of PL I in the 3D PL/PLE spectra (Fig. 2e and Supplementary Fig. 29). Furthermore, the excitation-dependent decay measurements of PL I and PL II were performed. Two exponential lifetimes were required to fit the PL I and PL II decays. The decay and rise of the τ1 and τ2 of PL I were accompanied by the rise and decay of the τ1 and τ2 of PL II (Fig. 2f, Supplementary Fig. 19, and Supplementary Table 4), which may result from the overlap of the two PL bands, similar to that reported for the Au20 and Au24 NCs29,32. Considering the correlation between the two PL bands, we deduced that PL I and PL II may originate from two distinct emitting states in Pt1Ag13. The PLE and wavelength-dependent PL spectra of Pd1Ag13 were also analyzed (Supplementary Figs. 30, 31). It was found that both PL I and PL II were present under excitation at 420, 497, and 600 nm. However, only PL II emission was observed under excitation at 680 nm. The result of excitation-dependent decay measurements of PL I and PL II in Pd1Ag13 was similar to that observed in Pt1Ag13 (Supplementary Table 5). Therefore, we posited that PL I and PL II in Pd1Ag13 may also stem from two distinct emitting states. Moreover, time-tracking UV-vis and PL spectra of Pt1Ag13 and Pd1Ag13 in 2-Me-THF solution were performed at room temperature, indicating its photo-stability for several hours (Supplementary Figs. 32, 33). Additionally, to determine whether the aggregates induced DE, PL tests on the Pt1Ag13 and Pd1Ag13 in 2-Me-THF solution at various concentrations were also conducted. As shown in Supplementary Figs. 34, 35, DE persisted even at low concentrations, eliminating the possibility of DE due to the aggregation-induced emission effect.Temperature-dependent photoluminescence of Pt1Ag13 and Pd1Ag13 nanoclustersTo further understand the nonradiative relaxation process of the two emitting states, temperature-dependent steady-state PL measurements of Pt1Ag13 and Pd1Ag13 in 2-Me-THF were performed (Fig. 3a, Supplementary Fig. 36a). Upon decreasing the temperature from 293 to 193 K, the PL I and PL II peaks of Pt1Ag13 exhibited blue shifts of 40 and 10 nm, respectively. The visualized color change of Pt1Ag13 with temperature and the chromaticity coordinates x and y were plotted on a CIE 1931 color space chromaticity diagram, showing a shift from reddish-orange (CIE: 0.65, 0.35) to orange (CIE: 0.61, 0.39), as shown in Fig. 3c. Notably, the PL I intensity increased 3.64-fold, while the PL II intensity remained essentially unchanged in the temperature range of 293-193 K (Supplementary Table 6). Additionally, the temperature-dependent intensity for PL I and PL II of Pt1Ag13 were quantitatively depicted in Fig. 3b. The behavior of PL I band of Pt1Ag13 was more typical, with the initial intensity I0 decreasing above 193 K owing to thermally activated quenching. With only one dominant nonradiative channel, this quenching process can be described by the Arrhenius expression48:$$I\left(T\right)=\frac{{I}_{0}}{1+\,a{e}^{\frac{{-E}_{a}}{{{{{{{\rm{k}}}}}}}_{{{{{{\rm{B}}}}}}}T}}}$$
(1)
Fig. 3: Temperature-dependent PL spectra of Pt1Ag13.a Variable-temperature PL spectra of Pt1Ag13 in 2-Me-THF. The color boxes represent the blue and red shift trends of PL I and PL II respectively. b Normalized integrated PL I and PL II intensities were fitted using Eqs. 1 and 2, respectively; the integration of PL II is separated as regions I and II. The colored box on the left represents Region I, and the colored box on the right represents Region II. c CIE 1931 color space chromaticity diagram showing the luminescence color change of Pt1Ag13 in the temperature range of 193-293 K.In our model, we considered a single dominant phonon-assisted nonradiative channel, where “a” represents the ratio of nonradiative and radiative probabilities, and “Ea” denotes the activation energy of the quenching channel. When Eq. 1 to the temperature dependence of the PL I intensity was applied, we obtained Ea values of 48.94 meV for Pt1Ag13.The temperature dependence of the PL II emission of Pt1Ag13 exhibited more complex behavior. The intensity of the PL II peak of Pt1Ag13 increased with temperature and reached its maximum at approximately 263 K (region I). Thereafter, it started to decrease as the temperature increased (region II). In region II, the decrease in PL II intensity followed a trend similar to that of the PL I band, indicating a nonselective thermally activated nonradiative relaxation pathway (Fig. 3b). However, in region I, an additional non-radiative channel appeared. To account for this dual-quenching behavior, Arrhenius fitting can be adapted to incorporate a second quenching term, resulting in the following modified expression:$$I\left(T\right)=\frac{{I}_{0}}{1+\,{a}_{1}{e}^{\frac{{-E}_{{a}_{1}}}{{{{{{{\rm{k}}}}}}}_{{{{{{\rm{B}}}}}}}T}}+{a}_{2}{e}^{\frac{{-E}_{{a}_{2}}}{{{{{{{\rm{k}}}}}}}_{{{{{{\rm{B}}}}}}}T}}}$$
(2)
The two competing processes (a1 > 0; a2 < 0) combined to produce the maximum using the fitting parameters from Supplementary Table 7.The a value of Pt1Ag13 decreased drastically from 160.26 (PL I) to 39.56 and -8.54 (PL II a1 and a2), indicating less dependence on the surface motif vibration-induced nonradiative decay in PL II. Although the low-frequency phonon modes were typically attributed to the Au-Au vibrations of the metal kernel in Au NCs, it was challenging to isolate Pt1Ag13 as two nonradiative quenching channels in region I. The origin of the nonradiative quenching channel in region I for Pt1Ag13 may be related to the thermally acclerated internal conversion (IC) between the two emitting states. In other words, the increase in the PL II emission intensity in region I was accompanied by the decrease of radiative PL I transition.The temperature-dependent steady-state PL behavior of Pd1Ag13 in 2-Me-THF closely resembled that observed in Pt1Ag13. The intensity of PL I was increased by 2.88 times, along with a 20 nm blue shift, while the intensity of PL II reached its maximum at 223 K with a 10 nm blue shift, as the temperature decreased. (Supplementary Fig. 36a, b and Supplementary Table 8). The CIE coordinates of (0.71, 0.29) were identical upon temperature decreasing (Supplementary Fig. 36c). The calculated Ea values was 115.73 meV and the a value of Pd1Ag13 also showed a sharp decrease from 115.73 (PL I) to 58.27 and -10.43 (PL II a1 and a2, Supplementary Table 9). Hence, we concluded that in both Pt1Ag13 and Pd1Ag13, PL I may originate from the core-shell CT states, as it was more sensitive to low temperatures owing to the suppression of nonradiative relaxation processes. While PL II, which showed less dependence on temperature, may originate from core-based states.To understand the photophysics of DE, we performed time-resolved transient absorption (TA) spectroscopy measurements with Pt1Ag13. We first looked into the nanosecond relaxation dynamics of Pt1Ag13 by performing ns-TA with excitation of 400 nm and 600 nm. Figure 4a showed the ns-TA data map with excitation of 400 nm that consisted of a negative band at 475 nm and a positive band across 520 nm to 900 nm. The negative band could be assigned to the ground state bleach (GSB) signal which coincided with the UV-vis absorption spectrum as shown in Fig. 4a, b, and the positive band was the excited state absorption (ESA) of the triplet state. The ns-TA data presented a monotonous decay without spectral shift, suggesting no new transient species were generated. The ns-TA data map (Fig. 4b) under 600 nm excitation was similar to that excited at 400 nm, which may be because the excited state dynamics of Pt1Ag13 under the different-energy excited laser were very close to each other thus making the ns-TA set-up cannot distinguish the differences. This was further demonstrated by the almost overlapped kinetic traces at 560 nm with an average lifetime of less than 1 μs (t1 = 71 ns, t2 = 625 ns, Fig. 4c), which was close to the lifetime obtained from the fluorescence lifetime (around 1 μs). We also conducted the fs-TA measurements under 400 nm excitation, the kinetic traces at 600 nm with a lifetime larger than 2 ns were displayed in Fig. 4d, and no more new transient components were obtained. These results indicated that TA spectroscopy mainly probed the dynamics of core-shell CT excited state (PL I), which was much stronger than core-based one (PL II). These results were consistent with the ns-TA test results of reported Au2032.Fig. 4: Excited-state dynamics of Pt1Ag13.a, b The ns-TA data of Pt1Ag13 under 400 nm (a) excitation and 600 nm (b) excitation, all time-resolved spectroscopy measurements are conducted with nitrogen protection. c The kinetic traces at 560 nm of Pt1Ag13 under 400 nm excitation and 600 nm excitation. The dark curves represent the fitting results of experimental data (light curves). d The kinetic trace at 600 nm extracted from the fs-TA data.Theoretical calculations on electronic structures and excited statesTo further investigate the nature of the dual-emitting states, time-dependent density functional theory (TD-DFT) calculations were performed on the optimized structure of the Pt1Ag13 NC. The Pt1Ag13 core is an open-shell superatom with seven superatomic valence electrons (7e). The concept of “open-shell” superatom was previously applied to Ag39 and Ag30749,50, corresponding to open-shell 17-electron and 135-electron superatoms, respectively. Supplementary Fig. 37 illustrates the highest occupied molecular orbitals (α-HOMOs and β-HOMOs) and the lowest unoccupied molecular orbitals (α-LUMOs and β-LUMOs), which are confined to the metal kernel and exhibit a typical superatomic shell (S2P5). The details of the superatomic shell of Pt1Ag13 are presented in Supplementary Table 10.The calculated UV-vis absorption spectrum of Pt1Ag13 in 2-Me-THF agrees well with the experimental results (Fig. 5a). The absorption spectrum of Pt1Ag13 can be divided into three regions, and three states (a, b and c) with higher oscillation intensities specifically chosen from the numerous excitation states. The first region locates at λ < 425 nm (Peak a, λmax = 401 nm), the second is at 425 nm < λ < 550 nm (Peak b, λmax = 460 nm) and the third is at λ > 550 nm (Peak c, λmax = 634 nm). Contributions from three types of transitions in absorption spectrum, including metal-centered transition (MC), metal-ligand charge transfer (MLFCT) and ligand-metal charge transfer (LFMCT) excited states, are also investigated and revealed in Fig. 5a, b. More details of the frontier orbitals, excited states and contributions of metal and ligand fragments are given in Fig. 5c and Supplementary Tables 10, 11.Fig. 5: DFT Calculations of Pt1Ag13.a Experimental and calculated absorption spectrum of Pt1Ag13 with contributions from metal-centered transition (MC), metal-ligand charge transfer (MLFCT) and ligand-metal charge transfer (LFMCT) excited states. b Intuitive diagram of charge transfer excited states. c Molecular orbital scheme of Pt1Ag13 showing the energy levels of frontier orbitals. (superatomic orbitals in Ag core (red), ligand-based π orbitals (blue), ligand-based π* orbitals (green), and the transition densities of the dominant MC (left) and MLCT (right) transitions are also depicted (hole: blue, electron: green).) d Proposed schematic dual emission mechanism of Pt1Ag13. (HE high energy, LE low energy, Ex excitation, ISC intersystem crossing, D0 doublet ground state, Dn core-based doublet excited states, Dn’ core-shell CT doublet excited states, Qn core-based quartet excited states, Qn’ core-shell CT quartet excited states, PL I and PL II phosphorescence emission processes, respectively).The low-energy (LE) absorption above 550 nm is dominated of MC states, where the transitions occur within the frontier superatomic orbitals, eg. from occupied super Px,y,z to unoccupied super Dxy,yz,zx,z2 orbitals. The intermediate range of the spectrum (from 425 nm to 550 nm) involves the mixed excited states that are combined with MLFCT, LFMCT and MC, where contributions of PFBT ligands are involved and TPP ligands are neglectable in these transitions. The high-energy (HE) states below 425 nm could be primarily ascribed to MLFCT states, which involves the transitions from superatomic orbitals of metal core to π* orbitals in PFBT ligands. As electron-poor character of the 7e superatomic Pt1Ag13 core (S2P5, one less valence electron from the 8e shell-closure), MLCT emission might hardly occur. However, PFBT ligands, with fluorine substituted benzene groups, show intense electronegativity and give rise to the low-lying the π* orbitals that is more easily accessible, where the transitions from metal core to PFBT ligands are observed. Therefore, ligand-effect of PFBT play an important role in this series of transition states. In short, high-, mid-, and low- energy transitions are denoted as core-shell CT states, mixed states and core-based states, respectively.Excitation of Pt1Ag13 into the HE absorption at 390 nm results in two emission bands (PL I and PL II), corresponding to core-shell CT and core-based absorptions, while excitation into the LE absorption band at 600 nm results in the emission mirroring the core-based absorption bands (PL II) (see Fig. 2d, e). The ratio of the core-shell CT states consistently decreases with wavelengths ranging from 390 to 630 nm (see Fig. 5a), which aligns with the evolutionary trend of the PL I intensity observed in Supplementary Fig. 38. This confirms that the CT contribution of phosphorescence in PL I primarily occurs from the core-shell CT states. Similarly, the evolutionary trends of PL II and core-based proportions were in agreement. Hence, it is evident that the PL I and PL II emissions originate from two distinct emitting states: core-shell CT and core-based states, respectively. Previous studies51 give evidence for the dual emission coming from two different emissive states in a single complex and thus violating Kasha’s rule52.TD-DFT calculations on the optimized structure of Pd1Ag13 was also performed, show similar nature of electron transitions with Pt1Ag13. The Pd1Ag13 also has a 7e open-shell superatomic core. The calculated UV-vis absorption spectrum of Pd1Ag13 in 2-Me-THF agrees well with the experimental results (Supplementary Fig. 39). The high- (419 nm), mid- (493 nm), and low- (640 nm) energy transitions are also classified as core-shell CT states, mixed states and core-based states respectively according to Supplementary Tables 12, 13.Based on the above experimental and theoretical results, the proposed DE mechanism of open-shell Pt1Ag13 is given in Fig. 5d. The low-lying doublet and quartet states are classified into core-based states (D1, Q1) and core-shell CT states (D1’, Q1’), respectively, and the details can be found in Supplementary Tables 11, 14. The HE absorption is primarily attributed to the core-shell CT, while the LE absorption is attributed to the inner superatomic core. These two types of electronic states experience rapid relaxation from their higher states to the lowest core-based state (D1) and the lowest core-shell CT state (D1’), respectively. After that, they undergo ISC processes to the core-based Q1 and core-shell CT Q1’ states (D1 → Q1, D1’ → Q1’) due to the intense spin-orbit coupling (SOC) interactions induced by Pt and Ag atoms and their close energy levels. As a result, a visible PL I emission is observed from the core-shell CT states, and an NIR PL II emission is observed from the core-based states. As the NIR PL II emission originates from the core states, it is found to be less affected by temperature variation. Given the analogous electron transition characteristics between Pd1Ag13 and Pt1Ag13, the proposed mechanism can also be applied to Pd1Ag13. This DE character of Pt1Ag13 and Pd1Ag13 NC largely depends on the role of electronegative PFBT ligands, providing an effective blueprint for designing materials with DE.
Dual-quartet phosphorescent emission in the open-shell M1Ag13 (M = Pt, Pd) nanoclusters
