A route to metalloligands consolidated silver nanoclusters by grafting thiacalix[4]arene onto polyoxovanadates

Metalloligands provide a potent strategy for manipulating the surface metal arrangements of metal nanoclusters, but their synthesis and subsequent installation onto metal nanoclusters remains a significant challenge. Herein, two atomically precise silver nanoclusters {Ag14[(TC4A)6(V9O16)](CyS)3} (Ag14) and {Ag43S[(TC4A)2(V4O9)]3(CyS)9(PhCOO)3Cl3(SO4)4(DMF)3·6DMF} (Ag43) are synthesized by controlling reaction temperature (H4TC4A = p-tert-butylthiacalix[4]arene). Interestingly, the 3D scaffold-like [(TC4A)6(V9O16)]11- metalloligand in Ag14 and 1D arcuate [(TC4A)2(V4O9)]6- metalloligand in Ag43 exhibit a dual role that is the internal polyoxovanadates as anion template and the surface TC4A4- as the passivating agent. Furthermore, the thermal-induced structure transformation between Ag14 and Ag43 is achieved based on the temperature-dependent assembly process. Ag14 shows superior photothermal conversion performance than Ag43 in solid state indicating its potential for remote laser ignition. Here, we show the potential of two thiacalix[4]arene modified polyoxovanadates metalloligands in the assembly of metal nanoclusters and provide a cornerstone for the remote laser ignition applications of silver nanoclusters.

The data analysis of mass spectrum was performed based on the isotope distribution patterns using Compass Data Analysis software (Version 4.4).

IX. Photocurrent measurement
Photocurrent test and Mott-Schottky experiment were carried out on a CHI660E electrochemistry workstation.The crystals (0.7 μmol) of Ag14 or Ag43 and naphthol (0.5 wt.%, 15 µL) were dispersed in 0.5 mL EtOH and the mixture was sonicated for about 30 min.Then the solution was transferred by pipet dropped on the cleaned ITO glass and the coated film was obtained after evaporation under ambient atmosphere.
The prepared ITO glass film was used as working electrode, a Pt wire as the counter electrode, and an Ag/AgCl electrode as the reference electrode in the aqueous solution of Na2SO4 (0.2 M) maintaining a bias voltage at 0.6 V.

X. Photothermal Conversion Studies
The crystals of Ag14 (2 mg) were dispersed in 0.1 mL EtOH and sonicated for about 10 min, then evenly applied to the surface of the match head.Photothermal measurements were conducted using 660 nm laser (CNI Laser MDL-MD-660-1.3W CE50050).The photothermal behavior of sample was monitored by thermal imaging camera (FLIR E54).Infrared photos and real-time temperatures were extracted from the video by FLIR tools software.

XI. X-ray Crystallography
Single crystals of Ag2, Ag14 and Ag43 with appropriate dimensions were chosen under an optical microscope and quickly coated with high vacuum grease (Dow Corning Corporation) to prevent decomposition.Single-crystal X-ray diffraction data of Ag2, Ag14 and Ag43 were collected on a Rigaku Oxford Diffraction XtaLAB Synergy diffractometer equipped with a HyPix-6000HE area detector at 100 K, 173 K and 100 K using Cu Kα (λ = 1.54184Å) from Photon Jet micro-focus X-ray Source.
The diffraction images were processed and scaled using the CrysAlis Pro software suite. 1 The structures were solved using the charge-flipping algorithm, as implemented in the program SUPERFLIP 2 and refined by full-matrix least-squares techniques against Fo 2 using the SHELXL program 3 through the OLEX2 interface. 4Hydrogen atoms at carbon were placed in calculated positions and refined isotropically by using a riding model.Appropriate restraints or constraints were applied to the geometry and the atomic displacement parameters of the atoms in the cluster.All structures were examined using the Addsym subroutine of PLATON 5 to ensure that no additional symmetry could be applied to the models.Pertinent crystallographic data collection and refinement parameters are collated in Supplementary Table 1.Selected bond lengths and angles are collated in Supplementary Table 2.
Based on the energy balance of the system, the photothermal conversion efficiency (η) can be calculated. 8-10 where m (0.74 g) and C p (1.189 J g -1 o C -1 ) are the mass and heat capacity of CHCl 3 .Qs is the photothermal heat energy input by irradiating I, and Q loss is thermal energy lost to the surroundings.When the temperature is maximum, the system is in balance.
where h is the heat transfer coefficient, s is the surface area of the container, ΔT max is the maximum temperature change.The η is calculated from the following equations: where A is absorbance of sample at 660 nm, t is the time of the the cooling process, T amb is 18 o C. According to the Equation (1-6), the η of the CHCl 3 solution of Ag14 at a concentration of 200 µM under 660 nm laser irradiation was calculated.A fitting linear of lnθ-T with a slope of -0.0076, by which τ s was calculated as 131.58 s Therefore, hs = 0.88 / 131.58 = 6.69 × 10 -3 J• o C - 1 •S -1 .ΔT sample = 38.2o C. ΔT solvent = 1.2 o C. A 1 = 0.04 ×10 = 0.4 (Supplementary Fig. 20).Eventually, η 1 = 6.69 × 10 -3 × (38.2 -1.2) / [0.9 × (1 -10 -0.4 )] = 45.69 %.Supplementary Fig. 21: Heating and cooling curve of the CHCl 3 solution of Ag14 at a concentration of 200 µM under 660 nm laser irradiation (a).Fitting linear of lnθ-T (b).