Aggregate assembly of ferrocene functionalized indium-oxo clusters

In this study, we synthesized multi-nuclear indium oxide clusters (InOCs) using 1,1′-ferrocene dicarboxylic acid (H2FcDCA) as the chelating and surface protection ligand. The obtained clusters include the cubane-type heptanuclear InOCs ([In7]) and the sandwich-type thirteen-nuclear InOCs ([In13]). Notably, [In13] represents the highest nuclear number reported within the InOC family. In addition, the presence of labile coordination sites in these clusters allowed for structural modification and self-assembly. A series of [In7] clusters with adjustable band gaps have been obtained and the self-assembly of [In7] clusters resulted in the formation of an Fe-doped dimer, [Fe2In12], and an imidazole-bridged tetramer, [In28]. Similarly, in the case of [In13] clusters, the coordinated water molecules could be replaced by imidazole, methylimidazole, and even a bridged carboxylic acid, allowing the construction of one-dimensional extended structures. Additionally, part of the H2FcDCA could be substituted by pyrazole. This flexibility in replacing solvent molecules offered diverse possibilities for tailoring the properties and structures of the InOCs to suit specific applications.


Electrochemical measurement
We prepared the working electrode by solution coating method as follows: the newly prepared sample (5 mg) and Nafion (10 μL) dissolved in 0.5 mL ethanol with ultrasound and 40 μL solution was uniformly dropped on clean FTO conductive glass (1.0 × 4.0 cm 2 , 10 Ω•cm -2 ).The photocurrent experiment was carried out on the three electrode system of the CHI760E electrochemical workstation, in which Pt sheet was the counter electrode and Ag/AgCl electrode was the reference electrode.The experiment was carried out in 0.2 M Na 2 SO 4 electrolyte at room temperature, and a 300 W Xe lightsource (PerfectLight, PLS-SXE300/300UV) with a 420 nm cut-off filter was used as a visible light source.Mott-Schottky experiment was carried out on a three electrode system of the electrochemical workstation (IM6, ZAHNER) at frequencies of 500 Hz, 1000 Hz, and 1500 Hz, with a voltage range of -1.0 V to 1.0 V (V vs .NHE, pH=7).

Figure S1 .Figure S2 .
Figure S1.((a, b, c, d)The bond length of In-O and Fe-O in the central cubane cluster cores of compound 1-4; (e) the observed torsion angles of the FcDCA 2-ligands is in compound 1-4.)

Figure S3 .
Figure S3.The crystal structure of compound 2, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S4 .
Figure S4.The crystal structure of compound 3, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S5 .
Figure S5.The crystal structure of compound 4, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S6 .
Figure S6.The crystal structure of compound 5, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S7 .
Figure S7.The crystal structure of compound 6, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S8 .
Figure S8.The crystal structure of compound 7, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S9 .
Figure S9.The crystal structure of compound 8, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S10 .
Figure S10.The crystal structure of compound 9, emphasizing its nano-sized dimensions (top (a) and side (c) views).

Figure S12 .Figure S13 .
Figure S12.(a) Compound 6 is stacked in AAA form along the cluster c-axis;(b) 7 is stacked along the cluster b-axis;(c) 8 is stacked along the cluster c-axis;(d) 9 is stacked along the cluster c-axis.

Figure S24 .
Figure S24.The TG plot of as synthesized 2.

Figure S25 .
Figure S25.The TG plot of as synthesized 3.

Figure S26 .
Figure S26.The TG plot of as synthesized 4.

Figure S27 .
Figure S27.The TG plot of as synthesized 5.

Figure S28 .
Figure S28.The TG plot of as synthesized 6.

Figure S29 .
Figure S29.The TG plot of as synthesized 7.

Figure S30 .
Figure S30.The TG plot of as synthesized 9.

Figure S32 .
Figure S32.UV-Vis spectra of 1 and the band gap is 1.90 eV.

Figure S 33 .
Figure S 33.UV-Vis spectra of 2 and the band gap is 2.20 eV.

Figure S 34 .
Figure S 34.UV-Vis spectra of 3 and the band gap is 1.85 eV.

Figure S 35 .
Figure S 35.UV-Vis spectra of 4 and the band gap is 2.25 eV.

Figure S 36 .
Figure S 36.UV-Vis spectra of 5 and the band gap is 2.00 eV.

Figure S 37 .
Figure S 37. UV-Vis spectra of 6 and the band gap is 2.10 eV.

Figure S 38 .
Figure S 38.UV-Vis spectra of 7 and the band gap is 2.01 eV.

Figure S 39 .
Figure S 39. UV-Vis spectra of 9 and the band gap is 2.20 eV.

Table S 2
. Crystal data and strutures refinement for 4-6.Empirical formula C 304 H 216 Fe 24 In 28 N 8 O 116 C 78 H 78 Fe 6 In 13 O 48 C 96 H 90 Fe 6 In 13 N 12 O 42 Table S 3. Crystal data and strutures refinement for 7

-9. Identification code InOC-7 InOC-8 InOC-9 Empirical formula
C 92 H 96 Fe 6 In 13 N 6 O 46 C 68 H 56 N 8 O 38 Fe 4 In 13 Cl 2 C 106 H 86 Fe 6 In 13 O 52 value of Fe II -O is 1.734Å.r o value of Fe III -O is 1.765Å.The calculated value of BVS value rounded to the nearest whole number 2. o

Table S 5
. ICP analyses of 1, 2, 4 and 5 (The total amount of In and Fe is normalized to 100%).