Syntheses, Crystal Structures, and Photothermal Conversion\nProperty of Aluminum Cluster Molecular Rings-Based Heterometallic\nComplexes

Effective combination of Al clusters\nwith functional motif is a\ngood way to expand the application of Al cluster materials. In this\nwork, by introducing noble-metal ions with photothermal property into\nthe assembly of aluminum clusters, four Al<sub>8</sub>-based mixed\nmetal complexes, {[Al<sub>8</sub>Ag<sub>2</sub>(OH)<sub>8</sub>(NA)<sub>16</sub>(CH<sub>3</sub>CN)<sub>2</sub>]·2SO<sub>3</sub>CF<sub>3</sub>}<i><sub>n</sub></i> (<b>Ag–Al</b><sub><b>8</b></sub>, <b>NA<sup>–</sup></b> <b>=</b> nicotinic acid), {[(H<sub>3</sub>O)<sub>2</sub>Al<sub>8</sub>Ag<sub>3</sub>Cl<sub>9</sub>(OH)<sub>8</sub>(NA)<sub>2</sub>(HNA)<sub>14</sub>]·AgCl<sub>4</sub>·Ag<sub>2</sub>Cl<sub>7</sub>·2SO<sub>3</sub>CF<sub>3</sub>}<i><sub>n</sub></i> (<b>AgCl-Al</b><sub><b>8</b></sub>), {[Al<sub>8</sub>Cu<sub>4</sub>Br<sub>3</sub>(OH)<sub>8</sub>(NA)<sub>16</sub>]·NA·HNA}<i><sub>n</sub></i> (<b>CuBr-Al</b><sub><b>8</b></sub><b>-1</b>) and {[Al<sub>8</sub>Cu<sub>4</sub>Br<sub>2</sub>(OH)<sub>8</sub>(NA)<sub>16</sub>]·2NA}<i><sub>n</sub></i> (<b>CuBr-Al</b><sub><b>8</b></sub><b>-2</b>),\nwere obtained. They are all constructed by the <b>Al</b><sub><b>8</b></sub> ring cluster as the building unit and Ag/AgCl/CuBr-pyridine\nN as the linkers. Moreover, the <b>Ag–Al</b><sub><b>8</b></sub> and <b>AgCl-Al</b><sub><b>8</b></sub> show\na photothermal conversion property under the irradiation of a 980\nnm infrared laser. The temperatures of <b>Ag–Al</b><sub><b>8</b></sub> and <b>AgCl-Al</b><sub><b>8</b></sub> can respectively increase to 50 and 32 °C, and the photothermal\nconversion efficiency can reach 26.62 and 28.64%. Furthermore, the\nphotothermal performance is reversible at least five irradiation cycles.\nThis work first reports Al–Ag mixed metal frameworks with photothermal\nconversion performance based on aluminum metal clusters, enriching\nthe family of Al cluster-based frameworks and expanding their application.