Two New Nonaborates with {B<sub>9</sub>} Cluster Open-Frameworks and Short Cutoff Edges
oleh: Chong-An Chen, Guo-Yu Yang
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2022-08-01 |
Deskripsi
Two new nonaborates, Na<sub>2</sub>Ba<sub>0.5</sub>[B<sub>9</sub>O<sub>15</sub>]·H<sub>2</sub>O (<b>1</b>) and Na<sub>4</sub>Ca<sub>1.5</sub>[B<sub>9</sub>O<sub>16</sub>(OH)<sub>2</sub>] (<b>2</b>), have been solvothermally made with mixed alkali and alkaline-earth metal cationic templates. <b>1</b> and <b>2</b> are constructed by two different types of nonaborate clusters. In <b>1</b>, the [B<sub>9</sub>O<sub>19</sub>]<sup>11−</sup> cluster is composed of three corner-sharing [B<sub>3</sub>O<sub>7</sub>]<sup>5−</sup> clusters, of which two of them interconnect to the 1D B<sub>3</sub>O<sub>7</sub>-based chains and are further bridged to the 3D framework with 7 types of 10-MR channels by another [B<sub>3</sub>O<sub>7</sub>]<sup>5−</sup> bridging cluster. The [B<sub>9</sub>O<sub>18</sub>(OH)<sub>2</sub>]<sup>11−</sup> cluster in <b>2</b> is made of four BO<sub>4</sub>-sharing [B<sub>3</sub>O<sub>8</sub>]<sup>7−</sup> clusters. As a 4-connected node, the interconnections of [B<sub>9</sub>O<sub>18</sub>(OH)<sub>2</sub>]<sup>11−</sup> construct the unpreceded 2D layer with large 14-MR windows, which are further joined by H-bonds to the 3D supramolecular framework. UV–Vis absorption spectra reveal that both <b>1</b> and <b>2</b> have short cutoff edges below 190 nm, exhibiting bandgaps of 6.31 and 6.39 eV, respectively, indicating their potential applications in deep UV (DUV) regions.