A novel ZnII-based metal-organic framework with the formula of {[Zn2(BBIP)2(NDC)2]·H2O}n (JXUST-5) derived from 3, 5-bis(benzimidazol-1-yl)pyridine (BBIP) and 1, 4-naphthalenedicarboxylic acid (H2NDC) has been synthesized. The adjacent ZnII ions are linked through two BBIP ligands to form a [Zn2(BBIP)2] secondary building unit (SBU). The neighbouring SBUs are further connected by NDC2− with μ2-η1: η1 and μ2-η1: η1: η1 bridging modes to form a two-dimensional (2D) framework. Topological analysis shows that JXUST-5 could be simplified as an uninodal fes topology with a point symbol of {4.82}. Furthermore, the 2D framework net could be extended through C-H···π interaction to form the three-dimensional supramolecular structure. Luminescent experiments suggest that JXUST-5 could selectively and sensitively recognize Al3+ and Ga3+ through fluorescence enhancement effect along with a relatively large red shift. The detection limits for Al3+ and Ga3+ are 0.17 and 0.69 ppm, respectively. Interestingly, the sensing process for both Al3+ and Ga3+ could be directly observed with naked eyes under 365 nm UV lamp. Notably, JXUST-5 could be recycled at least five times as a fluorescent sensor toward Al3+ and Ga3+, which is the second example of turn-on MOF based fluorescent sensor toward Ga3+.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |