Research On The Platinum(Ⅱ)-alkynyl Metal-organic Switch Materials

Under the stimuli of external signals, the luminescence or color of materials would have prominent changed, the materials also have reversible transformed with different stable status. which are called luminescent switch materials. The material subjects are cross issues of chem-istry and materialogy, which have attracted increased attention owing to their have particular induction and recognition. We classify the materials as organic compounds and transition metal complexes. Since transition metal complexes have many advantages, such as good thermal and photic stability, plentiful luminescence properties, easy synthesis etc, there is of course the important issue of finding suitable transition metal complexes for switch materials fileds. Up to now, a series of dual-stimuli-responsive switches based on transition metal com-plexes have been reported, but the materials which have multiple-stimuli-responsive have rarely been covered. Therefore, the development of multiple-stimuli-responsive switch mater-ials is a crucial subject that continues to fascinate chemists in academic research.In this paper, we used2,2’-bipyridine as ingredient, and successful access to two ligands,5,5’-bis(trimethylsilylethynyl)-2,2’-bipyridine and4-[(2-Trimethylsilyl)ethynyl]-2,2’-bipyridine. We prosperously got eleven platinum(II) complexes based on the two ligand, then fluorescence spectrum, UV/Vis and another instruments were used to carried out the thermo-, mechanical-, vapo-triggered switch properties, and photophysics properties. The constitution and structure of complexes were also measured. We found most of complexes have lumines-cent switch properties, even some complexes had multiple-stimuli-responsive properties, such as thermo-, mechanical-, vapo-triggered properties. For example, Complex1had vapo-trig-gered switch properties, it could recognize acetonitrile and chloroacetonitrile vapor. Complex2and4had thermo-and mechanical-triggered switch properties, Complex3,6and9had no stimuli responsive switch properties, Complex7,8,10and11only had mechanical-triggered switch properties, Complex5not only had thermo-and mechanical-triggered switch prop-erties, but also had vapo-triggered switch properties, the complex uniquely recognize chloro-form vapor. The transform mechanism of the switch materials is the intermolecular Pt-Pt distances were changed, meanwhile, the lowest emissive-energy have a conversion from MLCT/LLCT states to MMLCT/LLCT transitions.