Synthesis And Characterization Of Stimuli-responsive Tetrazole-based Copper(Ⅰ) Luminescent Complexes

Stimuli-responsive luminescent materials are a class of smart materials whose luminescence（such as the emissive color or emissive intensity）will change significantly under external stimuli,which can be potentially applied in many fields such as optical data storage,biological label,sensor and detection,security and anti-counterfeiting.Copper（Ⅰ）complexes are desired for the development of stimuli-responsive luminescent materials due to their diverse luminescence properties,low cost and low toxicity.The solid-state luminescence properties of copper（Ⅰ）complexes usually depend on the change of intermolecular interactions and the resulting molecular stacking patterns.In this thesis,two kinds of binuclear copper（Ⅰ）complexes showing stimuli-responsive luminescence properties have been designed and synthesized by using the pyridyl/pyrimidinyl tetrazole chelating ligand.The structure-activity relationship between their molecular structures,solid-state structures,molecular stacking modes and stimuli-responsive luminescence properties has been revealed by the characterization of their structures and properties.The detailed research contents are as follows:1.Two binuclear copper（Ⅰ）luminescent complexes exhibiting mechanochromic luminescence were designed and synthesized by using single-chelating pyridyl tetrazole ligands with different methylation positions（4-methyl-5-（2′-pyridyl）-1,2,3,4-tetrazole（4-mpytz H）and 5-methyl-5-（2′-pyridyl）-1,2,3,4-tetrazole（5-mpytz H））and bisphosphine ligand N,N-bis（diphenylphosphine）amine（dppa）.Single-crystal structure analysis shows that complexes 1 and 2 contain a{Cu₂（N^N）₂（dppa）₂}framework unit,in which two Cu（Ⅰ）atoms are bridged by two dppa ligands to form a boat-chair configuration of Cu₂P₄N₂octagonal ring and both Cu（Ⅰ）atom adopts a distorted tetrahedral N₂P₂coordination configuration.The results show that reversible mechanochromic luminescence conventions of complexes 1 and 2were attributed to the breaking and restoration of the NH_dppa???N_tetrazolehydrogen bond between the tetrazole-N atom and the dppa-NH group under grinding and CH₂Cl₂vapor,and the destruction and recovery of the ordered molecular arrangement of the complex.In addition,stimuli-responsive luminescence chromic characteristics of the two are also different:the former is reflected in the emissive intensity and the latter is reflected in the emissive color.It is indicated that stimuli-responsive luminescence chromic properties can be effectively regulated by changing the substitution position of the methyl on the pyridine ring.2.Two binuclear copper（Ⅰ）luminescent complexes 3 and 4 were synthesized by molecular assembly of the bis-chelating 5-（2′-pyrimidinyl）-1,2,3,4-tetrazole ligand（pmtz H）,two different organic bisphosphine ligands（POP and Xantphos）,and[Cu（CH₃CN）₄]（Cl O₄）.In these two complexes,pmtz H adopts the monoanionic bis-chelating bridging coordination mode.The results show that complex 3 exhibits luminescence mechanochromism and vapochromism,which is attributed to the orderly stacking arrangement of the complex regulated by the CHCl₃solvent molecules,and the destruction and reconstruction of Cl-O???H hydrogen bond between Cl O₄￣and CHCl₃,as confirmed by the PXRD,FT-IR and ¹H NMR studies of complex 3 in various states.Complex 4 only exhibits photoluminescence properties and has no stimuli-responsive luminescence properties similar to complex 3.The difference between the two structures is only one isopropyl bridging group between two organic phosphine ligands,which indicates that the reasonable selection of organic phosphine ligands is very important for the construction of stimuli-responsive luminescence materials.