Synthesis And Characterization Of Compounds And Water-Soluble Fluorescent Polymers Containing Pyrene Units

In recent years,water-soluble fluorescent polymers have become an effective and sensitive probe for further applying into identifying tumor cells and distinguishing different proteins and enzymes in biological field,which are attracting intense research interest.A quick and simple synthesis strategy of water-soluble fluorescent polymer has become one of the current research hotspots.Focus on those viewpoints,three compounds containing pyrene unit and three water-soluble fluorescent polymers containing pyrene unit were synthesized in this thesis.These compounds and polymers were characterized and tested by many modern analytical instrumental methods.1-（acryloyloxy hexyloxy）pyrene（B-C6）containing pyrene unit and acrylate group was synthesized using 1-hydroxypyrene as a kind of starting material.S-1-dodecyl-S’-[poly（N-Boc-acryloyl ethylene diamine）-2’-methyl propionic acid]trithiocarbonate（P1）with trithioester as an end group was prepared via reversible addition-fragmentationchaintransfer（RAFT）polymerizationwith N-butoxycarbonyl-acryloyl ethylene diamine（N-Boc-AEDA）as monomer.Boc-protected amino groups and regular structure fluorescent polymer containing pyrene unit（1-{3’-S-[poly（N-butoxycarbonyl-acryloylethylenediamine）-2’’-methylpropionic acid]}propionyloxy hexyloxy pyrene）（P2-C6）was prepared.Water-soluble fluorescent polymer（1-{3’-S-[poly（acryloyl ethylene diamine dihydrochloride）-2’-methyl propionic acid]}propionyloxy hexyloxy pyrene）（P3-C6）containing pyrene unit was obtained by the deprotection of the resulting Boc-protected polymer（P2-C6）with aqueous HCl.B-C6,P1,P2-C6 and P3-C6 were characterized and measured by Fourier transform infrared spectroscopy,nuclear magnetic resonance spectrometer,high-resolution mass spectrometer,gel permeation chromatography,UV-Visible spectrophotometer and fluorescence spectrophotometer,respectively.These results showed that P2-C6 exhibited bright blue-violet emission band.P2-C6 was soluble in common organic solvents,such as dichloromethane,trichloromethane and tetrahydrofuran.After deprotection,P3-C6 displayed good solubility in water and not only exhibited blue-violet fluorescence emission band in aqueous solution but also had the similar photoluminescent spectra to those of B-C6 and P2-C6 in dichloromethane.The fluorescence quantum yields of P2-C6 in dilute tetrahydrofuran and P3-C6 in dilute aqueous solution were measured to be 0.44 and 0.39,respectively.1-（acryloyloxy ethoxy）pyrene（B-C2）and 1-（acryloxy butoxy）pyrene（B-C4）were prepared with 1,2-dibromoethane,1,4-dibromobutane and 1-hydroxypyrene as reactant.The B-C2 and B-C4 reacted with P1,respectively.After removal the Boc-proteted,these water soluble fluorescence polymers P3-C2 and P3-C4 was obtained.Products of each step were characterized.The optical properties of P3-C2,P3-C4 and P3-C6 at different pH solutions were studied.In weak alkaline conditions,the primary amine were changing as cationic（NH₃⁺）form,the macromolecular chain more diastolic,thereby reducing the probability of aggregation of fluorescent molecules,therefore,samples emitted strong fluorescence.With the basic growing,some primary amine as NH₃⁺·OH^-form,reducing the number of primary amine cation,weakening the repulsive force,so that the molecular chains start to curl,increasing the probability of aggregation of fluorescent molecules,the fluorescence intensity was decreased.When the solution is acidic,the solution H⁺is more.More primary amine in NH₃⁺·Cl^-forms,reducing the number of primary amine cation,weakening repulsion.The macromolecular chain curled up,gather chance of fluorescent molecules increases.The fluorescence intensity decreased.The integrated area of P3-C2,P3-C4 and P3-C6 are rendering increases at first,then decreased with the increase of solution pH.