Synthesis And Characterization Of Bipyridine Cryptates And Catalytic Behavior Of Homoleptic Cyclopentadienyl Lanthanide Complexes For The Hydroboration Of Aldehydes And Ketones

In this thesis,catalytic properties of a series of homoleptic cyclopentadienyl lanthanide complexes for the hydroboration of aldehydes/ketones towards pinacolborane?HBpin?were also investigated.At the same time,fourteen substituted bipyridine compounds were synthesized from aromatic aldehydes as starting materials.Six bipyridine sodium cryptates and two bipyridine europium cryptates?21 and 22?were synthesized from these compounds.The fluorescence properties of 21 were studied.The sequence are listed below.1.The catalytic behavior of homoleptic cyclopentadienyl lanthanide complexes Cp₃Ln?Ln=Y?1a?,Yb?2a?,Nd?3a?,Sm?4a?,La?5a??for the hydroboration of aldehydes/ketones towards HBpin were explored.We screened the reaction conditions such as solvent,the loading of catalyst,reaction time and the ratio of substrate etc,in a systematic way.The results showed that complexes 1a to 5a can efficiently catalyzed the reaction under mild conditions and complex 5a exhibited higher activity.Under the condition of room temperature,0.01 mol%of the catalyst,tetrahydrofuran?THF?as solvent and 1.2 eq of HBpin relative to aldehydes/ketones,complex 5a showed good substrate scope.For most substrates,yields obtained were 96%or even more,and the activity of aldehyde significantly better than ketones.In addition,this kind of catalyst has good chemical selectivity.The results showed that only the carbonyl could react while other functional groups such as C=C,C?C and CN did not show any response.2.Fourteen 4,4',6,6'-substituted-2,2'-bipyridines were synthesized starting from furaldehyde or benzaldehyde using a multistep process and confirmed by ¹H NMR and ¹³C NMR.Subsequently,six bipyridine sodium cryptates were synthesized from these compounds?five bipyridine sodium cryptates are new compounds?.All bipyridine sodium cryptates have been confirmed by ¹H NMR,¹³C NMR and high resolution mass spectrum?HRMS?.3.Two bipyridine europium cryptates,[Eu?bpy·bpy·bpy]·2Cl·Br?bpy=6,6'-dimethylene-2,2'-bipyridine-4,4'-dimethylester??21?and[Eu?bpy¹·bpy¹·bpy²]·2Cl·Br?bpy¹=6,6'-dimethylene-2,2'-bipyridine-4,4'-dicarboxylic acid,bpy²=6,6'-dimethylene-2,2'-bipyridine-4,4'-diformylethylenediamine??22?were synthesized from above two mentioned bipyridine sodium cryptates.The structure of europium cryptate 21 was confirmed by IR spectroscopy,X-ray diffraction?XRD?.HRMS and XRD structure showed that cryptate 21 is cavernous structure and coordination number of center metal is ten.Europium cryptate 22 was characterized by HRMS and high performance liquid chromatography?HPLC?.4.The photoluminescence?PL?spectra,decay curve and the absolute quantum efficiency???of 21 are presented and 21 can be efficiently excited by near-UV light thus presents a bright red luminescence with the lifetime???of 0.32 ms and the?of70%.It is suggested that 21 is expected to be a potential efficient phosphor for lighting and display.