The Design And Synthesis Of 1,10-phenanthroline Derivatives And The Study On Properties Of Its Copper Complexes

1,10-phenanthroline is a typical nitrogen-containing bidentate ligand and its metal complexes have wide application in field of chemical catalysts,optical materials,bio-probe and so on.Especially,its complexes coordinated with copper were studied widely as a cheap and benign material for photo energy collection.The 1,10-phenanthroline structure has a direct and significant effect to its metal complexes on physical,chemical properties and application.The structure effect of nitrogen ligand is also vital research content of photosensitizers based on metal complexes.In this dissertation,a series of 1,10-phenanthroline derivatives were designed and synthesized,then their coppor complexes as photosensitizers were studied on spectrum properties and tested in water reduction reaction.Two synthesis methods of 2,9-disubstituted 1,10-phenanthroline derivatives were explored at firstly.The first method consists of four reaction steps.?,?-unsaturated acid intermediates were firstly synthesized from alkyl aldehyde and malonic acid by the knoevenagel reaction and decarboxylation reaction.Subsequently,1-phenyl-2,3-unsaturated ketone intermediates were obtained by acyl chlorination and Friedel-Crafts acylation reaction.Finally,2,9-disubstituted-4,7-diphenyl-1,10-phenanthroline was synthesized based on the condensation reaction of 1-phenyl-2,3-unsaturated ketone with o-phenylendiamine.The second method was used o-phenylendiamine and 3-Chloropropiophenone derivatives as initiator to produce 4,7-diaryl-1,10-phenanthroline intermediate.Subsequently,2,9-disubstituted-4,7-diaryl-1,10-phenanthroline derivative was synthesized successfully based on the nucleophilic addition of alkyl lithium to 1,10-phenanthroline intermediate under argon.The advantages and disadvantages between above two routes were compared and the second route was chosed as main synthesis method because of higher yield and shorter steps.At the same time,the optimizations of condition were made and the total yield is 21.9%.Next,2,9-dialkyl-4,7-multi-aryl 1,10-phenanthroline derivatives were synthesized from 4,7-(4,4'-dibromo)phenyl 1,10-phenanthroline by the Suzuki coupling reaction and the alkyl lithium nucleophilic addition reaction.By using new one-pot method,2,9-dialkyl-4,7-(4,4'-dicarboxyl)phenyl-1,10-phenanthrolines was getted through lithium halogen exchange reaction,alkyl lithium nucleophilic addition reaction and quenchic reaction by dry ice.Finally,with novel phenanthroline derivatives as a nitrogen ligand and Xantphos as a phosphorus ligand,Cu(I)(N^N)(P^P)PF6 complexes were synthesized.The spectrum properties of these copper complexes have been systematically studied and the activity of photo energy transformation in water reduction was tested.The result indicated that it is useless to make electron transfer from metal to ligand(MLCT)that the 4th and 7th sites of phenanthroloine were added more conjugation groups.Moreover,the rate of producing hydrogen and the turn over number(TON)of Cu complexes were at the same level,not matter added aryl groups at phenanthroloine ligand or not.When the carboxy groups were added at benzene ring attached to 4th and 7th site of phenanthroline,the absorption spectrum of Cu complexes was red shifted.The life of Cu complexes was increased and the TON was up to 1350 in water reduction due to the electron transfer ability improved by the electron withdrawing group at phenanthroline.