| In this dissertation, the synthesis, characterization and application of novelbis(imidazoline) ligands as well as their NCN pincer complexes and some ferrocenylderivatives were studied. The main contents are as follows:1. Synthesis and properties of novel NCN pincer complexes(1) A series of novel achiral and chiral C2-symmetric bis(imidazoline) ligands 3a-cand 3e-i have been synthesized from commercially available 1,3-benzene dicarbonyldichloride or 5-nitro-1,3-benzene dicarbonyl dichloride and amino alcohols in twosteps for the first time. All the compounds were characterized by 1H NMR, 13C NMR,DEPT, HSQC, HMBC, IR, MS and HRMS spectra. The molecular structures of 3aand 3g were further confirmed by single-crystal X-ray analysis.1a R1=H; 2a R1=H, R2=H; 3a R1=H, R2=H, R3=CH3;1b R1=NO2. 2b R1= H, R2=CH(CH3)2; 3b R1=H, R2=CH(CH3)2, R3=CH3;2c R1=H, R2=CH2Ph; 3c R1=H, R2=CH2Ph, R3=CH3;2d R1=NO2, R2=H; 3e R1=NO2, R2=CH(CH3)2, R3=CH3;2e R1=NO2, R2=CH(CH3)2; 3f R1=NO2, R2=CH2Ph, R3=CH3;2f R1=NO2, R2=CH2Ph. 3g R1=H, R2=H, R3=OCH3;3h R1=H, R2=CH(CH3)2, R3=OCH3;3i R1=H, R2=CH2Ph, R3=OCH3.(2) Two non-symmetric ligand 4d which contain an imidazoline and an oxazolinering as well as 5d which only contains an imidazoline ring were also isolated in thepreparation of bis(imidazoline) ligands. These new compounds were characterized by1H NMR, 13C NMR, DEPT, HSQC, IR, MS and HRMS spectra. A plausibleexplanation for the formation of these byproducts was proposed. 2d R1=NO2, R2=H 4d R1=NO2, R2=H, R3=CH3 5d R1=NO2, R2=H, R3=CH3(3) The direct cycloplatination reaction of bis(imidazoline) ligands 3a-e, 3e or 3g-iwith 1.2 equiv of Li2PtCl4 in refluxing acetic acid gave seven new pincer platinumcomplexes 6a-e, 6e and 6g-i. The products were well characterized by 1H NMR, 13CNMR, DEPT, HSQC, HMBC, IR, MS and HRMS spectra. The molecular structuresof 6c, 6g and 6i were further confirmed by single-crystal X-ray analysis.6a R1=H, R2=H, R3=CH3;6b R1=H, R2=CH(CH3)2, R3=CH3;6c R1=H, R2=CH2Ph, R3=CH3;6e R1=NO2, R2=CH(CH3)2, R3=CH3;6g R1=H, R2=H, R3=OCH3;6h R1=H, R2=CH(CH3)2, R3=OCH3;6i R1=H, R2=CH2Ph, R3=OCH3.The preliminary studies on the photoluminescent properties of the pincer platinumcomplexes were carried out. The results show that they are luminescent in CH2Cl2solution even at room temperature and display broad structureless emissions withλmaxat about 570-580nm. In order to develop high-efficiency emitters, we design andsynthesize a new pincer Pt(Ⅱ)σ-alkynyl complexes 7e. The compound 7e wascharacterized by 1H NMR, 13C NMR, HSQC and IR spectra. The molecular structureof the compound 7e was further confirmed by a single-crystal X-ray analysis. (4) The direct cyclopalladation reaction was carded out with 3b, 3g or 3h and 1.2equiv of Pd(OAc)2 in refluxing acetic acid, followed by treatment with a solution oflithium chloride in acetone/water. The cyclopalladated pincer complexes 8b, 8g and8h were successfully isolated by preparative TLC on silica gel plates. The productswere characterized by 1H NMR, 13C NMR, DEPT, HSQC, IR, MS and HRMSspectra.8b R1=H, R2=CH(CH3)2, R3=CH3;8g R1=H,R2=H,R3=OCH3;8h R1=H, R2=CH(CH3)2, R3=OCH3.The activity of 8g in the Suzuki reaction of aryl bromides with phenylboronic acidwas evaluated with various bases and solvents at different reaction temperatures. Thebest results were obtained with K3PO4·3H2O as the base in DMF at 140℃. Forexample, coupling of bromobenzene with phenylboronic acid could afford thebiphenyl product in a 99% yield by using 0.5 mol% of 8g in the presense ofK3PO4·3H2O in DMF at 140℃for 8h.Ar=m-NO2C6H4, p-NO2C6H4, o-CHOC6H4, m-CHOC6H4, Yields:＞95%;o-CH3C6H4, m-CH3C6H4, o-CH3OC6H4, m-CH3OC6H4, p-CH3OC6H4, Yields: 83-92%.2. Studies on the synthesis and cyclomercuration of bisferrocenylimines(1) Bisferrocenylimines 9a and 9b were prepared by the condensation ofp-phenylenediamine with formylferrocene or acetyferrocene in the presence of freshlyactivated Al2O3. Mercuration of formylferrocene imine (9a) only afforded thebis-(cyclomercurated) complex (10a). While mercuration of acetylferrocene imine (9b)also gave a monocyclomercurated complex (11) besides the bis-(cyclomercurated)complex (10h) with 10b being the major product. The mercurated products 10 and 11were characterized by 1H NMR, IR and elemental analysis spectra and the structure ofthe compound 10b was further confirmed by a single-crystal X-ray analysis. (2) The ferrocenylazines (12a and 12b) were readily prepared by condensation offormylferrocene or acetylferrocene with hydrazine hydrate. Mercuration offormylferrocene azine (12a) and acetylferrocene azine (12b) both afforded thebis-(cyclomercurated) complexes (14a) or (14b) as the major product, respectively. Inaddition, monocyclomercurated complex (13) was obtained from the reaction of 12a.While a tris-mercurated complex (15) instead of the correspondingmonocyclomercurated compound was isolated from 12b. The mercurated products 13,14 and 15 were characterized by IH NMR, IR and elemental analysis spectra. Themolecular structures of the compounds 13, 14b and 15 were further confirmed bysingle-crystal X-ray analysis.(3) The Hg-bridged symmetric bisferrocenyl derivatives 16a and 16b were obtainedfrom the reaction of mercurated formylferrocene or acetylferrocene with NaBH4 inCH3OH at room temperature. The products were characterized by 1H NMR and IRspectra. The molecular structures of the compounds 16a and 16b were furtherconfirmed by single-crystal X-ray analysis. 3. Synthesis and properties of novel ferrocenylimines containing heterocyclicringTweive ferrocenylimines containing heterocyclic ring (17a-I) were synthesized bycondensation of formylferrocene or acetylferrocene with heterocyclic amines. Theferrocenyl derivative 17m was obtained in the preparation of ferrocenylimine 17g.The products were characterized by 1H NMR, IR and MS. The molecular structures ofthe compounds 17f, 17h and 17i were further confirmed by single-crystal X-rayanalysis.The electrochemical studies revealed that the electrochemical properties of theseferrocenylimines were very similar, showing one pair of well-defined and stable redoxwaves in the potential rang of 0.20-1.20V at the GC electrode, which is attributed tothe Fc/Fc+ redox process. The process was confirmed as a reversible,diffusion-controlled one.The palladated ferrocenylimines containing heterocyclic rings were applied ascatalysts in the Heck reaction. They could efficiently promote the reaction ofiodobenzene and olefins without an inducing period.
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