Synthesis, Structure And Properties Of 1, 10-phenanthroline Derivatives And Its Complexes

1,10-phenanthroline (o-phenanthroline, phen) have been extensively used as ligand in both analytical and preparative coordination chemistry. The key feature of these nitr-ogen heterocycles containing six-membered rings is theirÏ€-electron deficiency, which makes them excellentÏ€acceptors and be used to stabilize various metal complexes in lower oxidation states. Aryl halides are important starting materials, However, halogen-ation of 1,10-Phenanthroline and other containing electron-withdrawing imine nitrogen(C=N-) with X2 usually requiresvery severe reaction conditions owing to theirÏ€-deficie-nt nature. For 1,10-Phenanthroline, any direct and selective halogenation way has not been explored. In this paper, we will report on the synthesis and properties of halogenation of o-phenanthroline and corresponding complexes [Cu(Cl4phen)(NO₃)]NO₃ (Cl4Phen=3,4,7,8-tetrachloro-1,10-phenanthroline),[Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH3CH2OH and the preparation of a new derivative ligand 3,4,7,8-tetrachloro-1,10-phenanthroline-5,6-dione.3,8-dibromophenanthroline was synthesized by the reaction of o-phenanthroline andBr2 in 1-chloro-butane with low yield 5 %. The reaction of Br2 and o-phenanthroline in SOCl2 was used to prepare 3,5,6,8-tetrabromophenanthroline, yield 46 %.3,4,7,8-tetrachloro-1,10-phenanthroline-5,6-dione was prepared by the reaction of 3,4,7,8-tetrachloro-1,10-phenanthroline and HNO3, H2SO4, KBr at 120℃for three hours.With 1,10-phenanthroline monohydrate,PCl5 and POCl3, 3,4,7,8-tetrachloro-1,10-Phenanthroline was synthesized, yield 56 %. Cu(â…¡) complex was obtained with the react-ion of 3,4,7,8-tetrachloro-1,10-Phenanthroline and Cu(NO3)3·3H2O, yield 82 %, Which was characterized by elemental analysis, IR, UV-vis, thermogravimetric analysis and ph-otoluminescence spectrum. The results show Cu(â…¡) was coordinated by two nitrogen of 3,4,7,8-tetrachloro-1,10-Phenanthroline and two oxygen atom from nitrate radical. Inaddition, there is a NO3- as the counterions.A novel Zn(â…¡) complex [Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH3CH2OH (Cl4Phen=3,4,7,8--tetrachloro-1,10-phenanthroline) has been synthesized with evolution method and char-acterized by single-crystal X-ray diffraction, elemental analysis, IR, thermogravimetric analysis and photoluminescence spectrum. Single-crystal X-ray diffraction reveals that complex crystallizes in the monoclinic system, space group P2(1)/c with a = 10.061(2) ?,b = 18.924(4) ?, c =18.189(4) ?;β= 100.94(3)°, and Z = 4. Complex Consists of cationic species [Zn(Cl₄phen)₂(H₂O)₂]₂+, two non-coordinatingnitrate radical anions and one l-attice ethanol molecular, in which Zn(II) ion is six-coordinated by four nitrogen atom-s of two 3,4,7,8-tetrachloro-1,10-phenanthroline molecules, two oxygen atoms of two chelating water molecules. Adjacent units are linked by hydrogen bonds andπ···πstackinginteractions to form three-dimensional structure.