| Summary: | 碩士 === 國立臺灣師範大學 === 化學學系 === 81 ===
Glycylglycinatocopper(II) complexes of the general formulas, [Cu(glygly) (LI) ].nH2O or [Cu(glygly)(L2)].nH2O, where glygly represents glycylglycine dianion, have been synthesized. The glycyiglycinate anion serves as a terdentate ligand which is with amino, ionized amide nitrogen, and carboxylate oxygen donor atoms bonded to Cu(II). Other monodentate ligands are imidazole(ImH), 2-methylimidazole (2MImH), N-methylimidazole (NMIm), 4-methylimidazole (4MImH), acethylhistamine(achmH), 4-Phenylimidazole (4PhImH), ammonia(NH3), 4-aminopyridine(4NH2py). The bidentates designated as L2 are bipyridine(bipy), 2-(2-aminoethyl)pyridine(2-aepy), phenanthroline (phen), neocuproin(neoc). Such Cu(II) complexes were characterized by elemental analysis, uv-vis, ir, epr spectroscopic measurements, and the in some cases single-crystal x-ray structures were determined. The bonding properties were elucidated.
By single-crystal x-ray diffraction method, the crystal and molecular structures of [Cu(glygly)(4NH2py)].2H2O, [Cu(glygly)(achmH)].2H2O, [Cu(glygly) (2-aepy)].H2O (square pyrimidal geometry), [Cu(glygly)(phen)].3H2O, [Cu(glygly) (neoc)].5H2O (distorted square pyrimidal geometry), have been determined. The crystal data of these five complexes were described as following:
(1) The [Cu(glygly)(achmH)].2H2O crystallizes in monoclinic space group P21/c with a=5.2119(1), b=16.405(4), c=18.524(5), β=92.79(2), Z=4, R=0.044, and Rw=0.041.
(2) The[Cu(glygly)(4NH2py)].2H2O crystallizes in monoclinic space group C2/c with a=20.0828, b=11.8351, c=13.4054, β=131.44, Z=4, R=0.051, and Rw=0.035.
(3) The [Cu(glygly)(2-aepy)].H2O crystallizes in monoclinic space group P21/c with a=8.3045(9), b=13.2057(2), c=13.0477(4), β=97.85(1), Z=4, R=0.043, and Rw=0.054.
(4) The [Cu(glygly)(phen)].3H2O crystallizes in triclinic space group P1 with a=7.8111(0), b=9.3704(9), c=13.5365(1), α=97.24(0), β=105.25(1), γ=104.24(1), Z=2, R=0.040, and Rw=0.060.
(5) The [Cu(glygly)(neoc)].5H2O crystallizes in monoclinic space group P21/n with a=5.813(1), b=14.4647(9), c=15.8135(9.8), β=98.58(0), Z=4, R=0.046,and Rw=0.031.
The solid state LF spectra of the complexes were deconvoluted into Gaussian component bands and the results were employed to interpret the bonding properties of the Cu(II)-N chromophores. In the meantime, the sequences of the d orbitals were assigned as following:
dx2-y2 > dz2 > dxz > dxy >dyz
It is obvious that the energy of dxz orbital of Cu(II) was elevated significantly and this situation results from excellent π-donating ability of the ionized amide nitrogen. On the other hand, the imidazole or pyridine rings of [Cu(glygly) (achmH)].2H2O, [Cu(glygly)(4NH2py)].2H2O complexes which lie nearly parallel to CuN3O coordination plane are suggested to have good π-donating interaction with Cu(II) dxz orbital also.
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