本研究內容包含一系列2, 6-二乙酸啶銅錯合物：Cu(dipic)(NH3)(H2O)和Cu(dipic)(L)。其中dipic代表三牙團配子2, 6-二乙酸啶，利用一個啶環上的氮和兩個羧酸上的氧來和二價銅配位。L 代表中性含氮單牙團配子，包括咪唑（ImH)、1-甲基咪唑(NMIm)、4-甲基咪唑(4MImH)、?啶(py)、4-甲基?啶(4dMapy)。利用元素分析、紅外線光譜來鑑定錯合物；紫外光－可見光光譜、電子順磁共振光譜和X-光單晶繞射結構解析等方法，來探討其分子構造、能層分佈及鍵結性質。
已有三個X-光單晶繞射結構解析的錯合物：Cu(diic)(NH3)(H2O)、Cu(dipic)(4dMapy)、Cu(dipic)NMIm)．1/2(H2O)。其資料如下： (1)Cu(dipic)(NH3)(H20)為三斜晶系(triclinic)，空間群P1的晶體，其晶格常數：a=4.873A, b=9.131A c=10.106A; α=78.85, β=86.l96, γ=86.58。每單位晶格含有2個分子，精算值R=0.035、Rw=0.046。(2)Cu(dipic)(4dMapy)為單斜晶系(monoclini)，空間群P21/C的晶體，其晶格常數：a=7.986A, b=11.960A, c=14.715A; β=101.05。每單位晶格含有4個分子，精算值R=0.040、Rw=0.046。(3) Cu(dipic)(NMIm) ．1/2(H2O)為三斜晶系(TRICLINIC)，空間群P1的晶體，其晶格常數；a=9.314A, b=12.049A, c=12.801A; α=113.34, β=99.91, γ=106.22。每單位晶格含有4個分子，精算值R=0.083、Rw=0.097。
比較此系列可見光光譜的高斯交疊解析結果，Cu(dipic)(NH3)(H2O)的d軌域能階順序標定為dx2-y2>>dz2>dxz>dxy>dyz，而其餘一系列四方共平面形的Cu(dipic)(L)，其d軌域能階順序為dx2-y2>>dxz>dxy>dyz>dz2。因dxz能階明顯上升，顯示2, 6-二乙酸啶配子中間的啶氮，與其對位的單牙團氮配位配子，兩者對二價銅交互作用最後的結果，具有π-供給(π-donor)的性質。且2, 6-二乙酸啶配子本身對二價銅即具有π-供給的性質。

Mixed-ligand dipicolinate copper (II) complexes, Cu(dipic)(NH3)(H2O) and Cu(dipic)(L), have been synthesized, where dipic stands for dipicolinate and L for imidazole (ImH), 1-methylimidazole(NMImH), 4-methylimidazole(4MImH), pyridine (py), 4-methylpyridine(4Mpy), 4-aminopyridine(4apy), and 4-dimethylaminopyridine(4dMapy). The complexes have been characterized by elemental analysis, UV-VIS, IR, and EPR spectroscopic measurements.
Molecular structures of Cu(dipic)(NH3)(H2O), Cu(dipic)(4dMapy) and Cu(dipic)(NMIm). 1/2(H2O) have been determined by three-dimensional X-ray diffraction method. The structures of other complexes are elucidated based on their spectral data. X-ray parameters are as follow: (1) Cu(dipic)(NH3)(H2O), triclinic, space group P1, a=4.873A, b=9.131A, c=10.106A, α=78.85, β=86.96, γ=86.58, Z=2, R=0.035, Rw=0.046。(2)Cu(dipic)(4dMapy), monoclinic, space group P21/C, a=7.986A, b=11.960A, c=14.715A, β=101.05, Z=4, R=0.040, Rw=0.046。 (3)Cu(dipic)(NMIm).1/2(H2O), triclinic, space group P1, a=9.314A, b=12.049A, c=12.801A, α=113.34, β=99.91, γ=106.22, Z=2, R=0.083, Rw=0.097。
Comparing the Gaussian component bands of electronic spectra of the dipicolinate Cu(II) complexes, the sequences of the d orbitals were assigned as dx2-y2>>dz2>dxz>dxy>dyz for Cu(dipic)(NH3)(H2O) and dx2-y2>>dxz>dxy>dyz>dz2 for Cu(dipic)(L).
It is obvious that the energy of the dxz orbital of the dipicolinate copper (II) complexes was raised significantly, suggesting that the central pyriding N atom of the tridentate dipicolinate and the heterovyclic unidentate ligands are π- donaor interacting with the Cu(II) dxz orbital.