Department of Chemistry, Capital Normal University, 105#, North Road of the West Third Ring, 100048, Beijing, China.
Dalton Trans. 2014 Apr 14;43(14):5357-63. doi: 10.1039/c3dt53221f.
[Cu(II)(phen)(HIMC(-))(H2O)]·[Cu(II)(phen)(HIMC(-))(NO3(-))]·NO3(-)·H2O (1) and [Cu(II)(2,2'-bipy)(HIMC(-))]·NO3(-)·xH2O (2) (phen = 1,10-phenanthroline, 2,2'-bipy = 2,2'-bipyridine, HIMC(-) = 1H-imidazole-4-carboxylate acid anion) have been synthesized at 180 °C, of which the HIMC(-) is produced by an in situ decarboxylation from H3IDC (1H-imidazole-4,5-dicarboxylic acid) in a one-pot hydrothermal reaction. The anticancer activity experiments in vitro show that 1 exhibited excellent activities against A549, Bel-7402 and HCT-8 cancer cells and is even better than the clinical anticancer drug 5-Fu (5-fluorouracil), while 2 shows little response toward the cancer cells. The single crystal X-ray diffraction indicated that complex 1 possess a co-planar [Cu(II)(N-N)(HIMC(-))] coordination geometry. The IR, elemental analysis and solid-state luminescent spectra of complexes 1 and 2 indicated that the composition of these two complexes are similar, whereas the 2,2'-bipy in complex 2 replaced phen in complex 1. The calculation by the Gaussian 03 program illustrated that the decrease in the energy gaps between π*-π from the free to the coordinated ligand for 2,2'-bipy and phen (ΔE) are 5.3 eV to 4.0 eV and 4.8 eV to 4.5 eV separately, and the relative changes of the Gibbs free energies (ΔG) for complex 1 and 2 decomposing into free Cu(2+) and ligands are about 0 kcal mol(-1) and 7 kcal mol(-1) respectively, which revealed that it is more stable when 2,2'-bipy is coordinated with Cu(II) than phen, and 1 is easier to disassociate into free Cu(2+) than 2. By relating the ΔE, ΔG, luminescent qualities and anticancer toxicities of the complexes with their composition, it can be concluded that both Cu(II) and their coordinated ligands are responsible for the inhibition against cancer cells.
[Cu(II)(phen)(HIMC(-))(H2O)]·[Cu(II)(phen)(HIMC(-))(NO3(-))]·NO3(-)·H2O（1）和[Cu(II)(2,2'-bipy)(HIMC(-))]·NO3(-)·xH2O（2）（phen = 1,10-菲咯啉，2,2'-bipy = 2,2'-联吡啶，HIMC(-) = 1H-咪唑-4-羧酸根阴离子）在 180°C 下合成，其中 HIMC(-)是由原位脱羧反应从 H3IDC（1H-咪唑-4,5-二羧酸）在一锅水热反应中产生的。体外抗癌活性实验表明，1 对 A549、Bel-7402 和 HCT-8 癌细胞表现出优异的活性，甚至优于临床抗癌药物 5-Fu（5-氟尿嘧啶），而 2 对癌细胞几乎没有反应。单晶 X 射线衍射表明，配合物 1 具有共面的[Cu(II)(N-N)(HIMC(-))]配位几何形状。配合物 1 和 2 的 IR、元素分析和固态发光光谱表明，这两个配合物的组成相似，而 2,2'-bipy 在配合物 2 中取代了配合物 1 中的 phen。Gaussian 03 程序的计算表明，从自由配体到配位配体的π*-π 能隙（ΔE）分别从 5.3eV 降低到 4.0eV 和从 4.8eV 降低到 4.5eV，以及配合物 1 和 2 分解成游离 Cu(2+)和配体的吉布斯自由能（ΔG）的相对变化约为 0 kcal mol(-1)和 7 kcal mol(-1)，这表明当 2,2'-bipy 与 Cu(II)配位时更稳定，而 1 比 2 更容易游离成 Cu(2+)。通过将配合物的 ΔE、ΔG、发光性质和抗癌毒性与其组成联系起来，可以得出结论，Cu(II)及其配位配体都对抑制癌细胞有贡献。
