Metal Complex Systems of Novel Spectroscopic Significance with Applications to Biochemical Probing

化学探针(报告分子)能够检测生物体系中的自组装介质，如脂质双层、细胞表面糖链和核酸，已被研究在这些微环境存在下的敏化光谱反应。在金属络合物体系中，(I)近红外(NIR)光吸收(低能电子跃迁)和(Ii)室温磷光(i-a)发现疏水环境，如表面活性剂胶束、人工脂质双层和脂质体，强烈地增强了MR的吸收(730 nm-850 nm，epsilon=(5-13)x10^4M^&lt；-1&gt；-1&lt；-1&gt；-1&gt；(i-b)用结构促进剂、结构破碎剂、…等几种添加剂，从影响水溶液结构的因素出发，研究了这种疏水环境识别的机理。更多和疏水的补水破碎剂。尿素是一种强烈的疏水性水合破碎剂，与脂质体介质一样，尿素的加入极大地促进了MIR的吸收。这表明这种识别依赖于这些螯合探针附近的水结构，而不是对感兴趣介质的亲脂性负责。(ii-a)铂(II)-7-碘-5-磺酸-8-喹啉螯合物的室温磷光(例如：475 nm，em。630rim)，特别是在N-十二烷基-β-D-麦芽糖苷胶束溶液中。这种糖基表面活性剂胶束的这种增强作用与生物研究中必要的糖链识别应用有关。(II-b)4-羟基吖啶具有更大的pi-电子体系，以利于更高的发光灵敏度。铂(II)络合物也是磷光的(例如。396 nm，em。448 rim)。小牛胸腺DNA对该络合物的发光有类似的增强作用，表明该络合物可以报道与DNA分子的插层相互作用。较少

Chemical probes (reporter molecules) which are capable of detecting self-assembly media in biological systems such as lipid bilayers, cell-surface sugar-chains, and nucleic acids have been investigated in terms of the sensitized spectroscopic response in the presence of such microenvironment. The photophysical processes amenable to this function are found in metal-complex systems ; (I) near-infrared (NIR) light absorption(low energy electronic transition) and (II) room-temperature phosphorescence.(I-a) It has been found that the hydrophobic environment, such as surfactant micelles, artificial lipid bilayers, and liposomes strongly enhances the MR absorption (730 nm - 850 nm, epsilon=(5-13)x10^4 M^<-1> cm^<-1>) of planar1 , 2-diaminobenzene chelates of Ni, Pd, and Pt ions.(I-b) The mechanistic investigation of this hydrophobic environment recognition has been made in terms of factors affecting solution structure of water with several additives of structure-promoters, structure-breakers, … More and hydrophobic hydration breakers. The addition of urea, a strong hydrophobic hydration breaker, gives rise to the great enhancement of the MIR absorption as the liposome medium does. This suggests that the recognition depends upon the water-structure in the close vicinity of these chelate probes, rather than being responsible for the lipophilicity of the media of interest.(II-a) The room-temperature phosphorescence from Pt(II) - 7-iodo-5-sulfo-8-quinolinol chelate (ex. 475 nm, em. 630 rim) is strongly facilitated in particular in n-dodecyl-beta-D-maltoside micellar solutions. This enhancement in such sugar-based surfactant micelles is interesting in relation with the applications tosugar-chain recognition necessary in biological studies.(II-b) 4-Hydroxyacridine possessing larger pi-electron system has been synthesized for the benefit of the greater luminescence sensitivity. The Pt(II) chelate is also phosphorescent (ex. 396 nm, em. 448rim) in the above sugar-based micelles. Calf thymus DNA gives the similar enhancement effect on the luminescence of the chelate, which indicates that the chelate can afford to report the intercalation interaction with DNA molecules. Less