A series of rhenium(I) polypyridine complexes functionalized with a diaminoaromatic moiety has been developed as phosphorescent sensors for nitric oxide (NO). The diamine complexes [Re(N⁁N)(CO)3(py-diamine)](CF3SO3) [py-diamine = 3,4-diaminopyridine; N⁁N = 1,10-phenanthroline (phen) (1a), 2,9-dimethyl-1,10-phenanthroline (Me2-phen) (2a), 3,4,7,8-tetramethyl-1,10-phenanthroline (Me4-phen) (3a), 4,7-diphenyl-1,10-phenanthroline (Ph2-phen) (4a)] were synthesized and characterized. These complexes were only weakly emissive due to the diaminoaromatic moiety that quenches the 3MLCT [dπ(Re) → π*(N⁁N)] emission by photoinduced electron transfer (PET). However, in the presence of NO, these diamine complexes were converted to the triazole derivatives [Re(N⁁N)(CO)3(py-triazole)](CF3SO3) [py-triazole = 1H-1,2,3-triazolo[4,5,c]pyridine; N⁁N = phen (1b), Me2-phen (2b), Me4-phen (3b), Ph2-phen (4b)], which revealed intense emission upon excitation. The emission of the complexes was independent to pH under neutral and basic conditions (pH > 6). The cytotoxicity and cellular uptake properties of these complexes were studied by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay and ICP-MS, respectively. The potential application of these complexes as intracellular NO sensors was also investigated.
一系列功能化有二
氨基芳香基团的
铼(I)多
吡啶复合物被开发作为
一氧化氮(NO)的
磷光传感器。这些二胺复合物 [Re(N⁁N)(CO)3(py-diamine)](CF3SO3) [py-diamine = 3,4-二
氨基吡啶;N⁁N = 1,10-
菲啉(phen)(1a),2,9-二
甲基-1,10-
菲啉(Me2-phen)(2a),3,4,7,8-四
甲基-1,10-
菲啉(Me4-phen)(3a),4,7
-二苯基-1,10-
菲啉(Ph2-phen)(4a)] 被合成并表征。由于二
氨基芳香基团通过光致电子转移(PET)使3MLCT [dπ(Re) → π*(N⁁N)]发射被猝灭,这些复合物仅表现出微弱的发射。然而,在NO的存在下,这些二胺复合物转化为三唑衍
生物 [Re(N⁁N)(CO)3(py-triazole)](CF3SO3) [py-triazole =
1H-1,2,3-三唑[4,5,c]
吡啶;N⁁N = phen (1b),Me2-phen (2b),Me4-phen (3b),Ph2-phen (4b)],这些衍
生物在激发时显示出强烈的发射。在中性和碱性条件下(pH > 6),这些复合物的发射与pH无关。通过3-(4,5-二
甲基-2-
噻唑基)-2,5-二
苯基
四唑(M
TT)法和I
CP-MS分别研究了这些复合物的细胞毒性和细胞摄取特性。此外,还研究了这些复合物作为细胞内NO传感器的潜在应用。