Faure Sébastien, Stern Christine, Guilard Roger, Harvey Pierre D
LIMSAG UMR 5633, Université de Bourgogne, 6 bd Gabriel, 21100 Dijon, France.
Inorg Chem. 2005 Dec 12;44(25):9232-41. doi: 10.1021/ic0508573.
The 4,6-bis(10-mesityl-5,15-di-p-tolylporpyrinyl)dibenzothiophene (H4DPSN) free base was obtained in five steps from commercially available materials. The metalation of DPSN2- with zinc(II), copper(II), and palladium(II) led to three new homobimetallic systems, (Zn)2DPSN, (Cu)2DPSN, and (Pd)2DPSN, respectively. The cofacial structures of these molecules offer the possibility of having dioxygen molecules inside the cavity for a period of time, allowing dynamic (collisional) phosphorescence quenching to be more efficient. The bimolecular excited-state deactivation rate constant for deactivation by dioxygen (kQ: (Pd)2DPB, 2.98x10(9); (Pd)2DPSN, 3.99x10(9); (Pd)2DPX, 6.94x10(9); (Pd)TPP, 8.95x10(9); (Pd)2DPS, 8.95x10(9) M-1 s-1) of (Pd)2DPSN, which exhibits an intense phosphorescence at 699 nm, was compared to those observed for (Pd)TPP, (Pd)2DPS, (Pd)2DPX, and (Pd)2DPB (TPP2-=tetraphenylporphyrin dianion, DPS4-=4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX4-=4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, and DPB4-=1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion). These collision-induced deactivation data were interpreted by estimating a series of physical parameters such as the surface area and bisporphyrin radii, the diffusion coefficient of the bismacrocycles, and the theoretical deactivation efficiency for the five compounds addressing the role of steric hindrance of the macrocycles on each other and the aryl groups at the meso positions. For sensing purposes, (Pd)2DPX is characterized by a Stern-Volmer constant kSV of 2.91x10(6) M-1, placing the lower detection limit for [O2] in solution at 0.58 ppm, which is better than that for (Pd)TPP (kSV=2.31x10(6) M-1; lower detection limit of 0.73 ppm), the classically used monoporphyrin complex.
4,6-双(10-均三甲苯基-5,15-二对甲苯基卟啉基)二苯并噻吩(H4DPSN)游离碱可通过五步从市售原料制得。DPSN2-与锌(II)、铜(II)和钯(II)进行金属化反应，分别得到三种新的同双核金属体系，即(Zn)2DPSN、(Cu)2DPSN和(Pd)2DPSN。这些分子的共面结构使得腔内有可能在一段时间内存在双氧分子，从而使动态(碰撞)磷光猝灭更有效。将在699 nm处呈现强烈磷光的(Pd)2DPSN与双氧猝灭的双分子激发态失活速率常数(kQ: (Pd)2DPB为2.98×10(9); (Pd)2DPSN为3.99×10(9); (Pd)2DPX为6.94×10(9); (Pd)TPP为8.95×10(9); (Pd)2DPS为8.95×10(9) M-1 s-1)与(Pd)TPP、(Pd)2DPS、(Pd)2DPX和(Pd)2DPB( TPP2- = 四苯基卟啉二价阴离子，DPS4- = 4,6-双[5-(2,8,13,17-四乙基-3,7,12,18-四甲基卟啉基)]二苯并噻吩四价阴离子，DPX4- = 4,5-双[5-(2,8,13,17-四乙基-3,7,12,18-四甲基卟啉基)]-9,9-二甲基氧杂蒽四价阴离子，DPB4- = 1,8-双[5-(2,8,13,17-四乙基-3,7,12,18-四甲基卟啉基)]联苯撑四价阴离子)的相应常数进行了比较。通过估算一系列物理参数，如表面积和双卟啉半径、双大环的扩散系数以及五种化合物的理论失活效率，来解释这些碰撞诱导失活数据，这些参数涉及大环之间的空间位阻以及中位芳基基团的作用。出于传感目的，(Pd)2DPX的斯特恩-沃尔默常数kSV为2.91×10(6) M-1，溶液中[O2]的检测下限为0.58 ppm，优于经典使用的单卟啉配合物(Pd)TPP(kSV = 2.31×10(6) M-1;检测下限为0.73 ppm)。
