Manganese nitrosyl MnNO}6 complexes of general formula [Mn(dpaqR)(NO)]ClO4 (1R), where dpaqR denotes a series of pentadentate monoamido ligands, 2-[N,N-bis(pyridin-2-ylmethyl)]-amino-N′-quinolin-8-yl-acetamido with R = OMe, H, Cl and NO2 at the 5-position of the quinoline moiety, were prepared. The derivatives 1R were characterized by 1H NMR, IR and UV–vis spectrometry as well as by single-crystal X-ray crystallography. The N–O bond and the amido CO bond stretching frequencies, as well as the redox potentials of 1R derivatives, substantially varied depending on the nature of the substituent group R on the quinoline ring, indicating that the π back-bonding from Mn to NO groups becomes weak as the substituent group R becomes more electron withdrawing. The nitro-substituted derivative 1NO2 is unique among the series; the tail of its absorption bands extends to the NIR region (up to 700 nm), and the apparent NO releasing rate from 1NO2 by light irradiation at 650 nm was ca. 4-fold higher than the other derivatives.
制备了通式为[Mn(dpaqR)(NO)]ClO4 (1R)的亚硝基
锰MnNO}6配合物,其中 dpaqR 表示一系列五价单
氨基
配体,2-[N,N-双(
吡啶-2-基甲基)]-
氨基-N′-
喹啉-8-基乙酰
氨基,
喹啉分子 5 位上的 R = OMe、H、Cl 和
NO2。衍
生物 1R 通过 1H-核磁共振、红外光谱、紫外-可见光谱以及单晶 X 射线晶体学进行了表征。1R 衍
生物的 N-O 键和
氨基 CO 键伸展频率以及氧化还原电位随
喹啉环上取代基 R 的性质不同而有很大的变化,这表明随着取代基 R 的电子撤回性增强,Mn 与 NO 基团之间的 π 反键作用会变弱。硝基取代衍
生物 1 在这一系列衍
生物中是独一无二的;其吸收带的尾部延伸到了近红外区域(高达 700 纳米),在 650 纳米波长的光照射下,1 的表观 NO 释放率比其他衍
生物高出约 4 倍。