Bandyopadhyay Nirmalya, Basu Pritha, Kumar Gopinatha Suresh, Guhathakurta Bhargab, Singh Pijush, Naskar Jnan Prakash
Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
Biophysical Chemistry Laboratory, Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India.
J Photochem Photobiol B. 2017 Aug;173:560-570. doi: 10.1016/j.jphotobiol.2017.06.044. Epub 2017 Jul 1.
A novel oxime based palladium(II) complex (1) has been synthesized out of the reaction of a Schiff base ligand, 1-phenyl-1-(pyridin-2-yl-hydrazono)-propan-2-one oxime (LH) with Na[PdCl] in THF. Red and diamagnetic 1 has thoroughly been characterized by several analytical and spectroscopic means like CHN, ESI-MS, FAB-MS, FT-IR, H NMR, C NMR, UV-Vis and molar electrical conductivity measurements. Geometry optimizations at the level of DFT reveals that the Pd(II) centre in 1 is nested in a square-planar 'NCl' coordination environment. Semi-empirical BVS mode of analysis was also undertaken to reproduce the oxidation state of the palladium centre. 1 shows quasi-reversible Pd(II)/Pd(III) and Pd(III)/Pd(IV) redox couples in its CV in acetonitrile. The photophysical studies reveal that 1 is two-fold less emissive than its tethering ligand. Several biophysical studies have been undertaken to demonstrate the binding aspects of DNA and RNA with 1. Ethidium bromide displacement study concludes that 1 is partially intercalated to the CT DNA. Thermodynamic parameters of binding have also been determined from temperature dependent fluorescence spectroscopy employing the van't Hoff plot. The binding constants as determined from McGhee-von Hippel equation (Scatchard plot) indicate that 1 is a good binder of both DNA and RNA. However, the magnitude of the binding constant as determined for RNA interaction with 1 is found to be higher than that for DNA interaction.
一种新型的肟基钯（II）配合物（1）是由席夫碱配体1-苯基-1-（吡啶-2-基-腙基）-丙酮肟（LH）与Na[PdCl]在四氢呋喃中反应合成的。红色且抗磁性的1已通过多种分析和光谱手段进行了全面表征，如CHN、电喷雾电离质谱（ESI-MS）、快原子轰击质谱（FAB-MS）、傅里叶变换红外光谱（FT-IR）、氢核磁共振（H NMR）、碳核磁共振（C NMR）、紫外可见光谱（UV-Vis）以及摩尔电导率测量。在密度泛函理论（DFT）水平上的几何优化表明，1中的钯（II）中心处于平面正方形的“NCl”配位环境中。还采用了半经验的布居数分析方法来重现钯中心的氧化态。1在乙腈中的循环伏安图中显示出准可逆的钯（II）/钯（III）和钯（III）/钯（IV）氧化还原对。光物理研究表明，1的发光强度比其连接配体低两倍。已经进行了多项生物物理研究来证明1与DNA和RNA的结合情况。溴化乙锭取代研究得出结论，1部分插入到CT DNA中。结合的热力学参数也已通过使用范特霍夫图的温度依赖性荧光光谱法确定。根据麦吉 - 冯·希佩尔方程（斯卡查德图）确定的结合常数表明，1是DNA和RNA的良好结合剂。然而，发现1与RNA相互作用时确定的结合常数大小高于与DNA相互作用时的结合常数。
