Fluorescence Spectroscopic Evidence for Hydrogen Bonding and Deprotonation Equilibrium between Fluoride and a Thiourea Derivative
作者:Pichandi Ashokkumar、Vayalakkavoor T. Ramakrishnan、Perumal Ramamurthy
DOI:10.1002/chem.201000837
日期:2010.11.22
Interaction of anions with thiourea‐linked acridinedione fluorophore was studied by absorption, 1H NMR, steady‐state and time‐resolved fluorescence techniques. Addition of AcO− and H2PO4− shows a genuine H‐bonded complex with thiourea receptor; whereas, F− shows stepwise H‐bonding and deprotonation of thiourea NH as confirmed by 1H NMR titration. Free receptor 1 shows emission maximum at 418 nm; whereas
通过吸收,1 H NMR,稳态和时间分辨荧光技术研究了阴离子与硫脲连接的a啶二酮荧光团的相互作用。ACO的加成-和H 2 PO 4 -示出了真正的氢键络合物与硫脲受体; 而,F -按步骤显示由确认硫脲NH的氢键和去质子化1个1 H NMR滴定。游离受体1在418 nm处显示最大发射;而,H键合的复合物1个⋅F -示出了新的红移最大发射在473nm的和去质子化1在502 nm处显示出发射峰。通过3D发射光谱研究探究了这三种不同发射物种的存在。自由受体之间的平衡1,1 ⋅F -氢键络合物和去质子1是由时间分辨荧光研究证实。的时间分辨面积归一化发射光谱(TRANES)1中F的存在-示出了在456 2个isoemissive点和分别为0-0.5 NS和1-20纳秒的时间延迟之间的479纳米,由于以下三个的存在发光种处于平衡状态。基于荧光光谱研究观察到的这种平衡进一步证明了较早报道的吸收和1H键和去质子过程的1