Studies on the interaction between 9-fluorenylmethyl chloroformate and Fe3+ and Cu2+ ions: Spectroscopic and theoretical calculation approach

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2014-11, Vol.132, p.361-368
• Main Authors: Gu, Zhenyan, Lei, Wu, Shi, Wenyan, Hao, Qingli, Si, Weimeng, Xia, Xifeng, Wang, Fengxiang
• Format: Article
• Language: English
• Subjects: 9-Fluorenylmethyl chloroformate; Fluorescence spectroscopy; Optical analysis; Quantum chemical calculation; Static quenching
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2014.05.025

[Display omitted] •FMOC-Cl shows special affinity to Fe3+ and Cu2+ ions over other metal ions.•Quenching mechanism of FMOC-Cl with Fe3+ and Cu2+ ions is static quenching.•The interaction force of FMOC-Cl with Fe3+ ions is larger than that with Cu2+ ions.•Calculations prove the interaction is attributed to the formed coordination bond. The interaction between 9-fluorenylmethyl chloroformate (FMOC-Cl) and Fe3+ and Cu2+ ions was investigated using fluorescence, UV/Vis absorption spectroscopies and theoretical calculation. The optical property of FMOC-Cl was studied in detail in absence and presence of various transition metal ions with particular affinity to Fe3+ and Cu2+ ions. With the fluorescence characteristic band centered at 307 and 315nm for FMOC-Cl, the introduction of Fe3+ or Cu2+ ions leads to the fluorescence quenching of FMOC-Cl with different shift and intensities of two fluorescent bands. It allows us to differentiate between FMOC-Cl and Fe3+ and Cu2+ ions interaction behavior. The study on fluorescent kinetics confirms that the fluorescence quenching of FMOC-Cl with Fe3+ and Cu2+ ions is based on the formation of non-fluorescent material, that is, static quenching. Further analyses of bond lengths, Mulliken atomic charges and the frontier orbital compositions for FMOC-Cl and its complexes with Fe3+ and Cu2+ ions were carried out. The theoretical calculations prove the fluorescence quenching originates from the formation of coordination bonds between the oxygen atom of the carbonyl group of FMOC-Cl and Fe3+ and Cu2+ ions. The commercially available FMOC-Cl can be used as excellent fluorescent probe toward Fe3+ and Cu2+ ions with high sensitivity.