Synthesis and electrochemistry of meso-substitutes dipyrromethene nickel (II) complexes

• Published in: Polyhedron Vol. 102; pp. 578 - 582
• Main Authors: Wang, Yemei, Xue, Zhaoli, Dong, Yuan, Zhu, Weihua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 14-12-2015
• Subjects: Dipyrromethene; Electrochemistry; Metalation; Spectroelectrochemistry; Synthesis; Electrochemistry; Metalation; Dipyrromethene; Synthesis; Spectroelectrochemistry
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2015.10.020

A series of dipyrromethene nickel (II) complexes have been synthesized and their optical and electrochemical properties have been investigated. The electron donating-withdrawing properties of the para-substituents on the two meso-phenyl rings have great affect the chemical peaks of aromatic protons as compare to normal metalloporphyrin complexes. [Display omitted]
Metalation of dipyrromethene (dipyrrin) (1a–c) with Ni(OAc)2 provides Ni-dipyrrole complexes (NiL2) (2a–c) in 37–47% yields. The complexes were characterized by mass spectrometry and UV–Vis absorption, 1H NMR spectroscopy and single crystal X-ray. In CH2Cl2, each compound undergoes two reversible one-electron reductions and one irreversible oxidation wave. In DMF, complexes 2a–c also undergoes two reversible one-electron reductions but with three irreversible oxidation waves were observed. The effect of substituents and solvent on redox potentials is discussed.