Synthese und Charakterisierung neuer fünf‐ und sechsfach koordinierter Mangan(II)‐Komplexe als Modellsysteme für manganabhängige Catecholdioxygenasen

Synthesis and Characterization of Novel Five‐ and Six‐coordinate Manganese Complexes as Catechol Dioxygenase Models The five‐ and six‐coordinate manganese complexes Mn(tphhp)Cl₂] {tphhp = N,N′‐bis(2‐pyridylmethyl)‐2‐(2‐pyridyl)hexahydropyrimidine} ( 1 ), Mn(bpma)Cl](ClO₄) {bpma = bis((2‐pyridylmethyl)((1‐methylbenzimidazol‐2‐yl)‐methyl)amine} ( 2 ) and Mn(L)TCC] {HL = (1‐hydroxy‐4‐nitrobenzyl)((1‐methylimidazol‐2‐yl)methyl)(2‐pyridylmethyl)amine} ( 3 ) were synthesized and characterized by various techniques such as single crystal X‐ray structure analysis, mass spectrometry, IR and UV/vis spectroscopy, cyclic voltammetry, and elemental analysis. 1 and 2 crystallize in the monoclinic space group P2₁/n (No. 14) ( 1 ) and P2₁/c (No. 14) ( 2 ). The ligand and the chlorine ions provide the N₃Cl₂‐donorset in 1 and the N₃Cl₂‐donorset in 2 , respectively. Compounds 1 and 2 show catalytic activity regarding the oxidation of 3,5‐di‐tertbutylcatechol to 3,5‐di‐tert‐butylchinon. To our knowledge, 1 and 2 are the first five‐coordinate manganese complexes that show catecholase activity. 3 crystallize in the orthorhombic space group P2₁2₁2₁ (No. 19) and the ligand and tetrachlorocatechol (TCC) build the N₃O₃‐donorset in 3 .