C. Bucher et al., Synthesis, X-ray structure, electrochemical, and EPR studies of a pentacoordinated Mn(II) tetramethylcyclam complex, INORG CHEM, 40(22), 2001, pp. 5722
The synthesis and full characterization of [(tmc)MnCl].X (where tine is 1,4
,8,11-tetramethyl-1,4,8,1 1-tetraazacyclotetradecane and X is BPh4- or BF4-
) are reported. The complex is of type I geometry. The manganese ion is pen
tacoordinated by the four tertiary nitrogen atoms of the macrocycle and one
axial chloride. Variable-temperature magnetic susceptibility da ta indicat
e that the oxidation state of the manganese ion is +II with S = 5/2. The EP
R spectrum exhibits unusual signals, with the main derivative line at g = 3
.7 and transitions at more than 900 mT. The cyclic voltammogram of this der
ivative consists of two reversible systems at +1.14 and +1.36 V vs SCE rela
ted by a chemical equilibrium attributed to an isomerization process.