A COMPARISON BETWEEN THE STRUCTURES OF [MN-III(BBPEN)] [PF6] AND [MN-III(BBPPN)][PF6] ROXYBENZYL)-N,N'-(2-PYRIDYLMETHYL)ETHYLENEDIAMINE, BENZYL)-N,N'-(2-PYRIDYLMETHYL)-1,3-PROPANEDIAMINE)

The reaction of Mn(OAc) . 2H(2)O in methanolic solution with ybenzyl)- N,N'-(2-pyridylmethyl)-1,3-propanediamine (H(2)bbppn; C29H32N4O2) affo rds upon addition of NH4PF6 green crystals of the monomeric [Mn-III(bb ppn)] [PF6] (2) complex. The crystal structure of 2 has been determine d by X-ray crystallography. Crystal data: monoclinic P2(1)/n (No. 14), a=12.762(1), b=12.543(2), c = 19.008(2) Angstrom, beta=93.18(2)degree s, V = 3038(1) Angstrom(3), Z=4. The structure has been refined to an R factor of 6.5% based on 2322 observed reflections. The arrangement o f bbppn(2-) around the Mn-III center in 2 is compared to the close rel ated [Mn-III(bbpen)] [PF6] (1) complex (H(2)bbpen = oxybenzyl)-N,N'-(2 -pyridylmethyl)ethylenediamine). The fundamental geometric difference between the two structures lies in the isomeric nature of the coordina tion of the N4O2-donor set, which results in quite different bond dist ances around the metal centers.