title: Lattice effects on the spin-crossover profile of a mononuclear manganese(III) cation.
abstract: Six solvated salts of a mononuclear manganese(III) complex with a chelating hexadentate Schiff base ligand are reported. One member of the series, [MnL]PF(6)⋅0.5 CH(3)OH (1), shows a rare low-spin (LS) electronic configuration between 10-300 K. The remaining five salts, [MnL]NO(3)⋅C(2)H(5)OH(2), [MnL]BF(4)⋅C(2)H(5)OH(3), [MnL]CF(3)SO(3)⋅C(2)H(5)OH (4), [MnL]ClO(4)⋅C(2)H(5)OH (5) and [MnL]ClO(4)⋅0.5 CH(3)CN (6), all show gradual incomplete spin-crossover (SCO) behaviour. The structures of all were determined at 100 K, and also at 293 K in the case of 3-6. The LS salt [MnL]PF(6)⋅0.5 CH(3)OH is the only member of the series that does not exhibit strong hydrogen bonding. At 100 K two of the four SCO complexes (2 and 4) assemble into 1D hydrogen-bonded chains, which weaken or rupture on warming. The remaining SCO complexes 3, 5 and 6 do not form 1D hydrogen-bonded chains, but instead exhibit discrete hydrogen bonding between cation/counterion, cation/solvent or counterion/solvent and show no significant change on warming.
authors.affiliation: Centre for Synthesis and Chemical Biology, School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Komala
authors.initials: K
authors.lastname: Pandurangan
authors.forename: Brendan
authors.initials: B
authors.lastname: Gildea
authors.forename: Caroline
authors.initials: C
authors.lastname: Murray
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Harding
authors.forename: Helge
authors.initials: H
authors.lastname: Müller-Bunz
authors.forename: Grace G
authors.initials: GG
authors.lastname: Morgan