Antiferromagnetic ordering in MnF(salen)

Antiferromagnetic order at TN=23 K has been identified in Mn(III)F(salen), salen = H14C16N2O2, an S = 2 linear-chain system. Using single crystals, specific heat studies performed in magnetic fields up to 9 T revealed the presence of a field-independent cusp at the same temperature where 1H NMR studies conducted at 42 MHz observed dramatic changes in the spin-lattice relaxation time, T1, and in the linewidths. Low-field (less than 0.1 T) magnetic susceptibility studies of single crystals and randomly-arranged microcrystalline samples reveal subtle features associated with the transition.