title: Influence of supramolecular bonding contacts on the spin crossover behaviour of iron(II) complexes from 2,2'-dipyridylamino/s-triazine ligands.
abstract: Reactions of the related ligands 2-(N,N-bis(2-pyridyl)amino)-4,6-bis(phenoxy)-(1,3,5)triazine (L1) and 2-(N,N-bis(2-pyridyl)amino)-4,6-bis(pentafluorophenoxy)-(1,3,5)triazine (L1(F)) with iron(II) thiocyanate produced two spin-crossover coordination compounds with distinct cooperative behaviours. trans-[Fe(L1)2(NCS)2]·2CH2Cl2 (1) displays a very gradual transition centred at T½ = 233 K, characterized by a ΔT80 (namely the temperature range within which 80% of the transition considered occurs) of 90 K, while that of fluorinated trans-[Fe(L1(F))2(NCS)2]·2CH3CN (3) is significantly more abrupt (and centred at T½ = 238 K), with a ΔT80 of 50 K, resulting from supramolecular contacts induced by the fluorinated phenol groups. The coordination compound equivalent to 1 with selenocyanate anions, namely trans-[Fe(L1)2(NCSe)2]·4CH2Cl2·4CH3OH (2), also exhibits SCO properties centred at T½ = 238 K, but the transition is very gradual (ΔT80 = 150 K). Light-induced excited spin-state trapping (LIESST) is effective although incomplete for 2 and 3, while it is complete with a T(LIESST) of 58 K for 1.
authors.affiliation: Departament de Química Inorgànica, QBI, Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain.
authors.forename: Nanthawat
authors.initials: N
authors.lastname: Wannarit
authors.forename: Olivier
authors.initials: O
authors.lastname: Roubeau
authors.forename: Sujittra
authors.initials: S
authors.lastname: Youngme
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Teat
authors.forename: Patrick
authors.initials: P
authors.lastname: Gamez