Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 5, 2012
Previous Article Next Article

Polymorphism and spin crossover in mononuclear FeII species containing new dipyridylamino-substituted s-triazine ligands

Author affiliations

Abstract

Four new dipyridylamino-substituted s-triazine ligands DBB (N2,N2,N4,N4-tetrabenzyl-N6,N6-di(pyridin-2-yl)-1,3,5-triazine-2,4,6-triamine), DDB (N2,N2,N4,N4-tetrabutyl-N6,N6-di(pyridin-2-yl)-1,3,5-triazine-2,4,6-triamine), DCCl (6-chloro-N2,N2-dicyclohexyl-N4,N4-di(pyridin-2-yl)-1,3,5-triazine-2,4-diamine) and DDT (N2,N2,N4,N4-tetraphenyl-N6,N6-di(pyridin-2-yl)-1,3,5-triazine-2,4,6-triamine), have been incorporated into eight new, 0D FeII compounds of type [FeII(NCX)2(L)2]·Solvent (where NCX = NCS, NCSe or N(CN)2). The polymorphic compounds α-trans-[FeII(NCS)2(DBB)2] (1) and β-trans-[FeII(NCS)2(DBB)2] (2) display, respectively, a relatively abrupt, complete, one-step spin transition with T½ ∼ 170 K, and a more gradual, complete, one-step spin transition with T½ ∼ 300 K. Gradual, one-step spin transitions are observed for trans-[FeII(N(CN)2)2(DBB)2]·2CH3CH2OH (3) and trans-[FeII(NCSe)2(DCCl)2]·2CH3OH (6) with T½ ∼ 280 K for both, while the one-step spin transition observed for a desolvated sample of trans-[FeII(NCSe)2(DDB)2]·2CH3OH (4) is relatively abrupt, showing hysteresis with T½↑ = 285 K and T½↓ = 275 K. The compounds cis-[FeII(NCS)2(DDB)2] (5) and trans-[FeII(NCS)2(DDT)2]·4CH2Cl2 (7) remain high spin, while structural data on trans-[FeII(NCSe)2(DDT)2]·4CH2Cl2 (8) suggests a spin transition at low temperatures. It is likely that distortion of the FeIIN6 octahedron, intermolecular interactions and molecular conformation are crucial in deciding both the T½ and abruptness of the spin transition for these species, although the nature of their influence varies. Variable temperature powder X-ray diffraction measurements on the polymorphs 1 and 2 reveal anisotropy in the unit cell parameters as the spin transition occurs.

Graphical abstract: Polymorphism and spin crossover in mononuclear FeII species containing new dipyridylamino-substituted s-triazine ligands

Back to tab navigation

Supplementary files

Publication details

The article was received on 25 Aug 2011, accepted on 25 Oct 2011 and first published on 06 Dec 2011


Article type: Paper
DOI: 10.1039/C1DT11597A
Citation: Dalton Trans., 2012,41, 1512-1523

  •   Request permissions

    Polymorphism and spin crossover in mononuclear FeII species containing new dipyridylamino-substituted s-triazine ligands

    T. M. Ross, B. Moubaraki, S. M. Neville, S. R. Batten and K. S. Murray, Dalton Trans., 2012, 41, 1512
    DOI: 10.1039/C1DT11597A

Search articles by author

Spotlight

Advertisements