877933-00-1Relevant academic research and scientific papers
Fe(III) clusters built with tripodal alcohol ligands
Jones, Leigh F.,Low, David M.,Helliwell, Madeleine,Raftery, James,Collison, David,Aromí, Guillem,Cano, Joan,Mallah, Talal,Wernsdorfer, Wolfgang,Brechin, Euan K.,McInnes, Eric J.L.
, p. 325 - 333 (2006)
Reaction of the tripodal ligand 1,1,1-tris(hydroxymethyl)ethane (H 3thme) with a variety of Fe(III) precursors under both ambient and solvothermal conditions has led to the isolation of a number of new complexes ranging in nuclearity from 4 to 16. These include the rhomb or diamond-like clusters [Fe4(thme)2Cl4(O2CR) 2(R′OH)2] (1, R = Me, R′ = Et; 2, R = Ph, R′ = Me; 3, R = CMe3, R′ = Me); the related nonanuclear and undecanuclear clusters [Fe9O4(O2CCMe 3)13(thme)2] (4) and [NEt4][Fe 11O4(O2CPh)10(thme) 4(dmhp)2Cl4] (5) (dmhp = 4,6-dimethyl-2- hydroxypyrimidine) and the octametallic and hexadecametallic wheels [Fe 8(O2CR)12(thme)4] (6, R = Ph; 7, R = CMe3) and [Fe16(EtO)4(O2CPh) 16(Hthme)12](NO3)4 (8). Magnetic studies reveal the presence of dominant antiferromagnetic interactions between the Fe centres in all eight complexes which results in the presence of small spin ground states for complexes 1-4 and 6-8. For 5 however, these stabilise an S = 11/2 spin ground state with an axial zero-field splitting parameter of D = -0.46 cm-1. Single crystal hysteresis loops in magnetisation versus external magnetic field measurements show the temperature and sweep rate dependence indicative of single-molecule magnetism behaviour.
