Exchange Coupling in Metal Complexes of the Second Transition Series: A Theoretical Exploration

Abstract

Theoretical methods based on density functional theory using hybrid functionals provide good estimates of the exchange coupling constants for complexes with metals of the second transition series, with accuracy similar to that previously obtained for complexes with lighter transition metals. The influence of the basis set and effective core potentials

Magnetic exchange interactions in cyano‐bridged MoIII binuclear complexes: Broken‐symmetry and density functional theory calculations

“…Desplanches et al 3 gave only the J values of [Mo 2 (CN) 11 ] 5− 7 using DFT‐BS with several other basis sets. The authors did not investigate it in detail.…”

“…In previous papers, the B3LYP method provides very good results for the evaluation of spin populations 16 and of the exchange coupling constants 17. Because the calculated results of Desplanches et al 3 show that all‐electron basis sets give results similar to those obtained with effective core potentials in calculating the J value of [Mo 2 (CN) 11 ] 5− 7, we employ only valence‐electron basis set LanL2DZ, proposed by Hay and Wadt 18. Although there is no experimental information about J for molecule b , we employ the difference‐dedicated configuration interaction (DDCI) method 19, 20 by means of the CASDI code 21, 22 to obtain the reference J values evaluated by calculating the energy difference between the lowest‐spin state (ELS) and the highest‐spin state (EHS) for comparison.…”

“…The authors confirmed that the substitution of Mo III for Cr III in metal–cyanide clusters was demonstrated as an effective means of increasing the strength of the magnetic exchange coupling and introducing magnetic anisotropy. In a recent work, Desplanches et al 3 succeeded in calculating the exchange coupling constants in metal complexes of the second transition series using a density functional theory (DFT), namely, Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Parr (B3LYP) combined with Noodleman's broken‐symmetry (BS) approach 4–6 using all‐electron basis set (MSV), several valence‐electron basis sets (LANL2DZ, CEP‐31G and CEP‐121G) and valence‐electron SDD for molybdenum atoms (and TZV [triple‐zeta all‐electron basis set] for the other atoms), respectively. Their calculated results, which are in excellent agreement with the experimental ones, show that all‐electron basis sets give results similar to those obtained with effective core potentials and that the antiferromagnetism of [Mo 2 (CN) 11 ] 5− 7 is stronger than that of [Cr 2 (CN) 11 ] 5− 8.…”

Adolescent–Adult discrepancies on the eating disorder examination: A function of developmental stage or severity of illness?

“…In a recent work, Desplanches et al 4 succeeded in calculating the exchange coupling constants in metal complexes of the second transition series, using density functional theory (DFT) combined with Noodleman's broken‐symmetry (BS) approach 5–7. We 8 also selected two cyano‐bridged Mo III binuclear complexes [Mo 2 (CN) 11 ] 5− 1 and [(Me 3 tacn) 2 Mo 2 (CN) 5 ] + (Me 3 tacn = N , N ′, N ″‐trimethyl‐triaz‐acyclononane) 2 to analyze the magneto‐structural correlations and the mechanisms of the magnetic coupling interactions through the spin‐density maps, using DFT‐BS.…”

“…We 8 also selected two cyano‐bridged Mo III binuclear complexes [Mo 2 (CN) 11 ] 5− 1 and [(Me 3 tacn) 2 Mo 2 (CN) 5 ] + (Me 3 tacn = N , N ′, N ″‐trimethyl‐triaz‐acyclononane) 2 to analyze the magneto‐structural correlations and the mechanisms of the magnetic coupling interactions through the spin‐density maps, using DFT‐BS. In the above theoretical work, Desplanches et al 4 and Zhang et al 8 only investigated the homo‐binuclear second transition metal complexes. However, we selected four cyano‐bridged hetero‐trinuclear and hetero‐polynuclear complexes to investigate the magnetic properties extending the research of magnetic coupling mechanism of 4 d systems.…”