Record Details

Theoretical studies on {3d-Gd} and {3d-Gd-3d} complexes: Effect of metal substitution on the effective exchange interaction

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Theoretical studies on {3d-Gd} and {3d-Gd-3d} complexes: Effect of metal substitution on the effective exchange interaction
 
Creator SINGH, SK
RAJESHKUMAR, T
CHANDRASEKHAR, V
RAJARAMAN, G
 
Subject SMMs
MCE
DFT calculations
Magnetic coupling in {3d-Gd-III}
{3d-Gd-III-3d} pair
Nearest neighbor interaction
1,2-Interactions
1,3-Interaction
Molecular coolant
SINGLE-MOLECULE-MAGNET
EFFECTIVE CORE POTENTIALS
HEXADENTATE SCHIFF-BASES
II/GD-III COUPLE
LANTHANIDE COMPLEXES
DINUCLEAR COMPLEXES
INTRINSIC PROPERTY
CRYSTAL-STRUCTURE
GROUND-STATE
DY COMPLEXES
 
Description Series of DFT calculations on [(LNi)-Ni-1(H2O)(2)Gd(NO3)(3)] (1) and their transition metal substituted models {(CrGdIII)-Gd-III}, {(FeGdIII)-Gd-II}, {(MnGdIII)-Gd-II} and {(CuGdIII)-Gd-II} have been performed to probe the electronic effects of the metal substitution on the sign and strength of magnetic coupling. Our results unfold an interesting observation that the strength of the exchange is related to the d-orbital occupancy with occupancy on the e(g) orbitals resulting in stronger ferromagnetic exchange while progressively filling the t(2g) orbitals leads to a reduction in the computed J values. Further, we extend our studies to the trinuclear {3d-Ln-3d} [L(2)M(2)Ln][ClO4] (LH3 = (S)P[N(Me)N = CH-C6H3-2-OH-3-OMe](3)) (here M = Cu2+, Ni2+ and Mn2+ and Ln = Gd-III and La-III)complexes possessing phosphorus, salicylideneaminooxy and Schiff base supported ligands to corroborate our findings in dinuclear models. By computing the nearest neighbor and next-nearest neighbor interactions in all three complexes, our studies reveal that the observation of strong exchange with e(g) occupancy is preserved also in the trinuclear complexes. This will have implications in the area of molecular coolants where Cu-II and Gd-III are the preferred choice as they inherit no/negligible anisotropy, but our finding suggests that Cu-II invariably also offers strong exchange interaction - a parameter unsuitable for ideal molecular coolants. Metals ions such as Mn-II and Cr-III are perhaps better choice for molecular refrigeration as they possess large spin values, negligible anisotropy and mediate relatively a weak magnetic exchange interaction.
 
Publisher PERGAMON-ELSEVIER SCIENCE LTD
 
Date 2014-10-14T17:53:21Z
2014-10-14T17:53:21Z
2013
 
Type Article
 
Identifier POLYHEDRON, 6681-86
http://dx.doi.org/10.1016/j.poly.2013.02.037
http://dspace.library.iitb.ac.in/jspui/handle/100/14617
 
Language en