Abstract
Two new dinuclear copper(II) complexes [Cu 2(PymPz) 2(N 3) 2Cl 2] (1), [Cu 2(PymPz) 2(N 3) 4] (2) and two new dinuclear cobalt(II) complexes [Co 2(PymPz) 2Cl 4] (3), [Co 2(PymPz) 2(N 3) 4] (4) [PymPz = 2-(3,5-dimethyl-1H-pyrazol-1-yl)-4,6-dimethylpyrimidine] have been synthesized and characterized crystallographically and spectroscopically. In each of the complexes 1, 2 and 4 the two adjacent metal centers are bridged by a pair of μ-1,1 azide groups whereas in 3 the metal centers are bridged by a pair of chloride ions. In the complexes, all the metal centers are pentacoordinated. In 1 and 2 the copper(II) centers have distorted square pyramidal geometry (τ = 0.18 for 1 and 0.091 for 2) but in 3 and 4 cobalt(II) centers have distorted trigonal bipyramidal geometry (τ = 0.619 for 3 and 0.557 for 4). Complexes 1 and 2 show antiferromagnetic interaction (J = -7.09 cm -1 for 1 and J = -17.00 cm -1 for 2) whereas 3 and 4 show ferromagnetic interaction (J = 7.44 cm -1 for 3 and J = 10.45 cm -1 for 4). Complex 3 displays an unprecedented ferromagnetic interaction over double μ-chloro bridges in the observed angle range (94.87°). The exchange pathways parameters for all the complexes have also been evaluated from density functional theoretical calculations to corroborate the bridging signatures with experimental findings.
Original language | English |
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Pages (from-to) | 258-266 |
Number of pages | 9 |
Journal | Polyhedron |
Volume | 38 |
Issue number | 1 |
DOIs | |
State | Published - 11 May 2012 |
Keywords
- Coordination
- Crystal
- DFT
- Magnetism