Crystal structure and EPR studies of Bis[1,3-Di(p-n-Octylphenyl) Propane-1,3-Dionato]Oxovanadium(IV)

Abstract

We report here the synthesis, crystal structure and Electron Paramagnetic Resonance (EPR) studies of the compound bis[l,3-di(p-n-octy1phenyI)propane- 1,3-dionato]oxovanadium(IV) abbreviated as C8(VO)C8. The molecular crystalline properties of this compound are dealt with in this paper. The compound crystallizes in the triclinic, Pi space group with a = 11.956(4), b = 15.802(5), c = 16.293(4) A, α = 103.22(2), β = 110.61(2), and γ = 90.88(3); 222. The two vanadium centers are crystallographically equivalent and the shortest V-V bond distance is 9.5803 A. The hyperfine splitting pattern in single crystal EPR spectrum clearly shows the presence of weak pair-wise magnetic interaction. The splitting originates in a combination of hyperfine and fine structure caused by dipolar and exchange coupling of nearest-neighboring molecules related by inversion through the unit cell origin. The sign and the value of the exchange coupling constant, J = + 30 G, was determined by simulation of EPR spectra. The principal g and A values obtained are gl = 1.934 and gl = 1.982, A1 = 192 G and Al = 69 G.