Magnetic resonance investigations of metal dithiolene complexes, beta'R(4)Z[Pd(dmit)(2)](2), have been performed. Although they ale isostructural with little differences in lattice parameters, their spin-spin correlation and antiferromagnetic transition temperature, T-N, show huge sample dependence. We found a close relationship between the T-N and inter-dimer interactions. The low temperature electronic states of a series of molecular conductors based on Pd(dmit), at ambient pressure are discussed from microscopic points of view.