A trinudear Mn（II） coordination complex Mna （HEDTA）2-10H20 （EDTA=ethylene diamine tetraacetic acid） 1 has been synthesized and characterized by X-ray crystal structure determination. In addition, IR spectrum, thermogravimetric analysis, electron paramagnetic resonance （EPR） spectra and magnetic susceptibility of this complex are discussed. X-ray determination indicates that six- and seven-coordinate modes between Mn（Yl） and H4EDTA exist alternately in 1. Furthermore, detailed discussion of magnetic ordering in tile temperature range of 2-300 K reveals the antiferromagnetic interactions in the complex.
The calculations on the potential energy curves and spectroscopic constants of the ground and low-lying excited states of BrCl^+, one of the important molecular ions in environment science, have been performed by using the multireference configuration interaction method at high level of theory in quantum chemistry. Through analyses of the effects of the spin-orbit coupling interaction on the electronic structures and spectroscopic properties, the multiconflguration characteristic of the X^2Π ground state and low-lying excited states was established. The spin-orbit coupling splitting energy of the X^2 Π ground state was calculated to be 1814 cm^(-1), close to the experimental value 2070 cm^(-1). The spin-orbit coupling splitting energy of the ~2Π(II) exited state was predicted to be 766 cm^(-1). The transition dipole moments and Frank-Condon factors of the 3/2(III)-X3/2 and 1/2(III)-1/2(I) transitions were estimated, and the radiative lifetimes of the two transitions were briefly discussed.
