Solid-state and theoretical structural study on(Eten=N-ethyl ethylenediamine)

摘要

The solid-state structure of trans-[ReO_2(Eten)_2]CF_3SO_3LiCF_3SO_3(Eten=N-ethyl ethylenediamine)crystallizing in the triclinic space group,P1,is reported.The title compound crystallizes as two independent trans-[ReO_2(Eten)_2]~+ cations,with each Re atom on an inversion center and a trans orientation with respect to the ethyl functionalized N-donor atom of the Eten ligand.A LiCF_3SO_3 co-crystallizes with the complexes,wherein the Li~+ cation occupies a distorted tetrahedral geometry as defined by four intermolecular oxygen interactions.Two of these are to the oxo ligands of the trans-[ReO_2(Eten)_2]~+ cations,thus forming infinite chains of alternating rhenium complexes and lithium cations.The average Re=O bond length is 1.765(3)A,with an average bite angle of 79.5(2)deg ,and average Re-N bond distances of 2.191(4)and 2.162(4)A for the unfunctionalized and functionalized N-donor atoms of the Eten ligand,respectively.The two rotamers in the asymmetric unit each have an eclipsed deltalambda conformation,and DFT optimized structures showed a remarkable agreement with the solid-state data.An energy distribution of eight different conformers were evaluated and correlated with the solid-state structure,spanning a difference of about 13 kJ mol~(-1),while the rotation barrier of 21.9 kJ mol~(-1)from eclipsed to staggered conformation was obtained.