Geometric Control of Ground State Multiplicity in a Copper(I) Bis(verdazyl) Complex
摘要:
A copper(I) complex of a 3-(6'-isopropylpyridyl)-substituted verdazyl was synthesized and characterized by X-ray crystallography and magnetic susceptibility. The complex crystallizes in the monoclinic space group C2/c with cell dimensions a = 22.544 angstrom, b = 11.576 angstrom, c= 17.157 angstrom, beta = 123.907 degrees, V = 3716.2 angstrom(3). The coordination geometry at copper is distorted tetrahedral, with the two ligand planes separated by 75 degrees. Magnetic susceptibility measurements indicate that the ground state of the diradical is a triplet at this geometry. Fitting to a simple Heisenberg Hamiltonian (H = -JS(1).S(2)) gave J = 47(1) cm(-1). The triplet ground state results from exchange mediated by the copper ion; in particular, the direction of the distortion from tetrahedral geometry appears to be essential to maintain the high-spin ground state.
Geometric Control of Ground State Multiplicity in a Copper(I) Bis(verdazyl) Complex
作者:David J. R. Brook、Gordon T. Yee、Mike Hundley、David Rogow、Janice Wong、Khanh Van-Tu
DOI:10.1021/ic1011764
日期:2010.9.20
A copper(I) complex of a 3-(6'-isopropylpyridyl)-substituted verdazyl was synthesized and characterized by X-ray crystallography and magnetic susceptibility. The complex crystallizes in the monoclinic space group C2/c with cell dimensions a = 22.544 angstrom, b = 11.576 angstrom, c= 17.157 angstrom, beta = 123.907 degrees, V = 3716.2 angstrom(3). The coordination geometry at copper is distorted tetrahedral, with the two ligand planes separated by 75 degrees. Magnetic susceptibility measurements indicate that the ground state of the diradical is a triplet at this geometry. Fitting to a simple Heisenberg Hamiltonian (H = -JS(1).S(2)) gave J = 47(1) cm(-1). The triplet ground state results from exchange mediated by the copper ion; in particular, the direction of the distortion from tetrahedral geometry appears to be essential to maintain the high-spin ground state.