THE X-RAY CRYSTAL AND MOLECULAR-STRUCTURE OF [BA(TDFND)(2).TETRAGLYME], THE FIRST MOLTEN BARIUM PRECURSOR FOR MOCVD APPLICATIONS

At 150 K [Ba(TDFND)(2).tetraglyme] crystallises in the P-1/c space gro up with a=17.15(2) Angstrom, b=10.735(5) Angstrom, c=22.830(7) Angstro m, beta=97.56(7)degrees, V=4165(5) Angstrom(3) Z=4. R(1)=0.0435, wR(2) =0.1079. The barium atom Is nine-co-ordinate, with binding to ail the O atoms, The two BaTDFND rings are planar but tilted by 26 degrees fro m being co-planar, The five O atoms of the tetraglyme ligand are also essentially co-planar, but this plane subtends angles of 88.8(1)degree s end 67.4(1)degrees to the two BaTDFND planes, The Ba-O (TDFND) bond lengths are longer than for other related compounds, but tire Ba-O (te traglyme) bond lengths are similar to those in [Ba(HFA)(2).tetraslyme] (HFA=CF3C(O)CHC(O)CF3). The low melting point and the fact that [Ba(T DFND)(2).tetraglyme], alone of barium complexes of this kind, can be e vaporated without decomposition at 1 atm are attributed to lower inter molecular forces for this compound and to its greater thermal stabilit y.