DIPHENYLBUTADIENE-BRIDGED GADOLINIUM COMPLEX [GDCL2(THF)(3)](2) (MU-PH2C4H4)CENTER-DOT-3THF - THE SYNTHESIS AND CRYSTAL-STRUCTURE

The diphenylbutadiene-bridged gadolinium complex [GdCl2(THF)(3)](2)(mu -Ph2C4H4). 3THF (1) has been obtained by the reaction of Gd(III) chlor ide with diphenylbutadienepotassium. The molecular structure of 1 was determined by X-ray diffraction. The complex 1 has a binuclear structu re in which a bridging diphenylbutadiene ligand is eta(4)-bonded to th e Gd atoms connecting two GdCl2(THF)(3) units, Both Gd atoms have a di storted octahedral environment. At the Gd atom the two Cl atoms are in trans positions and the four other coordination sites are occupied by the three O atoms of THF molecules and the eta(4)-bonded C4H4 fragmen t of a diphenylbutadiene ligand. In the two eta(4)-bonded GdC4H4 fragm ents one of the Gd-C eta(4)-distances is significantly elongated (2.86 (3) and 2.97(3) Angstrom) compared with other three (2.65(3)-2.69(3) a nd 2.67(3)-2.77(3) Angstrom). The magnetic moment of Gd, equal to 8.1 BM, is typical for Gd3+ compounds that is evidence for a formal charge of DPBD ligand of -2 in complex 1, However, the expected distribution of the C-C bond of the diene fragment as long-short-long is not reali zed. (C) 1997 Elsevier Science S.A.