SCANDIUM PICRATE COMPLEX WITH TRANS-1,4-DITHIANE-1,4-DIOXIDE

A new polynuclear scandium picrate complex [Sc-3(pic)(3)(TDTD)(1.5)(OH )(5)(H2O)] (pic)(H2O)(5) (pic=picrate) has been obtained by reacting h ydrated scandium picrate and trans-1,4-dithane1,4-dioxide (TDTD) in wa ter. The compound has been characterized by infrared spectra and X-ray structural analysis. It crystallizes in a monoclinic cell, space grou p PZ,, with a=13.528(5), b=26.002(4), c=15.421(3) Angstrom and beta=10 3.26(3)degrees, Z=4, dc=1.85 g cm(-3). The crystal structure consists of polymeric chains of centrosymmetric hexameric clusters of scandium ions, connected via TDTD bridges. The scandium coordination polyhedron s are formed by oxygens of hydroxyl units, shared between two or three scandium ions, monodentate or bidentate picrates, water molecules and TDTD ligands monodentate or bridging. The scandium coordination numbe rs are six for four scandium ions and seven for the remaining two. The Sc-Sc separations are: Sc(1)-Sc(2) 3.317(4), Sc(2)Sc(3) 3.392(3), Sc( 1)-Sc(2)' 3.430(3), Sc(1)Sc(S)' 3.462(2) and Sc(2)-Sc(2)' 3.460(2) Ang strom. Uncoordinated water molecules and picrate ions complete the cry stal structure.