Organic and organometallic compounds of the 1,3-dithiole-2-thione-4,5-dithiolate (dmit) ligand
Neutral diorganotin compounds of the 1,3-dithiole-2-thione-4,5-dithiolate ligand have been prepared. The syntheses of Me2Sndmit, Et2Sndmit, Bu2Sndmit, (C8H17)2Sndmit, (C10H21)2Sndmit and (C14H29)2Sndmit are described. For the purposes of indicating the formation of different structural phases, D.S.C. powder patterns are reported for initial and recrystallised samples of Me2Sndmit, Et2Sndmit and Bu2Sndmit. Since Et2Sndmit showed different tin environments by solid phase state N.M.R. and clearly different powder patterns after recrystallisation, the compound was recrystallised from various solvents in an attempt to determine how many crystalline forms exist. To date, two forms have been identified: orthorhombic and monoclinic. The single crystal X-ray structure analyses of these are described. It has also been shown that upon heating a transition from the orthorhombic to the monoclinic form occurs at 140°C. The crystal strict of Me2Sndmit has also been determined and is reported, along with Mossbauer parameters for Me2Sndmit and Me2Sndmio (dmio = 1,3-dithiole-2-one-4,5-dithiolate). Anionic organotin bis-dmit complexes of the form [RSn(dmit)2][Q]+ have also been prepared, with a view to investigating their electrochemical properties. The syntheses of complexes with R chain length ranging from 4 to 18 carbons are described. The problem of formation of [Sn(dmit)3][Q]2 is also discussed. D.S.C. curves and cyclic voltammograms for [C14H29Sn(dmit)2][C14H29NMe3] and [NEt4][(dmit)2SnC10H20Sn(dmit)2][NEt4] are also described. Chiral macrocycles have potential uses as catalysts for asymmetric bond-forming reactions and as selective to metal ions. A chiral macrocyclic derivative of dmit was synthesised from methyl-4,6-O-benzylidene-2,3-bis-O-[(2-iodoethoxyethyl)-ethyl]-α-D-glucopyranoside. Since reaction of this with dmit proved to be unexpectedly problematic, attempted reactions of the sugar derivative with Na2dmit in situ, isolated Na2dmit, [Zn(dmit)2][NEt4]2, [Ph2Sn(dmit)I][NEt4] and Cs2dmit are described.