The synthesis of the 1,3,2-dithiazolyl radical () derived from 3,4-dihydro-2H-1,5-benzodioxepine is described. Crystals of were grown by vacuum sublimation and adopt the orthorhombic space group . DC SQUID magnetometry reveals Curie-Weiss behavior for > 20 K ( = 0.
View Article and Find Full Text PDFThe synthesis and reactivity patterns of the strained dithiete ring are compared with their dimeric tetrathiocin counterparts and higher oligomers, highlighting: (i) their cycloaddition chemistry with organic dienophiles as a route to sulfur-containing heterocycles; (ii) their oxidative addition chemistry to low valent transition metal complexes to generate transition metal dithiolate complexes and; (iii) the base-catalysed isomerizations between different dithiete oligomers.
View Article and Find Full Text PDFThe preparation of a series of 4,4',5,5'-substituted benzo-fused 1,2,5,6-tetrathiocins X2C6H2S4C6H2X2 (1a-1g) were prepared from the reaction of S2Cl2 with 1,2-C6H4X2 (X = OMe, OEt; X2 = OCH2O, OCH2CH2O, OCH2CH2CH2O, MeNC([double bond, length as m-dash]O)NMe, O(CH2CH2O)4). The oxidative addition of 1a-1g to zero-valent Pd2dba3 or Pt2dba3 (dba = dibenzylideneacetone) in the presence of bis (diphenylphosphino)ethane (dppe) resulted in formation of the substituted mononuclear benzenedithiolate complexes M(L)(dppe) [L = dithiolate ligand; 2a-2g (M = Pd) and 3a-3g (M = Pt)] in 37-89% yield based on recrystallized material. Representative examples of M(L)(dppf) [dppf = bis-diphenylphosphinoferrocene; 4a, 4g (M = Pd) and 5g (M = Pt)] were prepared in a similar fashion.
View Article and Find Full Text PDFThe outcome of the oxidative addition reactions of bis(4',5'-dimethoxybenzo)-1,2,5,6-tetrathiocin to Pd2dba3 under microwave conditions is sensitive to the nature of the phosphine coreagent; the bidentate phosphines dppm, dppe, and dppf afford the mononuclear dithiolates (dmobdt)Pd(dppm) (4), (dmobdt)Pd(dppe) (2), and (dmobdt)Pd(dppf) (5), whereas more labile monodentate phosphines lead to aggregation; Ph3P afforded the dinuclear dithiolate (dmobdt)2Pd2(PPh3)2 (6), whereas (t)Bu3P generated the phosphine-free hexanuclear edge-capped octahedral complex Pd6(dmobdt)6 (7) [dmobdt = 4,5-dimethoxybenzenedithiolate, (MeO)2C6H2S2(2-)].
View Article and Find Full Text PDFOxidative addition of the electron-rich tetra-methoxy-dibenzo-1,2,5,6-tetrathiocine [(MeO)2C6H2S2]2 to zero-valent group 10 transition metal complexes in the presence of diphenylphosphinoethane (dppe) affords the corresponding dithiolate complexes, [(DMOBD)M(dppe)] (DMOBD = dimethoxybenzenedithiolato, (MeO)2C6H2S2(2-); M = Ni, Pd, Pt) in high yield which were characterized by single crystal X-ray diffraction. Whereas the Pd and Pt complexes exhibit two quasi-reversible 1e(-) oxidation processes, the nickel species undergoes a quasi-reversible 1e(-) reduction.
View Article and Find Full Text PDF