178960-97-9Relevant academic research and scientific papers
Synthesis, structure and redox properties of bis(cyclopentadienyl) dithiolene complexes of molybdenum and tungsten
Whalley, Alexandra L.,Blake, Alexander J.,Collison, David,Davies, E. Stephen,Disley, Helen J.,Helliwell, Madeleine,Mabbs, Frank E.,McMaster, Jonathan,Wilson, Claire,Garner, C. David
, p. 10457 - 10472 (2011/11/29)
The compounds [Cp2M(S2C2(H)R)] (M = Mo or W; R = phenyl, pyridin-2-yl, pyridin-3-yl, pyridin-4-yl or quinoxalin-2-yl) and [Cp2Mo(S2C2(Me)(pyridin-2-yl)] have been prepared by a facile and g
Direct Conversion of α-Substituted Ketones to Metallo-1,2-enedithiolates
Hsu, John K.,Bonangelino, Cecilia J.,Kaiwar, Sharada P.,Boggs, Christine M.,Fettinger, James C.,Pilato, Robert S.
, p. 4743 - 4751 (2008/10/09)
A new synthetic route to metallo-1,2-enedithiolates is presented. The addition of 1 equiv of the α-bromo ketones Ar-C(O)CHXR (X = Br) {Ar = 2-quinoxaline, 2-, 3-, or 4-pyridine, Ph, Cl-Ph, and pyrene (R = H); Ar = 2-quinoxaline (R = Me); and Ar = R = Ph} to Cp2Mo(SH)2 followed by the addition of base results in the formation of the corresponding metallo-1,2-enedithiolate Cp2Mo{η2-SC(Ar)C(R)S}. The α-tosyl ketones quinoxaline-C(O)CHR-tosyl {R = H, Me} and the α-phosphorylated ketone 3-pyridine-C(O)CH2-O-P(O)(OEt)2 yield the same products as the corresponding α-bromo ketones upon reaction with Cp2Mo(SH)2. The addition of acid to the heterocyclic substituted complexes yields Cp2Mo{η2-SC(HetH+)C(R)S}. Both Cp2Mo{η2-SC(quinoxaline)C(H)S}and [Cp2Mo{η2-SC(quinoxalinium)C(H)S}][BR4] have been crystallographically characterized. Cp2Mo{η2-SC(quinoxaline)C(H)S} crystalizes in the C2/c space group with a = 21.451(2) A?, b = 15.474 A?, c = 12.2201(13) A?, and β= 107.440(7)°. [Cp2Mo{η2-SC(quinoxalinium)C(H)S}][BF4] crystalizes in the P1? space group with a = 7.4009(8) A?, b = 10.1192(13)° A?, c = 15.930(4) A?; α = 81.49(2)°, β = 76.14(2)°, and γ = 85.784°. In the solid state [Cp2Mo{η2-SC(quinoxalinium)C(H)S}][BF4] π-stacks the heterocycle of two adjacent molecules with atom-atom distances of ≈ 3.6 A?. The stacks are limited to pairs of molecules, and there is no long-range order. The pKa values for the quinoxalinium (R = H and Me) and the 2-, 3-, and 4-pyridinium (R = H) complexes have been determined in acetonitrile to be 1 -3 units larger than the free heterocycles. The pKa of the pyridinium complexes follows the substitution trend 2 ≈ 4 > 3 > free pyridinium and is consistent with resonance stabilization of pyridinium by the metallo-1,2-enedithiolate. Electronic transitions in these complexes have been assigned to a LMCT transition and an ILCT transition by comparison of the various complexes accompanied with solvent sensitivity studies.
