Sulfur-rich CpCo(dithiolene) complexes: Isostructural or non-isostructural couples of CpCo(III) with CpNi(III) dithiolene complexes

• Main Authors: Nomura, Mitsushiro, Kondo, Shigemi, Yamashita, Souichi, Suzuki, Eriko, Toyota, Yoshiko, Alea, Glenn V., Janairo, Gerardo C., Fujita-Takayama, Chikako, Sugiyama, Toru, Kajitani, Masatsugu
• Format: text
• Published: Animo Repository 2010
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/682; https://animorepository.dlsu.edu.ph/context/faculty_research/article/1681/type/native/viewcontent
• Institution: De La Salle University

Eight new sulfur-rich [CpCo(dithiolene)] complexes were synthesized from [Zn(dmit)2]2- as a starting material. The structures, electrochemical behavior and electronic absorption spectra of the sulfur-rich [CpCo(S2C2S2Y)] complexes could be compared with the early data of analogous Ni complexes. [CpCo(pddt)] (Y = -(CH 2)3-), [CpCo(dpdt)] (Y = -CH2C(CH 2)CH2-), [CpCo(bddt)] (Y = -(CH2) 4-), [CpCo(dtdt)] (Y = -CH2SCH2-) and [CpCo(poddt)] (Y = -CH2C(O)CH2-) crystallized in all isostructural with the corresponding paramagnetic [CpNi(dithiolene)] complexes, but [CpCo(dmid)] (Y = CO), [CpCo(dddt)] (Y = -(CH2)2-) and [CpCo(F2pddt)] (Y = -CH2CF2CH2-) crystallized in non-isostructural with them. These molecules are associated with intermolecular short S⋯S contacts in the crystals. [CpCo(F 2pddt)] did not show any remarkable S⋯S contacts but indicated interesting fluorine segregation and Cp⋯Cp face-to-face interactions. Redox potentials of [CpCo(dithiolene)] complexes were obtained with the cyclic voltammetry measurements and dimerized by electrochemical oxidations. Electronic absorption spectra of [CpCo(dithiolene)] complexes showed visible absorption in the range of 585-701 nm as lowest energy wavelengths (ε = 9800-11,800 M-1 cm-1) in solutions, and they were higher energy than those of [CpNi(dithiolene)] complexes (near-IR). © 2010 Elsevier B.V.