title: Polymeric cobalt(ii) thiolato complexes - syntheses, structures and properties of [Co(SMes)2] and [Co(SPh)2NH3].
abstract: Reactions of [Co(N(SiMe3)2)2thf] with 2.1 equiv. of MesSH (Mes = C6H2-2,4,6-(CH3)3) yield dark brown crystals of the one dimensional chain compound [Co(SMes)2]. In contrast reactions of [Co(N(SiMe3)2)2thf] with 2.1 equiv. of PhSH result in the formation of a dark brown almost X-ray amorphous powder of 'Co(SPh)2'. Addition of aliquots of CH3OH to the latter reaction resulted in the almost quantitative formation of crystalline ammonia thiolato complexes either [Co(SPh)2(NH3)2] or [Co(SPh)2NH3]. Single crystal XRD reveals that [Co(SPh)2NH3] forms one-dimensional chains in the crystal via μ2-SPh bridges whereas [Co(SPh)2(NH3)2] consists at a first glance of isolated distorted tetrahedral units. Magnetic measurements suggest strong antiferromagnetic coupling for the two chain compounds [Co(SMes)2] (J = -38.6 cm-1) and [Co(SPh)2NH3] (J = -27.1 cm-1). Interestingly, also the temperature dependence of the susceptibility of tetrahedral [Co(SPh)2(NH3)2] shows an antiferromagnetic transition at around 6 K. UV-Vis-NIR spectra display d-d bands in the NIR region between 500 and 2250 nm. Thermal gravimetric analysis of [Co(SPh)2(NH3)2] and [Co(SPh)2NH3] reveals two well separated cleavage processes for NH3and SPh2upon heating accompanied by the stepwise formation of 'Co(SPh)2' and cobalt sulfide.
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. andreas.eichhoefer@kit.edu and Lehn Institute of Functional Materials, Sun Yat-Sen University, Guangzhou 510275, China and Karlsruhe Nano Micro Facility (KNMF), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Eichhöfer
authors.affiliation: Institut für Photonenforschung und Synchrotronstrahlung, Karlsruher Institut für Technologie (KIT), Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Gernot
authors.initials: G
authors.lastname: Buth