No abstract

That zinc in feeling: The complexes [(3,5‐Me2C5H3N)2Zn(ESiMe3)2] (E=Se, 1; E=Te, 2) are prepared and found to be good reagents for the generation of ternary MM′E materials. From 2 (see structure; Te red, Zn blue, Si yellow, N green), the ternary ZnCdTe nanocluster [Zn2.6Cd7.4Te4(TePh)12(PnPr3)4] (3) is prepared. The optical properties of 3 are shown to be modulated relative to those of related binary CdTe cluster molecules.

Coordination polymers showing redox activity have been constructed by using ferrocene-based bidentate ligands, 1,1'-(4-dipyridinethio)ferrocene (1) and 1,1'-(2-dipyridinethio)ferrocene (2). The ligand of 1 formed an Ag(I) coordination polymer, 1 x AgPF(6) x (CH(3)CN)(2) (3). This complex showed a 1-D double-chain structure, with a weak interchain Ag...Ag interaction. Combination of 1 with M(hfac)(2) (M = Mn, Cu, Zn) afforded 1-D chain complexes, 1 x M(hfac)(2) (M = Mn (5), Cu (6), Zn (7)). The complex 2 x CuPF(6) (8) showed a 1-D twisted helix-like chain structure.

Simple cationic sandwich complexes that contained alkyl- or halogen substituents provided ionic liquids (ILs) with the bis(perfluoroalkanesulfonyl)imide anion. Ferrocenium- and cobaltocenium ILs [M(C(5)H(4)R(1))(C(5)H(4)R(2))][Tf(2)N] (M=Fe, Co) and arene-ferrocenium ILs [Fe(C(5)H(4)R(1))(C(6)H(5)R(2))][Tf(2)N] were prepared and their physical properties were investigated. A detailed comparison of their thermal properties revealed the effects of molecular symmetry and substituents on their melting points. Their viscosity increased on increasing the length of the substituent on the cation and the perfluoroalkyl chain length on the anion. Upon cooling, ILs with low viscosities exhibited crystallization, whereas those with higher viscosities tended to exhibit glass transitions. Most of these salts showed phase transitions in the solid state. A magnetic-switching phenomenon was observed for the paramagnetic ferrocenium IL, which was associated with a liquid/solid transformation, based on the magnetic anisotropy of the ferrocenium cation. (57)Fe Mössbauer spectroscopy was applied to [Fe(C(5)H(4)nBu)(2)][Tf(2)N] to investigate the vibrational behavior of the iron atom in the crystal and glassy states of the ferrocenium IL.

In recent years, ionic plastic crystals have attracted much attention. Many metallocenium salts exhibit plastic phases, but factors affecting their phase transitions are yet to be elucidated. To investigate these factors, we synthesized octamethylferrocenium salts with various counteranions [Fe(CMeH)]X ([1]X; X = B(CN), C(CN), N(CN), FSA (= (SOF)N), FeCl, GaCl and CPFSA (= CF(SOCF)N)) and elucidated their crystal structures and phase behavior. Correlations between the crystal structures and phase sequences, and the shapes and volumes of the anions are discussed. Except for [1][CPFSA], these salts exhibit phase transitions to plastic phases at or above room temperature (T = 298-386 K), and the plastic phases exhibit either NaCl- or anti-NiAs-type structures. X-ray crystal structure analyses of these salts at 100 K revealed that they have structures in which cations and anions are alternately arranged, with the exception of [1][CPFSA]. [1][CPFSA] exhibits a structure in which anions and cations are separately stacked to form columns. [1][N(CN)] exhibits a polar crystal structure that undergoes a monotropic phase transition to a centrosymmetric structure. The magnetic susceptibilities of room-temperature plastic crystals [1][GaCl] and [1][FeCl] were investigated; the latter exhibits a small ferromagnetic interaction at low temperatures.