When an aqueous solution of sodium molybdate is added to an aqueous solution of ferric chloride, acidified with acetic acid, a giant {MoFe} cluster is instantaneously formed as the amorphous substance Na[MoFeO(CHCOO)(OH)(HO)]·180 HO (1). Compound 1 consists of aggregated nanovesicles of {MoFe} clusters, as confirmed by field-emission scanning electron microscopy and transmission electron microscopy images of 1. An aqueous suspension of 1 upon moderate heating results in the formation of crystalline nanoferric molybdate, which gives insight into understanding the formation of a yellow coating mineral, ferrimolybdite, frequently found on the ores of molybdenum.
When the giant icosahedral {Mo72Fe30} cluster containing compound [Mo72Fe30O252(CH3COO)12{Mo2O7(H2O)}2{H2Mo2O8(H2O)}(H2O)91]·150H2O (1) is refluxed in water for 36 h, it results in the formation of nanoiron molybdate, Fe2(MoO4)3, in the form of a yellow precipitate; this simple approach not only generates nanoferric molybdate at a moderate temperature but also helps to understand the stability of {Mo72Fe30} in terms of the linker-pentagon complementary relationship.
When dithiolene‐based coordination complexes [Bu4N]2[MII(tdas)2] (tdas2– = 1,2,5‐thiadiazole‐3,4‐dithiolate; M = Ni, Pd, Pt) are reacted separately with CuI, it results in the formation of chain‐like coordination polymers [Bu4N]2n[MII(tdas)2Cu4I4]n [M = Ni (compound 1), Pd (compound 2), Pt (compound 3)] in which each metal(bis)dithiolato complex unit supports a {CuI4I4} cluster unit. Two of the crystal structures and powder X‐ray diffraction studies confirm that compounds 1, 2 and 3 are isomorphous with each other showing the abundance of a doubly‐bridged “curved” chain‐like structure formed by the coordination of two “N” donor atoms of each [MII(tdas)2]2– complex unit to two Cu+ ions of two adjacent {CuI4I4} cluster units and by the coordination of two Cu+ ions of a {CuI4I4} cluster with its neighbouring two [MII(tdas)2]2– complex anions through their “N” donor atoms from opposite sides. Since the [MII(tdas)2]2– complex anion generally has a planar geometry, which becomes bent upon supporting a {CuI4I4} cluster in the present study, the Cu–S interaction in [MII(tdas)2Cu4I4]2– is responsible for the bending conformation of the metal–dithiolato complex unit. This bending structure of the complex anion [MII(tdas)2]2– in [MII(tdas)2Cu4I4]2– describes a situation where the central part of the complex anion is pulled away towards the {CuI4I4} cluster through Cu–S bonds. This causes a “curve‐like” structure throughout the resulting doubly‐bridged chain in compounds 1, 2 and 3. The second important aspect of the present work is an interesting reactivity of this doubly‐bridged coordination polymer with a bidentate chelating ligand, tetramethylethylenediamine (TMEDA). Compound [Bu4N]2n[NiII(tdas)2Cu4I4]n (1), a representative member of the series of compounds 1–3, was treated with TMEDA, which resulted in a square planar complex [Ni(tdas)(TMEDA)] (4) belonging to a mononuclear [MII(N2S2)]‐type system (where N2 = bidentate N∩N donor ligand, mostly a bipyridine type, and S2 = dithiolato ligand) representing an important class of compounds for photophysical properties. Compound 4 exhibits emission at room temperature in the visible region.
precipitate. Approximately 50% of the {Mo 72 Fe 30 } Keplerate are converted while 50% remain in solution. The stability of the giant icosahedral {Mo 72 Fe 30 } cluster is discussed in terms of a linker-pentagon complementary relationship. -(MEKALA, R.; SUPRIYA*, S.; DAS, S. K.; Inorg. Chem. 52 (2013) 17, 9708-9710, http://dx.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.