Sabbani Supriya

A cyclic supramolecular (H2O)4 cluster in an unusual Fe3 complex that aggregates to {Fe3}n with a zig-zag chainlike structure

An aqueous solution containing ferric chloride, acetic acid and 2-hydroxypyridine results in the solid-state isolation of an unusual mixed-ligand trinuclear iron(III) complex [Fe3(μ3-O)(μ2-CH3COO)6(C5H5NO)2(H2O)]ClO4·4H2O, 1, where the iron-coordinated water ligand forms a hydrogen-bonded water tetramer with three other solvent water molecules; the Fe3 clusters aggregate to {Fe3}nvia N–H⋯O type hydrogen bonds, forming a zig-zag chainlike structure.

A cyclic (H2O)4 cluster characterized in the solid state disappears on heating and regenerates from water vapor: A supramolecular reversible gas–solid reaction

An unusual trinuclear iron(III) cluster described herein, [Fe3(μ3-O)(μ2-CH3COO)6(C5H5NO)2(H2O)] ClO4·4H2O (1) (C5H5NO = 2-pyridone), features a cyclic hydrogen bonded supramolecular water tetramer at one of the iron centres, as characterized by X-ray crystallography and thermogravimetry. The water cluster is formed by one iron-coordinated water and three lattice/solvent water molecules. The molecular environment of the water tetramer in the crystal structure consists of a Fe3+ ion (which is covalently bonded to one water of the (H2O)4 cluster), a perchlorate anion and the fourth lattice water. The facile removal of the lattice water molecules was anticipated from the knowledge of the type of interaction of these water molecules with their surroundings. Indeed, this hydrogen bonded water tetramer disappears with the formation of dehydrated solid [Fe3(μ3-O)(μ2-CH3COO)6(C5H5NO)2(H2O)] ClO4 (2), when the compound 1 is heated at ∼135 °C. Interestingly, when the dehydrated solid 2 is exposed to water vapor, it regenerates to 1 in a gas–solid reaction. The exposure of 2 to D2O vapor yields partially deuterated complex [Fe3(μ3-O)(μ2-CH3COO)6(C5H5NO)2(H2O)] ClO4·4D2O (3). As expected, the material 3 changes to 2 on heating at ∼135 °C, which again, on exposure to water vapor, returns to 1. The reversible loss/formation of (H2O)4 cluster in a gas–solid reaction has been established by elemental analyses, IR and X-ray powder diffraction studies including the single crystal X-ray structural analysis of 1.

Hydrogen bonded supramolecular network in a simple organic–inorganic salt: hydrophilic gallery formed between two hydrophobic layers in the crystal structure of [C6H9N2]ClO4·H2O

Orthophenylene diammonium cation, perchlorate anion and a crystal water molecule assemble into a unique hydrogen bonded supramolecular network consisting of a hydrophobic double layer with a hydrophilic gallery in it.

Fate of a giant {Mo72Fe30}-type polyoxometalate cluster in an aqueous solution at higher temperature: understanding related Keplerate chemistry, from molecule to material.

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.

A simple Cu(II) complex, [CuII{C6H4(NH2)2}2(NO3)2] with an unprecedented hydrogen bonding supramolecular network in the solid state and its solution emission at room temperature in the visible region

Abstract The compound [CuII{C6H4(NH2)2}2(NO3)2], 1 has been prepared and characterized by spectroscopic methods and single crystal X-ray diffraction. 1 crystallizes in the orthorhombic space group Pcab (No. 61), with a=7.905 (4) A, b=9.865 (7) A, c=20.621 (9) A and Z=4. The structure was solved by direct method and refined by full-matrix least-squares on F2 to R=0.0351 for 1160 reflections with I>2σ(I). In the crystal structure of 1, an extended hydrogen bonding network is formed involving copper coordinated amine and nitrato ligands. Compound 1 displays emission in solution at room temperature in the visible region furnishing the first example of an emissive transition metal complex, where the ligand is benzene-1,2-diamine (φem=0.095, τ=2.97 ns).

Sulfate anion helices formed by the assistance of a flip-flop water chain

A flip-flop extended water structure assists the formation of sulfate anion helices (both left- and right-handed) in a crystalline hydrate of a simple organic-inorganic compound [C6H10N2]SO4. 1.5H2O (1).