Extended Polyoxometalate Framework Solids: Two Mn(II)-Linked {P₈W₄₈} Network Arrays

Abstract

Two polyoxometalate open framework (POMOF) materials have been synthesized using a secondary building unit (SBU) approach that facilitates the convergent assembly of multidimensional framework materials using a preassembled anionic SBU {P(8)W(48)}, with integrated "pore" 1 nm in diameter, and electrophilic manganese {Mn(2+)} linkers. This yields two new POMOFS with augmented hexagonal tiling (2 and 3), related to a known three-dimensional (3D) cubic array K(18)Li(6)[Mn(II)(8)(H(2)O)(48)P(8)W(48)O(184)]·108H(2)O (1), K(12)[Mn(II)(14)(H(2)O)(30)P(8)W(48)O(184)]·111H(2)O (2), and K(8)Li(4)[Mn(II)(14)(H(2)O)(26)P(8)W(48)O(184)]·105H(2)O (3). These frameworks have been crystallized from aqueous Li-buffered solutions of {P(8)W(48)} and Mn(II)(ClO(4))(2)·6H(2)O via careful control of the synthetic strategy akin to a crystal engineering approach using cation and temperature control to isolate different material architectures shown by compounds 1-3.

Temperature-induced racemic compounds and chiral conglomerates based on polyoxometalates and lanthanides: syntheses, structures and catalytic properties

“…So far, there are very limited examples of temperature-controlled self assembly of non-chiral POMs. For instance, Niu and coworkers reported three new inorganic-organic hybrid arsenomolybdates originated from different temperature ranges corresponding to different proportions of oxidized AsIJIII) atoms; 19 Cronin's group successfully isolated two 3D open framework materials using a preassembled anion {P 8 W 48 }, and electrophilic manganese Mn 2+ linkers by the temperature control; 20 Compounds 3 and 4 obtained at 25°C are chiral conglomerates, which crystallize in the chiral space group P2 1 . All four compounds as Lewis acid-base catalysts are very efficient in the cyanosilylation of carbonyl compounds and allow the reaction to be carried out under solvent-free conditions using only a low loading of the catalyst, which can be recovered and reused without displaying any significant loss of activity.…”

Synthetic Considerations in the Self-Assembly of Coordination Polymers of Pyridine-Functionalized Hybrid Mn-Anderson Polyoxometalates

“…[41][42][43][44] The second approach is to consider POMs as building blocks for porous structures, 45 with the aim of creating a bond between the POM and either an organic linker (usually a multitopic carboxylic acid or N-donor ligand) [46][47][48][49] or a transition metal. [50][51][52][53][54][55][56][57][58][59][60][61][62] The terminal oxygen atoms or hydroxyl groups of POMs can be substituted by the oxygen atoms of carboxylates, while capping transition metals in some POM species can be chelated by organic ligands, leading to extended frameworks. [63][64][65][66][67] Although this approach can allow rational design of desired structures by assessing the geometries and the coordination numbers of the secondary building units (POM and linker) 46,68,69 it is often not the case, and materials may form serendipitously.…”

An amperometric sensor of iodate based on the composite film of a crown heteropolyanions and Cu@Ag nanoparticles

“…Polyoxometalates (POMs) are a large family of transition-metal oxyanion clusters with d 0 electronic configurations, and possess extensive tunability in topology, size, electronic properties, elemental composition, and high stability, which associate them with interesting chemical and physical properties in medicine [1], in water oxidation catalysis [2][3][4], water reduction catalysis [5][6][7], photocatalytic hydrogen evolution [8], oxygen reduction reaction [9], nitrogen monoxide sensors [10], composite materials [11] and synthesizing of POMOFs [12]. It has been well known that POMs can undergo reversible multiple electron transfer reactions in a mild environment without causing other changes in many systems [13][14][15][16].…”