Polyoxotungstate-Surfactant Layered Crystal toward Conductive Inorganic-Organic Hybrid

Abstract

A polyoxotungstate-surfactant hybrid layered compound was synthesized as a single phase by using decatungstate ([W 10 O 32 ] 4− , W 10 ) and hexadecylpyridinium (C 16 py).The X-ray structure analysis combined with infrared spectroscopy and elemental analysis revealed the formula to be (C 16 py) 4 [W 10 O 32 ] (C 16 py-W 10 ). The layered structure consisted of alternative stacking of W 10 inorganic monolayers and interdigitated C 16 py bilayers with layered periodicity of 23.3 Å. Each W 10 anion in the W 10 inorganic monolayers was isolated by the hydrophilic heads of C 16 py. The hybrid crystals of C 16 py-W 10 decomposed at around 500 K. The conductivity of the hybrid layered crystal was estimated to be 4.8 × 10 −6 S cm −1 at 423 K by alternating current (AC) impedance spectroscopy.

Two Supramolecular Inorganic–Organic Hybrid Crystals Based on Keggin Polyoxometalates and Crown Ethers

“…Crystallographic data of Crystal 1 were collected using R-AXIS RAPID Scheme 1. The structure of (3-F-4-MeAnis + ), (3-IAnis + ), [18] …”

“…Single crystal X-ray diffraction analysis revealed that the supramolecular Crystal 1 crystallizes in the triclinic space group Pī ( Table 1). The asymmetric unit is composed of one [SMo 12 O 40 ] polyoxoanion, two (3-F-4-MeAnis) cations, two [18]crown-6 molecules, and one CH 3 CN molecule and contains as many as 179 atoms. In the crystal structure, two types of supramolecular cations with anti-paralleled arrangement can be observed as shown in Figure 1, viewed along the c-axis.…”

“…Polyoxometalates (POMs) composed of discrete early transition metal-oxide cluster anions possess many structural advantages for constructing supramolecular structures. First, POMs contain numerous exposed oxygen atoms which can act as potential hydrogen bonding interaction sites [16][17][18]. Lindqvist [Mo6O19] polyoxoanions, for example, contain three types of oxygen atoms: the exposed terminal oxygen Ot, the bridging oxygen Ob, and the central oxygen Oc.…”

“…Based on the structural advantages of POMs and crown ethers, in this study, we designed two novel supramolecular structural inorganic-organic hybrids [(3-F-4-MeAnis)( [18] …”

Polyoxotungstates in Molecular Boxes of Purine Bases

“…They have already been known for two centuries [1,2], and found numerous applications in a multitude of areas ranging from catalysis to pharmacology and remain of continuous interest, especially in the areas of design and synthesis of functional nanomaterials [3,4]. Polyoxotungstates occupy a special position among POMs, due to a multitude of fascinating structures and a wide scope of current and potential applications [5][6][7][8][9].…”