Inorganic–Organic Hybrid Surfactant Crystals: Structural Aspects and Functions

Abstract

Hybrid single crystals consisting of an organic surfactant and an inorganic moiety are promising functional materials. Layered crystals composed from alternate inorganic and surfactant layers are obtained by the template effect of long alkyl chain moiety. The composition, crystal packing, and molecular arrangement of the hybrid single crystals are controllable by changing the inorganic constituent and the surfactant molecular structure. The types of hybrid surfactant single crystals are twofold: (i) crystals consisting of discrete inorganic cation coordinated by ligands having amphiphilic moiety; and (ii) crystals comprising a surfactant cation and a discrete inorganic anion including polyoxometalate (POM) oxide clusters. The POM-surfactant hybrid single crystals are rather rare, and therefore promising as unprecedented functional materials. Their structural variation and functional properties are discussed.

Isomerization-induced introduction of metal cations into polyoxomolybdate-surfactant hybrid crystals

“…POMs have been hybridized with structure-directing surfactants [14][15][16] to obtain inorganic-organic hybrid crystals [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. The POM-surfactant hybrid crystals enable fine tuning of the structure and function by changing the combination of POM anion and surfactant cation.…”

Conductive Inorganic–Organic Hybrid Layered Crystals Composed of Keggin‐Type Polyoxotungstates and a Heterocyclic Surfactant

“…Polyoxometalate (POM) anions are promising as the inorganic component, due to their unique redox properties, and they can be selected to design the composition and functions of hybrid layered crystals. POMs have been successfully hybridized by surfactant cations to form inorganic–organic hybrids, and single crystals …”

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

“…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.…”