Investigations on the phase behaviors and structural properties of mono-, di- and poly-valent metal carboxylates are reviewed with reference to developments in experimental and theoretical concepts surrounding their liquid crystalline properties. The main methods of structural investigation such as X-ray diffraction, infrared and ¹³C-NMR spectroscopies are examined in detail on the basis of common synthetic routes leading to the isolation of pure compounds. A detailed review of the thermal behaviors of several metal carboxylates is presented along with proposed theories and molecular models for odd–even alternation, chain length effects, phase structures and mesophase formation. Theories explaining the effects of metal ion radii and chain unsaturation are also discussed. Proposed degradation mechanisms resulting in the formation of various products and kinetic studies are also considered. Though this review highlights a number of investigations on the structural and phase properties of the mostly widely studied carboxylates, the results presented here strongly indicate that there is room for further studies on some of these systems.

We report the facile hot-injection colloidal synthesis of near-stoichiometric CuInS₂ quantum dots at varying reaction times and temperatures which exhibit both optical and structural tunability with implications for enhanced photovoltaic utility.

The thermotropic phase behaviour of a homologous series of even chain length polymeric zinc(II) n-alkanoates, Zn(C_nH_2n-1O₂)₂ (ZnC_4–20) has been studied by means of differential scanning calorimetry (DSC) and temperature variation polarising light microscopy. The compounds exhibit both enantiotropic and monotropic phase behaviour on heating to the isotropic liquid and on cooling back to the room temperature solid, as seen from the following phase sequences: ZnC_4–12, Lamellar Crystal ↔ Crystal I ↔ Crystal II ↔ Isotropic Melt; ZnC_14–16, Lamellar Crystal ↔ Crystal I ↔ Isotropic Liquid; ZnC_18–20, Lamellar Crystal → Isotropic Liquid, Lamellar Crystal ← Smectic C ← Isotropic Liquid. The total enthalpy and entropy change for melting increase linearly with chain length and are higher than expected for complete fusion of alkyl chains suggesting that the step-wise melting process involves fusion of alkyl chains and changes in electrostatic interactions in the polar region of the molecule. The phase diagrams show that phase sequences for first and second heating cycles are almost indistinguishable, where the lamellar crystal is most stable for the long chain length homologues. In addition, there is a stable mesomorphic region over a narrow temperature range, at high temperatures for the long chain length compounds. Polymorphism is exhibited and is dependent on the method of preparation.

Herein is discussed tunable absorption and emission properties of Ag _x Cu _y InS ₂ quantum dots involving wurtzite to chalcopyrite phase transformation dependent on Ag ⁺ dopant content.