Highly efficient syntheses of nano mixed-anions lead(II) thiocyanate/nitrate and lead(II) thiocyanate coordination polymers by sonochemical process

Nanostructured materials via green sonochemical routes - Sustainability aspects

The production of environmentally friendly nanostructured materials with well-defined properties is a major challenge. Characteristics of the nanomaterials such as dimensionality, size and morphology strongly affect their performance in various applications. Additionally, sustainability considerations require an acceptable level of efficiency while being economically feasible and environmentally benign. The use of ultrasonic irradiation (UI) is a green and powerful technology, which can be applied for the synthesis of a variety of nanostructured materials. This review critically discusses the progress made in the fabrication of environmentally benign engineered nanomaterials with various dimensionalities (i.e., zero, one, two, or three dimensions) assisted by UI. The evolution and current status in this area are further illustrated using a scientometric approach. Application of UI for the synthesis of nanostructured materials has been also assessed according to the main sustainability pillars including the performance and environmental compatibility, as well as the relevant economic and social considerations. The outlook as well as recommendations for future research has been also provided and discussed towards the promotion of sustainable nanomaterials synthesis and application in various fields.

Ultrasonic-assisted synthesis of nano lead(II) coordination polymer as precursors for preparation of lead(II) oxide nano-structures: Thermal, optical properties and XRD studies

Nano structure of a lead (II) coordination polymer [Pb₂(C₂Cl₃O₂)₂(NO₃)₂(C_l2H₈N₂)₂]_n (1), has been synthesized by a sonochemical method in different concentrations. The nano particles were characterized by scanning electron microscopy (SEM) X-ray powder diffraction (XRD), FT-IR spectroscopy and elemental analyses. The thermal stability of nano structure is closely investigated via thermal gravimetric (TGA), and compared with crystalline structure. The compounds are then heated to 600 °C to produce PbO nano particles. The resulting PbO is characterized through XRD and SEM analyses. Concentration of initial reagents effects on size and morphology of nano-structured compound 1 have been studied and show that low concentrations of initial reagents decreased particles size and leaded to uniform nano particles morphology. The photoluminescence properties of the prepared compound, as crystalline and as nanoparticles, have been investigated. The result showed a good correlation between the size and emission wavelength.

Ultrasonic assisted synthesis of a new one-dimensional nanostructured Mn(II) coordination polymer derived from azide and new multi-topic nitrogen donor ligand

A new Mn(II) coordination polymer, [Mn(L₁)₂(N₃)₂]_n (1), L₁  = 3,4-bis(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole, was synthesized by the reaction of ligand L₁ and mixtures of manganese(II) acetate and sodium azide via branched tube method. Compound 1 was structurally characterized by single-crystal X-ray diffraction. The results show that 1 is a 1D helix coordination polymer. Also nanostructures of 1 have been prepareded by sonochemical process at ambient temperature. The effects of two different concentrations of initial reagents on the size and morphology of the nanoparticles were studied and the products were characterized by X-ray powder diffraction and scanning electron microscopy (SEM). Also the comparison of the thermal stability of bulk form and nanoparticles of 1 was investigated by thermal gravimetric and differential thermal analyses.

Synthesis and characterization of nano-peanuts of lead(II) coordination polymer [Pb(qcnh)(NO3)2]n with ultrasonic assistance: A new precursor for the preparation of pure-phase nano-sized PbO

A sonochemical method was used to synthesize nano-peanuts of a new lead(II) coordination 1D polymer, [Pb(qcnh)(NO₃)₂]_n (1), where qcnh=2-quinolincarbaldehyde nicotinohydrazide. The compound was characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and single crystal X-ray analysis. The X-ray structure revealed that the Pb(II) atom is coordinated by one oxygen and three nitrogen atoms from two qcnh ligands and five oxygen atoms from three nitrate ligands in an 8+1 fashion with a PbN₃O₆ donor set. One of the PdN distances in the vicinity of the central atom is a bit longer (Pb1N1=2.939(4) Å), which shows the effect of the 6s² lone electron pair localized within the valence shell of the lead(II) atom. PbO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XRD to be 28nm. The morphology and size of the prepared PbO nanoparticles were further studied using SEM.