Evidence of a Lead Metathesis Product from Calcium Hydroxyapatite Dissolution in Lead Nitrate Solution

Calcium hydroxyapatite, CaHAp, synthesized by the precipitation method, was utilized to study the calcium-lead metathesis reaction on dissolution in a lead nitrate solution under reflux conditions to prepare larger lead hydroxyapatite, PbHAp, crystals from CaHAp. SEM images show development of crystalline PbHAp on the surfaces of CaHAp. The needle-like crystal morphology observed for PbHAp after 24 h reaction time developed into hexagonal-rod crystal morphology within 48 h reaction time. The largest PbHAp crystals obtained from 48 h reaction time have approximate size of 10 × 10 × 40 μm. Powder X-ray diffraction results show mixed phases of CaHAp and PbHAp due to difficulty in separating the PbHAp product from the CaHAp substrate. The PbHAp peaks observed after 24 h of reaction sharpen and increase in intensity after 48 h of reaction confirming that the PbHAp phase is the major product for the 48 h reaction time. EDX results of the crystalline products show high intensity Pb peaks with lead to phosphorous ratio (5 : 3) as expected for PbHAp. Lower intensity Ca peaks are also observed, consistent with incomplete coverage of the CaHAp growth substrate

Supplementary data for article: Chongboriboon, N.; Samakun, K.; Inprasit, T.; Kielar, F.; Dungkaew, W.; Wong, L. W.-Y.; Sung, H. H.-Y.; Ninković, D. B.; Zarić, S. D.; Chainok, K. Two-Dimensional Halogen-Bonded Organic Frameworks Based on the Tetrabromobenzene-1,4-Dicarboxylic Acid Building Molecule. CrystEngComm 2019, 22 (1), 24–34. https://doi.org/10.1039/c9ce01140d

Supplementary material for: [https://doi.org/10.1039/c9ce01140d]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3795

Precipitation and characterization of barium arsenate

โครงการหนึ่งอาจารย์หนึ่งผลงา

Halogen-Bonding-Driven Self-Assembly of Solvates of Tetrabromoterephthalic Acid

Halogen bonding is one of the most interesting noncovalent attractions capable of self-assembly and recognition processes in both solution and solid phase. In this contribution, we report on the formation of two solvates of tetrabromoterephthalic acid (H2Br4tp) with acetonitrile (MeCN) and methanol (MeOH) viz. H2Br4tp·2MeCN (1MeCN) and H2Br4tp·2MeOH (2MeOH). The host structures of both 1MeCN and 2MeOH are assembled via the occurrence of simultaneous Br···Br, Br···O, and Br···π halogen bonding interactions, existing between the H2Br4tp molecular tectons. Among them, the cooperative effect of the dominant halogen bond in combination with hydrogen bonding interactions gave rise to different supramolecular assemblies, whereas the strength of the halogen bond depends on the type of hydrogen bond between the molecules of H2Br4tp and the solvents. These materials show a reversible release/resorption of solvent molecules accompanied by evident crystallographic phase transitions

Self-Assembly of 1D Double-Chain and 3D Diamondoid Networks of Lanthanide Coordination Polymers through In Situ-Generated Ligands: High-Pressure CO2 Adsorption and Photoluminescence Properties

Two new lanthanide-based coordination polymers, [Sm2(bzz)(ben)6(H2O)3]·0.5H2O (1) and [Eu(bbz)(ben)3] (2), were synthesized and characterized. The described products were formed from in situ-generated benzoate (ben) and N’-benzoylbenzohydrazide (bbz) ligands, which were the products of transformation of originally added benzhydrazide (bzz) under hydrothermal conditions. Compound 1 exhibits a one-dimensional (1D) double-chain structure built up from the connection of the central Sm3+ ions with a mixture of bzz and ben ligands. On the other hand, 2 features a 3D network with a 4-connected (66) dia topology constructed from dinuclear [Eu2(ben)6] secondary building units and bbz linkers. High-pressure CO2 sorption studies of activated 1 show that maximum uptake increases to exceptionally high values of 376.7 cm3 g−1 (42.5 wt%) under a pressure of 50 bar at 298 K with good recyclability. Meanwhile, 2 shows a typical red emission in the solid state at room temperature with the decay lifetime of 1.2 ms

Two-dimensional halogen-bonded organic frameworks based on the tetrabromobenzene-1,4-dicarboxylic acid building molecule

Two-dimensional (2D) halogen-bonded organic frameworks were readily engineered by strong and directional effects of the primary Br⋯O and the secondary Br⋯π halogen bonding interactions from the tetrabromobenzene-1,4-dicarboxylic acid (H2Br4BDC) building molecule involving 100% supramolecular yields. The 2D assembly can function as a host layered framework for the intercalation of various guest solvents including acetone (ATN), ethanol (EtOH), dimethyl sulfoxide (DMSO), and ethylene glycol (EG) resulting in a 1 : 2 host : guest complexation stoichiometry viz. H2Br4BDC·2S (S = ATN (1ATN), EtOH (2EtOH), DMSO (3DMSO), and EG (4EG)). All the solvates show remarkable similarities in their 2D layered sheets and the bilayer distance significantly responds to the size, shape, molecular conformation, and strength of the hydrogen bonding capability of the intercalated solvent molecules. The transition between solvate formation and desolvation was found to be facile and reversible upon the desolvation-resolvation process. The estimated Br⋯O halogen bonding energy of the solvates is in the -0.6 to -1.7 kcal mol-1 range, which was determined by quantum-mechanical calculations based on density functional theory (DFT) calculations. Furthermore, to quantitatively identify the host-guest intermolecular interactions of these solvates, they were visually compared by Hirshfeld surface analysis.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3796