Molecular design of lipophilic disalicylic acid compounds with varying spacers for selective lead(II) extraction

Studies on heavy metal removal efficiency and antibacterial activity of 2-(diphenylphosphino)aminopyridine

“…Mixtures of extractants have been employed by different investigators to extract Ni 2+ , Co 2+ , Pb 2+ and Cd 2+ at relatively low pH (1-3) [46][47][48], however, there are few single extractants that can extract metal ions efficiently at lower pH values. Most extractants are used commercially and are not effective for the recovery of these metals in a highly acidic medium (pH < 4) [45,46,[49][50][51][52][53][54][55]. 2-(diphenylphosphino)aminopyridine showed good efficiency and affinity for metal ions at pH 2 according to the results obtained, making it suitable for solvent extractions in acidic media.…”

Mammalian Cell Cytotoxicity, Antibacterial Activity and the Properties of Methylenebis(Hydroxybenzoic Acid) and Its Related Zinc(II) Complex

“…3,3 ′ -Methylenebis(2-hydroxybenzoic acid), MHB, Scheme 1, was obtained using the recipe outlined in the literature [2][3][4] as follows: 180 g of 50% sulfuric acid, 27.6 g of hydroxybenzoic acid and 9.4 g of 30% formaldehyde, which were refluxed for 7 h. To remove any remaining unreacted hydroxybenzoic acid, the separated powder was allowed to cool, filtered out, extensively cleaned with cold water and then hot water/ethanol solutions. After being separated and recrystallized from acetone, the cream powder was allowed to air dry for 48 h. The MHB is soluble in ethanol, acetone, carbon tetrachloride, diethyl ether, dimethylformamide (DMF) and dimethylsulphoxide (DMSO) but insoluble in water.…”

“…NMR spectrum: According to a prior report [2], the 1 H NMR spectrum of the MHB revealed signals at 2.5 (CH 2 , d), 11.2 (COOH, s, broad), 11.6 (phenolic OH, s, broad) and 6.7-7.9 (aromatic protons, m), Figure 3 Along with their diamagnetism and white color, the Zn II (d 10 configuration) could be regarded as a limit for the spectroscopic description of Zn derivatives due to their diamagnetism and white color. Conversely, the lack of ligand field stabilization might provide extremely flexible coordination geometry that is exclusively controlled by the ligands' charge and steric hindrance [28,29].…”

“…Literature has documented just a few syntheses of certain methylenebis(hydroxybenzoic acid) compounds [1]. Recently, the very selective extractions of Pb(II) over Ni(II), Cd(II), Cu(II) and Zn(II) from aqueous solution into chloroform was studied for methylenebis(hydroxybenzoic acid) ligands having different spacers between two hydroxybenzoic/salicylic acid unites [2]. It was reported that an ethylene spacer shows a superior Pb(II) extraction selectivity compared to Cu(II).…”

Overcoming barriers with non-covalent interactions: supramolecular recognition of adamantyl cucurbit[n]uril assemblies for medical applications

“…Namely, the adamantane cage is long known to be an efficient scaffold in supramolecular recognition processes, both in chemical and biological systems. 26 Going from our own experience, adamantane and similar cage compounds have demonstrated an amazing versatility and can serve as a backbone in various cation [27][28][29][30][31][32][33][34] and anion receptors [35][36][37][38][39][40][41][42][43][44] as well as being desirable guest molecules in inclusion complexes. [45][46][47][48][49][50][51] While in macrocyclic receptors the adamantane cage usually serves as a rigid backbone that reduces the conformational mobility of a macrocycle and thus pre-organizes the receptor molecule for binding, in the inclusion complexes the role of adamantane is primarily limited to enabling preferential binding of the polycyclic subunit into a host molecules.…”