"\u0160ime\u010Dek, Jakub" . . "Complexation of Metal Ions with TRAP (1,4,7-Triazacyclononane Phosphinic Acid) Ligands and 1,4,7-Triazacyclononane-1,4,7-triacetic Acid: Phosphinate-Containing Ligands as Unique Chelators for Trivalent Gallium"@en . "11310" . . "Complexation of Metal Ions with TRAP (1,4,7-Triazacyclononane Phosphinic Acid) Ligands and 1,4,7-Triazacyclononane-1,4,7-triacetic Acid: Phosphinate-Containing Ligands as Unique Chelators for Trivalent Gallium"@en . "Inorganic Chemistry" . "Three phosphinic acid 1,4,7-triazacyclononane (TACN) derivatives bearing methylphosphinic (TRAP-H), methyl(phenyl)phosphinic (TRAP-Ph), or methyl-(hydroxymethyl)phosphinic acid (TRAP-OH) pendant arms were investigated as members of a new family of efficient Ga3+ chelators, TRAP ligands (triazacyclononane phosphinic acids). Stepwise protonation constants of ligands and stability constants of their complexes with Ga3+, selected divalent metal, and Ln3+ ions were determined by potentiometry. These ligands exhibit high thermodynamic selectivity for Ga3+ over the other metal ions and a selective complexation of smaller Mg2+ over Ca2+. Stabilities of the Ga3+ complexes are dependent on the basicity of the donor atoms: [Ga(NOTA)] (log KGaL = 29.6) > [Ga(TRAP-OH)] (log KGaL = 23.3) > [Ga(TRAP-H)] (log KGaL = 21.9). The [Ga(TRAP-OH)] complex exhibits unusual reversible rearrangement of the %22in-cage%22 N3O3 complex to the %22out-of-cage%22 O6 complex. The in-cage complex is present in acidic solutions, and at neutral pH, Ga3+ ion binds hydroxide anion, induces deprotonation and coordination of the P-hydroxymethyl group(s), and moves out of the macrocyclic cavity; the hypothesis is supported by a combination of results from potentiometry, multinuclear nuclear magnetic resonance spectrometry, and density functional theory calculations. Isomerism of the phosphinate Ga3+ complexes caused by a combination of the chelate ring conformation, the helicity of coordinated pendant arms, and the chirality of the coordinated phosphinate groups was observed. All Ga3+ complexes are kinetically inert in both acidic and alkaline solutions. Complex formation studies in acidic solutions indicate that Ga3+ complexes of the phosphinate ligands are formed quickly (minutes) and quantitatively even at pH <2. Compared to common Ga3+ chelators (e.g., 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) derivatives), these novel ligands show fast complexation of Ga3+ over a broad pH range."@en . "I, P(GA203/09/1056), P(OC 179), S, Z(MSM0021620857)" . "RIV/00216208:11310/12:10119144" . . . "http://dx.doi.org/10.1021/ic202103v" . "14"^^ . "0020-1669" . "Complexation of Metal Ions with TRAP (1,4,7-Triazacyclononane Phosphinic Acid) Ligands and 1,4,7-Triazacyclononane-1,4,7-triacetic Acid: Phosphinate-Containing Ligands as Unique Chelators for Trivalent Gallium" . . "RIV/00216208:11310/12:10119144!RIV13-GA0-11310___" . . . "000298712000074" . "Hermann, Petr" . "1" . . . . . . "51" . "128199" . "[DD537FA04598]" . . . . "10.1021/ic202103v" . . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . . . . . . . . . "Plutnar, Jan" . . . . "Schulz, Martin" . . "Three phosphinic acid 1,4,7-triazacyclononane (TACN) derivatives bearing methylphosphinic (TRAP-H), methyl(phenyl)phosphinic (TRAP-Ph), or methyl-(hydroxymethyl)phosphinic acid (TRAP-OH) pendant arms were investigated as members of a new family of efficient Ga3+ chelators, TRAP ligands (triazacyclononane phosphinic acids). Stepwise protonation constants of ligands and stability constants of their complexes with Ga3+, selected divalent metal, and Ln3+ ions were determined by potentiometry. These ligands exhibit high thermodynamic selectivity for Ga3+ over the other metal ions and a selective complexation of smaller Mg2+ over Ca2+. Stabilities of the Ga3+ complexes are dependent on the basicity of the donor atoms: [Ga(NOTA)] (log KGaL = 29.6) > [Ga(TRAP-OH)] (log KGaL = 23.3) > [Ga(TRAP-H)] (log KGaL = 21.9). The [Ga(TRAP-OH)] complex exhibits unusual reversible rearrangement of the %22in-cage%22 N3O3 complex to the %22out-of-cage%22 O6 complex. The in-cage complex is present in acidic solutions, and at neutral pH, Ga3+ ion binds hydroxide anion, induces deprotonation and coordination of the P-hydroxymethyl group(s), and moves out of the macrocyclic cavity; the hypothesis is supported by a combination of results from potentiometry, multinuclear nuclear magnetic resonance spectrometry, and density functional theory calculations. Isomerism of the phosphinate Ga3+ complexes caused by a combination of the chelate ring conformation, the helicity of coordinated pendant arms, and the chirality of the coordinated phosphinate groups was observed. All Ga3+ complexes are kinetically inert in both acidic and alkaline solutions. Complex formation studies in acidic solutions indicate that Ga3+ complexes of the phosphinate ligands are formed quickly (minutes) and quantitatively even at pH <2. Compared to common Ga3+ chelators (e.g., 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) derivatives), these novel ligands show fast complexation of Ga3+ over a broad pH range." . "7"^^ . . . . "5"^^ . . "Havl\u00ED\u010Dkov\u00E1, Jana" . "Kub\u00ED\u010Dek, Vojt\u011Bch" . "potentiometry; stability; computational methods; 68-Ga; 1,4,7-triazanonane; macrocycle; phosphinates; gallium complexes"@en . "Notni, Johannes" . "Complexation of Metal Ions with TRAP (1,4,7-Triazacyclononane Phosphinic Acid) Ligands and 1,4,7-Triazacyclononane-1,4,7-triacetic Acid: Phosphinate-Containing Ligands as Unique Chelators for Trivalent Gallium" .