91-04-3Relevant articles and documents
The preparation of dicompartmental multifunctional group ligands
Khaniani, Yeganeh,Golchoubian, Hamid
, p. 2817 - 2823 (2006)
A convenient method for the preparation of the phenol-based ligands 1,6-bis(2-thiophenyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-methylbenzyl)-2, 5-diazahexane and 1,6-bis(5-methyl-2-thiophenyl)-2,5-bis(2-hydroxy-3- hydroxymethyl-5-methyl-benzyl)-2,5-diazahexane possessing two dissimilar compartments having multifunctional groups is reported. To synthesize these ligands, an equivalent of 1,6-bis(2-thiophene)-2,5-diazahexane or 1,6-bis(5-methyl-2-thiophene)-2,5-diazahexane and two equivalents of 2,2-dimethyl-6-methyl-8-(chloromethyl)benzo-1,3-dioxin were reacted in the presence of Na2CO3 in 1,4-dioxane, followed by acid hydrolysis of an acetonide-protecting group. Characterization data for the new compounds is reported. Copyright Taylor & Francis Group, LLC.
DINUCLEATING LIGAND OR DINUCLEAR METAL COMPLEX
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Paragraph 0048; 0060-0061, (2021/03/19)
To provide a dinuclear metal complex that can be synthesized simply and easily and has a proper anticancer action.SOLUTION: The present disclosure provides a dinucleating ligand represented by the following formula (I) and a dinuclear metal complex thereof (where X is H or a substituted carbamoyl group, R1, R2, R3, and R4 independently represent H or a C1-8 linear or branched alkyl group).SELECTED DRAWING: None
Electronic Effects of Ligand Substitution in a Family of CoII2 PARACEST pH Probes
Thorarinsdottir, Agnes E.,Tatro, Scott M.,Harris, T. David
supporting information, p. 11252 - 11263 (2018/09/14)
We report three new Co2-based paramagnetic chemical exchange saturation transfer (PARACEST) probes with the ability to ratiometrically quantitate pH. A CoII2 complex, [LCo2(etidronate)]-, featuring tetra(carboxamide) and OH-substituted etidronate ligands with opposing pH-dependent CEST peak intensities, was previously shown to exhibit a linear correlation between log(CESTOH/CESTNH) and pH in the pH range 6.5-7.6 that provided a sensitivity of 0.99(7) pH unit-1 at 37 °C. Here, we demonstrate through a series of CF3-functionalized CoII2 complexes [(XL′)Co2(etidronate)]- (X = NO2, F, Me), that modest changes in the electronic structure of CoII centers through remote ligand substitution can significantly affect the NMR and CEST properties of Co2-based PARACEST probes. Variable-pH NMR and CEST analyses reveal that the chemical shifts of the ligand protons are highly affected by the nature of the X substituent. The ratios of OH and NH CEST peak intensities at 115 and 88, 93 and 79, and 88 and 76 ppm for X = NO2, F, and Me, respectively, afford pH calibration curves with remarkably high sensitivities of 1.49(9), 1.48(7), and 2.04(5) pH unit-1 across the series. The 1.5-2-fold enhancement in pH sensitivity for the CF3-functionalized Co2 probes stems from the complete separation of the OH and NH CEST peaks. Furthermore, incorporation of electron-withdrawing CF3 groups shifts the detection window to a more acidic range of pH 6.2-7.4. Finally, the CoII2 complexes are found to be extremely robust toward substitution and oxidation in aqueous solutions. Taken together, these results highlight the unique ability of transition metal-based PARACEST probes to provide a highly sensitive concentration-independent measure of pH and demonstrate that modest ligand modifications can be a powerful tool for optimizing the pH sensing performance of these probes.
