4730-54-5Relevant articles and documents
Phosphoric triamides. 31Phosphorus NMR chemical shift as a function of the P-N bond characteristics
Bourne, Susan A.,Mbianda, Xavier Y.,Modro, Tomasz A.,Nassimbeni, Luigi R.,Wan, Huijie
, p. 83 - 88 (1998)
Six phosphoric triamides in which amide nitrogens are incorporated into an increasing number (from 0 to 3) of the 1,3,2-diazaphospholidin-2-one rings have been prepared and their crystal structures have been determined. The structural changes from the non-cyclic to the mono-, di- and tri-cyclic systems result in the decrease of the N-P-N bond angles and the increase of the P-N bond distance. These changes are paralleled by a strong deshielding of the 31P nucleus, leading to an exceptionally high δp value for the tricyclic derivative. The δp-structural parameters relationship is discussed in terms of the changes in hybridization of phosphorus and the variation in the P-N bond order.
Measurement of the rate of copper(II) exchange for 64Cu complexes of bifunctional chelators
Maheshwari, Vidhi,Dearling, Jason L.J.,Treves, S. Ted,Packard, Alan B.
, p. 318 - 323 (2012)
Measurement of the rate of loss of 64Cu from the chelators used in the preparation of 64Cu-labeled proteins is critical to the development of effective 64Cu-labeled radiopharmaceuticals. Typically, however, this assessment has been made indirectly, by comparison of the relative uptake of the labeled proteins in the liver, or under non-physiological conditions such as hot 5 M HCl. In the present study, we measured the rate of loss of 64Cu from a series of chelators (DOTA, TETA, and NOTA) that are commonly used to label proteins as a function of [Cu2+] (1, 2, and 5 μM) and pH (7.5, 6.0. and 5.0). We found that 64Cu-NOTA is somewhat more kinetically stable than 64Cu-TETA and that both 64Cu-NOTA and 64Cu-TETA are much more kinetically stable than 64Cu-DOTA. Furthermore, the rate of loss of 64Cu from Cu-DOTA increased with higher [Cu 2+] and pH while the rate of loss of 64Cu from Cu-TETA and Cu-NOTA was minimally dependent on [Cu2+] and pH. These results suggest that NOTA is preferable to TETA and DOTA for the preparation of 64Cu-labeled proteins.
DINUCLEATING LIGAND OR DINUCLEAR METAL COMPLEX
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Paragraph 0048; 0056-0057, (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
Comparative studies of the electronic, binding and photophysical properties of a new nona-dentate hemi-cage tripodal HQ pendant trizaza-macrocycle with unfilled, half-filled and completely filled lanthanide ions
Baral, Minati,Kanungo, B. K.,Rohini
, p. 16040 - 16059 (2018/10/04)
The present paper describes the comparative studies of the electronic, photophysical and binding properties of a new C3-symmetric polydentate ligand, 1,4,7-tris-{(5-methylene-8-hydroxyquinoline)-1,4,7-triazacyclononane} (9N3Me5Ox), and its complexes with 4f0, 4f7, and 4f14 metal ions (La3+, Gd3+, and Lu3+) by experimental and theoretical methods using DFT, TDDFT, TDDFTB, ETS-NOCV, NBO and Ligand Field DFT (LFDFT). The ligand and the complexes were synthesized and characterized through elemental analysis, molar conductance, TGA, FT-IR, FT-NMR, 1H-1H COSY and ESI-mass spectrometry techniques. The spectral data and structural studies revealed the formation of nine-coordinate compounds with the general formula [Ln(9N3Me5Ox)(H2O)3], in which the nonadentate chelator acted as a trinegative hexadentate ligand coordinating to the metal ions through three sets of O,N-donors of 8-hydroxyquinoline groups and three coordinated water molecules. The molecular modeling studies suggest that the metal ion can be easily encapsulated in its central cavity forming hemi-cage complexes without altering the basic metal-ligand coordination sphere. The nature of the bonding between the lanthanide ions and 9N3Me5Ox3?, elucidated by means of the natural bond orbital (NBO), Morokuma-Ziegler energy decomposition analysis (ETS-NOCV) scheme, suggests that the Ln-L bonds are more electrostatic (~82percent) than covalent (~18percent). The covalent character of the complexes increases in the order Lu > La > Gd. The photoluminescence spectral studies of the metal complexes revealed that the observed luminescence of the compounds in the solid state and solution is of different origin. The vibrational, 1H and 13C NMR spectral data obtained from the DFT optimized structures showed good agreement with the experimental results. The excitation and emission behaviours of the ligand and the complexes were established by molecular orbital analysis of the ground state DFT geometry as well as of the excited state optimized geometry using TD-DFT and TD-DFTB orbital analysis, excitation and emission properties.