Synthesis and Magnetic Relaxation Properties of Paramagnetic Gd-complexes of New DTPA-bis-amides. The X-ray Crystal Structure of [Gd(L)(H2O)]？H2O (L = DTPA-bis(4-carboxylicphenyl)amide)

Gd-Complexes of New Arylpiperazinyl Conjugates of DTPA-Bis(amides): Synthesis, Characterization and Magnetic Relaxation Properties

“…Complexes 1 and 2 are highly hygroscopic and were isolated as hydrated solids. The appearance of the ν (OH) band from the water of crystallization at 3426 and 3480 cm −1 , supported this observation [13]. The disappearance of the carbonyl stretching bands of the free ligands at 1728 and 1733 cm −1 in both complexes 1 and 2 indicated the participation of the carbonyl groups in coordination [21].…”

“…To overcome the inherent limitations of anionic Gd-complexes and to improve the tissue and/or organ-specificity, the preparation of neutral Gd-macrocyclic analogues for the development of efficient (“optimized”) CAs is highly desirable [9,10,11,12]. Earlier reports have suggested that incorporation of alkyl and aromatic groups in the side arm of diethylenetriamine pentaacetic acid (DTPA) rendered excellent relaxivity and water solubility [13,14,15]. In the light of the above, we have designed novel ligands from the reaction of DTPA-bis(anhydride) with suitably modified arylpiperazines and subsequently transformed them into their corresponding Gd(III)-complexes 1 and 2 .…”

Heterometallic lanthanide complexes with site-specific binding that enable simultaneous visible and NIR-emission

“…Single crystal X-ray diffraction structures reported for aminophenyl trifluoromethyl Yb III (DO3A) (CCDC ID: EGOWUV) and bis-aminocarboxyphenyl Gd III (DTPA) (CCDC ID: QEZGIM) complexes with analogous phenyl moieties allow approximate calculation of these distances via superimposition and preliminary energy minimization. Crystal structures were used without modification and manipulated into a feasible geometry before undergoing optimization in Avogadro to yield an average Yb III –Gd III distance of 11.9 Å ( Supplementary Figure S2.34 ) ( Dutta et al, 2006 ; Pujales-Paradela et al, 2019 ). Examples of multimetallic architectures that exhibit intermetallic energy transfer often report shorter distances (≤10 Å) ( Natrajan et al, 2009 ; Maniaki et al, 2023 ).…”

“…Crystal structures were used without modification and manipulated into a feasible geometry (Carnall et al, 1968a;Carnall et al, 1968b;Sastri et al, 2003). Frontiers in Chemistry frontiersin.org before undergoing optimization in Avogadro to yield an average Yb III -Gd III distance of 11.9 Å (Supplementary Figure S2.34) (Dutta et al, 2006;Pujales-Paradela et al, 2019). Examples of multimetallic architectures that exhibit intermetallic energy transfer often report shorter distances (≤10 Å) (Natrajan et al, 2009;Maniaki et al, 2023).…”

Lanthanide complexes with polyaminopolycarboxylates as prospective NMR/MRI diagnostic probes: peculiarities of molecular structure, dynamics and paramagnetic properties

“…Other example of the selectivity of DTPA-bis(amide) ligands for the Gd(III) ion over the endogenous metal ions such as Zn(II), Ca(II), and Cu(II), and relaxivities (r 1 and r 2 ) of Gd(III)-DTPA-bis(amide) complexes both in aqueous and hydroxypropyl-b-cyclodextrin (HP-b-CD) solutions reported by T. J. Kim [194]. HP-b-CD is biocompatible and has been used in the preparation of aqueous solution of water-insoluble drugs [195] It is known that a significant increase in relaxivity is established when ''host-guest'' inclusion complexes are formed between the hydrophobic b-cyclodextrin cavity Fig.…”