Abstract Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid sensor can be adjusted directly monitor species proposed sensing scheme based on NV spin relaxometry. We adopt single-step method...

Given the practical advantages of (68)Ga isotope in positron emission tomography applications, gallium complexes are gaining increasing importance biomedical imaging. However, strong tendency Ga(3+) to hydrolyze and slow formation very high stability macrocyclic altogether render coordination chemistry difficult explain why kinetic data on rather scarce. Here we report solution solid-state studies formed with ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, (DOTA)(4-), its...

For application in positron emission tomography (PET), PrP9, a N,N',N''-trisubstituted triazacyclononane with methyl(2-carboxyethyl)phosphinic acid pendant arms, was developed as (68)Ga(3+) complexing agent. The synthesis is short and inexpensive. Ga(III) Fe(III) complexes of PrP9 were characterized by single-crystal X-ray diffraction. Stepwise protonation constants thermodynamic stabilities metal determined potentiometry. complex possesses high stability (log K([GaL])=26.24) degree kinetic...

A new macrocyclic DOTA-like ligand (BPAMD) for bone imaging and therapy containing a monoamide bis(phosphonic acid) bone-seeking group was designed synthesized. Its lanthanide(III) complexes were prepared characterized by 1H 31P NMR spectroscopy. The Gd(III)−BPAMD complex investigated in detail 17O relaxometric studies to inspect parameters relevant its potential application as an MRI contrast agent. Sorption experiments conducted with Gd(III) Tb(III) using hydroxyapatite (HA) model of...

Given its five unpaired d-electrons, long electronic relaxation time, and fast water exchange, Mn(2+) is a potential candidate for contrast agent application in medical magnetic resonance imaging. Nevertheless, the design of chelators that ensure stable complexation optimal properties remains coordination chemistry challenge. Here, we report synthesis two pyridine-containing ligands L1 L2, with 15-membered triaza-dioxa-crown pentaaza-crown ether macrocycles, respectively, characterization...

Mn2+ complexes represent an alternative to Gd3+ chelates which are widely used contrast agents in magnetic resonance imaging. In this perspective, we investigated the of two 12-membered, pyridine-containing macrocyclic ligands bearing one pendant arm with a carboxylic acid (HL1, 6-carboxymethyl-3,6,9,15-tetraazabicyclo[9.3.1] pentadeca-1(15),11,13-triene) or phosphonic function (H2L2, 6-dihydroxyphosphorylmethyl-3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene). Both were...

A monophosphonate analogue of H4dota, 1,4,7,10-tetraazacyclododecane-4,7,10-tris(carboxymethyl)-1-methylphosphonic acid (H5do3aP), and its complexes with lanthanides were synthesized. Multinuclear NMR studies reveal that, in aqueous solution, lanthanide(III) the ligand exhibit structures analogous to those H4dota complexes. Thus, central ion is nine-coordinate, surrounded by four nitrogen atoms, three acetate one phosphonate oxygen water molecule an apical position. For H5do3aP Ln(III) ions...

New bifunctional H4dota-like ligands with three acetic acid and one phosphinic pendant arms propionate (H5do3apPrA) or 4-aminobenzyl (H4do3apABn) reactive groups bound to the phosphorus atom were investigated. Potentiometric studies showed that have a similar basicity parent H4dota stability constants of their complexes sodium(I) selected lanthanide(III) ions are also similar. Formation acid-assisted decomplexation kinetics yttrium(III) series (H4dota its phosphinic/phosphonic analogues)...

Abstract Diethylenetriamine‐ N,N,N′,N′′,N′′ ‐pentaacetic acid (DTPA) and 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic (DOTA) scandium(III) complexes were investigated in the solution solid state. Three 45 Sc NMR spectroscopic references suitable for aqueous solutions suggested: 0.1 M Sc(ClO 4 ) 3 1 aq. HClO ( δ =0.0 ppm), ScCl HCl =1.75 ppm) 0.01 [Sc(ox) ] 5− (ox 2− =oxalato) K 2 C O =8.31 ppm). In solution, [Sc(dtpa)] complex =83 ppm, ▵ ν =770 Hz) has a rather symmetric ligand field...

Magnetic resonance imaging using fluorinated contrast agents (19F MRI) enables to achive highcontrast in images due the negligible fluorine background living tissues. In this pilot study, we developed new biocompatible, temperature-responsive, and easily synthesized polymeric nanogels containing a sufficient concentration of magnetically equivalent atoms for 19F MRI purposes. The structure is based on amphiphilic copolymers two blocks, hydrophilic poly[N-(2-hydroxypropyl)methacrylamide]...

A series of lanthanide(III) complexes formulated as M[Ln(Hdo3ap)].xH(2)O (M = Li or H and Ln Tb, Dy, Er, Lu, Y) with the monophosphonate analogue H(4)dota, 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic-10-methylphosphonic acid (H(5)do3ap), was prepared in solid state studied using X-ray crystallography. All structures show that (Hdo3ap)(4-) anion is octadentate coordinated to a ion similarly other H(4)dota-like ligands, i.e., forming O(4) N(4) planes are parallel have mutual angle smaller...

Abstract In an aqueous solution at room temperature, 1,4,8,11‐tetraazacyclotetradecane‐1,8‐bis(methylphosphonic acid) (H 4 L 1 ) and Cu I form a pentacoordinated (pc) complex, pc‐[Cu(L )] 2− , exhibiting conformation of the cyclam ring. At high complex isomerises to hexacoordinated isomer, trans ‐O,O‐[Cu(L with ‐ III four ring nitrogen atoms one phosphonate oxygen atom are arranged around in structure that is half‐way between trigonal bipyramid tetragonal pyramid, phosphonic acid group...

Three novel phosphorus-containing analogues of H(5)DTPA (DTPA = diethylenetriaminepentaacetate) were synthesised (H6L1, H5L2, H5L3). These compounds have a -CH2-P(O)(OH)-R function (R OH, Ph, CH2NBn2) attached to the central nitrogen atom diethylenetriamine backbone. An NMR study reveals that these ligands bind lanthanide(III) ions in an octadentate fashion through three atoms, P-O oxygen and four carboxylate atoms. The complexed ligand occurs several enantiomeric forms due chirality...

A new bifunctional octa-coordinating ligand containing an aminobenzyl moiety, DO3APABn (H4DO3APABn = 1,4,7,10-tetraazacyclododecane-4,7,10-triacetic-1-{methyl[(4-aminophenyl)methyl]phosphinic acid}), has been synthesized. Its lanthanide(III) complexes contain one water molecule in the first coordination sphere. The high-resolution 1H and 31P spectra of [Eu(H2O) (DO3APABn)]- show that twisted square-antiprismatic form is more abundant respect to corresponding Eu(III)-DOTA complex. NMRD...

Two new macrocyclic DOTA-like chelates containing one phosphonate pendant arm were synthesised as potential contrast agents for MRI (magnetic resonance imaging). The bind to the lanthanide(III) in an octadentate manner, via four nitrogen atoms, three carboxylate and oxygen atoms. Solution structures of [Ln(do3apOEt2)(H2O)] [Ln(do3apOEt)(H2O)]− studied using 31P 1H NMR spectroscopy SAP (square-antiprismatic)/TSAP (twisted square-antiprismatic) isomerism was observed. Depending on nature ion,...

Abstract Five DOTA‐like ligands lacking a water molecule in the first coordination sphere of their Gd III complexes, namely phosphinates H 4 DOTP , hm and Et phosphonate monoesters OEt OBu were synthesized with aim exploring influence second hydration on relaxivity complexes. The Ln complexes characterized by potentiometry time‐resolved luminescence; are thermodynamically much less stable than that DOTA, no is coordinated inner sphere. crystal structures free ligand determined X‐ray...

H3nota derivatives are among the most studied macrocyclic ligands and widely used for metal ion binding in biology medicine. Despite more than 40 years of chemical research on H3nota, comprehensive study its solution chemistry has been overlooked. Thus, coordination behavior with several divalent ions was detail respect to application as a chelator copper radioisotopes medical imaging therapy. In solid-state structure free ligand zwitterionic form, one proton is bound cavity through strong...

The Cu II complex of 1,8-bis(2-hydroxybenzyl)-cyclam forms an unexpected variety isomers differing in the mutual orientation substituents on cyclam nitrogen atoms, protonation phenolate pendant, and ligand denticity.

Abstract Five geminal bis(phosphonates) containing an amino group in the α, γ or δ position of carbon chain have been synthesised and their acid–base complexation properties with Cu 2+ , Zn Ca Mg Na + ions studied by potentiometry. Determination stability constants complexes divalent metal is complicated formation precipitates. The results these studies show a negligible effect hydroxo α on ligands. presence position, however, decreases basicity, which lower ability bis(phosphonates)....

Solution properties of complexes a new H 4 dota-like ligand containing three acetate and one methylphosphonate pendant arms (H 5 do3ap, L) were studied. The exhibits high last dissociation constant (p K A = 13.83) as consequence the presence phosphonate moiety. In solution, successive attachment protons leads to several reorganizations protonation sites neutral zwitterionic species do3ap has same solution structure in solid state, where nitrogen atom binding opposite atoms are protonated....

A novel conjugate of a polysaccharide and Gd(III) chelate with potential as contrast agent for magnetic resonance imaging (MRI) was synthesized. The structure the derived from H5DTPA by replacing central pendant arm phosphinic acid functional group, which covalently bound to inulin. On average, each monosaccharide unit inulin attached approximately one (0.9) moiety. average molecular weight is 23110 number Gd3+ ions per molecule 24. ligand binds ion in an octadentate fashion via three...

Abstract A novel bimodal fluorescence/MRI probe based on a cyclodextrin scaffold has been synthesized and characterized. The final agent employs the fluorescein (F) functionality as fluorescence marker Gd III complex of macrocyclic DOTA‐based ligand (GdL) having one aminobenzyl‐phosphinic acid pendant arm an MRI probe, statistical composition 6.9 ‐F 0.1 ‐β‐CD. Slow rotational dynamics (governed by very rigid scaffold) combined with fast water exchange (ensured chosen ligand) resulted in high...

A new class of macrocyclic ligands based on 1-oxa-4,7-diazacyclononane was synthesized and their Mn2+ complexes were investigated with respect to stability relaxation properties. Each ligand has two pendant arms involving carboxylic (H2L1 — 1-oxa-4,7-diazacyclononane-4,7-diacetic acid), phosphonic (H4L2 1-oxa-4,7-diazacyclononane-4,7-bis(methylenephosphonic acid)), phosphinic (H2L3 1-oxa-4,7-diazacyclononane-4,7-bis(methylenephosphinic acid)) or phenylphosphinic (H2L4...