Synthesis of hexa aza cages, SarAr-NCS and AmBaSar and a study of their metal complexation, conjugation to nanomaterials and proteins for application in radioimaging and therapy.

A novel hexa aza cage, N(1)-(4-isothiocyanatobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1,8-diamine (SarAr-NCS) was synthesized in good yield and characterized by (1)H NMR and electrospray mass spectrometry.

An unusually flexible expanded hexaamine cage and its Cu(II) complexes: variable coordination modes and incomplete encapsulation.

The bicyclic hexaamine "cage" ligand Me(8)tricosaneN(6) (1,5,5,9,13,13,20,20-octamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosane) is capable of encapsulating octahedral metal ions, yet its expanded cavity allows the complexed metal to adopt a variety of geometries comprising either hexadentate or pentadentate coordination of the ligand.

Octahedral and trigonal prismatic structure preferences in a bicyclic hexaamine cage for zinc(II), cadmium(II) and mercury(II) ions.

The synthesis and characterisation of complexes of the hexaamine cage ligand facial-1,5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosane (fac-(Me)(5)-D(3 h)tricosaneN(6)) with Zn(II), Cd(II) and Hg(II) is reported.

Positron emission tomography (PET) imaging of neuroblastoma and melanoma with 64Cu-SarAr immunoconjugates.

The advancement of positron emission tomography (PET) depends on the development of new radiotracers that will complement (18)F-FDG. Copper-64 ((64)Cu) is a promising PET radionuclide, particularly for antibody-targeted imaging, but the high in vivo lability of conventional chelates has limited its clinical application. The objective of this work was to evaluate the novel chelating agent SarAr (1-N-(4-aminobenzyl)-3, 6,10,13,16,19-hexaazabicyclo[6.

An expanded cavity hexaamine cage for copper(II).

The crystal structure of the bicyclic hexaamine complex [Cu(fac-Me5-tricosane-N6)](ClO4)2.H2O (fac-Me5-tricosane-N6 = facial-1,5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.

New 64Cu PET imaging agents for personalised medicine and drug development using the hexa-aza cage, SarAr.

The success of positron emission tomography (PET) in personalised medicine and drug development requires radioisotopes that provide high quality images and flexible chemistry for a broad application. 64Cu is arguably one of the most suitable PET isotopes for imaging with the evolving target agents, but there are not many appropriate chelating agents for 64Cu and this has limited its wider application. The bi-functional chelator, SarAr is known to bind 64Cu2+ quantitatively (i.

Facile cobalt(III) template synthesis of novel branched hexadentate polyamine monocarboxylates.

New hexadentate polyamine monocarboxylate ligands, 11-amino-9-(2-aminoethyl)-3,6,9-triazaundecanoate (tren-engly-), 12-amino-10-(2-aminoethyl)-3,7,10-triazadodecanoate (tren-tngly-) and 13-amino-11-(2-aminoethyl)-3,8,11-triazatridecanoate (tren-bngly-), were synthesized by intramolecular coupling of tetradentate tris(2-aminoethyl)amine (tren) and didentate N-([small omega]-formylalkyl)glycinates, OCH(CH2)nNHCH2CO2-, in easily and stereoselectively assembled cobalt(III) templates, p-[Co(tren){(RO)2CH(CH2)nNHCH2CO2}](O3SCF3)2, n = 1-3 (R = Me or Et). The reaction sequences comprised assembly of the template from [Co(tren)(O3SCF3)2]O3SCF3 (1) and (RO)2CH(CH2)nNHCH2CO2Et, deprotection of the pendant acetal in acid, intramolecular condensation of the resulting aldehyde with a coordinated primary amine at intermediate pH to form the imine and reduction of this by NaBH4. For n= 1, imine formation occurred exclusively at the primary amine trans to the carboxylate producing the hexadentate 11-amino-9-(2-aminoethyl)-3,6,9-triazaundeca-5-enoato (tren-enimgly-) complex, i-[Co(tren-enimgly)]Cl2.

Specificity in template syntheses of hexaaza-macrobicyclic cages: [Pt(Me5-tricosatrieneN6)]4+ and [Pt(Me5-tricosaneN6)]4+.

The racemic C3 hexadentate cage complex, [Pt(Me5-tricosatrieneN6)]Cl4 (1,5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosa- 3,14,18-triene)platinum(IV) tetrachloride), was synthesised stereospecifically and regiospecifically from a reaction of the bis-triamine template [Pt(tamc)2]Cl4 (bis[1,1,1-tris(aminomethyl)ethane]- platinum(IV) tetrachloride) with formaldehyde and then propanal, in acetonitrile under basic conditions.

Assembly of polyamines via amino acids from three components using cobalt(III) template methodology.

A versatile and efficient template synthesis has been developed to synthesise novel polyamines [e.g. rac-N3-(3-aminopropyl)butane-1,3-diamine, isospermidine 1] via amino acids [e.

Cobalt Cage Complexes with N(3)S(3) Donor Sets and Differing Cavity Sizes: A Novel Macrobicyclic Cage with a Contracted Cap.

Treatment of the cobalt(III) complex of the hexadentate tripodal N(3)S(3) ligand ten (4,4',4' '-ethylidynetris(3-thiabutan-1-amine) with propanal and paraformaldehyde under basic conditions, followed by borohydride reduction and reoxidation of the metal center, leads largely to the encapsulated (red) metal complex cation [Co(Me(2)-N(3)S(3)sar)](3+) (Me(2)-N(3)S(3)sar = 1,8-dimethyl-3,13,16-trithia-6,10,19-triazabicyclo[6.6.6]icosane).

Synthesis, Characterization, and Reactivity of Urea Derivatives Coordinated to Cobalt(III). Possible Relevance to Urease.

The syntheses of a cobalt(III) complex, 2, containing N-(2-pyridylmethyl)urea and of six complexes, 3, containing phenyl-substituted N-2-pyridylmethyl-N'-(X)phenylureas (where X = 4-H, 4-CH(3), 4-Br, 3-Cl, 4-CF(3), and 4-NO(2)), have been accomplished by reaction of [(en)(2)Co(OSO(2)CF(3))(2)](CF(3)SO(3)) with the urea ligands in tetramethylene sulfone. The complexes have been characterized by UV-vis, FTIR, (1)H NMR, and (13)C NMR spectra along with elemental analysis. Also, X-ray crystallographic analysis of 2 confirms that the urea ligand chelates as a bidentate through the pyridyl nitrogen atom and the endo deprotonated, urea nitrogen atom to form a stable five-membered ring.

Critical Evaluation of Metal Complex Molecular Mechanics. Part 1. Cobalt(III) Hexaamines.

The ability of available molecular mechanics programs to calculate structures and relative energies of metal complexes is examined via a comparative study of five different force fields: Molmec, Momec91(H), Momec91(C), Xnviron, and Spartan. The method used for assessing the validity of the force fields showed that four of the force fields were able to reproduce successfully the structures of various Co(III) hexaamine cations determined by X-ray analysis, even when these structures were considerably distorted. In certain cases, the calculated relative steric energies were not reliable.

Ligand Dehydrogenation in Ruthenium-Amine Complexes: Reactivity of 1,2-Ethanediamine and 1,1,1-Tris(aminomethyl)ethane.

The mechanisms of oxidative ligand dehydrogenation in high-valent ruthenium hexaamine complexes of bidentate 1,2-ethanediamine (en) and tridentate 1,1,1-tris(aminomethyl)ethane (tame) are elucidated in detail. In basic aqueous solution, [Ru(III)(tame)(2)](3+) undergoes rapid initial deprotonation (pK(III) = 10.3).