Metal complexes of cyclic triamines.  1.  Complexes of 1,4,7-triazacyclononane ([9]aneN3) with nickel(II), copper(II), and zinc(II)

YANG, RITA; Zompa, Leverett J.

doi:10.1021/ic50161a007

Cited by 163 publications

(99 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1,4,7-triazacyclononane [19] 4 (HO 2 CCMe 3 ) 4 ] (0.70 g, 0.74 mmol) in toluene (5 mL) was added to a solution of tacn (0.35 g, 2.7 mmol) in toluene (5 mL), and the resultant blue solution was stirred for 5 min. Pink crystals of A began to form during this time.…”

Section: Methodsmentioning

confidence: 99%

Templating Open‐ and Closed‐Chain Structures around Metal Complexes of Macrocycles

et al. 2004

View full text Add to dashboard Cite

The ability to control the structures of polymetallic complexes is a key concern if we are ever to exploit their properties. A lot of beautiful science has emerged with this challenge, as shown by the grid structures created by Lehn [1] and Thompson, [2] or the panel structures created by Fujita.[3] A particularly attractive idea is to template the structure about an otherwise innocent ion to modify the structure without changing electronic properties. The work of Saalfrank et al. in which different sized metallocryptands were templated is particularly relevant here, [4] as is the work of Raymond and coworkers in which the geometry of the molecule is varied from a dimetallic helix to a tetrahedron depending on the presence of a tetrahedral counterion.[5] Our work has concerned new methods to influence structure, and, in the case of cyclic chromium fluoride cages, we have shown that the size of metal rings can be influenced by the choice of secondary ammonium cations. [6, 7] Here we use metal complexes of macrocycles as templates to show that further unusual structures can be formed.Previously [6] The facile synthesis of these compounds led us to look more widely at a reaction matrix that contains chromium fluoride, pivalate ion, a second metal ion, and templates that contain NH groups. When the second metal is nickel and the template is a simple azacrown ether, either 1,4,7-triazacyclonane (tacn) or 1,4,7,10-tetraazacyclododecane (cyclen), the macrocycle binds the nickel ion and the resultant complex then acts as the template.Initially, chromium fluoride, nickel carbonate, and tacn were treated in pivalic acid to give [Ni(tacn) 2 ][Cr 8 Ni 2 -F 10 (O 2 CCMe 3 ) 20 ] (1), [8] in which the dicationic mononuclear nickel complex was found within a dianionic ring (Figure 1).A better route to 1 involved the prior preparation of [Ni(tacn) 2 ](O 2 CCMe 3 ) 2 and addition of this complex to the reaction mixture (CrF 3 , NiCO 3 , and pivalic acid). The metal sites within the dianion are disordered: two Ni 2+ ions are present according to microanalytical measurement and charge-balance considerations. The structure of the mononuclear dication is very similar to that of [Ni(tacn) 2 ] 2+ crystallized with simpler anions, [10] however, disorder in the structure renders a meaningful comparison of bond lengths difficult. Each of the M···M edges of the ten-metal ring, which is almost planar, is bridged by one fluoride and two pivalate ions in a similar manner to [Cr 7 NiF 8 (O 2 CCMe 3 ) 16 ] À . Each of the NH groups of the two tacn ligands are involved in hydrogen bonds; these bonds are longer than the hydrogen bonds found when simpler amines are used (N···F contacts range from 2.98 to 3.30 rather than 2.7-2.9 ). [6] With the Cr-F-pivalate system, octa-, [6] nona-, [7] and decanuclear metal rings could be synthesized by variation of the template. If 1,4,7, Figure 2) [8] results. The fifteen metal sites define an "S", in which a Ni 2+ ion is located at the center of the "S" and two Ni

show abstract

Section: Methodsmentioning

confidence: 99%

Templating Open‐ and Closed‐Chain Structures around Metal Complexes of Macrocycles

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Bistriazacyclononanenickel(1I) perchlorate (15), [Ni(9-aneN3)Z]-(C104)>, was prepared using a modified preparation of the ligand as described (13). The corresponding nickel(II1) salt was formed on addition of a slight stoichiometric excess of aquocobalt(1II) (16) …”

Section: Methodsmentioning

confidence: 99%

“…other redox systems (13,22) where no protonation equilibria are involved there is no observed rate dependence of The observed second order rate constant, ko, may be expressed as Equation [15] may be rearranged as where SQ' is the semiquinone radical with no assumption made as to the state of protonation of the species. A rate expression [16] A marked increase in rate is observed with increasing pH which may be associated with the acid dissociation of the reductants, the almost identical pH profiles for each reaction reflecting the similarity of pK, values for the substrates.…”

Section: E"mentioning

confidence: 99%

Kinetics and mechanism of the oxidation of benzenediols and ascorbic acid by bis(1,4,7-triazacyciononane)nickel(III) in aqueous perchlorate media

McAuley¹,

Spencer²,

West³

1985

Can. J. Chem.

View full text Add to dashboard Cite

A. MCAULEY, LEE SPENCER, and P. R. WEST. Can. J . Chem. 63, 1198Chem. 63, (1985. The reactions of the outer-sphere electron transfer reagent, Ni(9-aneN&", (Dis(l,4,7-triazacyclononane)nickel(III) ion) with ascorbic acid, hydroquinone, catechol, and resorcinol have been investigated. The absence of any proton related equilibria with the oxidant provides a means of ascribing the observed inverse hydrogen ion dependences to reactions of the dissociated ascorbate or quinolate ions, (HA-). The data are consistent with the rate-determining one-electron transfer reactions: k, ~i ( 9 -a~~~~)~~' + HA-4 Ni(9-ane N-c)2" + HA followed by rapid oxidation of the radical ions formed. In the reaction with ascorbic acid, kl -0 and k 2 ( T = 25°C) = 5.2

show abstract

“…In this study, the dinucleating ligand 2,6-bis(1,4,7-triazacyclonon-1-ylmethyl)-4-methylphenol (bcmp) with two 9-membered aza-crown binding sites was chosen because of the well-established high affinity of Cu 2+ ions for 1,4,7-triazacyclonane (tacn). The logK value for mononuclear Cu(tacn) 2+ is 15.5, suggesting that a highly stable bcmp complex is formed under physiological conditions [27]. Furthermore, Cu complexes of tacn ligands are generally good catalysts for phosphate ester hydrolysis [28,29].…”

Section: About 10mentioning

confidence: 99%

DNA damage and induction of apoptosis in pancreatic cancer cells by a new dinuclear bis(triazacyclonane) copper complex

Montagner

Gandin

Marzano

et al. 2015

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

The dinuclear copper(II) complex [Cu 2 {bcmp(-H)}(μ-OH)](NO 3 ) 2 ·H 2 O (1, bcmp = 2,6-bis(1,4,7-triazacyclonon-1-ylmethyl)-4-methylphenol) has been synthesized and characterized by electrospray ionization mass spectrometry, potentiometric titration and cyclovoltammetry. The X-ray structure of the analogous perchlorate salt [Cu 2 {bcmp(-H)}(μ-OH)](ClO 4 ) 2 ·2.5H 2 O (2) was determined. Cytotoxicity studies showed very promising activity of 1 against various pancreatic tumor cell lines with IC 50 values comparable or even lower than those of cisplatin. The Cu complex displayed low toxicity against a human non-tumor cell line (HEK 293) demonstrating selectivity for cancer cells. 1 converts supercoiled pUC19 plasmid DNA into the nicked form at micromolar concentrations in the absence of added reductants. A detailed kinetic study on the hydrolysis of the DNA model bis(2,4-dinitrophenyl) phosphate (BDNPP) has been performed. 1 hydrolyses BDNPP with a second order rate constant of 0.047 M s −1 at pH 8 and 40°C. Finally, single cell electrophoresis (comet assay) and fluorescence microscopy analysis showed that 1 interacts with cellular DNA and induces apoptotic cell death of Capan-1 pancreatic cancer cells. Western blotting analysis indicated that the Cu complex activates the p53 dependent pathway of apoptosis.

show abstract

Metal complexes of cyclic triamines. 1. Complexes of 1,4,7-triazacyclononane ([9]aneN3) with nickel(II), copper(II), and zinc(II)

Cited by 163 publications

References 5 publications

Templating Open‐ and Closed‐Chain Structures around Metal Complexes of Macrocycles

Templating Open‐ and Closed‐Chain Structures around Metal Complexes of Macrocycles

Kinetics and mechanism of the oxidation of benzenediols and ascorbic acid by bis(1,4,7-triazacyciononane)nickel(III) in aqueous perchlorate media

DNA damage and induction of apoptosis in pancreatic cancer cells by a new dinuclear bis(triazacyclonane) copper complex

Contact Info

Product

Resources

About