Synthesis of a nitrogen mustard ligand on a cobalt(III) metal centre

Downward, Alan M.; Polson, Matthew I. J.; Kerr, William R.; Kariyawasam, Janadari; Hartshorn, Richard M.

doi:10.1016/j.poly.2012.08.002

Cited by 6 publications

(10 citation statements)

References 25 publications

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“…1, right). 30 This preliminary work supports the use of amino alcohol ligands as an alternative synthetic route towards nitrogen mustard Co(III) complexes of the kind that we require. We have now extended this work to incorporate a range of functional group and coordination chemistry for mustard complexes and their precursors.…”

Section: Introductionsupporting

confidence: 69%

“…In particular, we needed to establish how this would mesh with the functional group chemistry needed to produce the mustard ligands on the complex, and to extend the work that we had already published. 30 The triflate complex (OC-6-23′)-[Co(ceen) 2 (Cl)(OTf )]OTf (3) was synthesised from the reaction of ceen complex (OC-6-23′)-[Co(ceen) 2 (Cl)(NO 2 )]Cl (2) with HOTf, according to literature procedure (Scheme 5, pathway A). 30 Complex 3 was obtained as a green powder, separated from a purple solution by filtration.…”

Section: Expanding the Coordination Chemistrymentioning

confidence: 99%

“…[26][27][28][29] However, we have been interested in developing methods in which the nitrogen mustard is formed from a precursor that is already coordinated to Co(III). 30 Specifically, we have been exploring the coordination and reactivity of amino alcohol ligands on the Co(III) metal centre (Schemes 3 and 5). 30 Previously, we reported the synthesis and structural analysis of complexes (OC-6-12′)-[Co(heen) 2 (NO 2 ) 2 ]NO 3 (1) and (OC-6-23′)-[Co(ceen) 2 (Cl)(NO 2 )]Cl (2), where heen and ceen are N-(2-hydroxyethyl)ethane-1,2-diamine and N-(2-chloroethyl) ethane-1,2-diamine, respectively (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…1 and 2). 30 Furthermore, it was shown that the reaction of complex 2 with trifluoromethanesulfonic acid (HOTf ) afforded complex (OC-6-23′)-[Co(ceen) 2 (Cl)(OTf )]OTf (3, Fig. 1, right).…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of nitrogen mustards on cobalt(iii)

Kariyawasam,

Zibaseresht,

Polson

et al. 2023

Dalton Trans.

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Section: Introductionsupporting

confidence: 69%

Section: Expanding the Coordination Chemistrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of nitrogen mustards on cobalt(iii)

Kariyawasam,

Zibaseresht,

Polson

et al. 2023

Dalton Trans.

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“…The long Co–O contacts are well within the sum of the van der Waals radii (3.44 Å). The bis(nitrate) is comparable to other cobalt bis(nitrate) complexes with two other ancillary donors. − Cobalt bis(nitrite) complexes are usually N-bound and six-coordinate, − and we hypothesize the nitrite ligands are O-bound in (DIM)Co(NO 2 ) 2 to accommodate bidentate binding and provide a six-coordinate environment about the cobalt center. The structure of the zinc bis(nitrate) has two bidentate nitrates, each with one long (2.22 Å) and one short (2.09 Å) Zn–O distance.…”

Section: Resultsmentioning

confidence: 72%

An Integrated View of Nitrogen Oxyanion Deoxygenation in Solution Chemistry and Electrospray Ion Production

et al. 2021

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There has been an increasing interest in chemistry involving nitrogen oxyanions, largely due to the environmental hazards associated with increased concentrations of these anions leading to eutrophication and aquatic “dead zones”. Herein, we report the synthesis and characterization of a suite of MNO x complexes (M = Co, Zn: x = 2, 3). Reductive deoxygenation of cobalt bis(nitrite) complexes with bis(boryl)pyrazine is faster for cobalt than previously reported nickel, and pendant O-bound nitrito ligand is still readily deoxygenated, despite potential implication of an isonitrosyl primary product. Deoxygenation of zinc oxyanion complexes is also facile, despite zinc being unable to stabilize a nitrosyl ligand, with liberation of nitric oxide and nitrous oxide, indicating N–N bond formation. X-ray photoelectron spectroscopy is effective for discriminating the types of nitrogen in these molecules. ESI mass spectrometry of a suite of M(NO x ) y (x = 2, 3 and y = 1, 2) shows that the primary form of ionization is loss of an oxyanion ligand, which can be alleviated via the addition of tetrabutylammonium (TBA) as a nonintuitive cation pair for the neutral oxyanion complexes. We have shown these complexes to be subject to deoxygenation, and there is evidence for nitrogen oxyanion reduction in several cases in the ESI plume. The attractive force between cation and neutral is explored experimentally and computationally and attributed to hydrogen bonding of the nitrogen oxyanion ligands with ammonium α-CH2 protons. One example of ESI-induced reductive dimerization is mimicked by bulk solution synthesis, and that product is characterized by X-ray diffraction to contain two Co(NO)2 + groups linked by a highly conjugated diazapolyene.

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