Borate complexes of benzohydroxamic acid and some of its derivatives

Fields, Alan R.; Daye, Barbara M.; Christian, Robert

doi:10.1016/0039-9140(66)80190-x

Cited by 14 publications

(9 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also the 17 O NMR, FTIR, N vs. O alkylation experiments points towards the same line . In contrast to these studies, other group of authors has shown the oxygen atom protonation . Recently, number of authors have pointed out coexistence of both the protonated species but one form is preferred over the other depending on the medium and substituents on HA .…”

Section: Resultsmentioning

confidence: 89%

Coordination Modes of Hydroxamates in Neptunium (V) Complexes in Aqueous Solution

Dumpala

Rawat²,

Bhattacharya

et al. 2017

ChemistrySelect

View full text Add to dashboard Cite

A theoretical study to understand molecular structures and coordination modes of neptunium complexes with three different substituent hydroxamates viz., acetohydroxamate (AHA), benzhydroxamate (BHA) and salicylhydroxamate (SHA) was carried out using density functional theory (DFT). The geometries for different complexes reported in literature M x L y H z (x:y:z) viz 1:1:1, 1:2:2 and 1:2:0 were optimized and interaction energies (DE) for complexation process were calculated to obtain the most probable structures of complexes. The DE value revealed, the complex stability order as NpO 2 + -SHA > NpO 2 -AHA > NpO 2 -BHA which is in agreement with the reported experimental data. Higher negative charge on AHA compared to BHA leads to its higher interaction with NpO 2 which in turn reflects in shorter Np-O eq (ligand) bond distances. In 1:1:1 complex of NpO 2 -SHA, the binding mode involving ortho hydroxyl group and -NHO À oxygen atom (seven membered ring) shows most negative interaction energy.However, for binding of second ligand in 1:2:2 NpO 2 -SHA complex, steric effects dominate and the mode involving five membered ring through oxygen atoms of -CONHO À is most stable.

show abstract

Section: Resultsmentioning

confidence: 89%

Coordination Modes of Hydroxamates in Neptunium (V) Complexes in Aqueous Solution

Dumpala

Rawat²,

Bhattacharya

et al. 2017

ChemistrySelect

View full text Add to dashboard Cite

show abstract

“…[11] Although structures of this type were reported for some isolated diphenylborinic acid complexes of Nsubstituted hydroxamic acids, [18] less electrophilic boric acid does not interact with N-substituted hydroxamic acids. [19] One may speculate however, that intramolecular ion pairing with deprotonated ortho-hydroxyl group can stabilize electrostatically the ammonium ion making structure 3 in principle possible. The question in this case is how stable are PBA complexes with hydroxamic acids without involvement of ortho-hydroxyl group in boronic acid binding.…”

Section: Resultsmentioning

confidence: 99%

“…An alternative structure 3 for SHA‐NMe complex (Scheme ) involving O,O‐chelation of doubly deprotonated SHA without direct involvement of phenolic OH group was suggested . Although structures of this type were reported for some isolated diphenylborinic acid complexes of N‐substituted hydroxamic acids, less electrophilic boric acid does not interact with N‐substituted hydroxamic acids . One may speculate however, that intramolecular ion pairing with deprotonated ortho ‐hydroxyl group can stabilize electrostatically the ammonium ion making structure 3 in principle possible.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamic and structural study of complexation of phenylboronic acid with salicylhydroxamic acid and related ligands

Martínez‐Aguirre

Flores-Álamo

Yatsimirsky

2018

Applied Organom Chemis

View full text Add to dashboard Cite

Stability constants of boronate complexes with a highly efficient bioconjugation ligand salicylhydroxamic acid, its derivatives and some structurally related compounds were determined by potentiometric and spectroscopic titrations at variable pH allowing one to obtain detailed stability – pH profiles and to identify the optimum pH for complexation with each ligand. The N,O‐binding of salicylhydroxamic acid via condensation of boronic acid with phenolic OH and hydroxamic NH groups was established by crystal structure determination of isolated complexes with phenylboronic and 4‐nitrophenylboronic acids. Although this type of binding is impossible for N‐methylated salicylhydroxamic acid it still forms stable boronate complexes supposedly involving unusual 7‐membered –O‐B‐O‐ cycle supported by 1H NMR studies. Hydroxamic acids lacking ortho‐OH group and salicyloyl hydrazide form less stable boronate complexes, which nevertheless possess stabilities similar to those of catechole complexes and may be useful for conjugation applications. In contrast to other ligands, which form tetrahedral anionic complexes, salicylamidoxime forms tetrahedral, but neutral boronate complex with high stability in weakly acid solutions. The highest affinity in neutral and acid solutions surpassing that of salicylhydroxamic acid is observed with 2,6‐dihydroxybenzhydroxamic acid (Kobs = 5.2 × 104 at pH 7.4). Fairly stable mono‐ and bisboronate complexes are formed with 2,5‐dihydroxy‐1,4‐benzdihydroxamic acid, which also possesses intense fluorescence and may serve as a boronic acid sensor with detection limit 4 μM. Results presented in this study provide quantitative basis for rational applications of hydroxamic acid derivatives in bioconjugation and sensing.

show abstract

“…Borate complexes of benzohydroxamic acid and some of its derivatives were studied by Christian and co-workers (68). A 1:1 complex with borate was formed by the primary hydroxamlc acids between pH 6 and 11.…”

Section: Structure and Nomenclaturementioning

confidence: 99%

Chelating ion exchange with macroreticular hydroxamic acid resins

Phillips

View full text Add to dashboard Cite

Borate complexes of benzohydroxamic acid and some of its derivatives

Cited by 14 publications

References 13 publications

Coordination Modes of Hydroxamates in Neptunium (V) Complexes in Aqueous Solution

Coordination Modes of Hydroxamates in Neptunium (V) Complexes in Aqueous Solution

Thermodynamic and structural study of complexation of phenylboronic acid with salicylhydroxamic acid and related ligands

Chelating ion exchange with macroreticular hydroxamic acid resins

Contact Info

Product

Resources

About