Dielectric relaxation studies of N,N-dimethyl formamide and N,N-dimethyl acetamide on complexation with phenols

Malathi, M.; Sabesan, R.; Krishnan, S.

doi:10.1016/s0921-5107(03)00086-2

Cited by 19 publications

(12 citation statements)

References 6 publications

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“…This is in agreement with the fact [20][21] that the process of viscous flow involves greater interference by neighbours than does dielectric relaxation as the latter takes place by rotation only whereas the viscous flow involves both the rotational and translational forms of motion.…”

Section: Resultssupporting

confidence: 91%

Dielectric Relaxation Studies of Ternary Liquid Mixtures of Dimethyl Phthalate with Triethylamine in the Microwave Region

Mushtaq¹,

Khan²

2014

IJIRSET

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ABSTRACT:The molecular structure and molecular forces in liquids and solutions in particular have been investigated by dielectric relaxation studies. The nature and strength of the molecular interactions have been established as the main cause for the chemical behavior of compounds. The dielectric behavior of Triethylamine with Dimethyl Phthalate has been studied at microwave frequency 9.36 GHz at different temperatures 303K, 308K and 313K. Different dielectric quantities like dielectric constant (ε′), dielectric loss (ε″), static dielectric constant (ε 0 ) and dielectric constant at optical frequency (ε α ) have been determined. The relaxation time τ has been calculated by both Higasi's method and Cole-Cole method. The complex system investigated shows the maximum relaxation time values at temperatures by both Higasi's method and Cole-Cole method.

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Section: Resultssupporting

confidence: 91%

Dielectric Relaxation Studies of Ternary Liquid Mixtures of Dimethyl Phthalate with Triethylamine in the Microwave Region

Mushtaq¹,

Khan²

2014

IJIRSET

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“…This indicates that the 1:1 complex formation is the predominant value in substituted benzyl alcoholmethacrylates systems. Similar results were reported by Malathi et al, 13 in some carbonyl + phenol derivative systems.…”

Section: Resultssupporting

confidence: 91%

Molecular Interaction Studies of Benzyl Alcohols with Methacrylates in Carbon Tetrachloride using Frequency Domain Technique

Radhakrishnan¹,

Ramachandran²,

Samuvel³

2016

Orient. J. Chem

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The dielectric relaxation of benzyl alcohol substitutents (benzyl alcohol, m-methylbenzyl alcohol and m-nitrobenzyl alcohol) with methyl methacrylate and butyl methacrylate in dilute solution of carbon tetrachloride is measured at 9.37 GHz using Frequency domain (X-band) technique. Different dielectric parameters like dielectric constant (ε'), dielectric loss factor (ε'') at Microwave frequency, static dielectric constant (ε 0 ) and dielectric constant at infinite dilution (ε ∞ ) at optical frequency have been determined. From the measured dielectric data, the relaxation time (t) calculated using Higasi method and activation energies (DF t and DF h ) have been determined. All the dielectric parameters that are vary with the substitutent change in benzyl alcohol and chain length of acrylic esters. Suggests that, the proton donating ability is varying with the substitution of benzyl alcohol and proton accepting ability is varying with the chain length of acrylic esters. The relaxation time and molar free energy activation of 1:1 molar ratio is greater than other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirm that the existence of most likely 1:1 complex formation between the studied systems and also complex formation formed between free hydroxyl group of substituted benzyl alcohols and carbonyl group of acrylic esters (MMA and EMA).

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“…The measured IR band of 1683 cm -1 is comparable to the C=O stretching frequencies reported for acetamide and N,Ndimethylformamide. [80][81][82] To investigate the potential ligand substitution reaction in more detail, we additionally performed a series of kinetic studies using different concentrations of initial 68 Ga complex, varying pH, and different temperatures. Since the use of NaCl in the radiolabelling reaction was unavoidable, and attempts to remove chloride from the formulation using e.g.…”

Section: Studies On the Interconversion Of 68 Ga-7mentioning

confidence: 99%

Gallium Complexation, Stability, and Bioconjugation of 1,4,7-Triazacyclononane Derived Chelators with Azaheterocyclic Arms

et al. 2017

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We have recently introduced a 1,4,7-triazacyclononane (TACN) based chelating system with additional five-membered azaheterocyclic substituents for complexation of radioactive Cu ions. In this work, we investigated the complexation properties of these novel chelators with Ga. In labeling experiments, we could show that the penta- and hexadentate imidazole derivatives NODIA-Me 4 and NOTI-Me 1 can be labeled with Ga in specific activities up to ∼30 MBq nmol, while the corresponding thiazole derivative NOTThia 2 did not label satisfactorily under identical conditions. NMR studies on the Ga complexes of 1 and the model compound NODIA-Me-NH-Me 5 revealed formation of rigid 1:1 chelates with a slow macrocyclic interconversion and inert Ga-N bonds to the methylimidazole residues on the NMR time scale. The TACN-derived bifunctional chelator NODIA-Me was furthermore conjugated to a prostate-specific membrane antigen (PSMA) targeting moiety to give the corresponding bioconjugate NODIA-Me-PSMA 7. Serum stability and ligand challenge experiments of Ga-7 confirmed formation of a stable complex for up to 4 h. The remaining coordination site of five-coordinate Ga complexes was found to be occupied by monodentate ligands including hydroxide and chloride anions depending on the conditions. According to density functional theory calculations, coordination of monodentate ligands as well as of the amide group for the bioconjugated ligand are energetically plausible. Finally, the labeled bioconjugateGa-7 exhibited rapid renal clearance in biodistribution studies performed by small animal PET imaging with no indication of transchelation/demetalation in vivo. Altogether, our results provide strong evidence for a stable Ga complexation of our novel TACN-based chelators bearing imidazole arms. Despite the formation of two complexes incorporating different monodentate ligands in vitro, the imidazole type ligands show promise as chelating agents for the future development of gallium based radiopharmaceuticals.

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Dielectric relaxation studies of N,N-dimethyl formamide and N,N-dimethyl acetamide on complexation with phenols

Cited by 19 publications

References 6 publications

Dielectric Relaxation Studies of Ternary Liquid Mixtures of Dimethyl Phthalate with Triethylamine in the Microwave Region

Dielectric Relaxation Studies of Ternary Liquid Mixtures of Dimethyl Phthalate with Triethylamine in the Microwave Region

Molecular Interaction Studies of Benzyl Alcohols with Methacrylates in Carbon Tetrachloride using Frequency Domain Technique

Gallium Complexation, Stability, and Bioconjugation of 1,4,7-Triazacyclononane Derived Chelators with Azaheterocyclic Arms

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