Organometallic molecular modelling - the computational chemistry of metallocenes: a review

Fey, Natalie

doi:10.1002/(sici)1097-4660(199909)74:9<852::aid-jctb131>3.0.co;2-t

Cited by 40 publications

(41 citation statements)

References 49 publications

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“…The main interactions which stabilize the titanocene / cyclodextrin complex in vacuum were bond stretching energy, the angle bending energy, the torsional energy, and the energy arising from van der Waals interactions of non-bonded pairs of atoms. Due to the fact that all titanocene compounds from the studied series are chemically similar molecules, we have an internal consistency from the force field point of view [15,40-49]. …”

Section: Resultsmentioning

confidence: 99%

“…These problems could be resolved in two ways: synthetically modifying the titanocene structure (laborious, other physico-chemical and biological analyses needed) or finding new formulations with enhanced properties [11,13,15,19,24-27]. Natural or chemically modified cyclodextrins (cyclic oligosaccharides with hydrophobic inner cavities and hydrosolubilizing outer groups) are widely used for protection, enhancing water solubility, and controlled release properties of bioactive compounds [28-34].…”

Section: Introductionmentioning

confidence: 99%

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Titanocene / cyclodextrin supramolecular systems: a theoretical approach

Riviş

Hădărugă

Gârban

et al. 2012

Chemistry Central Journal

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BackgroundRecently, various metallocenes were synthesized and analyzed by biological activity point of view (such as antiproliferative properties): ruthenocenes, cobaltoceniums, titanocenes, zirconocenes, vanadocenes, niobocenes, molibdocenes etc. Two main disadvantages of metallocenes are the poor hydrosolubility and the hydrolytic instability. These problems could be resolved in two ways: synthetically modifying the structure or finding new formulations with enhanced properties. The aqueous solubility of metallocenes with cytostatic activities could be enhanced by molecular encapsulation in cyclodextrins, as well as the hydrolytic instability of these compounds could be reduced.ResultsThis study presents a theoretical approach on the nanoencapsulation of a series of titanocenes with cytotoxic activity in α-, β-, and γ-cyclodextrin. The HyperChem 5.11 package was used for building and molecular modelling of titanocene and cyclodextrin structures, as well as for titanocene/cyclodextrin complex optimization. For titanocene/cyclodextrin complex optimization experiments, the titanocene and cyclodextrin structures in minimal energy conformations were set up at various distances and positions between molecules (molecular mechanics functionality, MM+). The best interaction between titanocene structures and cyclodextrins was obtained in the case of β- and γ-cyclodextrin, having the hydrophobic moieties oriented to the secondary face of cyclodextrin. The hydrophobicity of titanocenes (logP) correlate with the titanocene-cyclodextrin interaction parameters, especially with the titanocene-cyclodextrin interaction energy; the compatible geometry and the interaction energy denote that the titanocene/β- and γ-cyclodextrin complex can be achieved. Valuable quantitative structure-activity relationships (QSARs) were also obtained in the titanocene class by using the same logP as the main parameter for the in vitro cytotoxic activity against HeLa, K562, and Fem-x cell lines.ConclusionsAccording to our theoretical study, the titanocene/cyclodextrin inclusion compounds can be obtained (high interaction energy; the encapsulation is energetically favourable). Further, the most hydrophobic compounds are better encapsulated in β- and γ-cyclodextrin molecules and are more stable (from energetically point of view) in comparison with α-cyclodextrin case. This study suggests that the titanocene / β- and γ-cyclodextrin complexes (or synthetically modified cyclodextrins with higher water solubility) could be experimentally synthesized and could have enhanced cytotoxic activity and even lower toxicity.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Titanocene / cyclodextrin supramolecular systems: a theoretical approach

Riviş

Hădărugă

Gârban

et al. 2012

Chemistry Central Journal

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“…A review [26] of the computational chemistry of metallocenes investigated the application of ab initio and DFT methods to the modelling of transition-metal complexes and in particular ferrocene. It concluded that, in general, DFT methods could reproduce geometries for transition-metal complexes much more accurately than MP2 calculations.…”

Section: Resultsmentioning

confidence: 99%

“…The success of the refinement, for which R G = 0.059 (R D = 0.043), can be gauged on the basis of the radialdistribution and experimental -theoretical difference \P-C ring -P 120.3(4) 120.5 -p 26 \C ring -P-P 99.6(2) 99.3 -a Refers to B3PW91/aug-cc-pVQZ-PP/6-311+G*. b Distances (r) are in pm, angles (\) and torsional angles (/) in°.…”

Section: Resultsmentioning

confidence: 99%

The molecular structure of using gas-phase electron diffraction and ab initio and DFT calculations

Wann

Hinchley

Robertson

et al. 2007

Journal of Organometallic Chemistry

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“…Cyclopentadiene (Cp) is the most commonly used reagent for the synthesis of many metallocenes which contains transition metals and their derivatives on the account of the wide range of their applications [14][15][16] and it is one of the versatile ligands in organometallic chemistry [17]. Since the discovery of ferrocene [18,19], the Cp chemistry of the main-group elements (s-and p-block elements) has experienced great progress, especially for last two decades [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Probing the selective separation of potassium ion from sodium ion with cyclopentadienyl anion as receptor: a computational study

Desai

2015

J Mol Model

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A systematic computational study has been carried out using post-Hartree-Fock and density functional theory methods on half sandwich (M-Cp), sandwich (Cp-M-Cp), inversed sandwich (M-Cp-M), and multi-decker chain complexes of alkali metal ions (Na(+), and K(+)). The binding affinity of cyclopentadienyl anion (Cp) with K(+) and Na(+) ions has been studied in half sandwich, sandwich, inversed sandwich, and multi-decker chain complexes. These complexes have been examined in the aqueous phase. The calculated results show that Cp anion can preferentially bind with Na(+) ion over K(+) ion in aqueous phase. The results obtained from DFT calculations have been compared with the crystal structures of Cp-Na and Cp-K complexes. The Bader's atoms in molecule (AIM) analysis were performed to characterize the non-covalent cation-π interactions in the Cp-M complexes. The calculated electron density at cage critical point indicates the strength of the Cp-M complexes. Energy decomposition analysis (EDA) has also been performed to investigate the origins of these interactions. The electrostatic interaction contributes significantly to the total interaction energy in Cp-M complexes. The relative stability difference of cyclopentadienyl anion (Cp) with K(+) and Na(+) ions in aqueous phase can be exploited for the separations from mixture such as sea bittern. The lower stability of K-Cp complex can induce to precipitate the K(+) ions more easily than the corresponding Na(+) ions. Graphical Abstract Potassium ion from sodium ion with cyclopentadienyl anion as receptor.

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Organometallic molecular modelling - the computational chemistry of metallocenes: a review

Cited by 40 publications

References 49 publications

Titanocene / cyclodextrin supramolecular systems: a theoretical approach

Titanocene / cyclodextrin supramolecular systems: a theoretical approach

The molecular structure of using gas-phase electron diffraction and ab initio and DFT calculations

Probing the selective separation of potassium ion from sodium ion with cyclopentadienyl anion as receptor: a computational study

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