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Pregled bibliografske jedinice broj: 646155

The Effect of Specific Solvent-Solute Interactions on Complexation of Alkali-Metal Cations by a Lower-Rim Calix[4]arene Amide Derivative


Horvat, Gordan; Stilinović, Vladimir; Kaitner, Branko; Frkanec, Leo; Tomišić, Vladislav
The Effect of Specific Solvent-Solute Interactions on Complexation of Alkali-Metal Cations by a Lower-Rim Calix[4]arene Amide Derivative // Inorganic chemistry, 52 (2013), 21; 12702-12712 doi:10.1021/ic4019184 (međunarodna recenzija, članak, znanstveni)


Naslov
The Effect of Specific Solvent-Solute Interactions on Complexation of Alkali-Metal Cations by a Lower-Rim Calix[4]arene Amide Derivative

Autori
Horvat, Gordan ; Stilinović, Vladimir ; Kaitner, Branko ; Frkanec, Leo ; Tomišić, Vladislav

Izvornik
Inorganic chemistry (0020-1669) 52 (2013), 21; 12702-12712

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Calixarenes; cations; supramolecular chemistry; solvation; structure elucidation; molecular dynamics

Sažetak
Complexation of alkali-metal cations with calix[4]arene secondary-amide derivative, namely 5, 11, 17, 23-tetra(tert-butyl)-25, 26, 27, 28- tetra(N- hexylcarbamoylmethoxy)calix[4]arene (L) in benzonitrile (PhCN) and methanol (MeOH) was studied by means of microcalorimetry, UV and NMR spectroscopies, and in the solid state by X-ray crystallography. The inclusion of solvent molecules (including acetonitrile, MeCN) in the calixarene hydrophobic cavity was also investigated. The classical molecular dynamics (MD) simulations of the systems studied were carried out. By combining the results obtained using the mentioned experimental and computational techniques, an attempt was made to get as detailed insight into the complexation reactions as possible. The thermodynamic parameters, i.e. equilibrium constants, reaction Gibbs energies, enthalpies and entropies, of the investigated processes were determined and discussed. The stability constants of the 1:1 (metal:ligand) complexes measured by different methods were in very good agreement. Solution Gibbs energies of the ligand and its complexes with Na+ and K+ in methanol and acetonitrile were determined. It was established that from the thermodynamic point of view, apart from cation solvation, the most important reason for the huge difference in the stability of these complexes in the two solvents lay in the fact that the transfer of complex species from MeOH to MeCN was quite favorable. That could be at least partly explained by a more exergonic inclusion of the solvent molecule in the complexed calixarene cone in MeCN as compared to MeOH, which was supported by MD simulations. Molecular and crystal structures of the lithium cation complex of L with the benzonitrile molecule bound in the hydrophobic calixarene cavity were determined by single-crystal X-ray diffraction. As far as we are aware, for the first time the alkali-metal cation was found to be coordinated by the solvent nitrile group in a calixarene adduct. According to the results of MD simulations, the probability of such orientation of the benzonitrile molecule included in the ligand cone was by far the largest in the case of LiL+ complex. Owing to the favorable PhCN–Li+ interaction L was proven to have the highest affinity towards the lithium ion in benzonitrile, which was not the case in the other solvents examined (in acetonitrile sodium complex was the most stable, whereas in methanol complexation of lithium was not even observed). That could serve as a remarkable example showing the importance of specific solvent–solute interactions in determining the equilibrium in solution.

Izvorni jezik
Engleski

Znanstvena područja
Kemija



POVEZANOST RADA


Projekt / tema
098-0982904-2912 - Samo-udruživanje u gelovima i sinteza funkcionalnih hibridnih materijala (Leo Frkanec, )
119-1191342-2960 - Elektroliti i koordinacijske reakcije u otopini (Vladislav Tomišić, )
119-1193079-3069 - Novi organski i koordinacijski spojevi - sinteza i suodnos struktura-svojstvo (Branko Kaitner, )

Ustanove
Institut "Ruđer Bošković", Zagreb,
Prirodoslovno-matematički fakultet, Zagreb

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus
  • MEDLINE


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