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Cuesta IG, De Merás AS, Pelloni S, Lazzeretti P. Understanding the ring current effects on magnetic shielding of hydrogen and carbon nuclei in naphthalene and anthracene. J Comput Chem 2009; 30:551-64. [DOI: 10.1002/jcc.21083] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Benzi C, Barone V, Tarroni R, Zannoni C. Order parameters of alpha,omega-diphenylpolyenes in a nematic liquid crystal from an integrated computational and 13C NMR spectroscopic approach. J Chem Phys 2006; 125:174904. [PMID: 17100476 DOI: 10.1063/1.2363994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The orientational order parameters and conformational behavior of five relatively large rodlike molecules, biphenyl, trans-stilbene, 1,3-diphenyl-butadiene, 1,3,5-diphenyl-hexatriene, and 1,3,5,7-diphenyl-octatetraene, dissolved in the thermotropic liquid crystal ZLI-1167, have been studied using an integrated approach combining (13)C NMR measurements and quantum mechanical computations of carbon chemical shift tensors. Besides biphenyl, the phenyl moiety of all structures has been found to have a high rotational mobility in the temperature range of the present experiments. The rank-two order parameter <P(2)> in the nematic phase is found to increase steadily from the shortest to the longest term of the series at any temperature within the nematic range. The molecular biaxiality order parameter <D(02) (2)> is found to be small and essentially constant with temperature, giving further support to the common assumption of effective uniaxiality for these probes.
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Affiliation(s)
- Caterina Benzi
- Dipartimento di Chimica, Università Federico II, Complesso Monte S. Angelo, Via Cintia, I-80126 Naples, Italy.
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Pavanello M, Mennucci B, Ferrarini A. Quantum-mechanical studies of NMR properties of solutes in liquid crystals: A new strategy to determine orientational order parameters. J Chem Phys 2005; 122:064906. [PMID: 15740407 DOI: 10.1063/1.1843812] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a quantum-mechanical method to calculate the tensorial NMR magnetic properties of molecules in liquid crystals. The method exploits a density functional description for the solute and the integral equation formalism version of the polarizable continuum model to include the effects of the dielectric anisotropy of the solvent on the wave function of the solute molecule and on its response to an applied magnetic field. Taking into account the dependence of the calculated molecular tensors on the solute orientation, we have derived the necessary expressions to relate such tensors to the spectral observables. These equations are then used to determine order parameters by calculating the nuclear shieldings of various solutes in the nematic ZLI-1167. Comparisons with experimental data of the same parameters are finally presented.
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Affiliation(s)
- Michele Pavanello
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, 56126 Pisa, Italy
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Benzi C, Cossi M, Barone V, Tarroni R, Zannoni C. A Combined Theoretical and Experimental Approach to Determining Order Parameters of Solutes in Liquid Crystals from 13C NMR Data. J Phys Chem B 2005; 109:2584-90. [PMID: 16851261 DOI: 10.1021/jp045908g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ordering properties of an anisotropic liquid crystal can be studied by recording 13C NMR spectra at different temperatures for a number of rigid solutes. The traditional difficulty in analyzing 13C data comes from the scarcity of experimental information about the carbon shielding tensors and from their limited transferability among different solutes. We show that these obstacles can be overcome by computing high-level ab initio shielding tensors, also including the solvent effects by the polarizable continuum model. The reliability of this combined approach is carefully verified, and the order parameters of several solutes are obtained by reanalyzing previously published spectra. The quality of the results is shown to be comparable to deuterium NMR without the need of isotopic substitution.
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Affiliation(s)
- Caterina Benzi
- Dipartimento di Chimica, Università Federico II, Complesso Monte S. Angelo, via Cintia, I-80126 Napoli, Italy
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di Matteo A, Ferrarini A. Effects of Induction Interactions on the Orientational Order of Solutes in Liquid Crystals. J Phys Chem B 2001. [DOI: 10.1021/jp0040805] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrea di Matteo
- Dipartimento di Chimica Fisica, Università di Padova, 2 via Loredan, 35131 Padova, Italy
| | - Alberta Ferrarini
- Dipartimento di Chimica Fisica, Università di Padova, 2 via Loredan, 35131 Padova, Italy
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di Matteo A, Ferrarini A, Moro GJ. Effects of Electrostatic Interactions on Orientational Order of Solutes in Liquid Crystals. J Phys Chem B 2000. [DOI: 10.1021/jp000891x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrea di Matteo
- Dipartimento di Chimica Fisica, Università di Padova 2 via Loredan, 35131 Padova, Italy
| | - Alberta Ferrarini
- Dipartimento di Chimica Fisica, Università di Padova 2 via Loredan, 35131 Padova, Italy
| | - Giorgio J. Moro
- Dipartimento di Chimica Fisica, Università di Padova 2 via Loredan, 35131 Padova, Italy
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Ligabue A, Pincelli U, Lazzeretti P, Zanasi R. Current Density Maps, Magnetizability, and Nuclear Magnetic Shielding Tensors for Anthracene, Phenanthrene, and Triphenylene. J Am Chem Soc 1999. [DOI: 10.1021/ja9900656] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea Ligabue
- Contribution from the Dipartimento di Chimica dell'Università di Modena, via G. Campi 183, 41100 Modena, Italy, and Dipartimento di Chimica, Università degli Studi di Salerno, via S. Allende, 84081 Baronissi (SA), Italy
| | - Ugo Pincelli
- Contribution from the Dipartimento di Chimica dell'Università di Modena, via G. Campi 183, 41100 Modena, Italy, and Dipartimento di Chimica, Università degli Studi di Salerno, via S. Allende, 84081 Baronissi (SA), Italy
| | - Paolo Lazzeretti
- Contribution from the Dipartimento di Chimica dell'Università di Modena, via G. Campi 183, 41100 Modena, Italy, and Dipartimento di Chimica, Università degli Studi di Salerno, via S. Allende, 84081 Baronissi (SA), Italy
| | - Riccardo Zanasi
- Contribution from the Dipartimento di Chimica dell'Università di Modena, via G. Campi 183, 41100 Modena, Italy, and Dipartimento di Chimica, Università degli Studi di Salerno, via S. Allende, 84081 Baronissi (SA), Italy
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Huang Z, Sandström D, Henriksson U, Maliniak A. Carbon-13 NMR Investigations of the Orientational Order in a Columnar Liquid Crystal. J Phys Chem B 1998. [DOI: 10.1021/jp981870u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhi Huang
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Physical Chemistry, The Royal Institute of Technology, S-100 44 Stockholm, Sweden
| | - Dick Sandström
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Physical Chemistry, The Royal Institute of Technology, S-100 44 Stockholm, Sweden
| | - Ulf Henriksson
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Physical Chemistry, The Royal Institute of Technology, S-100 44 Stockholm, Sweden
| | - Arnold Maliniak
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Physical Chemistry, The Royal Institute of Technology, S-100 44 Stockholm, Sweden
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Burnell EE, de Lange CA. Prediction from Molecular Shape of Solute Orientational Order in Liquid Crystals. Chem Rev 1998; 98:2359-2388. [PMID: 11848965 DOI: 10.1021/cr941159v] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. E. Burnell
- Laboratory for Physical Chemistry, University of Amsterdam, Nieuwe Achtergracht 127-129, 1018 WS Amsterdam, The Netherlands
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Berardi R, Spinozzi F, Zannoni C. A multitechnique maximum entropy approach to the determination of the orientation and conformation of flexible molecules in solution. J Chem Phys 1998. [DOI: 10.1063/1.476975] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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