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Sahu S, Sharma A, Mishra AK. Multiparametric Sensing of Membrane Bilayer Properties with a Highly Environment-Susceptible Fluorophore. J Phys Chem B 2018; 122:7308-7318. [DOI: 10.1021/acs.jpcb.8b02140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Saugata Sahu
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Ashutosh Sharma
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Ashok Kumar Mishra
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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González-Rosende ME, Castillo E, Jennings WB, Malone JF. Stereodynamics and edge-to-face CH-π aromatic interactions in imino compounds containing heterocyclic rings. Org Biomol Chem 2017; 15:1484-1494. [PMID: 28116383 DOI: 10.1039/c6ob02618d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By comparison with close contact interactions between benzene rings there is a paucity of experimental data available for attractive interactions involving aromatic heterocyclic rings, especially for small molecules in solution. Herein we describe aromatic heterocyclic and carbocyclic edge-to face interactions and conformational stereodynamics of N-1,2-diphenylethyl imines bearing a phenyl group and either a 2-pyridyl, 3-pyridyl, 2-thiophene or 2-furanyl moiety on the imino carbon. X-ray crystal structures have been determined for two compounds. Slow rotation about the phenyl-imino bond in the E-isomers and around the heterocycle-imino bond in the Z-isomers of the pyridyl compounds was observed at low temperatures by NMR. Abnormally large shielding of one ortho hydrogen indicates that both the imino phenyl and heterocycle rings can engage in an edge-to-face interaction with the N-terminal phenyl moiety in the appropriate isomer. Some rotational barriers around the phenyl-imino and heterocycle-imino bonds were measured.
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Affiliation(s)
- M Eugenia González-Rosende
- Departamento de Farmacia, Universidad CEU Cardenal Herrera, Avda. Seminario s/n, 46113, Moncada, Valencia, Spain.
| | - Encarna Castillo
- Departamento de Farmacia, Universidad CEU Cardenal Herrera, Avda. Seminario s/n, 46113, Moncada, Valencia, Spain.
| | - W Brian Jennings
- Department of Chemistry and Analytical & Biological Chemistry Research Facility, University College Cork, Cork, Ireland.
| | - John F Malone
- School of Chemistry & Chemical Engineering, The Queen's University of Belfast, Belfast BT9 5AG, UK
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Rajeswari K, Pandiarajan K. 1H and 13C NMR spectral study of some 3,5-bis[(E)-thienylmethylene]piperidin-4-ones. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1110-1118. [PMID: 21233008 DOI: 10.1016/j.saa.2010.12.062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Revised: 12/12/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
(1)H and (13)C NMR spectra have been recorded for 3,5-bis[(E)-thienylmethylene]piperidin-4-one (1a), 3',3″-dimethyl-3,5-bis[(E)-thienylmethylene]piperidin-4-one (1b), 5',5″-dibromo-3,5-bis[(E)-thienylmethylene]piperidin-4-one (1c), their 1-methyl derivatives 2a-c and 3,5-bis[(E)-thienylmethylene]-2r,6c-diphenylpiperidin-4-one (3a). For selected compounds 2D spectra have been recorded. The spectral data are used to study the configuration and conformation of these molecules. The chemical shifts are discussed in light of steric, electronic and magnetic anisotropic effects. The magnetic anisotropic effects of thiophene ring and phenyl group are noteworthy. (1)H-(1)H COSY spectrum of 2b suggests that long-range (1)H-(1)H coupling, up to seven bonds, is possible in it. HMBC spectrum of 2b displays the magnetic nonequivalence of C-2 and C-6 and protons at these carbons.
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Affiliation(s)
- K Rajeswari
- Department of Chemistry, Annamalai University, Annamalainagar, Chidhambaram, Tamil Nadu, India
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Rhyman L, Abdallah HH, Ramasami P. Quantum mechanical study of the syn-anti isomerisation of 2-tellurophenecarboaldehyde: vive la différence. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:258-263. [PMID: 21055998 DOI: 10.1016/j.saa.2010.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 08/23/2010] [Accepted: 10/01/2010] [Indexed: 05/30/2023]
Abstract
The syn- and anti-conformers of 2-tellurophenecarboaldehyde are studied in the gas phase. A transition state is also modelled for the syn-anti isomerisation. Computations are done using different methods namely HF, DFT/B3LYP, MP2 and CCSD(T). The basis set used for all atoms is 6-311++G(d,p) except that LanL2DZ ECP is used for tellurium atom only. The optimised molecular structures and related structural parameters of these conformers are reported. The energy differences between the syn- and anti-conformers, associated rotational barriers and thermodynamic parameters are derived from the computations. The infrared frequencies of these conformers are also reported with appropriate assignments. This study is extended to include solvent effect and the conformers are fully optimised (DFT/B3LYP) using the integral equation formalism in the Polarisable Continuum model. In the gas phase, the theoretical rate constant for the unimolecular conversion, anti conformer to transition state, is reported for the first time; DFT/B3LYP (4.82×10(30) s(-1)) and MP2 (7.81×10(30) s(-1)). It is found that the structures are not much affected by the solvents but energy difference increases and rotational barrier decreases. The results indicate that there is a close agreement with the predictions from the different theoretical methods. The results obtained are critically analysed and compared with the furan, thiophene and selenophene analogues. A major factor affecting conformational preference and the mole fraction is the charge on the chalcogen heteroatom in the ring. An interesting outcome of this work is that in both the gas phase and solutions, the syn conformer is more stable and exists almost exclusively.
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Affiliation(s)
- L Rhyman
- Department of Chemistry, University of Mauritius, Réduit, Mauritius
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Potgieter K, Mayer P, Hosten E, Gerber TIA. 2-[5-(Benzo[d]thia-zol-2-yl)thio-phen-2-yl]benzo[d]thia-zole. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o531. [PMID: 21580303 PMCID: PMC2983588 DOI: 10.1107/s1600536810004009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 02/01/2010] [Indexed: 05/30/2023]
Abstract
The structure of the title compound, C(18)H(10)N(2)S(3), consists of a central thio-phene ring and two terminal thia-zole rings. The two S atoms of the thia-zole rings are trans to the thio-phene S atom sulfur. The thia-zole rings are approximately coplanar with the thio-phene ring, with dihedral angles of 6.23 (11) and 4.81 (11)° between them. In the crystal, zigzag chains are formed along [010] by weak C-H⋯N inter-actions.
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Affiliation(s)
- Kim Potgieter
- Department of Chemistry, Nelson Mandela Metropolitan University, 6031 Port Elizabeth, South Africa
| | - Peter Mayer
- Department of Chemistry, Ludiwig-Maximilians University, D-81377 München, Germany
| | - Eric Hosten
- Department of Chemistry, Nelson Mandela Metropolitan University, 6031 Port Elizabeth, South Africa
| | - Thomas I. A. Gerber
- Department of Chemistry, Nelson Mandela Metropolitan University, 6031 Port Elizabeth, South Africa
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Theoretical study of 2-selenophenecarboaldehyde in the gas and solution phases: Rotational barrier, energy difference and thermodynamic parameters. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.04.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Katritzky AR, Akhmedov NG, Doskocz J, Mohapatra PP, Hall CD, Güven A. NMR spectra, GIAO and charge density calculations of five-membered aromatic heterocycles. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45:532-43. [PMID: 17534885 DOI: 10.1002/mrc.1967] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The B3LYP/6-31+G(d) molecular geometry optimized structures of 17 five-membered heterocycles were employed together with the gauge including atomic orbitals (GIAO) density functional theory (DFT) method at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p) and B3LYP/6-311+G(2d,p) levels of theory for the calculation of proton and carbon chemicals shifts and coupling constants. The method of geometry optimization for pyrrole (1), N-methylpyrrole (2) and thiophene (7) using the larger 6-311++G(d,p) basis sets at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p), B3LYP/6-31+G(2d,p) and B3LYP/cc-pVTZ levels of theory gave little difference between calculated and experimental values of coupling constants. In general, the (1)H and 13C chemical shifts for all compounds are in good agreement with theoretical calculations using the smaller 6-31 basis set. The values of nJHH(n=3, 4, 5) and rmnJ(CH)(n=1, 2, 3, 4) were predicted well using the larger 6-31+G(d,p) and 6-311++G(d,p) basis sets and at the B3LYP/6-31+G(d,p), B3LYP/6-311++G(d,p), B3LYP/6-31+G(2d,2p) levels of theory. The computed atomic charges [Mülliken; Natural Bond Orbital Analysis (NBO); Merz-Kollman (MK); CHELP and CHELPG] for the B3LYP/6-311++G(d,p) geometry optimized structures of 1-17 were used to explore correlations with the experimental proton and carbon chemical shifts.
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Affiliation(s)
- Alan R Katritzky
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
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Tung JY, Chen JH. Electrostatic forces that determine O,O-trans versus O,S-cis conformers in the aminated porphyrin complexes of Cd(N-NHCO-2-C4H3O-tpp)(OAc) and Cd(N-NHCO-2-C4H3S-tpp)(OAc). Polyhedron 2007. [DOI: 10.1016/j.poly.2006.08.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rivelino R, Coutinho K, Canuto S. A Monte Carlo-Quantum Mechanics Study of the Solvent-Induced Spectral Shift and the Specific Role of Hydrogen Bonds in the Conformational Equilibrium of Furfural in Water. J Phys Chem B 2002. [DOI: 10.1021/jp026318q] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roberto Rivelino
- Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP, Brazil
| | - Kaline Coutinho
- CIIB, Universidade de Mogi das Cruzes, CP 411, 08701-970 Mogi das Cruzes, SP, Brazil
| | - Sylvio Canuto
- Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, SP, Brazil
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Baldridge KK, Jonas V, Bain AD. Ground state gas and solution phase conformational dynamics of polar processes: Furfural systems. J Chem Phys 2000. [DOI: 10.1063/1.1313790] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Contreras R, de Azúa M, Giribet C, Aucar G, de Bonczok R. Viewpoint 8 — polarization propagator analysis of spin-spin coupling constants. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0166-1280(93)87009-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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The Conformations of Acyl Groups in Heterocyclic Compounds. ADVANCES IN HETEROCYCLIC CHEMISTRY 1987. [DOI: 10.1016/s0065-2725(08)60161-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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