0000000001301480
AUTHOR
Anna Zakrzewska
Tuning the Electronic Properties of the Dative N-B Bond with Associated O-B Interaction: Electron Localizability Indicator from X-Ray Wavefunction Refinement.
Despite the immense growth in interest in difluoroborate dyes, the nature of the interactions of the boron atom within the N-BF2 -O kernel is not yet fully understood. Herein, a set of real-space bonding indicators is used to quantify the electronic characteristics of the dative N-B bond in difluoroborate derivatives. The atoms-in-molecules (AIM) partitioning scheme is complemented by the electron localizability indicator (ELI-D) approach, and both were applied to experimental and theoretical electron-density distributions (X-ray constrained wavefunction fitting vs. DFT calculations). Additionally, Fermi orbital analysis was introduced for small DFT models to support and extend the findings…
Influence of Substituent and Benzoannulation on Photophysical Properties of 1-Benzoylmethyleneisoquinoline Difluoroborates
A series of 1-benzoylmethyleneisoquinoline difluoroborates were synthesized, and their photophysical properties were determined. The effect of the substituent and benzoannulation on their properties was investigated to make a comparison with recently published results focused on related quinolines. The photophysical properties of isoquinoline derivatives differ from those of quinolines, and the most pronounced differences are found for the fluorescence quantum yields. Both experimental and theoretical approaches were used to explain the observed photophysical properties.
ChemInform Abstract: 4-Fluoroanilines: Synthesis and Decomposition.
Abstract Fourteen N- and/or 2-substituted 4-fluoroanilines were prepared (the series includes N–C2-bridged compounds). Some of them were found to be thermally unstable when dissolved in chloroform. Both 19 F NMR spectra and comparison of GIAO-DFT calculated and experimental 13 C chemical shifts were used to suggest decomposition products of 4-fluoroanilines.
2-Methyl-4-phenyl-3,4-dihydroquinazoline
The title compound, C15H14N2, was formed during the lithiation of 2-methylquinazoline with phenyllithium followed by hydrolysis of the intermediate lithium 2-methyl-4-phenyl-4H-quinazolin-3-ide. NMR spectra as well as single-crystal X-ray structural data indicate that the reaction product to have the same structure in chloroform solution as in the crystalline state. The phenyl substituent is twisted out of the plane of the 3,4-dihydroquinazoline ring system by 86.47 (7)°. In the crystal, intermolecular N—H...N interactions connect the molecules into infinite chains.
2,2-Difluoro-3-(4-fluorophenyl)-2H-benzo[e][1,3,2]oxazaborinin-3-ium-2-uide
There is one independent molecule in the asymmetric unit of the title compound, C13H9BF3NO, which crystallizes in the non-centrosymmetric space groupCc. In the molecular structure, the BF2-carrying ring is distorted from planarity and its mean plane makes a dihedral angle of 42.3 (1)° with the 4-fluorophenyl ring. F atoms are involved in all of the short intermolecular contacts of the crystal structure, which link molecules to form chains along [001] and [010].
Substituent Effect in 2-Benzoylmethylenequinoline Difluoroborates Exhibiting Through-Space Couplings. Multinuclear Magnetic Resonance, X-ray Diffraction, and Computational Study
The series of nine 2-benzoylmethylenequinoline difluoroborates have been synthesized and characterized by multinuclear magnetic resonance, X-ray diffraction (XRD), and computational methods. The through-space spin-spin couplings between (19)F and (1)H/(13)C nuclei have been observed in solution. The NMR chemical shifts have been correlated to the Hammett substituent constants. The crystal structures of six compounds have been solved by XRD. For two derivatives the X-ray wave function refinement was performed to evaluate the character of bonds in the NBF(2)O moiety by topological and integrated bond descriptors.
4-Fluoroanilines: synthesis and decomposition
Abstract Fourteen N- and/or 2-substituted 4-fluoroanilines were prepared (the series includes N–C2-bridged compounds). Some of them were found to be thermally unstable when dissolved in chloroform. Both 19 F NMR spectra and comparison of GIAO-DFT calculated and experimental 13 C chemical shifts were used to suggest decomposition products of 4-fluoroanilines.
13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines
Abstract: Chemical shifts of the para carbon atoms, δ(13C-4), in a series of aromatic amines were used to calculate the Ãp, ÃR and ÃOR substituent constants for different amino groups. 1-Pyrrolidino, N,N-di-n-butylamino and N,N-diethylamino groups were found to be the most strong electron-donors. ortho-Substitution decreases the donor properties of the amino group. The amino groups in 2,6-di-i-propylaniline and N,N-2,6-tetramethylaniline have very weak electron-donor properties. The nitrogen atom in benzoquinuclidine and N,N-dimethyl-2,6-di-i-propylaniline have an electron-acceptor character. The calculated substituent constants of the amino groups studied are consistent with the s…
Substituent effects on the photophysical properties of fluorescent 2-benzoylmethylenequinoline difluoroboranes: A combined experimental and quantum chemical study
Abstract In this study, we demonstrate a successful synergy between theory and experiment and report on the photophysical properties of a recently synthesized series of substituted 2-benzoylmethylenequinoline difluoroboranes with a view towards the effect of substitution on their properties. In general difluoroboranes are known to have a bright fluorescence but for some analogs the properties are not fully understood. Quantum chemistry methods have been applied in order to explain a complex structure of the absorption and emission spectra and to gain an insight into the charge redistribution upon the excitation of the investigated molecules. We demonstrate that the spectra of this important…
CCDC 901286: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
CCDC 1014209: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
CCDC 1014211: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
CCDC 901285: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
CCDC 1014210: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
CCDC 1014212: Experimental Crystal Structure Determination
Related Article: Anna Zakrzewska, Erkki Kolehmainen, Arto Valkonen, Esa Haapaniemi, Kari Rissanen, Lilianna Chęcińska, and Borys Ośmiałowski|2013|J.Phys.Chem.A|117|252|doi:10.1021/jp311072q
2-Methyl-4-phenyl-3,4-dihydroquinazoline
The title compound, C15H14N2, was formed during the lithiation of 2-methylquinazoline with phenyllithium followed by hydrolysis of the intermediate lithium 2-methyl-4-phenyl-4H-quinazolin-3-ide. NMR spectra as well as single-crystal X-ray structural data indicate that the reaction product to have the same structure in chloroform solution as in the crystalline state. The phenyl substituent is twisted out of the plane of the 3,4-dihydroquinazoline ring system by 86.47 (7)°. In the crystal, intermolecular N-HN interactions connect the molecules into infinite chains. peerReviewed