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Molecular Geometry as a Source of chemical Information. Part I: How H-Bonding Modifies Molecular Structure in the Vicinity of Hydrogen Donating Group. The Case of Phenol Derivatives Interacting with Nitrogen and Oxygen Bases

Szatyłowicz H., Krygowski T.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 9

1719-1731

EN

Analysis of geometrical patterns of 635 variously substituted phenols in H-bonding complexes with bases revealed that C1O, C1C2, C1C6 bond lengths as well as ipso bond angle change regularly with variation of the acidity (pKa) of phenols. The Bent-Walsh rule is fulfilled and the approximate linear dependence between the above mentioned geometry parameters works. The perturbation in the OH group, due to H-bonding, is transmitted even on further fragments of the ring. DFT modelling at the B3LYP/6-311+G** level of theory for the simplest cases illustrate nicely the conclusion derived for variously substituted systems.

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Changes in Aromaticity in the Ring of Monosubstituted Benzene Derivatives

Krygowski T., Stępień B.

Polish Journal of Chemistry

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2004

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Vol.78 /nr 11-12

2213-2217

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Free Energy Contribution Due to the Specific Solvation of Anions. A Comparison of "Pure" Acidity Solvent Scales

Jaworski J., Krygowski T.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 2

221-225

EN

Four "pure" acidity solvent parameters (i.e. assumed to be free from non-specific solvation) proposed in the literature on quite different basis: E of Koppel and Palm [1], EN of Krygowski et al. [2], _ of Taft and Kamlet [3,4] and SAof Catalán and Díaz [5] gave the same contribution of the specific solvation of chloride ion to its standard molar free energy of transfer between a given solvent and water, as expected for "pure" scales.

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Angular Group Induced Bond Alternation (AGIBA). Part VIII. Crystal and Molecular Structure of 2,3,6,7-Tetrahydro-1H,5H-pyrido{3,2,1-ij]quinoline-9-carbaldehyde(E,E)-azine. A Competition Between the AGIBA and the Through Resonance Effects

Krygowski T., Findebka E., Anulewicz-Ostrowska R., Nowacki J.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 9

1249-1254

EN

Low temperature (100 K) X-ray diffraction study of 2,3,6,7-tetrahydro-1H,5H-pyrido[ 3,2,1-ij]quinoline-9-carbaldehyde(E,E)-azine provided the molecular geometry allowing to study a competition between the AGIBA and through resonance effects. The simplified derivatives, for which geometry was obtained by optimization at B3LYP/6- 311G** level of theory, supported the results for the title compound and the conclusion that the AGIBA effect and the through resonance may exist simultaneously in systems with appropriate substituents.

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Angular Group Induced Bond Alternation (AGIBA). Part VII. The Case of a Branched Substituent - the Carboxylic Group

Krygowski T., Pindelska E.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 2-3

325-329

EN

Angular groups attached to aromatic rings cause an increase of the double bond localization, called Angular Group Induced Bond Alternation (AGIBA). The effect for the groups with single bonds, X-Y, increases the double bond character of the cis CC bond in the ring, whereas the groups with double bonds, X=Y, work in the opposite way. The group with a branched structure, like the carboxylic one, should exhibit an enhancement of the AGIBA effect. Analyses of 61 geometries for p-substituted derivatives of benzoic acid, as well as of the geometry of benzoic acid optimized at B3LYP/6-311G** level of theory, show that there is no cooperative effect in this kind of substituent.

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An Empirical Estimation of the Interactions H delta+...Cl-. The Crystal and Molecular Structure of the 1-Methyl-2-tert-butylamino-4-isopropyl-5(4H)-imidazolone hydrochloride

Krygowski T., Grabowski S. J., Anulewlcz-Ostrowska R., Izdebski J., Fiertek D.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 1

129-135

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Furo[2,3-b]pyrrole Derivatives : Syntheses and Reactions in the Furan and Pyrrole Ring

Sleziak R., Krutosikova A., Cyrański M., Krygowski T.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 2

207-217

EN

6-Substitued furo[2,3-b] pyrrole-5-carboxylic acids 2b-d as well as their 2-formyl-substitued derivatives 4a-d have been prepared by alkaline hydrolysis of the corresponding esters 1b-d and 3a-d, respectively. A different behaviour of methyl 6H-furo[2,3-b]pyrrole-5-carboxylate 1a in comparison with the 4Hfuro[3,2-b] pyrrole isomer has been discussed in a framework of different acidity of proton of NH group. The hypothesis has been supported by ab initio B3LYP/6-311+G**DTF calculations. The 2-formylated derivatives 3b-d were used for synthesis the propenoid acids 5b-d, the corresponding acid azides 6b-d, new disubstitued ureas 9 or 10, 2-cyano-derivatives 11a-d, which were transfored into the corresponding amidines 12 and substitued arylureas 13 as well as to 5'-tetrazolyl derivative 14. Further methyl 2-triphenylmethyl-6Hfuro[2,3-b]pyrrole-5-carboxylate 15 and its Michael addition product 16 were prepared.

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Crystal and molecular structure of 3-(2,4,6-trimethyl-phenyl)-8-phenyl-oxo-1,7-dioxa-2-azaspiro[4,4]non-2-ene

Anulewicz-Ostrowska R., Piętka E., Krygowski T., Micuch P., Fisera L.

Polish Journal of Chemistry

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1999

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vol. 73 nr 4

727-733

EN

Crystal and molecular structure of 3-(2,4,6-Trimethylphenyl)-8-phenyl-oxo-1,7-dioxa-2-azaspiro[4,4]non-2-ene has been determined by X-ray diffraction technique. Crystal data for C21H21NO3: monoclinic, C2/c, a=20.969(4) A, b=10.319(2) A, c=16.601(3) A, b=97.5(3)0, Z=8, R=0.0658 for 3477 reflections. Contrary to the solution, in the crystalline state only one conformer exists.

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Crystal and Molecular Structure of 1,3,5-Trimethoxy-2,4,6-trinitrobenzene : Mesomeric Effects for Out-of-plane Twisted Substituents

Anulewicz-Ostrowska R., Krygowski T., Cyrański M., Matuszewska M.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 11

1895-1901