Herring-bone π–π interactions in <i>trans</i>-2,6-diphenyl-2,3,5,6-tetrahydrothiapyran-4-one

Narasimhamurthy, T.; Benny, J. C. N.; Pandiarajan, K.; Rathore, R. S.

doi:10.1107/s0108270103019577

Cited by 13 publications

(18 citation statements)

References 3 publications

(1 reference statement)

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“…Some selected bond lengths, bond angles, and torsion angles, are given in Table 5. The intramolecular distances of the molecule are consistent with those published for similar compounds [17]. It is worth mentioning that the bond lengths C9-S17 = 1.836(3)Å and S17-C16 = 1.796(3)Å reflect the divalency of the sulfur atom.…”

Section: Crystal Structures Of 4b 4c and 5asupporting

confidence: 78%

Thermolysis of Some Spirobenzopyran-3’,2-[1,3,4]oxadithiino- [5,6-c]benzopyran-4’-ones in the Presence of Some Homodienes and Crystallographic Studies of Some Adducts

Hegab

Moustafa

2006

Zeitschrift Für Naturforschung B

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The very reactive α-oxo-thioketone derivatives 2a -d, generated via thermolysis of spirobenzopyran-3',2- [1,3,4]oxadithiino [5,6-c]benzopyran-4'-ones 1a -d, reacted with 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene under [4+2]-cycloaddition to afford spirobenzopyran-3',6-thiapyran-4'-one adducts 3a -d and spirobenzopyran-3',3-thiabicyclo[2.2.2]oct-5-en-4'-one adducts 4a -d, respectively. On the other hand, the reaction of α-oxo-thioketones 2a -d with isoprene afforded regioselectively only 3-methyl-thiapyran derivatives 5a -d. Single crystal X-ray diffraction studies of 4b, 4c, and 5a give a good support for the established structure.

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Section: Crystal Structures Of 4b 4c and 5asupporting

confidence: 78%

Thermolysis of Some Spirobenzopyran-3’,2-[1,3,4]oxadithiino- [5,6-c]benzopyran-4’-ones in the Presence of Some Homodienes and Crystallographic Studies of Some Adducts

Hegab

Moustafa

2006

Zeitschrift Für Naturforschung B

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“…The head‐to‐tail arrangement is of the zigzag type, as previously classified 45. Additionally, these molecules are linked together by π( p ‐iodo‐Phe) · · · π( p ‐iodo‐Phe) interactions,46, 47 giving rise to a network of π · · · π interactions similar to the herringbone type along the a axis46, 48 (Figure 4c). The calculated parameters, characterizing π · · · π interactions are provided in Table IV.…”

Section: Resultsmentioning

confidence: 64%

“…The calculated parameters, characterizing π · · · π interactions are provided in Table IV. The coexisting networks of (i) strong head‐to‐tail hydrogen bonds along the b axis and (ii) aromatic π · · · π interactions along the a axis is an exceptional feature since the hydrogen‐bond and π · · · π interactions have frequently been observed to have insulating nature, i.e., presence of one tend to exclude the other 46, 48…”

Section: Resultsmentioning

confidence: 99%

Conformational investigations on analogs of inflammation response inducing chemotactic tripeptide fMLP

Rathore

2005

Biopolymers

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Conformations of three analogs of for-L-Met-L-Leu-L-Phe-OH (fMLP), which initiates inflammatory response by interaction with the formyl peptide receptor (FPR), have been investigated by the application of the X-ray crystallographic technique. The investigated analogs of fMLP peptides are as follows: for-L-Met-1-amino-1-cyclooctane-carbonyl(Ac8c)-L-Phe-OMe; for-L-Met-L-Leu-L-p-iodo-Phe-OH; and for-L-Met-di-n-propylglycyl(Dpg)-L-Phe-OMe. The peptide backbone in and is constrained at position of fMLP by the introduction of Calpha,alpha-disubstituted glycines. In peptide, Phe-OMe is substituted by p-iodo-Phe-OH. Crystal structures reveal an overall folded conformation adopted by and. The former is folded in the type II beta-turn, which is stabilized by an intramolecular 1<--4 (formyl) C==O...H--N (Phe) hydrogen bond, whereas the latter is folded in an open turn without any intramolecular hydrogen bond. On the other hand, peptide has an extended conformation, and two different molecules in a crystallographic asymmetric unit form an antiparallel beta-sheet-like structure. In and, residues Ac8c and Dpg adopt left-handed helical and fully extended (C5) conformations, respectively. The cyclooctane ring in Ac8c acquires a boat-chair conformation. Crystal packing of is characterized by the association of aliphatic-aromatic rings via a C--H...pi interaction. In the crystal of, contrary to the usual observations, peptides are interlinked via networks of head-to-tail hydrogen bond and pi...pi interactions, which are generally observed to be mutually exclusive. The structure-function mechanism of the ligand-receptor interaction is discussed.

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“…Because in the case of biphenyl substituted polymer P5 has biplanarity of the biphenyl ring, Since the two phenyl rings are perpendicular to each other, the close packing of the chains through the higher p-p* interactions of two aromatic rings is allowed. 18 Polymer P4, which has dibenzyloxy substitution in the 3,5-positions of the pendant unit undergoes olefin C¼C decay to some extent slower than the biphenyl-substituted polymer P5. Generally, the formation of a cyclobutane ring as a result of photocrosslinking leads to bulk structure neighboring the backbone of the polymer chain and leads to a decrease in both the decay rate and photocrosslinking.…”

Section: Uv Spectral Studiesmentioning

confidence: 99%

Newly Synthesized Photocrosslinkable Liquid-Crystalline Polymers and their Properties

Kumar

Subramanian

2014

Photocured Materials

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This chapter deals with a hitherto unreported newer root of synthesis of photocrosslinkable polymers containing pendant chalcone moieties with different substituents. The main aim of present research work is to synthesis photocrosslinkable polymers containing pendant chalcone moiety that exhibits both liquid-crystalline and photocrosslinking properties. The polymers were synthesized with various substituents in their terminal position to pendant chalcone unit and acrylic unit. All the five polymers P1–P5 were synthesized by the free-radical polymerization method. The predetermined quantities of monomers were dissolved in THF solvent and AIBN was used as initiator. The polymerization was carried out under nitrogen (inert) atmosphere for 48 h. The number (Mn) and weight average (Mw) molecular weight of the polymers were obtained by the gel permeation chromatography (GPC) method. The thermogravimetric analysis (TGA) results indicate that the polymers show good thermal stability, since the phenyl group in the case of polymers P1, P2 and P4 gives better thermal and thermal oxidative stability required for a negative photoresists. Liquid-crystalline behavior of polymers were identified by DSC thermogram and confirmed by hot-stage polarized optical microscope images. Photocrosslinking behavior of all the polymers were investigated by UV-Vis spectroscopy, the cross linking of all the polymers proceed via cyclobutane ring formation during 2π+2π cycloaddition reaction on irradiation with 254-nm UV light. The surface morphology studies of both virgin and photocrosslinked polymers were investigated by scanning electron microscope (SEM) analysis. The photocrosslinked polymer sample confirms the loosely held dispersion of polymeric material, while virgin polymer exhibits compact stringent dispersion of the polymeric surface.

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Herring-bone π–π interactions in trans-2,6-diphenyl-2,3,5,6-tetrahydrothiapyran-4-one

Cited by 13 publications

References 3 publications

Thermolysis of Some Spirobenzopyran-3’,2-[1,3,4]oxadithiino- [5,6-c]benzopyran-4’-ones in the Presence of Some Homodienes and Crystallographic Studies of Some Adducts

Thermolysis of Some Spirobenzopyran-3’,2-[1,3,4]oxadithiino- [5,6-c]benzopyran-4’-ones in the Presence of Some Homodienes and Crystallographic Studies of Some Adducts

Conformational investigations on analogs of inflammation response inducing chemotactic tripeptide fMLP

Newly Synthesized Photocrosslinkable Liquid-Crystalline Polymers and their Properties

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