Photoexcitations in Oligothiophenes: The Role of Conformation Mobility and Intermolecular Interactions.

1999 ◽  
Vol 598 ◽  
Author(s):  
Chiara Botta ◽  
Silvia Destri ◽  
William Porzio ◽  
Gianni Bongiovanni ◽  
Andrea Mura ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Intermolecular Interactions ◽  
Photophysical Properties ◽  
Supramolecular Organization ◽  
Relaxation Processes ◽  
Chain Packing ◽  
Backbone Conformation ◽  
Packing Arrangement

ABSTRACTThe optical properties of substituted and unsubstituted oligothiophenes are analysed with respect to their supramolecular organization in the solid state. The spectra typical of the isolated molecules are obtained by reducing the intermolecular interactions by both lateral chain substitution and by inclusion in a host organic crystal. The photophysical properties of the weakly interacting oligothiophenes are strongly influenced by their backbone conformation and conformational mobility. Oligomers included in the channels of a guest crystal show fast torsional relaxation processes during the photoexcitation. Powders of β-substituted oligomers display optical properties dependent on the conformation of their particular chain packing arrangement.

Exploring the Relationship between Intermolecular Interactions and Solid-State Photophysical Properties of Organic Co-Crystals

2018 ◽  
Vol 123 (14) ◽  
pp. 9311-9322 ◽  
Author(s):  
Rohit Bhowal ◽  
Suprakash Biswas ◽  
Athulbabu Thumbarathil ◽  
Apurba L. Koner ◽  
Deepak Chopra
Keyword(s):  
Solid State ◽  
Intermolecular Interactions ◽  
Photophysical Properties ◽  
The Relationship

The Role of Intermolecular Interactions in Solid State Fluorescent Conjugated Polymer Chemosensors

2011 ◽  
Vol 22 (2) ◽  
pp. 583-589 ◽  
Author(s):  
Sherryllene S. Pinnock ◽  
Catherine N. Malele ◽  
Justin Che ◽  
Wayne E. Jones
Keyword(s):  
Solid State ◽  
Intermolecular Interactions ◽  
Conjugated Polymer

The design of new photochromic polymers incorporating covalently or ionically linked spiropyran/polyoxometalate hybrids

2017 ◽  
Vol 5 (25) ◽  
pp. 6343-6351 ◽  
Author(s):  
Irene Bazzan ◽  
Patricia Bolle ◽  
Olivier Oms ◽  
Hanène Salmi ◽  
Nadine Aubry-Barroca ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Photochromic Polymers ◽  
Grafting Onto

Novel photochromic polymers highlight through their solid-state optical properties the key role of grafting onto the coloration and fading kinetics.

The Role of Metallurgical Solid State Phase Transformations on the Formation of Residual Stress in Laser Cladding and Heating

2014 ◽  
Vol 777 ◽  
pp. 19-24 ◽  
Author(s):  
Ryan Cottam ◽  
Vladimir Luzin ◽  
Kevin Thorogood ◽  
Yat C. Wong ◽  
Milan Brandt
Keyword(s):  
Residual Stress ◽  
Solid State ◽  
Phase Transformations ◽  
Contour Method ◽  
Second Phase ◽  
Heating And Cooling ◽  
Second Phase Particles ◽  
The Matrix ◽  
Packing Arrangement

There are two major types of solid state phase transformations in metallic materials; the formation of second phase particles during heat treatments, and the transformation of the matrix from one crystalline packing arrangement to another during either heating or cooling. These transformations change the spacing between adjacent atoms and can thus influence the residual stress levels formed. The heating and cooling cycles of materials processing operations using lasers such as cladding and melting/heating, can induce phase transformations depending on the character of the material being processed. This paper compares the effects of the different phase transformations and also the influence of the type of laser processing on the final residual stress formed. The comparisons are made between laser clad AA7075, laser clad Ti-6Al-4V and laser melted nickel-aluminium bronze using neutron diffraction and the contour method of measuring residual stress.

Role of halogen-involved intermolecular interactions and existence of isostructurality in the crystal packing of —CF3 and halogen (Cl or Br or I) substituted benzamides

2018 ◽  
Vol 74 (6) ◽  
pp. 574-591 ◽  
Author(s):  
Pradip Kumar Mondal ◽  
Rahul Shukla ◽  
Subha Biswas ◽  
Deepak Chopra
Keyword(s):  
Solid State ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Noncovalent Interactions ◽  
X Ray Diffraction ◽  
Substituted Benzamides ◽  
Size Type ◽  
Substituted Benzamide ◽  
Van Der Waals Radii

A total of 23 benzamides are obtained through a simple reaction between chloro-/bromo-/iodoaniline and trifluoromethylbenzoyl chloride and characterized using single-crystal X-ray diffraction. Crystal structures of three series of benzamides based on N-chlorophenyl–trifluoromethyl–benzamide (nine compounds), N-bromophenyl–trifluoromethyl–benzamide (six compounds), and N-iodophenyl–trifluoromethyl–benzamide (eight compounds) are prepared to analyse the halogen-mediated noncovalent interactions. The influences of Cl/Br/I and trifluoromethyl substituents on the respective interactions are examined in the presence of a strong N—H...O hydrogen bond. This exercise has resulted in the documentation of frequently occurring supramolecular synthons involving halogen atoms in the crystal packing of benzamide molecules in the solid state. In the present study, a detailed quantitative evaluation has been performed on the nature, energetics, electrostatic contributions, and topological properties of short and directional intermolecular interactions derived from the electron density on halogenated benzamides in the solid state. Besides these, the occurrence of three-, two- and one-dimensional isostructurality in halogen (Cl or Br or I) substituted benzamide analogues is also investigated. A `region of co-existence' involving halogen-based intermolecular interactions in the vicinity of the sum of the van der Waals radii has been identified. Thus, the nature of the halogen (effective size), type of interaction and the packing characteristics via presence of additional interactions establish the subtle, yet important, role of cooperativity in intermolecular interactions in crystal packing.

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