Electronic Transport In Molecules

With the view to synthesize and characterize the enhanced pharmaceutical properties of the solid-liquid dispersions of binary drug system through green chemical techniques present communication have been undertaken for detailed investigation of thermodynamic and interfacial properties of benzimidazole(BI)and β. naphthol (βN)binary eutectic and non-eutectic drug dispersions. Eutecticsoliddispersion was observed at a 0.657-mole fraction of β. naphthol (βN)and melting temperature 90C.
Thermodynamic quantities; Partial and Integral excess Gibbs energy (gE), excess enthalpy (hE), excess entropy (sE) of eutectic and non-eutectic dispersions were determined with the help of activity coefficient data. The negative deviation from ideal behaviour has been seen in the system which refers stronger association between unlike molecules during the formation of the binary mix. The negative value of Gibbs free energy of mixing (GM) refers to the mixing for all eutectic and non-eutectic dispersions as spontaneous. The solid-liquid interfacial characteristics.e., the entropy of fusion per unit volume (SV), solid-liquid interfacial energy (), roughness parameter (α), grain boundary energy and roughness parameter (α) of eutectic and non-eutectic solid dispersions have been reported. The size of the critical nucleus at different undercooling has been found in nanoscale,  which may be a  big significance in the pharmaceutical world.  The value of the roughness parameter, α > 2was  observed which manifests the faceted and irregular growth leads in the system.

Bisazo Tröger base analogs are claw-looking molecules that carry two identical but independent photoswitching groups. These bisazo compounds, like dual switches, can be at EE, EZ, and ZZ photoisomerization states while the ∧-shape void of Tröger base scaffold may also introduce an additional possibility of stereoisomerism by holding the photoisomerizable groups in endo or exo positions. To date, the exact molecular geometries of the isomerizable analogs of Tröger's base have not been elaborated. Owing to the special features and potential applications of these molecules, herein their photoisomerization is probed. The gleaned data from 15N isotope labeling and a variety of spectroscopic, spectrophotometric, crystallographic, and computational techniques have revealed the structure of the studied photoisomers and suggested their use in the design of molecular pull and push mechanisms, light driven actuators, and artificial muscles.

Molecular place exchange is a versatile method which is applied for the synthesis of the organic molecule-gold nanoparticle hybrid materials. In principal any molecules with suitable anchor group can be used for carrying  out  place  exchange. Furthermore  if  the  molecules  have anchor  group  on  both  ends  then  the adjacent nanoparticles can be  interlinked by virtue of chemical bonding between gold and anchor group. There are many  factors  that tend  to inhibit the  connection  of  new  molecule  with  the  surface  of  the nanoparticles and  hence limit  the  success of the place  exchange reaction. The  results and  explanation in this  document addresses one  such  factor  which  is  the  length  of  the  molecule. In  this  experiment organic molecules with  lengths longer  than  the  average  distance between  the adjacent  nanoparticles were  used. The molecules had thiol anchor groups on both ends which could bind to two adjacent gold surfaces. The nanoparticles were  trapped  between  nanoelectrodes that  were made  using  gold  and  were spaced  by  as small  as  20nm. Place  exchange  reaction  was  carried  out  after  trapping  the  nanoparticles. The  electrical characterization  was  performed  to  test  if  the  molecules  linked the  adjacent  gold  surfaces.  The  results showed that the longer the length of the molecules was: the smaller was the measured electrical resistance. This  is counter  intuitive which  is indicative  of  the  fact  that the  longer  molecules tend  to  cause  better connection of  the hybrid material between  the  nanoelectrodes rather  than  the  adjacent  nanoparticles  and hence result in higher electrical conduction as compared to smaller molecules.

(5) (PDF) The causes of the unusual electrical resistance of the gold nanoparticle-organic molecule hybrid material confined between sub 20nm spaced gold-nanoelectrodes 1- When the molecule is longer than the spacing between the nanoparticles. Available from: https://www.researchgate.net/publication/338607765_The_causes_of_the_unusual_electrical_resistance_of_the_gold_nanoparticle-organic_molecule_hybrid_material_confined_between_sub_20nm_spaced_gold-nanoelectrodes_1-_When_the_molecule_is_longer_than_the_s [accessed Feb 02 2020].