Stereoregular hybrid azobenzene-cyclosiloxanes with photoinduced reversible solid to liquid transition properties

Well-defined cyclic silanol derivatives

“…90 Recently, Migulin et al described two new extended all-ciscyclic siloxanes bearing the photoactive azobenzene groups 92 and 93, prepared from compound 65 as well. 91 C-C coupling reaction. In 2009, Pizzotti et al reported a new family of functionalized all-cis-T 4 96-99 with four organic second-order nonlinear optical (NLO) chromophores being obtained, respectively, from 54 via Suzuki reaction, from 55 via the Heck reaction, from 56 via nucleophilic substitution and from 57 via Sonogashira reaction.…”

“…Related all-cis-T 4 92 and 93 (Table 7) bearing four phenyl groups and four unidirectionally oriented photoactive azobenzene moieties were shown to undergo reversible trans-cis photoisomerization processes. 91 Interestingly, the molecular packing arrangement of these hybrid molecules depends on the length of the alkyl spacer between the macrocycle and the azobenzene group, thus driving the kinetics and thermodynamics of the photoisomerization. For shorter propyl spacers (compound 92), the trans-cis isomerization was found to be faster than in the case of the longer alkyl spacer (C11, compound 93) probably due to possible interactions existing between the adjacent azobenzene groups.…”

Cyanostilbene‐Based AIEgen Smart Film: Optical Switching by Engineering Molecular Packing Structure and Molecular Conformation Through Thermal and Photoinduced Monotropic Phase Transition

“…For the development of smart organic materials with target properties, many material scientists and engineers have tried to understand the thermodynamic and kinetic relationships between chemical structure, molecular packing structure and for meso-nanostructure, organic-inorganic hybrids, and functional amphiphiles. [39][40][41][42][43][44][45] In this context, there have been several reports about the synthesis and application of cyclosiloxanebased molecules, but the thermodynamic and kinetic relationships between the chemical structure, molecular packing structure, and resulting material properties of cyclosiloxane-based functional molecules need to be further studied.…”

“…[ 32–38 ] In particular, it is notable that cyclosiloxanes have advantages in view of geometry and dimensional diversity, multifunctionalization, relatively flexible building unit for meso‐nanostructure, organic–inorganic hybrids, and functional amphiphiles. [ 39–45 ] In this context, there have been several reports about the synthesis and application of cyclosiloxane‐based molecules, but the thermodynamic and kinetic relationships between the chemical structure, molecular packing structure, and resulting material properties of cyclosiloxane‐based functional molecules need to be further studied.…”

Synthesis of 1,1,3,3,5,5-Hexamethyl-7,7-diorganocyclotetrasiloxanes and Its Copolymers

“…Cyclosiloxanes can be used as an initial reagent for the preparation of siloxane homo- and copolymer rubbers and liquids [ 1 , 2 , 3 , 4 ], as well as functional precursors for molecular design [ 5 , 6 , 7 , 8 , 9 ], cross-linking reagents [ 10 ], flame retardants [ 11 ], components of compositions for dry cleaning and detergents [ 12 , 13 , 14 ], solvents for coloring fabrics [ 15 , 16 , 17 , 18 , 19 ] and in cosmetics for various purposes, including skin and hair care products, deodorants/antiperspirants, makeup products, etc. [ 20 , 21 , 22 , 23 ].…”