Cinnamate moiety

The photosensitized crosslinking of amorphous polymeric films containing dimerizable cinnamate moieties show quantum yields of dimerization of about 0.04 (4). Sensitization of such films by ketocoumarins proceeds via triplet-triplet energy transfer (2) (see Scheme V). The irradiations were performed at 405 nm at a wavelength... 

The solution (dichloromethane) spectra of polymers X, XI, and IX can be seen in Fig. 1. Surprisingly, the absorption spectrum of the l.c. p-methoxycinnamate polymer, IX, showed a 10 nm red shift relative to the two non-l.c.-cinnamate polymers, X and XI. We suggest that, in the thermodynamically most stable conformation the p-methoxycinnamate moiety was intramolecularly perturbed by the phenyl ester group. The ester, phenyl p-methoxycinnamate also shows this perturbation, but the alkyl and cycloalkyl esters do not. CPK (Corey-Pauling-Koltun) molecular models sow that the phenyl ester group could assume an orientation that was almost coplanar with the cinnamate moiety which could easily give rise to a 10 nm red shift (see Fig. 2). 

The triplet state must be at the energy level close to 50-55 kcal/mole for the cinnamate moiety. 

The preparation and properties of many other polymers containing pendant aryl azide groups were described by Delzenne and Laridon The polymers were prepared by interfacial polycondensation of azido-substituted acid chlorides with diols and diamines. Also, in one experiment, a cinnamate moiety was combined with an azide group, together in one pendant functional structure... 

An unexpected oxidative esterification of cinnamaldehydes by cinnamyl bromides is catalysed by a simple NHC, A,A -dibenzyl-benzimidazolium chloride, in up to 86% yield in DBU, using dioxygen or Mn02 as oxidant. The mechanism has been probed by 0-labelling, and neither cinnamyl nor cinnamate moieties undergo cis-trans isomerization during the process. The reaction has been successfully extended to other aldehydes, although electron-rich cases are poor substrates. ... 

The alkene groups of the cinnamate moieties subsequently undergo a [2 -I- 2] cycloaddition reaction under irradiation (Scheme 13.3). This cycloaddition results in a cross-linked polymer suitable as a negative tone photoresist [4]. 

Nakayama Y, Matsuda T (1992) Preparation and characteristics of photocrosslinkable hydrophilic polymer having cinnamate moiety. J Polym Sci A, Polym Chem 30 2451-2457 Monch 1, Makarov D, Koseva R, Baraban L, Kamaushenko D, Kaiser C, Arndt K-F, Schmidt OG (2011) Rolled-up magnetic sensor nanomembrane architecture for in-flow detection of magnetic objects. ACS Nano 5(9) 7436-7442... 

This compound is an example of a graftable functional monomer having in addition a hydrophilic residue. Composition may im-dergo photo-grafting via exposition under natural light or artificial suitable UV source. Responsible for photo-grafting is the cinnamic moiety in the compound. 

Connection of two cinnamate chromophores has frequently been used to attain high local concentrations of reactants, thereby circumventing the inefficiency of the above-mentioned bimolecular dimerization reactions. An extreme example of this approach is embodied in the cyclophane structures 3, in which two cinnamate moieties undergo photodimerization to give quantitatively the P-truxinate dimer with a quantum yield of Similarly, the bis-cinnamamide 4 furnished 48% of P-truxinimide upon... 

Since the mid-eighties, the term supramolecular chemistry has come to signify the programmed self-assembly of complex architectures through the interplay of noncovalent interactions. " In the case of the dimerization of cinnamate derivatives, Beak and Ziegler presented, over 20 years ago, the first example of the use of hydrogen bonding in solution to accelerate the usually inefficient cycloaddition reaction. In their work, the self-complementary pyridone unit was used to direct the head-to-head dimerization of the appended cinnamate moieties. 

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