As colloidal self-assembly increasingly approaches the complexity of natural systems, an ongoing challenge is to generate non-centrosymmetric structures. For example, patchy, Janus or living crystallization particles have significantly advanced the area of polymer assembly. It has remained difficult, however, to devise polymer particles that associate in a directional manner, with controlled valency and recognition motifs. Here, we present a method to transfer DNA patterns from a DNA cage to a polymeric nanoparticle encapsulated inside the cage in three dimensions. The resulting DNA-imprinted particles (DIPs), which are 'moulded' on the inside of the DNA cage, consist of a monodisperse crosslinked polymer core with a predetermined pattern of different DNA strands covalently 'printed' on their exterior, and further assemble with programmability and directionality. The number, orientation and sequence of DNA strands grafted onto the polymeric core can be controlled during the process, and the strands are addressable independently of each other.

ABSTRACT. Linear trans-polypentenamers are highly desired materials among the synthetic tire additives due to their comparable physical properties to natural rubber. Transpolypentenamer can be prepared by equilibrium ring-opening metathesis polymerization (ROMP) using well-defined ruthenium catalyst systems. This unique feature of the equilibrium polymerization reaction opens a way for the synthesis of durable, environmentally benign elastomers where polymers including synthetic tire additives can be synthesized and readily recycled using the same transition metal catalyst system. The addition of silica fillers significantly improves the physical properties of the composite materials in comparison to the use of polymeric material. It is also known that the structural effects and the polymer-filler surface interaction are of prime importance. Herein, we report on the synthesis of silica filler compatible recyclable polypentenamer co-polymers via equilibrium ROMP of cyclopentene 1 and 4-(triethoxy)siloxy cyclopentene 11. It has been demonstrated that polypentenamer tire additive can be synthesized via equilibrium ROMP affording polymers with high yields (> 80%) at 0 ºC and can be readily depolymerized at 40 ºC and/or under diluted condition using the same metathesis catalyst systems. Furthermore, the polypentenamer can also be synthesized in neat at room temperature and at very low (10 5 ) monomer/catalyst ratio. This methodology is based on the synthesis of polyolefins utilizing ruthenium based metathesis catalyst via equilibrium ROMP of cyclopentenes and their silylated derivatives.3

Oxygenation of α-pinene using photochemically generated singlet oxygen ( 1 O 2 ) was studied in detail in several continuous flow photochemical reactors. Ferrioxalate actinometry and reaction kinetic data were used to compare light sources and reactor geometries, such as the immersed-well, an annular recirculating and microfluidic reactors. It is shown that reactor miniaturization, control of intensity and of spectral composition of light, and elevated oxygen pressure are the crucial factors for safe and efficient photo-oxygenation reactions. Higher quantum yields were generally obtained with the microreactor-LED assemblies due to better energy utilization, compared to all other systems studied. For the single-phase microreactor-LED system, an optimization model has been developed that revealed a broad optimal design window.

Efficient automated synthesis of sequence-controlled “DNA–Teflon” polymers with potential drug delivery and bioimaging applications.

Sequence-defined polymers with customizable sequences, monodispersity, substantial length, and large chemical diversity are of great interest to mimic the efficiency and selectivity of biopolymers. We report an efficient, facile, and scalable synthetic route to introduce many chemical functionalities, such as amino acids and sugars in nucleic acids and sequence-controlled oligophosphodiesters. Through achiral tertiary amine molecules that are perfectly compatible with automated DNA synthesis, readily available amines or azides can be turned into phosphoramidites in two steps only. Individual attachment yields on nucleic acids and artificial oligophosphodiesters using automated solid-phase synthesis (SPS) were >90% in almost all cases. Using this method, multiple water-soluble sequence-defined oligomers bearing a range of functional groups in precise sequences could be synthesized and purified in high yields. The method described herein significantly expands the library of available functionalities for nucleic acids and sequence-controlled polymers.