A one-step selective method based on the hydrosilylation of 2,5-norbornadiene with commercially available silanes in the presence of a Pd-catalyst and bulky ligand R-MOP is developed for the synthesis of exo-isomers of silicon-containing norbornenes. This approach leads to the formation of exclusively exo-isomers. The absence of the steps of alkylation with organometallic reagents and photochemical isomerization makes the proposed approach attractive for the targeted design and synthesis of new polymeric materials with the required properties.

One-step and selective approach to the synthesis of Si-containing exo-norbornenes has been developed based on hydrosilylation reaction of norbornadiene-2,5 with unactivated silanes using Pd-complexes in the presence of bulky ligands. This approach leads to only exo-isomers of norbornene derivatives. The absence of alkylation step by organometallic compounds or photochemical isomerization makes the suggested approach promising for the synthesis of new polymeric materials with desired properties.

The expansion of the range of available and reactive monomers allowing preparation of novel polymeric materials, is an actual task of polymer chemistry. This mini-review is devoted to the polymerization of tricyclo [4.2.1.02,5]non-7-enes (tricyclononenes) and tricyclo[4.2.1.02,5]nona-3,7-dienes (tricyclonona-dienes)–norbornene type monomers containing norbornene and cyclobutane or cyclobutene fragments in the molecules. Their synthesis is carried out using available cyclopentadiene or quadricyclane, which is a product of norbornadiene photo-isomerization. The features of ring-opening metathesis and addition polymerization of tricyclononenes with participation of double bond in the norbornene fragment are highlighted. Examples of the polymerization of a wide range of tricyclononenes with F-, Si-, O-, and N-containing substituents have demonstrated that they are noticeably more active monomers than norbornenes with the same substituents. The main successes have been achieved in the synthesis of F- and Si-substituted polytricyclononenes, which are promising materials for lithography and membrane gas separation.

A one-step selective method for the synthesis of exo isomers of silicon-containing norbornenes by hydrosilylation of norbornadiene-2,5 with non-activated silanes in the presence of a Pd catalyst and bulky ligands has been developed. This approach leads to the formation of exo isomers only. The absence of stages of alkylation with organometallic reagents and photochemical rearrangement makes this approach attractive for directed design and synthesis of new polymeric materials showing required properties.

A new metathesis polynorbornene containing bulky and reactive silatrane side groups is synthesized, and its gas-transport properties are investigated. The metathesis polymerization of 3-silatranyltricyclo[ 4.2.1.02.5]non-7-ene is conducted in the presence of the first-generation Grubbs catalyst. The homopolymer is obtained with a nearly quantitative yield of 98% and a molecular mass of Mw = 1.3 × 106 (Ð = 3.7). According to X-ray phase analysis, the homopolymer is amorphous and its glass-transition temperature is 232°С (DSC). The gas permeability of the metathesis polymer for a set of gases, including He, H2, O2, N2, CO2, and CH4, is investigated, and the corresponding diffusion and solubility coefficients are determined.

The molecular properties of the additive poly(bis(trimethylsilyl)tricyclononene) with the vicinal position of two side groups Si(CH3)3 in the monomer unit are studied for the first time, and its conformational and kinetic properties are compared with those of the isomer with the geminal position of the same groups. Using the methods of static/dynamic light scattering and viscometry for the samples of the vicinal isomer, the hydrodynamic parameters of molecules are determined and their molecular mass dependences in toluene are ascertained. In addition, the Kuhn segment length of this isomer is estimated. The kinetic rigidity of vicinal and geminal isomers is evaluated by 1H NMR relaxation from the mobility of protons in Si(CH3)3 groups. The reasons behind different gas permeabilities of the films based on the polymers with the vicinal and geminal positions of Si(CH3)3 side groups in the monomer unit are discussed.

This comprehensive review surveys recent research trends in the addition polymerization of functionalized norbornenes for the macromolecular design of high performance materials in terms of catalyst activity, monomer reactivity, modifications and potential applications of addition polynorbornenes bearing functional groups. The structure of addition polynorbornene backbones is responsible for their high thermal resistance and chemical stability. In order to impart desired properties to the polymers, various functional side groups can be incorporated into the monomer units by the Ti-, Ni-, or Pd-catalyzed polymerization of norbornenes, which are available via cycloaddition reactions or norbornadiene-2,5 modifications. Based on the use of different substituents in the norbornene monomer units and different polymer compositions, the addition polynorbornenes have been successfully developed for the preparation of pervaporation, gas-separation, and proton-conducting membranes, sensors, catalyst supports, and for applications as photoresist, electrooptical, and dielectric materials etc. (C) 2018 Elsevier B.V. All rights reserved.

Gas-chromatographic determination of the diffusion coefficients that allows for the compressibility of the mobile phase has been suggested. The diffusion coefficients were determined for light hydrocarbons С1–С4 in four polymers with a high free volume, which are candidates for use as gas-separating membranes. The diffusion coefficients calculated from chromatographic data were shown to be one or two orders of magnitude smaller than the values obtained by the membrane method. This may be due to the presence of an additional flow through the membrane caused by the pressure gradient across the membrane in membrane methods.

The homologous series of additive poly[3-(trimethylsilyl)tricyclononene-7] with two heminal substituents Si(CH3)3 in the side cycle of the monomer unit is studied for the first time via the methods of viscometry and static and dynamic light scattering in the range of molecular masses of (29–770) × 103. The scaling ratios for the intrinsic viscosity and the coefficient of translational diffusion of macromolecules in toluene at 298 K are obtained, and the equilibrium rigidity of the polymer chain is determined. The hydrodynamic and conformation properties of the polymer are compared to an analog with only one Si(CH3)3 substituent in the monomer unit. It is found that the introduction of the second side substituent in the heminal position increases the equilibrium rigidity of the additive poly[3-(trimethylsilyl)tricyclononene-7] by 1.4 times and has a far stronger effect on the kinetic rigidity of the polymer. With the use of the 1Н NMR relaxation method, it is shown that the mobility of side groups of the polymer with two substituents decreases significantly and the correlation times of hydrogen atoms of Si(CH3)3 groups exceed some 20 times the corresponding values for the analog with one Si(CH3)3 group in the monomer unit cycle.

The porosity of a number of additive silicon-containing polytricyclononenes from the class of highly permeable polymers has been systematically studied for the first time by the method of low-temperature nitrogen adsorption/desorption. It has been shown that these polymers have a large specific surface area (390−790 m2/g) and are microporous. Dominant pore size ranges from 7 to 10 Å depending on the number of Me3Si groups in a monomer unit and their relative position.

Kinetic data for the unusual [2π + 2σ + 2σ]-cycloaddition of quadricyclane to tetracyanoethylene in toluene have been obtained for the first time. The same reaction in 1,4-dioxane appears to be the most exothermic among known cycloaddition reactions. The entropy of activation and reaction volume differ only slightly from the corresponding parameters of conventional Diels–Alder reactions.