The synthesis of a variety of poly(norbornene)s (PNB)s bearing acetoxy, hydroxy, and vinyl end groups was accomplished. PNBs with an acetoxy group at one terminus and a vinyl group at the other were prepared using norbornene, ruthenium-based olefin metathesis catalyst (PCy3)2Cl2RuCHPh, and allyl acetate as a chain transfer agent (CTA). Employing a more active catalyst, (1,3-dimesityl-4,5-dihydroimidazol-2-ylidene)(PCy3)Cl2RuCHPh, and 1,4-diacetoxy-2-butene as the CTA afforded telechelic PNBs bearing acetoxy groups at both ends of the polymer chains. Molecular weights were controlled by varying the initial monomer/CTA ratio and were in agreement with their theoretical values. Using a similar procedure, acetoxy end-terminated PNBs were also obtained by degradation of high molecular weight PNB. Removal of the acetoxy groups afforded the corresponding hydroxy-terminated polymers with number-averaged functionalities close to two. Mechanisms are proposed for the formation of the end-functionalized polymers. Correction factors for characterizing PNBs by gel permeation chromatography (GPC) are also suggested.

The synthesis of poly(styrene)-b-poly(butadiene)-b-poly(styrene) (SBS) and poly(methyl methacrylate)-b-poly(butadiene)-b-poly(methyl methacrylate) (MBM) triblock copolymers with poly-(butadiene) (PBD) segments containing 100% 1,4-microstructure is described. Bis(allyl chloride) and bis-(2-bromopropionate) terminated telechelic PBD's were synthesized by the ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene in the presence of the corresponding difunctional chain transfer agents. These telechelic PBDs were subsequently used as difunctional macroinitiators for the heterogeneous atom transfer radical polymerization (ATRP) of styrene and methyl methacrylate to form SBS and MBM triblock copolymers. Triblock structure was confirmed by selective PBD degradation. In addition, the tandem ROMP-ATRP approach was successfully extended to a "one-pot" synthesis.

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Reported are the synthesis, characterization, and crystal structures of two mixed‐ligand copper(II) complexes containing bis[N‐(2,6‐diisopropylphenyl)imino]acenaphthene (o,o′‐iPr2C6H3‐BIAN). In both complexes, namely [Cu(AcOH)(o,o′‐iPr2C6H3‐BIAN)Cl2] (1) and [Cu(acac)(AcOH)(o,o′‐iPr2C6H3‐BIAN)](ClO4) (2) (acac = acetylacetonate and AcOH = acetic acid), the copper ions are in a distorted square‐pyramidal coordination environment with an acetic acid molecule in each apical position. The two imine nitrogen atoms of o,o′‐iPr2C6H3‐BIAN occupy the basal plane with the two chloride atoms and the two oxygen atoms of acac in complexes 1 and 2, respectively. Complex formation results in certain structural changes inside the rigid N−N ligand. Such changes led to an increased planarity of the o,o′‐iPr2C6H3‐BIAN backbone, and produced a nearly perpendicular angle between the naphthalene and the aromatic imine planes. In complex 2, the more perpendicular arrangement of the o,o′‐diisopropylphenyl groups shielding the copper centre was structurally allowed by the elongation of one of the metal‐to‐ligand bonds and by the relatively larger N−Cu−N bite angle. Also discussed are IR, magnetic, and UV/Vis measurements.

The synthesis of ring-opening metathesis polymerization (ROMP) chain transfer agents (CTA)s bearing methacrylate or epoxide end functionality was accomplished. In the presence of these CTAs, the ROMP of cyclooctadiene (COD) initiated with (PCy3)2Cl2RudCHPh afforded the respective telechelic poly(butenylene)s with either methacrylate or epoxide end groups. Control over the polymer molecular weight was demonstrated by varying the COD/CTA ratio. Successful cross-linking by thermal or photochemical initiation of the bis(methacrylate)-functionalized telechelic poly(butenylene)s or through acid catalysis of the bis(epoxide)-functionalized telechelic poly(butenylene)s was accomplished. While crosslinking was found to reduce solubility of the polymers, it greatly enhanced their thermal stability.