One-component" soft material Frank-Kasper (FK) phases are an intriguing structural form of matter that possess periodically ordered structures arising from the self-reconfiguration and close packingo fa ni nitial assembly of identical "deformable" spheres into two or more size-or shape-distinct sets of particles.S ignificant challenges that must still be addressed to advance the field of soft matter FK phases further,h owever,i nclude their rare and unpredictable occurrence,u ncertain mechanisms of solid-state assembly,a nd low thermodynamic stability.H ere we show that ar eadily-accessible sugar-polyolefin conjugate quantitatively produces an exceptionally stable solid-state FK A15 phase through arapid and irreversible thermotropic order-order transition, which contrary to other prevailing proposed mechanisms,d oes not require mass transfer between particles or large structural reorganization in the bulk to establish unit cell non-equivalency.Our results provide the basis for arealistic strategy for obtaining practical and scalable quantities of adiverse range of sugar-polyolefin FK A15 phases with unique intrinsic physical properties and chemical reactivities not previously seen in such systems.Periodically-ordered, "one-component" soft matter Frank-Kasper (FK) phases,w hich arise from the topological close packing (TCP) of "deformable" sphere-shaped particles,have now been experimentally verified for amphiphilic liquid crystals and dendrons,b lock copolymers," giant" molecules and surfactants,a nd colloidal nanoparticles. [1][2][3][4][5][6][7][8][9] Frank and Kasper [10] originally developed the concept of TCP to rationalize how the complex crystal structures of certain intermetallic alloys arise through the packing of asymmetric polyhedra that are associated with different sets of atoms that define ap articular coordination number, CNx, where x = 12,14,15, or 16. Forexample,asshown in Figure 1, the unit cell of the cubic FK A15 (Pm3 n)p hase,w hich is found for some bimetallic alloys with A 3 Bstoichiometry (e.g. Nb 3 Sn), can be seen as arising from two crystallographically equivalent B sites that reside within CN12 distorted icosahedra, while six equivalent face-shared As ites are associated with CN14 polyhedra. Other commonly encountered bimetallic FK phases include the Laves C14 and C15 structures for A 2 B alloys (e.g.MgZn 2 ), and the complex s phase for AB alloys of

A general and versatile synthetic strategy for producing practical quantities of a wide range of phenyl-groupterminated hetero-and homotelechelic semicrystalline polyethenes and amorphous atactic and semicrystalline isotactic poly(α-olefins) is reported. The phenyl groups serve as synthons for functionalities of additional classes of telechelic polyolefins that can be "unmasked" through simple high yielding postpolymerization reactions. A demonstration of the value of these materials as building blocks for structural classes of polyolefin-based synthetic polymers was provided by syntheses of well-defined polyolefinpolyester di-and triblock copolymers that were shown to adopt microphase-segregated nanostructured mesophases in the condensed phase.

One-component" soft material Frank-Kasper (FK) phases are an intriguing structural form of matter that possess periodically ordered structures arising from the self-reconfiguration and close packingo fa ni nitial assembly of identical "deformable" spheres into two or more size-or shape-distinct sets of particles.S ignificant challenges that must still be addressed to advance the field of soft matter FK phases further,h owever,i nclude their rare and unpredictable occurrence,u ncertain mechanisms of solid-state assembly,a nd low thermodynamic stability.H ere we show that ar eadily-accessible sugar-polyolefin conjugate quantitatively produces an exceptionally stable solid-state FK A15 phase through arapid and irreversible thermotropic order-order transition, which contrary to other prevailing proposed mechanisms,d oes not require mass transfer between particles or large structural reorganization in the bulk to establish unit cell non-equivalency.Our results provide the basis for arealistic strategy for obtaining practical and scalable quantities of adiverse range of sugar-polyolefin FK A15 phases with unique intrinsic physical properties and chemical reactivities not previously seen in such systems. Periodically-ordered, "one-component" soft matter Frank-Kasper (FK) phases,w hich arise from the topological close packing (TCP) of "deformable" sphere-shaped particles,have now been experimentally verified for amphiphilic liquid crystals and dendrons,b lock copolymers," giant" molecules and surfactants,a nd colloidal nanoparticles. [1-9] Frank and Kasper [10] originally developed the concept of TCP to rationalize how the complex crystal structures of certain intermetallic alloys arise through the packing of asymmetric polyhedra that are associated with different sets of atoms that define ap articular coordination number, CNx, where x = 12, 14, 15, or 16. Forexample,asshown in Figure 1, the unit cell of the cubic FK A15 (Pm3 n)p hase,w hich is found for some bimetallic alloys with A 3 Bstoichiometry (e.g. Nb 3 Sn), can be seen as arising from two crystallographically equivalent B sites that reside within CN12 distorted icosahedra, while six equivalent face-shared As ites are associated with CN14 polyhedra. Other commonly encountered bimetallic FK phases include the Laves C14 and C15 structures for A 2 B alloys (e.g.MgZn 2), and the complex s phase for AB alloys of

A toolbox of living coordination polymerization methods based on CPAM group 4 metal initiators has been applied for the stereomodulation of poly(4‐methyl‐1‐pentene) (PMP) tacticity to provide new fundamental forms in which thermal phase transitions, Tg and Tm, can be adjusted over a wide range. Also reported for the first time are the synthesis and properties of authenticated 1,2‐regioregular atactic PMP, which serves to correct past errors regarding this fundamental polyolefin.

Two-state, stereomodulated living coordinative chain transfer polymerization (LCCTP) of 1,6-heptadiene has been achieved to produce a series of cis-poly­(methylene-1,3-cyclohexane) (cis-PMCH) with stereochemical microstructures that vary between two limiting forms as a function of the optical purity of the chiral C 1-symmetric hafnium preinitiator 1 when activated by the borate co-initiator B1 in the presence of a fixed excess amount of ZnEt2. Optical purity as a programmable variable was demonstrated by premixing the pure homochiral (S C,S Hf) and (R C,R Hf) enantiomers of 1 in different ratios prior to activation. In contrast, the LCCTP of 1,5-hexadiene using a “racemic” mixture of 1 to produce cis/trans-poly­(methylene-1,3-cyclopentane) (cis/trans-PMCP) was less successful due to the loss of stereocontrol for insertion under chain transfer conditions that arises with site epimerization at the transition metal center. A correlation is proposed between the diastereoselectivity and efficiency for the cyclization step in propagation and the magnitude of site epimerization due to reversible chain transfer. These results serve to validate the strategy of using the optical purity of an initiator as a programmable parameter for controlling polyolefin tacticity as well as to better establish the criteria that are required for achieving successful stereomodulated LCCTP for the production of next generation polyolefin materials.