Olefin metathesis polymerization: Some recent developments in the precise polymerizations for synthesis of advanced materials (by ROMP, ADMET)

One-pot synthesis of end-functionalised soluble star-shaped polymers by living ring-opening metathesis polymerisation using a molybdenum-alkylidene catalyst

“…[1][2][3][4][5][6][7][8][9][10] Reported examples for the synthesis by adopting living ring-opening metathesis polymerisation (ROMP) [11][12][13][14][15][16][17][18][19][20][21][22][23] via arm (brush) rst [24][25][26][27][28][29][30] and core rst (in-out) [31][32][33][34][35] approaches by sequential addition of monomers/cross linkers (CLs) are known. Moreover, related examples for synthesis of cross-linked polymers (which are insoluble in common organic solvents) by ROMP are also known, 36-39 especially in terms of application as monolith materials for separation.…”

“…In particular, the approach by the sequential living ROMP of norbornene (NBE) and crosslinking reagent (1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo-endodimethano-naphthalene, CL) using a Mo-alkylidene catalyst enables us to introduce functionality to the polymer chain ends (star surface) through cleavage of the polymer-metal double bonds with aldehyde via Wittig-type reaction. 15,23,[31][32][33][34][40][41][42] However, the previous reports [31][32][33][34] adopting the so called Method 1 (shown in Scheme 1) only demonstrated synthesis of soluble polymers with a small number of arms under limited conditions (5 or 10 equiv. of CL, [31][32][33][34] shown below in Table 1) due to the difficulty of molecular weight control, as also described below.…”

“…has also been chosen as the initiator due to its ability to prepare the multi-block ringopened copolymers in a precise manner with moderate propagation as well as with complete conversion of monomers. 15,23,[40][41][42] This is also due to that the initiator shows markedly higher reactivity toward strained cyclic olens (norbornene derivatives) than the internal olens (in the ringopened polymers). 45 has also been chosen as the cross-linker, and the polymerisation was terminated with 4-pyridine carboxaldehyde.…”

Well‐Defined End‐Functionalized Conjugated Polymers/Oligomers Exhibiting Unique Emission Properties through the End Groups: The Exclusive Synthesis by Combined Olefin Metathesis with Wittig‐type Coupling

“…Conjugated polymers and the oligomers are known to be promising molecular electronics applied to electronic and optoelectronic devices . Recently, considerable attention has been paid to the precision synthesis (polymers/oligomers), because their device performances (mobility of charged carriers, luminescence, etc.) are highly affected by called defect (such as halogen [and/or palladium] contaminated, regio‐/stereo‐irregularity, cross‐linking [through coupling reactions], sulfur remained in the main chain, etc.).…”

“…Transition metal catalyzed acyclic diene metathesis (ADMET) polymerization, a polycondensation accompanying by‐production of ethylene (or propylene), has been known as an efficient method for the synthesis ( Scheme ), as demonstrated in PFVs, PPVs, and poly( N ‐alkylcarbazole‐2,7‐vinylene)s (PCVs), and poly(thienylene vinylene)s . The resultant polymers (especially PFVs and PPVs) are defect‐free possessing high stereo‐regularity (all trans olefinic double bonds), and display better photophysical properties than those prepared by the other methods .…”