Chirality induction in platinum-containing polyaryleneethynylenes by exchange from achiral phosphine ligands to P-chiral phosphine ligands

Synthesis of geometry-controlled platinum-containing polymers bearing optically active bidentate phosphine ligands

“…The present polymers exhibited CD spectroscopic signals originating from the optically active diphosphine ligand, whose spectroscopic pattern coincided with the TD-DFT simulated spectrum of 5′ , a virtually simplified analogue of 5 , obtained using the geometries of C, N, O, P and Pt atoms obtained from the single crystal X-ray analysis of 5 . The chirality of the phosphine ligand did not transfer to the main chain of the polymers, in contrast to the polymers bearing a Pt complex ligated with P*-chiral diphosphines, 23 in which the P* atoms directly affect the chiral environment around the Pt center to cause chiral twist at the main chain. The present study clarified not only the synthetic method for obtaining cis -Pt-containing polymers, but also the requisite of chirality transfer from the ligand to the main chain of the polymers.…”

“…Apparently, the chirality of the ligand does not transfer to the main chain, as previously reported for cis -Pt-containing polyphenyleneethynylenes ligated with P*-chiral phosphines. 23,27 It is considered that the coordination of P*-chiral phosphines to Pt chirally twists the main chain of such polymers, resulting in efficient chirality transfer from the ligand to the backbone polymer. In fact, an analogous polymer to that in the present work, –[PtP(Ph) 2 {1,4-C 6 H 4 CONHC*H[CH(CH 3 ) 2 ]CO 2 CH 3 }(CC–1,4-C 6 H 4 –CC)] n – exhibits no evidence of chirality transfer in the non-aggregated state.…”

“…We also synthesized cis -Pt polyynes with diphosphine ligands by a ligand exchange reaction of trans -Pt polyynes with 1,2-bis(diphenylphosphino)ethane 21 and (2 S ,3 S )-bis(diphenylphosphino)butane, 22 as well as P*-chiral diphosphine ligands. 23 The polymers exhibited chiroptical properties based on the chirally twisted main chains, in which the chirality was transferred from the diphosphine ligands. In the present study, we synthesized geometrically controlled Pt-containing polyphenyleneethynylenes ligated with diphosphines.…”

Sintering of Platinum-Containing Conjugated Polymers: Gas Adsorption and Catalysis of the Formed Pt–Carbon Composites

“…We have reported a series of Pt-containing complexes and poly­(aryleneethynylene)­s, some of which adopt chirally regulated secondary structures. − Manners and co-workers synthesized metal nanoparticles by sintering poly­(arylene­ethynylene)­s with Pt complex moieties in the main chain tethering ferrocene moieties . Thus, Pt-containing π-conjugated polymers are expected to serve as precursors of Pt–carbon composites.…”

Control of Geometric Structure and Catalytic Function of Platinum-Containing Polymers Linked with Bidentate Phosphine Ligands

“…It is important that the helical pitch matches the ligand length for folding into helices without forming intermolecularly cross-linked polymers. Even when such polymers do not fold into helices, chirality transfer can occur from optically active bidentate phosphine ligands, including BenzP* and QuinoxP* to optically inactive Pt-containing polymers. , …”