A ladder tetrazine polymer is disclosed.

A ladder tetrazine polymer is disclosed.

A polybenzodifuran ladder polymer is disclosed.

A polybenzodifuran ladder polymer is disclosed.

A polybenzodifuran ladder polymer is disclosed.

A ladder tetrazine polymer is disclosed.

A polybenzodifuran ladder polymer is disclosed.

A molecule includes at least one moiety represented by: ##STR00001##
where R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from hydride group and groups different from hydride group, and X.sup.1 and X.sup.2 are bridging moieties including a carbon atom or a heteroatom.

A cathode active material having a polymer with helical perylene diimide (hPDI) subunits with the side-chains of the helical perylene diimide (hPDI) subunits removed and a method of manufacturing the cathode active material are provided. A rechargeable battery cell with the polymer as a cathode material, a magnesium metal anode, and an ether-based electrolyte.

Disclosed herein are ladder polymers comprising fused aromatic and non-aromatic rings. Also disclosed are the manufacture and use of these ladder polymers, e.g., in separation membranes, such as membrane for gas separation.