Strict self-assembly of [Fe(cyclam)]³⁺and [hydrogenbis(1,1′-ferrocenedicarboxylate)]³–into a novel mixed-valent one-dimensional polymer containing an FeIIIN₄O₂chromophore

trans-[FeIII(cyclam)][{Fc(CO2)2}2H], 1, (cyclam = 1,4,8,11-tetraazacyclotetradecane; [Fc(CO2)2]2–= 1,1′-ferrocenedicarboxylate) strictly self-assembles via FeIII–carboxylate covalent bonds and hydrogenbiscarboxylate hydrogen bonds to form a one-dimensional polymer that contains the first crystallographically characterized FeIIIN4O2 chromopore.